CA2011677A1 - Methods and apparatus for obtaining arterial blood samples - Google Patents
Methods and apparatus for obtaining arterial blood samplesInfo
- Publication number
- CA2011677A1 CA2011677A1 CA 2011677 CA2011677A CA2011677A1 CA 2011677 A1 CA2011677 A1 CA 2011677A1 CA 2011677 CA2011677 CA 2011677 CA 2011677 A CA2011677 A CA 2011677A CA 2011677 A1 CA2011677 A1 CA 2011677A1
- Authority
- CA
- Canada
- Prior art keywords
- syringe
- plunger
- flow
- distal
- proximal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Investigating Or Analysing Biological Materials (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Apparatus and methods for simultaneously obtaining clinical laboratory and arterial blood gas samples are disclosed. The apparatus includes a flow-through plunger configured for being detachably secured to the tip of a standard arterial blood gas syringe. The flow-through plunger has a conduit through the center thereof which permits blood to flow through the plunger into the arterial blood gas syringe. The flow-through plunger preferably has a diameter larger than the diameter of the arterial blood gas syringe. In this way, the combination of flow-through plunger and arterial blood gas syringe function as a plunger assembly for a larger syringe, preferably a clinical laboratory blood sample syringe.
Both a clinical laboratory blood sample and an arterial blood gas sample may be obtained by introducing arterial blood into the clinical laboratory syringe barrel and passing the blood through the flow-through plunger into the arterial blood gas syringe. Arterial blood may be introduced into the clinical laboratory syringe through either a direct hypodermic needle puncture into an artery or by coupling the laboratory syringe barrel to an ex-vivo arterial blood source.
Apparatus and methods for simultaneously obtaining clinical laboratory and arterial blood gas samples are disclosed. The apparatus includes a flow-through plunger configured for being detachably secured to the tip of a standard arterial blood gas syringe. The flow-through plunger has a conduit through the center thereof which permits blood to flow through the plunger into the arterial blood gas syringe. The flow-through plunger preferably has a diameter larger than the diameter of the arterial blood gas syringe. In this way, the combination of flow-through plunger and arterial blood gas syringe function as a plunger assembly for a larger syringe, preferably a clinical laboratory blood sample syringe.
Both a clinical laboratory blood sample and an arterial blood gas sample may be obtained by introducing arterial blood into the clinical laboratory syringe barrel and passing the blood through the flow-through plunger into the arterial blood gas syringe. Arterial blood may be introduced into the clinical laboratory syringe through either a direct hypodermic needle puncture into an artery or by coupling the laboratory syringe barrel to an ex-vivo arterial blood source.
Description
2011~77 BACKG~tOU~3V OF T~:E I~'JENTION
-: 1. Field o~ the Invention ~ The invention relates to apparatus and methods for ; obtaining blood samples. `~lore particularly, the present (~ invention is directed to apparatus and methods for obtaining both arterial blood gas and clinical laboratory samples from 8 a single hypodermic needle puncture of a patient.
1~ 2. Technologv Review Blood samples are routinely ob~ained in virtually all l_ areas of medical health care. Analysis of a person's blood 13 provides a significant amount of infcrmation regarding the 1~ person's overall state of health. Blood for clinica~
I laboratory analysis is most often obtained by venipuncture 16 (puncture of a vein). Puncturing a vein to obtain blood for l_ clinical laboratory analysis is preferred in most cases 18 because veins are generally close to the s~in's surface, 19 transport large quantities or blood, and the blood flows in _ 20 the vein at a lower pressure than in the arteries.
~1 In specific instances, however, venous blood samples do ~ F~ not provide the information desired. Many times it is _-3~ necessary to know the arterial blood gas concentration and z ~ pH of the arterial blood in order to correctly diagnose and treat certain diseases and conditions. ~rterial blood gas ~6 (sometimes referred to as "ABG") analysis provides a 20~1~77 I ~ measurement of the partial pressure oL o:. aen and o carbon - ¦ dioxide in arterial blooa, as ~/ell as ~h2 ?H 0~ the blood.
The partial ?ressure o o~ygerl, together ;ith hemoglobin l ~hemoglobin is also derived from an ~.BG), is a measurement -. of the amount of oxygen in arterial blood. .~rterial blood ~, gas analysis provides means for assessing the adequacy of oxygenation and ventilation of the blood. This provides a ~ direct indication of lung function in supplying oxygen to 9 the body and in removing carbon dioxide. Arterial blood gas 1~) analysis also provides information regarding t~.e acid-base Il balance in the body and whether acidosis or alkalosis is 17 present and if so to what degree.
13 Obtaining a sample of arterial blood for blood gas 1~ analysis is generally much more difficult than obtaining a~
l sample of blood from a vein. Arteries are generally located 16 deeper within the patient making them more difficult to locate and requiring a deeper hypodermic puncture. Arteries 18 also operate under significantly higher pressure than veins, 19 increasing the risk of hemorrhage after puncturing the n artery. Perhaps the most significant procedural difference '71 in obtaining arterial samples as opposed to venous samples '7_ is that the arterial blood samples are preferably not exposed to air. Any air bubbles in the arterial blood sample may affect the ultimate measurement of the partial pressure of oxygen within the blood.
~6 ' ' 2013 6r~'iro~
Increasillgly the blood gas technician is being ask~d .o , collect not only a sample for blooà gas analysis, but also a samp]e ~or standard clinical laboratory analysis. ~ormally the two blood samples are obtained bv independently puncturing a vein to obtain the clinical laboratorv blood . sample and puncturing an artery to obtain the arterial blood gas sample. This technique, however, requires two separate needle punctures to obtain the t~lo blood samples. This technique increases the time and difficulty in obtaining the 1() necessary samples.
11 In some situations it may be difficult or inconvenient l_ for the technician to obtain blood from a vein, yet both a 13 clinical laboratory sample and an arterial blood gas sample 1~ are needed. Such cases may arise, for e~ample, in a code~
I blue emergency situation (cardiac arrest) or where a 16 suitable vein cannot be located on the patient. In these l_ cases, one technique for obtaining both clinical laboratory 18 blood samples and arterial blood gas samples is by taking a 19 blood gas syringe with a three-way valve stop-cock placed between the blood gas syringe tip and the hypodermic n needle. The clinical laboratory blood sample syringe is ~_~,Q ~'7 attached to the three-way valve at a right angle to the ~ ;3 blood gas syringe. Using this apparatus, the three-way Z ~Q ~ valve is positioned such that the tlood gas syringe fills.
~, _ , Then the valve is turned, while the needle is still placed ~6 within the artery, such that the laboratory sample syringe
-: 1. Field o~ the Invention ~ The invention relates to apparatus and methods for ; obtaining blood samples. `~lore particularly, the present (~ invention is directed to apparatus and methods for obtaining both arterial blood gas and clinical laboratory samples from 8 a single hypodermic needle puncture of a patient.
1~ 2. Technologv Review Blood samples are routinely ob~ained in virtually all l_ areas of medical health care. Analysis of a person's blood 13 provides a significant amount of infcrmation regarding the 1~ person's overall state of health. Blood for clinica~
I laboratory analysis is most often obtained by venipuncture 16 (puncture of a vein). Puncturing a vein to obtain blood for l_ clinical laboratory analysis is preferred in most cases 18 because veins are generally close to the s~in's surface, 19 transport large quantities or blood, and the blood flows in _ 20 the vein at a lower pressure than in the arteries.
~1 In specific instances, however, venous blood samples do ~ F~ not provide the information desired. Many times it is _-3~ necessary to know the arterial blood gas concentration and z ~ pH of the arterial blood in order to correctly diagnose and treat certain diseases and conditions. ~rterial blood gas ~6 (sometimes referred to as "ABG") analysis provides a 20~1~77 I ~ measurement of the partial pressure oL o:. aen and o carbon - ¦ dioxide in arterial blooa, as ~/ell as ~h2 ?H 0~ the blood.
The partial ?ressure o o~ygerl, together ;ith hemoglobin l ~hemoglobin is also derived from an ~.BG), is a measurement -. of the amount of oxygen in arterial blood. .~rterial blood ~, gas analysis provides means for assessing the adequacy of oxygenation and ventilation of the blood. This provides a ~ direct indication of lung function in supplying oxygen to 9 the body and in removing carbon dioxide. Arterial blood gas 1~) analysis also provides information regarding t~.e acid-base Il balance in the body and whether acidosis or alkalosis is 17 present and if so to what degree.
13 Obtaining a sample of arterial blood for blood gas 1~ analysis is generally much more difficult than obtaining a~
l sample of blood from a vein. Arteries are generally located 16 deeper within the patient making them more difficult to locate and requiring a deeper hypodermic puncture. Arteries 18 also operate under significantly higher pressure than veins, 19 increasing the risk of hemorrhage after puncturing the n artery. Perhaps the most significant procedural difference '71 in obtaining arterial samples as opposed to venous samples '7_ is that the arterial blood samples are preferably not exposed to air. Any air bubbles in the arterial blood sample may affect the ultimate measurement of the partial pressure of oxygen within the blood.
~6 ' ' 2013 6r~'iro~
Increasillgly the blood gas technician is being ask~d .o , collect not only a sample for blooà gas analysis, but also a samp]e ~or standard clinical laboratory analysis. ~ormally the two blood samples are obtained bv independently puncturing a vein to obtain the clinical laboratorv blood . sample and puncturing an artery to obtain the arterial blood gas sample. This technique, however, requires two separate needle punctures to obtain the t~lo blood samples. This technique increases the time and difficulty in obtaining the 1() necessary samples.
11 In some situations it may be difficult or inconvenient l_ for the technician to obtain blood from a vein, yet both a 13 clinical laboratory sample and an arterial blood gas sample 1~ are needed. Such cases may arise, for e~ample, in a code~
I blue emergency situation (cardiac arrest) or where a 16 suitable vein cannot be located on the patient. In these l_ cases, one technique for obtaining both clinical laboratory 18 blood samples and arterial blood gas samples is by taking a 19 blood gas syringe with a three-way valve stop-cock placed between the blood gas syringe tip and the hypodermic n needle. The clinical laboratory blood sample syringe is ~_~,Q ~'7 attached to the three-way valve at a right angle to the ~ ;3 blood gas syringe. Using this apparatus, the three-way Z ~Q ~ valve is positioned such that the tlood gas syringe fills.
~, _ , Then the valve is turned, while the needle is still placed ~6 within the artery, such that the laboratory sample syringe
2 0 1 ~ 6 ~ 7 I ~ is filled. This apparat~s per:ni~J ~oth blood sa;nples to be ¦ obtained from a single arterial punct-1rY.
This technique however rDquires ~o ~echnicians. The first technician punctures the artery ana o~tains the arteriai blocd gas samDle. Once the blood gas sampie is , obtained the second technician must turn the three--.tav valve to direct the blood flow into the clinical laboratory 8 syringe and then pull on the clinical laboratory syr;nge () plunger to fill the syringe with blood. This "pullins" is 1() at a 90 angle from the blood gas syringe ~hile the needle 11 is within the artery. The first technician must hold the .~ hypodermic needle within the artery steady t7hile the second 13 technician draws the clinical laboratory blood sample.
-~This procedure is botn inefficient and a~kward for the~
1 technicians. Moreover, the method Doses the clear danger or 16 trauma to the artery. It is generally recognized that .1hen 1- manual ~7ithdra-~al of the blood gas syringe piston is 18 required traumatization of the artery may result. The risk 9 of trauma is particularly severe where the cliwnical ~o laboratory piston is pulled at a 90 angie relative to the _ ~1needle ~tithin the artery. There is a significant risk that a '~ the sharp tip of the hypodermic needle could sever or damage ~ x-~ 3 the artery resulting in serious hemorrhage.
Z ~~ 2~An arterial line catheter is often inserted into E ~ ~ ~. patients from whom frequent arterial blood samples are ~h required. The arterial line catheter is kept free of blood 20~16 clots by the pressurized ~lo;~ o~ an arlticoagulant, such as , sodium heparin, through the cat;nete~n orcer to obtain an arterial blocd sample Erom an arterial line, a stop-cock in lthe arterial line catheter is ~djusted to stop the ~,anticoagùlant flow and permit the a!terial blood to fill the line. The desired samples are then taken. For each sample, the arterial line is momentarily open and e:~posed to the 8atmosphere. Thus, where both a clinical laboratory sample gand blood gas sample are requested, the arterial line is ~open at least three times: first, to connect an arterial 11blood gas syringe; second, to remove the arterial blood gas .~syringe and connect the clinical laboratory syringe; and 13third, to remove the clinical laboratory syringe. Each time 1~the arterial line is open, there is a risk of introducinq 1_infection into the patient.
16From the foregoing, it will be appreciated that what is 1needed in the art are apparatus and me~hods for obtaining 18clinical laboratory and arterial blood gas samples which 19require only a single hypodermic needle puncture. It-tlould ~obe a significant advancement in the art to provide apparatus -1and methods .or obtaining clinical laboratory and arterial _blood gas samples which reduce the risk of arterial trauma . . ~ c ~ 3to the patient.
z -~It would be a further advancement in the art to provide , apparatus and methods for obtaining clinical laboratory and arterial blood gas samples in t~hich only one technician is 2 ~ 7 ~
r~quired to obtain both samples. It would be yet ano.her important zdvancement in the art to provide apparatus and methods for obtainina clinical laboratory and arterial blcod sas samples which reduce the risk of infec~ion to tr.e , patient.
~, Such methods and apparatus are disclosed and claimed herein.
9 BRIEF SU~APY AND OBJECTS OF THE INV~NTION
1(1 11 The present invention is directed to a dual-chambered _ linear syringe. The invention can be used anytime it is 13 necessary to obtain two independent fluid samples from a 1~ single source. For example, the c,resent invention may be, I used for obtaining blood samples or samoles of other body 16 fluids. The present invention may even be adapted for non-_ medical uses.
18 Preferably, the present invention includes a proximal 19 syringe (proximal to the technician) nested within a l~rger ~0 distal syringe barrel. An important fea-ure of the present ,1 invention is a flow-through plunger configured for being ~ - c ~, detachably secured to the tip of the pro~imal syringe. The - '-3~ flow-through plunger is attached to the proximal syringe in -~- the same manner as a hypodermic needle is attached to the ~ r. ,~_ syringe, such as through a luer lock-type coupling. The ~6 flow-through plunger has a conduit through the center . ~ . .
.
2 ~
~hereo~ hich permits the fluid sample to flo~ rrom the :Larger distal syringe, through the ?lunge~, and into the proximal syringe.
1 The fl~w~through plunger ~referably has a diameter -, slightly larger than the diameter of the pro:~:imal syringe.
, 'rhe flow-through plur.ger includes a pis~on having sealing means radially disposed about the outer periphery of the piston for forming a slidable seal within the distal syringe () barrel. In this t~ay the flow-th~ough plunger, in 1o combination with the proximal syringe, function as a plunger 11 assembly for the distal syringe.
12 In one preferred embodiment within the scope of the 1:~ present invention, the proximal syringe comprises a standard 1~ arterial blood gas syringe, and the distal syringe comprises~
1~ a clinical laboratory syringe. This embodiment is 16 configured for obtaining both a clinical laboratory blood 1- sample and an arterial blood gas sample from a single source 18 of arterial blood.
19 As discussed above, the apparatus of .he pr~sent r~ ~ invention may be used to obtain two fluid samples frcm a , 21 single fluid source. One method for obtaining such fluidAJ F~ samples includes connecting the distal syringe to the fluid 23 source. This may involve the use of a hypodermic needle if ~ 2~ a body fluid is to be obtained, or the use of some other , 's connecting means. The fluid samples are then obtained by26 drawing thë proximal syringe out of the distal syringe 2011~ ~, barrel, thereby filling the distal syringe barrel witn one Eluid sample. The plunger sha~t withir. .he pro:~imal svringe is then preferably withdrawn to obtain the fluid sam?le l r"ithin the pro:~imal syringe barrel. ~-t will oe appreciated ; that the fluid sample flows .rom the distal s~ringe barrel, ~, through the flow-through plunger, and into the pro:~imal _ syringe.
8 The method for obtaining a clinical laboratory blood 9 sample and arterial blood gas sample from a single hypodermic needle puncture varies depending upon the source of arterial blood. For example, if the blood is to be 1~ obtained directly from a patient's artery, the arterial l3 blood gas syringe preferably has a vented plunger within the 11 syringe barrel or a plunger having a gas permeable, but~
lS liquid impermeable, membrane. Plungers which allow the air 16 within the syringe to escape as the syringe Eills with blood 1, are referred to generically as vented plungers.
l8 Prior to inserting the hypodermic needle into the ls artery, the vented plunger and the flow-through plunge-r are preferably adjusted within their respective syringe barrels 'l to a preset location representing the desired quantity of , blood for both blood samples. Upon puncturing the artery, _ 3 ,~ '3 both syringe barrels rapidly fill with blood from the arterial blood pressure. As the blood fills the syringe barrels, the alr within the syringe barrels is vented _g_ .
.
. . .
. ' , 2 ~ 7 I through the vented plunger. In this lay, ai. bubbles :~ introduced into the ar~erial blood gas samDle are minimized.
. If the source of arterial blood is frcm an arterial :Line catheter, or an umbilical arterial cathe~er, then ~r.e . plunger ~ithin the arterial blood gas syringe does not need , to be vented. An air-tight unit may be preferred.
Both the flow-through syringe plunger and the Dlunger .~ within the arterial blood gas syringe are preferably ) positioned far into their respective syringe barrels. By o pulling back on the proximal blood gas syringe, which is attached to the flow-through plunger, the distal clinical '? laboratory syringe is filled with blood. The oroximal blood l3 gas syringe plunger is then pulled bac~ to obtain the l~ arterial blood gas sample. The blood flows from ~he dis~al~
I; clinical laboratory syringe barrel through the flow-through 16 plunger, and into the pro:~imal arterial blood gas syringe l7 barrel.
I8 In both of the foregoing methods, the proximal blood l9 gas syringe may contain a quantity of anticoagulant to inhibit coagulation of the blood sample. An anticoaguiant is desired because the coagulation orocess alters the true ~r ?- blood gas values. Moreover, it would be dif~icult or ~ _ ?3 impossible to accurately measure blood gas values from a ~ ~ r. coagulated mass of blood.
_~ ~ After both blood samples are obtained, the proximal ~6 blood gas syringe is removed from the flow-through plunger 2~1~ 6~
and capped. The distal clinical labo.a~ory s~ringe is , capped at the plunger site by replacing ~he arterial blood gas syringe lith a conventional plunger roa adapted to t~ist l onto the flow-through plunger.
; A primary object of the presen. invention is to provide ~, apparatus and methods for obtaining two separate and independent fluid samples from a single fluid source.
x More particularly, an object of the present invention ~ is to provide apparatus and methods for obtaining clinical 1() laboratory and arterial blood gas samples which require a l single hypodermic needle puncture.
12 Another important object of the present invention is to 13 provide apparatus and methods foz obtaining clinical 1~ laboratory and arterial blood gas sampies which reduce the~
risk of trauma to the patient.
16 An additional object of the ?resent invention is to l_ provide apparatus and methods for obtaining clinical 18 laboratory and arterial blood gas samples in which only one 19 technician is required to obtain bot.h samples.
_ ~0 A further important object of the present invention is n ~1 to provide apparatus and methods for obtaining clinical 22 laboratory and arterial blood gas samples which reduce the _p-~ 23 risk of infection to the patient.
~'.3~1~ 24 These and other objects and features of the present ,~ 2. invention will become more fully apparent from the following 26 description and appended claims taken in conjunction with ` .' .
2 ~ i 7 che accomparlying drawings, or ~a~ be learned from the , Dractice of the invention.
BRIEF DESCRIPTION OF ?H~ DR.~WINGS
.~
, Figure 1 is an exploded perspective view of one embodiment of a dual-chambered linear syringe structure ~ within the scope of the present invention;
) Figure 2 is an assembled longitudinal cross-sectional 1~) view of the embodiment illustrated in Figure l; and Figure 3 is a perspective view of a flow-through l_ plunger within the scope of the present invention.
1:~
1~ DETAILED DESC~IPTION OF ~E PREFERRED EMBODIMENTS
1.;
16 Reference is not7 made to the dra;~ings wherein like l parts are designated with like numerals throughout.
18 Referring first to ~igure 1, one presently preferred 19 embodiment of the apparatus of the present inventi~n is ,~ illustrated in an exploded perspective Eormat. The present ~1 invention is a dual-chambered linear syringe 10 designed for obtaining tt~o separate and independent fluid samples from a ~ _3 single fluid source.
z 3 ~.__ The two chambers are formed by a smaller, proximal ~; syringe 12 positioned t1ithin a larger, distal syringe 16.
This technique however rDquires ~o ~echnicians. The first technician punctures the artery ana o~tains the arteriai blocd gas samDle. Once the blood gas sampie is , obtained the second technician must turn the three--.tav valve to direct the blood flow into the clinical laboratory 8 syringe and then pull on the clinical laboratory syr;nge () plunger to fill the syringe with blood. This "pullins" is 1() at a 90 angle from the blood gas syringe ~hile the needle 11 is within the artery. The first technician must hold the .~ hypodermic needle within the artery steady t7hile the second 13 technician draws the clinical laboratory blood sample.
-~This procedure is botn inefficient and a~kward for the~
1 technicians. Moreover, the method Doses the clear danger or 16 trauma to the artery. It is generally recognized that .1hen 1- manual ~7ithdra-~al of the blood gas syringe piston is 18 required traumatization of the artery may result. The risk 9 of trauma is particularly severe where the cliwnical ~o laboratory piston is pulled at a 90 angie relative to the _ ~1needle ~tithin the artery. There is a significant risk that a '~ the sharp tip of the hypodermic needle could sever or damage ~ x-~ 3 the artery resulting in serious hemorrhage.
Z ~~ 2~An arterial line catheter is often inserted into E ~ ~ ~. patients from whom frequent arterial blood samples are ~h required. The arterial line catheter is kept free of blood 20~16 clots by the pressurized ~lo;~ o~ an arlticoagulant, such as , sodium heparin, through the cat;nete~n orcer to obtain an arterial blocd sample Erom an arterial line, a stop-cock in lthe arterial line catheter is ~djusted to stop the ~,anticoagùlant flow and permit the a!terial blood to fill the line. The desired samples are then taken. For each sample, the arterial line is momentarily open and e:~posed to the 8atmosphere. Thus, where both a clinical laboratory sample gand blood gas sample are requested, the arterial line is ~open at least three times: first, to connect an arterial 11blood gas syringe; second, to remove the arterial blood gas .~syringe and connect the clinical laboratory syringe; and 13third, to remove the clinical laboratory syringe. Each time 1~the arterial line is open, there is a risk of introducinq 1_infection into the patient.
16From the foregoing, it will be appreciated that what is 1needed in the art are apparatus and me~hods for obtaining 18clinical laboratory and arterial blood gas samples which 19require only a single hypodermic needle puncture. It-tlould ~obe a significant advancement in the art to provide apparatus -1and methods .or obtaining clinical laboratory and arterial _blood gas samples which reduce the risk of arterial trauma . . ~ c ~ 3to the patient.
z -~It would be a further advancement in the art to provide , apparatus and methods for obtaining clinical laboratory and arterial blood gas samples in t~hich only one technician is 2 ~ 7 ~
r~quired to obtain both samples. It would be yet ano.her important zdvancement in the art to provide apparatus and methods for obtainina clinical laboratory and arterial blcod sas samples which reduce the risk of infec~ion to tr.e , patient.
~, Such methods and apparatus are disclosed and claimed herein.
9 BRIEF SU~APY AND OBJECTS OF THE INV~NTION
1(1 11 The present invention is directed to a dual-chambered _ linear syringe. The invention can be used anytime it is 13 necessary to obtain two independent fluid samples from a 1~ single source. For example, the c,resent invention may be, I used for obtaining blood samples or samoles of other body 16 fluids. The present invention may even be adapted for non-_ medical uses.
18 Preferably, the present invention includes a proximal 19 syringe (proximal to the technician) nested within a l~rger ~0 distal syringe barrel. An important fea-ure of the present ,1 invention is a flow-through plunger configured for being ~ - c ~, detachably secured to the tip of the pro~imal syringe. The - '-3~ flow-through plunger is attached to the proximal syringe in -~- the same manner as a hypodermic needle is attached to the ~ r. ,~_ syringe, such as through a luer lock-type coupling. The ~6 flow-through plunger has a conduit through the center . ~ . .
.
2 ~
~hereo~ hich permits the fluid sample to flo~ rrom the :Larger distal syringe, through the ?lunge~, and into the proximal syringe.
1 The fl~w~through plunger ~referably has a diameter -, slightly larger than the diameter of the pro:~:imal syringe.
, 'rhe flow-through plur.ger includes a pis~on having sealing means radially disposed about the outer periphery of the piston for forming a slidable seal within the distal syringe () barrel. In this t~ay the flow-th~ough plunger, in 1o combination with the proximal syringe, function as a plunger 11 assembly for the distal syringe.
12 In one preferred embodiment within the scope of the 1:~ present invention, the proximal syringe comprises a standard 1~ arterial blood gas syringe, and the distal syringe comprises~
1~ a clinical laboratory syringe. This embodiment is 16 configured for obtaining both a clinical laboratory blood 1- sample and an arterial blood gas sample from a single source 18 of arterial blood.
19 As discussed above, the apparatus of .he pr~sent r~ ~ invention may be used to obtain two fluid samples frcm a , 21 single fluid source. One method for obtaining such fluidAJ F~ samples includes connecting the distal syringe to the fluid 23 source. This may involve the use of a hypodermic needle if ~ 2~ a body fluid is to be obtained, or the use of some other , 's connecting means. The fluid samples are then obtained by26 drawing thë proximal syringe out of the distal syringe 2011~ ~, barrel, thereby filling the distal syringe barrel witn one Eluid sample. The plunger sha~t withir. .he pro:~imal svringe is then preferably withdrawn to obtain the fluid sam?le l r"ithin the pro:~imal syringe barrel. ~-t will oe appreciated ; that the fluid sample flows .rom the distal s~ringe barrel, ~, through the flow-through plunger, and into the pro:~imal _ syringe.
8 The method for obtaining a clinical laboratory blood 9 sample and arterial blood gas sample from a single hypodermic needle puncture varies depending upon the source of arterial blood. For example, if the blood is to be 1~ obtained directly from a patient's artery, the arterial l3 blood gas syringe preferably has a vented plunger within the 11 syringe barrel or a plunger having a gas permeable, but~
lS liquid impermeable, membrane. Plungers which allow the air 16 within the syringe to escape as the syringe Eills with blood 1, are referred to generically as vented plungers.
l8 Prior to inserting the hypodermic needle into the ls artery, the vented plunger and the flow-through plunge-r are preferably adjusted within their respective syringe barrels 'l to a preset location representing the desired quantity of , blood for both blood samples. Upon puncturing the artery, _ 3 ,~ '3 both syringe barrels rapidly fill with blood from the arterial blood pressure. As the blood fills the syringe barrels, the alr within the syringe barrels is vented _g_ .
.
. . .
. ' , 2 ~ 7 I through the vented plunger. In this lay, ai. bubbles :~ introduced into the ar~erial blood gas samDle are minimized.
. If the source of arterial blood is frcm an arterial :Line catheter, or an umbilical arterial cathe~er, then ~r.e . plunger ~ithin the arterial blood gas syringe does not need , to be vented. An air-tight unit may be preferred.
Both the flow-through syringe plunger and the Dlunger .~ within the arterial blood gas syringe are preferably ) positioned far into their respective syringe barrels. By o pulling back on the proximal blood gas syringe, which is attached to the flow-through plunger, the distal clinical '? laboratory syringe is filled with blood. The oroximal blood l3 gas syringe plunger is then pulled bac~ to obtain the l~ arterial blood gas sample. The blood flows from ~he dis~al~
I; clinical laboratory syringe barrel through the flow-through 16 plunger, and into the pro:~imal arterial blood gas syringe l7 barrel.
I8 In both of the foregoing methods, the proximal blood l9 gas syringe may contain a quantity of anticoagulant to inhibit coagulation of the blood sample. An anticoaguiant is desired because the coagulation orocess alters the true ~r ?- blood gas values. Moreover, it would be dif~icult or ~ _ ?3 impossible to accurately measure blood gas values from a ~ ~ r. coagulated mass of blood.
_~ ~ After both blood samples are obtained, the proximal ~6 blood gas syringe is removed from the flow-through plunger 2~1~ 6~
and capped. The distal clinical labo.a~ory s~ringe is , capped at the plunger site by replacing ~he arterial blood gas syringe lith a conventional plunger roa adapted to t~ist l onto the flow-through plunger.
; A primary object of the presen. invention is to provide ~, apparatus and methods for obtaining two separate and independent fluid samples from a single fluid source.
x More particularly, an object of the present invention ~ is to provide apparatus and methods for obtaining clinical 1() laboratory and arterial blood gas samples which require a l single hypodermic needle puncture.
12 Another important object of the present invention is to 13 provide apparatus and methods foz obtaining clinical 1~ laboratory and arterial blood gas sampies which reduce the~
risk of trauma to the patient.
16 An additional object of the ?resent invention is to l_ provide apparatus and methods for obtaining clinical 18 laboratory and arterial blood gas samples in which only one 19 technician is required to obtain bot.h samples.
_ ~0 A further important object of the present invention is n ~1 to provide apparatus and methods for obtaining clinical 22 laboratory and arterial blood gas samples which reduce the _p-~ 23 risk of infection to the patient.
~'.3~1~ 24 These and other objects and features of the present ,~ 2. invention will become more fully apparent from the following 26 description and appended claims taken in conjunction with ` .' .
2 ~ i 7 che accomparlying drawings, or ~a~ be learned from the , Dractice of the invention.
BRIEF DESCRIPTION OF ?H~ DR.~WINGS
.~
, Figure 1 is an exploded perspective view of one embodiment of a dual-chambered linear syringe structure ~ within the scope of the present invention;
) Figure 2 is an assembled longitudinal cross-sectional 1~) view of the embodiment illustrated in Figure l; and Figure 3 is a perspective view of a flow-through l_ plunger within the scope of the present invention.
1:~
1~ DETAILED DESC~IPTION OF ~E PREFERRED EMBODIMENTS
1.;
16 Reference is not7 made to the dra;~ings wherein like l parts are designated with like numerals throughout.
18 Referring first to ~igure 1, one presently preferred 19 embodiment of the apparatus of the present inventi~n is ,~ illustrated in an exploded perspective Eormat. The present ~1 invention is a dual-chambered linear syringe 10 designed for obtaining tt~o separate and independent fluid samples from a ~ _3 single fluid source.
z 3 ~.__ The two chambers are formed by a smaller, proximal ~; syringe 12 positioned t1ithin a larger, distal syringe 16.
3 '6 The conventional plunger and plunger shaft normally 2 ~ 7 7 associated with the distal syringe are repiaced by a flow-. t;nrc~gh plunger 11 attached to the .ip o~ the pro-ximai :~ syrir.ge 12. Thus, the flow-through plunce! 11 and the pro:imal syringe 12 combine to act as a pluncer and plunser , shart for the distal syringe 16. The pro:ci~al syrinqe 12 , includes a conventional plunger 18 and plunger shaft 20.
In operation, the flow-through plunger 11 and proximal syringe 12 provide a piston function for the distal syringe 16, permitting the distal syringe 16 to be filled with the desired fluid sample. Similarly, actuating .he conventional l plunger 18 and plunger shaft 20 within the proximal syringe l~ 12 permits the proximal syringe 12 to be filled with the 1:3 fluid sample. The fluid sample 10ws .^rom the distal 1.~ syringe 16 to the proximal syringe 12 by passing tnrough the~
1.; flow-through plunger 11.
l6 Figure 1 shows one embodiment of the flow-through l/ plunger 11, a proximal syringe 12, and a distal 18 syringe 16. Flow-th~ough plunger 11 includes a ~low-through 1~ adapter 22. Plunger 11 is cons;ructed much ~ like 2n conventional syringe plungers except that plunger 11 -_ .,l includes a conduit 24 or bore through the center thereof to a ~ allow the passage of blood or other fluids through the _r. F ~, :, 3 piston. Plunger 11 is preferably constructed of a hard ~ compressed rubber or other suitable resilient material which ,~ ~.; is capable of forming a slidable seal within a distal 3 ~6 syringe 16.
201 ~ ~77 Flow-through adap~er 22 is designed to be attached to , plunger ll such that the [low-throuqn adapter and piston together form conduit 21. Flow-throuqh adapter 22 is l preferably press fit and sealed ~ithin conduit 24 and held ; in place due to pressure and sealant ~rom the resilient , material of plunger 11. Flow-through adapter 22 is _ generally tubular in shape such that when positioned within plunger 11, conduit 24 continues through flow-through ~ adapter 22 creating an open passageway through the center of the flow-through plunger 11.
1l Flow-through adapter 22 may have a twisting lip 26 adapted to be removably secured to a twist-on locking device 13 or luer lock-type coupling mechanism found on many l~ conventional syringe tips. In one preferred embodiment,~
1; twisting lip 26 is a male luer lock coupling. Because flow-16 through adapter 22 is adapted to be removably secured to the l_ syringe tips, flow-through adapter 22 is preferably 18 constructed of a rigid material. It has been found that l9 existing hard plastic materials used in the medical ar~s are suitable materials.
Proximal syringe 12 includes a syringe barrel 28 and a 2~ plunger shaft 20. Proximal syringe 12 is preferably a A " ~ ~.~--âs _-3~ 23 conventional arterial blood gas syringe. Plunger shaft 20 -~A3~ 2~ is preferably positioned within pro~imal syringe barrel 12. At the distal end of plunger shaft 20 is a plunger ~6 18. Plunger 18 is preferably a vented plunger. Por the - ` 20 3 ~7 1 purposes of this application, a vented plunger ~ gas , permeable but liquid impermeable. This incluaes Do~h ~ien ed plungers known in the art, as well as membrane plungers such l as the one described in United States Patent .~o. ','2 " /45 ; to Ford, issued l~ay 4, 1982.
, At the distal end of proximal syringe barrel 28 is coupling device 30. Coupling device 30, as found on many ~ conventional syringes, is a twist-on locking device or luer .~ lock-type coupling known in the art. In most cases, coupling device 30 is adapted to receive a hypodermic Il needle. However, in the apparatus of the present invention 12 illustrated in Figure 1, coupling device 30 is adapted to 13 receive flow-through plunger 11 and locks onto flow-through 1~ adapter 22.
Also illustrated in Figure 1 is distal syringe 16.
l6 Distal syringe 16 is preferably a conventional syringe for 1- obtaining a clinical laboratory blood sample. Dis~al 18 syringe 16 includes a distal syringe barrel 32 having a l9 inside diameter configured to receive flow-thrcugh p~unger 11. A coupling device 34 is located at the proximal end of -~7` ~1 distal syringe barrel 32. Coupling device 34 is preferably r ^ ~ a conventional twist-on locking device or luer lock-type ~r~ F ~ . ~
-3~i-,$7 ~ coupling similar to coupling device 30. Coupling device 34 Z e3~e7 ,~ is configured for receiving a hypodermic syringe needle ~not . shown) or the luer lock coupling of a three way stop-cock.
~6 ': '' 2 ~ 7 ~t the proximal end of distal s~risge barrel 32 is an annular ~ip 36.
, Referring no~ to ~igure 2, the embodiment o. Figure 1 is assembled and illustrated in a cross-sectiona~ view. In Figure 2, pro~imal syringe 12 is sho-~n 1ith a s~aller ~, outside diameter than the inside diameter of distal syringe 16. In this manner, proximal syringe 12 may literally fit ~ inside distal syringe 16.
'3 As discussed above, proximal syringe 12 may preferably 1() be a conventional arterial blood qas syringe and distal ll syringe 16 may preferably be a clinical laboratory 1~ syringe. Generally, the blood sample size required for l:3 clinical laboratory analysis is significantly larger than l~ the sample size required for blood gas analysis. Typically,~
l:; an arterial blood gas sample should be in the range ~rom 16 about 1 cc (cubic centimeter) to about 3 cc, whereas a ~, typical clinlcal laboratory blood sample may range from 18 about 6 cc to about 20 cc, depending on the particular set of conditions. Thus, although it would be possible to '0 reverse the functicns o the proximal and distal syringes, _ ~1 in most cases it is preferable to obtain a larger clinical _? laboratory sample than arterial olood gas sample.
~F~ ? 73 The method for obtaining a clinical laboratory blood z c~ sample and arterial blood gas sample from a single ~ hypodermic puncture varies depending upon the source of a ,?6 arterial blood. If the blood is to be obtained directly ' -:
2~
from a patient's artery, ~hen plunger 18 of the Droximal , syringe 12 is preEerably vented. A vented olunger 18 allo~/s air within both syrinqes 12 and 16 to escape as the syrinse fills ~tith blood.
. Prior to inserting the hypodermic needle into the , artery, plunger 18 and flow-through plunger 11 are preferably adjusted within proximal syringe barrel 12 and distal syringe barrel 16, respectively, to a preset location (3 representing the desired quantity of blood for both blood lo samples. Upon puncturing an artery, both syringe barrels Il fill with blood under the arterial blood pressure. As blood Iz7 fills the syringe barrels, the air ~ithin the syringe 1:~ barrels is vented through the vented plunger 18. In this 1~ manner, air bubbles within the arterial blood gas sample are 1; minimized.
16 If the source of arterial blood is from an arterial 17 line catheter, an umbilical arterial catheter, or some other l8 external arterial blood source, then plunger 18 is not necessarily vented. As a result, pro.cimal syringe 12 in ~0 this situation, would preferably be a conventional air-tight syringe. Both flow-through syringe plunger 11 and plunger 2~ 18 are preferably positioned far into their respective syringe barrels. By pulling back on pro:cimal syringe 12, to which the flow-through plunger 11 is attached, distal 'S syringe barrel 32 is filled with blood. Plunger shaft 20 is 76 then preferably pulled back to obtain the arterial blood gas ' 20~3.~'7 sample withill Dro~imal SyLinge barrel 12. The blood flo~s ~ Erom distal syringe bacrel 32 through 10~-through plun~er : 11 and into pro~imal syringe barrel 1~.
In both o~ the foregoing methods proximal syringe . barrel 12 pre~erat71y contains a quanti~y o~ anticoagu1ant to , inhibit coagulation of the blood gas sample. An anticoagulant is desired because blood coagulation destroys the integrity of accurate blood gas analysis. Anv suitable 9 anticoagulant known in the art may be used. It has been lo found that lithium heparin produces satisfactory results.
11 After both blood samples are obtained, the proximal syringe 12 is removed from the flow-through plunger 11 by l3 simply untwisting coupling device 30. Any incidental air 1~ bubbles remaining within proximai syringe barrel 12 are~
1; removed and coupling device 30 is capped to preven~
16 atmospheric gas from compromising the blood gas anal-Jsis.
1. The distal syringe, containing the clinical laboratory blood 18 sample, is then capped at the rlo~-through plunger site by 19 replacing pro:~imal syringe 12 ~ith a conventional p~unger 7o shaft or other type of plug (not shown) adapted to twist ~1 onto the flow-through syrinse plunger 11. The blood samples are then delivered to their respective laboratories for ,C -' _ analysis.
3~ _1 Figure 3 illustrates an additional embodiment of a flow-through plunger assembly 38 within the scope of the ~6 present invention. Flow-through assembly 38, shown in an 2 0 ~ 16 l' .
eYploded Eormat, includes a flo~-~h~ough plunger 4Z and an O-ring 44. Flow-througn pl~nger 12 has a conduit 46 or bo~e ; througn the center thereo. to permit blood or fluid to clow through the flow-through plunger 42. A tristing lip 48 is , secured to flow-through ?lunger ~2. In one preferred ~, embodiment within the scope of the present invention, _ t~isting lip 48 is integrally molded with flow-through plunger ~2. Twisting lip 48 is adapted to be removably (J secured to a conventional twist-on locking device or luer IV lock-type coupling.
ll When assembled O-ring 44 is radially disposed about the 12 outer periphery of flow-through plunger 42. O-ring 44 1~ provides means for forming a slidable seal within a distal 1.~ syringe barrel. O-ring ~4 is preferably constructed of a 1; resilient material such as hard compressed rubber.
16 In summary, the present invention provides apparatus 1~ and methods for obtaining ttlo independent fluid samples from 18 a single fluid source. More particularly, the present 19 invention .provides apparatus and methods for obtaining clinical laboratory and arterial blood gas samples which require only a single hypodermic needle puncture to a a ~ patient. This is accomplished by the unique dual-chamber ~- ~
linear syringe disclosed herein which features a flow-e~ 2~ through plunger.
a ~ 2s The present invention further provides apparatus and ~6 methods for obtaining clinical laboratory and arterial blood -" ::
201~67 l gas sam~les t~hich reduce the risk o~ ~raull1a to the patient's . arter es OnLy a single pu~cture is ~eauired and no twistlng OL^ the device is required ~hile the needle is disposed within the artery. In addition, only one , technician is required to obtain both blood sampies instead . of t~o techniclans required for existing techniaues.
_ Furthermore, because the present invention enables both 8 the clinical laboratory and arterial blood gas samples to be 9 obtained simultaneously, the risk of infection to the 1~ patient is substantially reduced. No manipulations are 11 required that would expose a patient's artery to an 12 unsterile outside environment.
13 The invention may be embodied in other specific forms 1~ without departing from its spirit or essential character-~
_ istics. The described embodiments are to be considered in 16 all respects only as illustrative and not restrictive. The 1_ scope of the invention is, therefore, indicated by the 18 appended claims rather than by the foregoing description.
19 All changes which come within the meaning and ranqe of _ ~n equivalency o the claims are to be embraced within their c~
scope.
>3 ;Z; CB ~ ~ 7 E ~.~
~6
In operation, the flow-through plunger 11 and proximal syringe 12 provide a piston function for the distal syringe 16, permitting the distal syringe 16 to be filled with the desired fluid sample. Similarly, actuating .he conventional l plunger 18 and plunger shaft 20 within the proximal syringe l~ 12 permits the proximal syringe 12 to be filled with the 1:3 fluid sample. The fluid sample 10ws .^rom the distal 1.~ syringe 16 to the proximal syringe 12 by passing tnrough the~
1.; flow-through plunger 11.
l6 Figure 1 shows one embodiment of the flow-through l/ plunger 11, a proximal syringe 12, and a distal 18 syringe 16. Flow-th~ough plunger 11 includes a ~low-through 1~ adapter 22. Plunger 11 is cons;ructed much ~ like 2n conventional syringe plungers except that plunger 11 -_ .,l includes a conduit 24 or bore through the center thereof to a ~ allow the passage of blood or other fluids through the _r. F ~, :, 3 piston. Plunger 11 is preferably constructed of a hard ~ compressed rubber or other suitable resilient material which ,~ ~.; is capable of forming a slidable seal within a distal 3 ~6 syringe 16.
201 ~ ~77 Flow-through adap~er 22 is designed to be attached to , plunger ll such that the [low-throuqn adapter and piston together form conduit 21. Flow-throuqh adapter 22 is l preferably press fit and sealed ~ithin conduit 24 and held ; in place due to pressure and sealant ~rom the resilient , material of plunger 11. Flow-through adapter 22 is _ generally tubular in shape such that when positioned within plunger 11, conduit 24 continues through flow-through ~ adapter 22 creating an open passageway through the center of the flow-through plunger 11.
1l Flow-through adapter 22 may have a twisting lip 26 adapted to be removably secured to a twist-on locking device 13 or luer lock-type coupling mechanism found on many l~ conventional syringe tips. In one preferred embodiment,~
1; twisting lip 26 is a male luer lock coupling. Because flow-16 through adapter 22 is adapted to be removably secured to the l_ syringe tips, flow-through adapter 22 is preferably 18 constructed of a rigid material. It has been found that l9 existing hard plastic materials used in the medical ar~s are suitable materials.
Proximal syringe 12 includes a syringe barrel 28 and a 2~ plunger shaft 20. Proximal syringe 12 is preferably a A " ~ ~.~--âs _-3~ 23 conventional arterial blood gas syringe. Plunger shaft 20 -~A3~ 2~ is preferably positioned within pro~imal syringe barrel 12. At the distal end of plunger shaft 20 is a plunger ~6 18. Plunger 18 is preferably a vented plunger. Por the - ` 20 3 ~7 1 purposes of this application, a vented plunger ~ gas , permeable but liquid impermeable. This incluaes Do~h ~ien ed plungers known in the art, as well as membrane plungers such l as the one described in United States Patent .~o. ','2 " /45 ; to Ford, issued l~ay 4, 1982.
, At the distal end of proximal syringe barrel 28 is coupling device 30. Coupling device 30, as found on many ~ conventional syringes, is a twist-on locking device or luer .~ lock-type coupling known in the art. In most cases, coupling device 30 is adapted to receive a hypodermic Il needle. However, in the apparatus of the present invention 12 illustrated in Figure 1, coupling device 30 is adapted to 13 receive flow-through plunger 11 and locks onto flow-through 1~ adapter 22.
Also illustrated in Figure 1 is distal syringe 16.
l6 Distal syringe 16 is preferably a conventional syringe for 1- obtaining a clinical laboratory blood sample. Dis~al 18 syringe 16 includes a distal syringe barrel 32 having a l9 inside diameter configured to receive flow-thrcugh p~unger 11. A coupling device 34 is located at the proximal end of -~7` ~1 distal syringe barrel 32. Coupling device 34 is preferably r ^ ~ a conventional twist-on locking device or luer lock-type ~r~ F ~ . ~
-3~i-,$7 ~ coupling similar to coupling device 30. Coupling device 34 Z e3~e7 ,~ is configured for receiving a hypodermic syringe needle ~not . shown) or the luer lock coupling of a three way stop-cock.
~6 ': '' 2 ~ 7 ~t the proximal end of distal s~risge barrel 32 is an annular ~ip 36.
, Referring no~ to ~igure 2, the embodiment o. Figure 1 is assembled and illustrated in a cross-sectiona~ view. In Figure 2, pro~imal syringe 12 is sho-~n 1ith a s~aller ~, outside diameter than the inside diameter of distal syringe 16. In this manner, proximal syringe 12 may literally fit ~ inside distal syringe 16.
'3 As discussed above, proximal syringe 12 may preferably 1() be a conventional arterial blood qas syringe and distal ll syringe 16 may preferably be a clinical laboratory 1~ syringe. Generally, the blood sample size required for l:3 clinical laboratory analysis is significantly larger than l~ the sample size required for blood gas analysis. Typically,~
l:; an arterial blood gas sample should be in the range ~rom 16 about 1 cc (cubic centimeter) to about 3 cc, whereas a ~, typical clinlcal laboratory blood sample may range from 18 about 6 cc to about 20 cc, depending on the particular set of conditions. Thus, although it would be possible to '0 reverse the functicns o the proximal and distal syringes, _ ~1 in most cases it is preferable to obtain a larger clinical _? laboratory sample than arterial olood gas sample.
~F~ ? 73 The method for obtaining a clinical laboratory blood z c~ sample and arterial blood gas sample from a single ~ hypodermic puncture varies depending upon the source of a ,?6 arterial blood. If the blood is to be obtained directly ' -:
2~
from a patient's artery, ~hen plunger 18 of the Droximal , syringe 12 is preEerably vented. A vented olunger 18 allo~/s air within both syrinqes 12 and 16 to escape as the syrinse fills ~tith blood.
. Prior to inserting the hypodermic needle into the , artery, plunger 18 and flow-through plunger 11 are preferably adjusted within proximal syringe barrel 12 and distal syringe barrel 16, respectively, to a preset location (3 representing the desired quantity of blood for both blood lo samples. Upon puncturing an artery, both syringe barrels Il fill with blood under the arterial blood pressure. As blood Iz7 fills the syringe barrels, the air ~ithin the syringe 1:~ barrels is vented through the vented plunger 18. In this 1~ manner, air bubbles within the arterial blood gas sample are 1; minimized.
16 If the source of arterial blood is from an arterial 17 line catheter, an umbilical arterial catheter, or some other l8 external arterial blood source, then plunger 18 is not necessarily vented. As a result, pro.cimal syringe 12 in ~0 this situation, would preferably be a conventional air-tight syringe. Both flow-through syringe plunger 11 and plunger 2~ 18 are preferably positioned far into their respective syringe barrels. By pulling back on pro:cimal syringe 12, to which the flow-through plunger 11 is attached, distal 'S syringe barrel 32 is filled with blood. Plunger shaft 20 is 76 then preferably pulled back to obtain the arterial blood gas ' 20~3.~'7 sample withill Dro~imal SyLinge barrel 12. The blood flo~s ~ Erom distal syringe bacrel 32 through 10~-through plun~er : 11 and into pro~imal syringe barrel 1~.
In both o~ the foregoing methods proximal syringe . barrel 12 pre~erat71y contains a quanti~y o~ anticoagu1ant to , inhibit coagulation of the blood gas sample. An anticoagulant is desired because blood coagulation destroys the integrity of accurate blood gas analysis. Anv suitable 9 anticoagulant known in the art may be used. It has been lo found that lithium heparin produces satisfactory results.
11 After both blood samples are obtained, the proximal syringe 12 is removed from the flow-through plunger 11 by l3 simply untwisting coupling device 30. Any incidental air 1~ bubbles remaining within proximai syringe barrel 12 are~
1; removed and coupling device 30 is capped to preven~
16 atmospheric gas from compromising the blood gas anal-Jsis.
1. The distal syringe, containing the clinical laboratory blood 18 sample, is then capped at the rlo~-through plunger site by 19 replacing pro:~imal syringe 12 ~ith a conventional p~unger 7o shaft or other type of plug (not shown) adapted to twist ~1 onto the flow-through syrinse plunger 11. The blood samples are then delivered to their respective laboratories for ,C -' _ analysis.
3~ _1 Figure 3 illustrates an additional embodiment of a flow-through plunger assembly 38 within the scope of the ~6 present invention. Flow-through assembly 38, shown in an 2 0 ~ 16 l' .
eYploded Eormat, includes a flo~-~h~ough plunger 4Z and an O-ring 44. Flow-througn pl~nger 12 has a conduit 46 or bo~e ; througn the center thereo. to permit blood or fluid to clow through the flow-through plunger 42. A tristing lip 48 is , secured to flow-through ?lunger ~2. In one preferred ~, embodiment within the scope of the present invention, _ t~isting lip 48 is integrally molded with flow-through plunger ~2. Twisting lip 48 is adapted to be removably (J secured to a conventional twist-on locking device or luer IV lock-type coupling.
ll When assembled O-ring 44 is radially disposed about the 12 outer periphery of flow-through plunger 42. O-ring 44 1~ provides means for forming a slidable seal within a distal 1.~ syringe barrel. O-ring ~4 is preferably constructed of a 1; resilient material such as hard compressed rubber.
16 In summary, the present invention provides apparatus 1~ and methods for obtaining ttlo independent fluid samples from 18 a single fluid source. More particularly, the present 19 invention .provides apparatus and methods for obtaining clinical laboratory and arterial blood gas samples which require only a single hypodermic needle puncture to a a ~ patient. This is accomplished by the unique dual-chamber ~- ~
linear syringe disclosed herein which features a flow-e~ 2~ through plunger.
a ~ 2s The present invention further provides apparatus and ~6 methods for obtaining clinical laboratory and arterial blood -" ::
201~67 l gas sam~les t~hich reduce the risk o~ ~raull1a to the patient's . arter es OnLy a single pu~cture is ~eauired and no twistlng OL^ the device is required ~hile the needle is disposed within the artery. In addition, only one , technician is required to obtain both blood sampies instead . of t~o techniclans required for existing techniaues.
_ Furthermore, because the present invention enables both 8 the clinical laboratory and arterial blood gas samples to be 9 obtained simultaneously, the risk of infection to the 1~ patient is substantially reduced. No manipulations are 11 required that would expose a patient's artery to an 12 unsterile outside environment.
13 The invention may be embodied in other specific forms 1~ without departing from its spirit or essential character-~
_ istics. The described embodiments are to be considered in 16 all respects only as illustrative and not restrictive. The 1_ scope of the invention is, therefore, indicated by the 18 appended claims rather than by the foregoing description.
19 All changes which come within the meaning and ranqe of _ ~n equivalency o the claims are to be embraced within their c~
scope.
>3 ;Z; CB ~ ~ 7 E ~.~
~6
Claims (24)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A dual-chambered linear syringe for simultaneously obtaining two fluid samples from a single fluid source comprising:
a distal syringe barrel having a first open end, a second open end adapted for attachment to a fluid source, and a bore communicating between said ends;
a proximal syringe barrel having a first open end, a second open end, and a bore communicating between said ends, said proximal syringe barrel having an outside diameter smaller than the inside diameter of the distal syringe barrel;
a flow-through plunger detachably secured to the second open end of the proximal syringe and configured such that it is capable of forming a slidable seal within the bore of said distal syringe barrel, said flow-through plunger having a conduit through the center thereof to permit fluid flow therethrough;
wherein said proximal and distal syringe barrels are detachable in such a manner as to leave said flow-through plunger within said distal syringe barrel such that two generally enclosed fluid samples can be simultaneously obtained from a single fluid source in communication with said distal syringe.
a distal syringe barrel having a first open end, a second open end adapted for attachment to a fluid source, and a bore communicating between said ends;
a proximal syringe barrel having a first open end, a second open end, and a bore communicating between said ends, said proximal syringe barrel having an outside diameter smaller than the inside diameter of the distal syringe barrel;
a flow-through plunger detachably secured to the second open end of the proximal syringe and configured such that it is capable of forming a slidable seal within the bore of said distal syringe barrel, said flow-through plunger having a conduit through the center thereof to permit fluid flow therethrough;
wherein said proximal and distal syringe barrels are detachable in such a manner as to leave said flow-through plunger within said distal syringe barrel such that two generally enclosed fluid samples can be simultaneously obtained from a single fluid source in communication with said distal syringe.
2. A dual-chambered linear syringe for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 1, wherein the proximal syringe barrel comprises an arterial blood gas syringe.
3. A dual-chambered linear syringe for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 1, wherein the proximal syringe barrel has a volume for obtaining a blood sample size in the range from about 1 cc to about 2 cc.
4. A dual-chambered linear syringe for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 2, wherein the arterial blood gas syringe further comprises a slidable plunger which is gas permeable and liquid impermeable.
5. A dual-chambered linear syringe for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 1, wherein the flow-through plunger is detachably secured to the second open end of the proximal syringe barrel through use of a luer lock coupling.
6. A dual-chambered linear syringe for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 1, wherein the sealing means comprises an O-ring disposed around the outside diameter of the flow-through plunger.
7. A dual-chambered linear syringe for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 1, wherein the flow-through plunger and the sealing means are integrally molded.
8. A syringe for simultaneously obtaining two liquid samples from a single source comprising:
a distal syringe comprising a distal syringe barrel having a first open end, a second open end adapted for mounting a detachable hypodermic needle on the opening thereof, and a bore communicating between said ends;
a generally cylindrical plunger slidably mounted within the bore of the distal syringe barrel having a distal end, a proximal end, and conduit means through the center thereof to permit the flow of liquid therethrough;
sealing means radially disposed about the outer periphery of said plunger for forming a slidable seal within the bore of said distal syringe barrel;
a proximal syringe comprising a proximal syringe barrel having a first open end for receiving a slidable plunger, a second open end adapted for receiving the cylindrical plunger on the opening thereof, and a bore communicating between said ends;
means for detachably securing the cylindrical plunger to the second open end of the proximal syringe barrel such that when the cylindrical piston is secured to the proximal syringe barrel and positioned within the distal syringe barrel, the conduit means of the cylindrical piston provides a fluid passageway from the distal syringe barrel to the proximal syringe barrel and such that the proximal syringe can be detached leaving the plunger within the distal syringe; and a plunger slidably mounted in the bore of the proximal syringe barrel having a plunger shaft partially extending out of the first open end of the proximal syringe barrel.
a distal syringe comprising a distal syringe barrel having a first open end, a second open end adapted for mounting a detachable hypodermic needle on the opening thereof, and a bore communicating between said ends;
a generally cylindrical plunger slidably mounted within the bore of the distal syringe barrel having a distal end, a proximal end, and conduit means through the center thereof to permit the flow of liquid therethrough;
sealing means radially disposed about the outer periphery of said plunger for forming a slidable seal within the bore of said distal syringe barrel;
a proximal syringe comprising a proximal syringe barrel having a first open end for receiving a slidable plunger, a second open end adapted for receiving the cylindrical plunger on the opening thereof, and a bore communicating between said ends;
means for detachably securing the cylindrical plunger to the second open end of the proximal syringe barrel such that when the cylindrical piston is secured to the proximal syringe barrel and positioned within the distal syringe barrel, the conduit means of the cylindrical piston provides a fluid passageway from the distal syringe barrel to the proximal syringe barrel and such that the proximal syringe can be detached leaving the plunger within the distal syringe; and a plunger slidably mounted in the bore of the proximal syringe barrel having a plunger shaft partially extending out of the first open end of the proximal syringe barrel.
9. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 8, wherein the proximal syringe comprises an arterial blood gas syringe.
10. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 9, wherein the proximal syringe is configured to obtain a blood sample size in the range from about 1 cc to about 3 cc.
11. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 10, wherein the proximal syringe includes a slidable plunger which is gas permeable and liquid impermeable.
12. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 10, wherein the distal syringe comprises a clinical laboratory syringe.
13. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 12, wherein the distal syringe is configured to obtain a blood sample size in the range from about 6 cc to about 20 cc.
14. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 13, wherein the means for detachably securing the cylindrical plunger to the second open end of the proximal syringe barrel comprises a male luer lock coupling.
15. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 14, wherein the cylindrical plunger and the male luer lock coupling are integrally molded.
16. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 15, wherein the sealing means comprises an O-ring.
17. A syringe device for obtaining a clinical laboratory blood sample and an arterial blood gas sample from a patient as defined in claim 14, wherein the plunger and the sealing means are integrally molded of a resilient material.
18. A method for simultaneously obtaining two fluid samples from a single fluid source comprising the steps of:
obtaining a dual-chambered linear syringe comprising a distal syringe, a proximal syringe positioned within the distal syringe, and a flow-through plunger detachably secured to the proximal syringe and positioned within the distal syringe, said flow-through plunger comprising conduit means through the center thereof to permit fluid flow from the distal syringe into the proximal syringe and sealing means radially disposed about the outer periphery of said flow-through syringe plunger for forming a slidable seal within the distal syringe, said flow-through plunger, said plunger being detachable from said proximal syringe in such a manner as to leave the plunger within the distal syringe;
connecting the distal syringe with a fluid source;
introducing fluid into the distal syringe; and passing at least a portion of the fluid through the flow-through plunger into the proximal syringe.
obtaining a dual-chambered linear syringe comprising a distal syringe, a proximal syringe positioned within the distal syringe, and a flow-through plunger detachably secured to the proximal syringe and positioned within the distal syringe, said flow-through plunger comprising conduit means through the center thereof to permit fluid flow from the distal syringe into the proximal syringe and sealing means radially disposed about the outer periphery of said flow-through syringe plunger for forming a slidable seal within the distal syringe, said flow-through plunger, said plunger being detachable from said proximal syringe in such a manner as to leave the plunger within the distal syringe;
connecting the distal syringe with a fluid source;
introducing fluid into the distal syringe; and passing at least a portion of the fluid through the flow-through plunger into the proximal syringe.
19. A method for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 18, wherein the fluid to be sampled comprises blood.
20. A method for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 18 wherein the connecting step comprises attaching a hypodermic needle to a syringe tip formed on the distal syringe and inserting the hypodermic needle into an artery of a patient.
21. A method for simultaneously obtaining two fluid samples from a single fluid source as define din claim 18 wherein the connecting step comprises removably attaching the distal syringe to an arterial line catheter, or umbilical arterial catheter.
22. A method for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 21, wherein the introducing step comprises telescopically withdrawing the plunger/syringe assembly from within the distal syringe, thereby filling the distal syringe with blood.
23. A method for simultaneously obtaining two fluid samples from a single fluid source as defined in claim 22, wherein the passing step comprises telescopically withdrawing a slidable plunger positioned within the proximal syringe, thereby causing blood to pass through the flow-through plunger and fill the proximal syringe with blood.
24. A method for simultaneously obtaining a clinical laboratory blood sample and an arterial blood gas sample from a single hypodermic needle puncture comprising the steps of:
obtaining a dual-chambered linear syringe having a clinical laboratory syringe, an arterial blood gas syringe having a vented plunger therewithin, and a flow-through plunger detachably secured to a syringe tip formed on the arterial blood gas syringe, said flow-through plunger comprising conduit means through the center thereof to permit blood flow into the arterial blood gas syringe and sealing means radially disposed about the outer periphery of said flow-through plunger for forming a slidable seal within the clinical laboratory syringe, said arterial blood gas syringe being positioned within the clinical laboratory syringe;
attaching a hypodermic needle to a syringe tip formed on the clinical laboratory syringe;
inserting the hypodermic needle into an artery thereby allowing arterial blood to flow into the clinical laboratory syringe, through the flow-through syringe plunger, and into the arterial blood gas syringe;
removing the hypodermic needle from the artery; and separating the arterial blood gas syringe from the flow-through plunger while the flow-through syringe plunger remains within the clinical laboratory syringe.
LCM:jnh108561.08
obtaining a dual-chambered linear syringe having a clinical laboratory syringe, an arterial blood gas syringe having a vented plunger therewithin, and a flow-through plunger detachably secured to a syringe tip formed on the arterial blood gas syringe, said flow-through plunger comprising conduit means through the center thereof to permit blood flow into the arterial blood gas syringe and sealing means radially disposed about the outer periphery of said flow-through plunger for forming a slidable seal within the clinical laboratory syringe, said arterial blood gas syringe being positioned within the clinical laboratory syringe;
attaching a hypodermic needle to a syringe tip formed on the clinical laboratory syringe;
inserting the hypodermic needle into an artery thereby allowing arterial blood to flow into the clinical laboratory syringe, through the flow-through syringe plunger, and into the arterial blood gas syringe;
removing the hypodermic needle from the artery; and separating the arterial blood gas syringe from the flow-through plunger while the flow-through syringe plunger remains within the clinical laboratory syringe.
LCM:jnh108561.08
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2011677 CA2011677A1 (en) | 1990-03-07 | 1990-03-07 | Methods and apparatus for obtaining arterial blood samples |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2011677 CA2011677A1 (en) | 1990-03-07 | 1990-03-07 | Methods and apparatus for obtaining arterial blood samples |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2011677A1 true CA2011677A1 (en) | 1991-09-07 |
Family
ID=4144471
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2011677 Abandoned CA2011677A1 (en) | 1990-03-07 | 1990-03-07 | Methods and apparatus for obtaining arterial blood samples |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2011677A1 (en) |
-
1990
- 1990-03-07 CA CA 2011677 patent/CA2011677A1/en not_active Abandoned
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4936315A (en) | Methods and apparatus for obtaining arterial blood samples | |
| US5947932A (en) | Closed system blood sampling device | |
| EP0301913B1 (en) | Blood aspiration assembly | |
| US5531672A (en) | Blood aspiration assembly components and blunt needle aspirators | |
| AU697232B2 (en) | In situ calibration system for sensors located in a physiologic line | |
| US4981140A (en) | Method and apparatus for arterial and venous blood sampling | |
| US4257426A (en) | Vacuum assisted anti-coagulant syringe device for taking blood samples | |
| US5193545A (en) | Device for determining at least one medical variable | |
| EP0486059B1 (en) | Disposable cartridge for sampling and analyzing body fluids | |
| US4393882A (en) | Method and device for collecting, transporting, and delivering micro samples of blood | |
| US3572315A (en) | Intravascular catheter with gas-permeable tip | |
| US4763648A (en) | Method and apparatus for arterial and venous blood sampling | |
| US5269317A (en) | Intravenous blood sampling apparatus | |
| US6155991A (en) | Apparatus and method for collecting blood samples | |
| EP0248670A2 (en) | Dialysis system | |
| US5086783A (en) | Blood sampling device | |
| CA2175056A1 (en) | Fluid sample collection and introduction device | |
| US4559052A (en) | Multiple use container for the packaging of fluids | |
| AU2772302A (en) | Method and kit of components for delivering blood to a portable clinical analyzer | |
| US5518005A (en) | Syringe apparatus for separating blood and method for using same | |
| CA2011677A1 (en) | Methods and apparatus for obtaining arterial blood samples | |
| CN109998567A (en) | A kind of automatic needle protection-closing integration vim and vigour acquisition needle | |
| CN211131294U (en) | Lumbar puncture needle capable of measuring oxygen partial pressure and biochemical indexes of cerebrospinal fluid | |
| CN211066659U (en) | Intraoperative blood gas analysis and blood sampling device | |
| CN215078614U (en) | Trace arterial blood gas hemostix |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |