JP4625640B2 - Cuffed tube - Google Patents

Description

  The present invention relates to a cuffed tube used by being connected to a ventilator.

In general, a tracheostomy tube or a distal end portion of a tracheal tube is provided with a balloon-like cuff that expands and contracts by taking in and out air.
(I) The purpose of the cuff is to obtain an airtight state for sending inspiration to the lungs by artificial positive pressure. If this is the case, this airtight may be obtained only during the inspiratory phase, except for the need for PEEP in critically ill patients, but in reality it is maintained without distinction even in the expiratory phase where no airtightness is required. This imposes psychological pain on patients who are mildly ill and who are about to leave the ventilator as well as physically suffering more than necessary, and at the same time depriving them of the opportunity to speak.

(Ii) The cuff is generally inflated with a pressure sufficiently higher than the pressure in the trachea (for example, about 20 mmHg or more) in order to prevent the pressure in the trachea from leaking into the upper airway. This has a risk of serious damage to the mucous membrane of the tracheal wall having a delicate structure.

It has been pointed out that continuous and excessive lateral pressure applied to the inner wall of the trachea may cause damage to the fine structure of the tracheal mucosa and further form ulcers, eventually leading to granulation and tracheal stenosis. The degree of such invasion is considered to depend on the degree of side pressure (ii) applied to the inner wall of the cuff and its applied time (i).
Therefore, the degree of invasion can be reduced by reducing one or both of them in a range that does not impair ventilation, which is the original purpose, more than necessary.

Conventionally, for example, the following method has been proposed as a method for controlling the cuff pressure in order to reduce damage to the tracheal inner wall due to the cuff pressure.
(1) A system in which the cuff is inflated with air intake pressure to be airtight a. A method of communicating a cannula and a cuff (for example, see Patent Documents 1 to 3).
b. Double cuff system (for example, see Patent Document 4)
(2) A method in which airtightness is achieved by a check-type valve such as a skirt-like valve (see, for example, Patent Documents 5 to 7).
(3) A method of controlling the cuff pressure using an external pressure source (see, for example, Patent Document 8).
US Patent No. 5318021 US Pat. No. 3,565,079 US Pat. No. 3,707,151 US Pat. No. 3,481,339 US Pat. No. 3,616,799 US Pat. No. 3,709,227 US Pat. No. 3,769,983 US Pat. No. 5,487,383

However, a. In small difference in the trachea pressure P _T and the cuff pressure P _C, it is insufficient bulging of the cuff during inspiration. In (1) b. Then, a. The cuffs are doubled on the outside to increase the airtightness with the inner wall of the trachea. However, since exhalation is difficult to escape to the upper airway, it is difficult to utter, and it cannot be said to be a realistic structure.
In addition, the method of controlling the cuff pressure using an external pressure source requires a special ventilator equipped with an external pressure source and equipment for controlling the flow of air into and out of the cuff. Has problems that are difficult to apply.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cuffed tube that can obtain a minimum required cuff pressure to the extent that the cuff swells and is airtight only in the intake phase and does not impair ventilation. To do.

In order to achieve the above object, the present invention provides the above connection of a breathing circuit comprising an inspiratory pipe for sending inhalation from a ventilator to a patient, an exhalation pipe through which the patient's exhalation passes, and a connection pipe connecting them at the patient mouth side. A tube with a cuff attached to a tube and having a distal end inserted into a patient's trachea, comprising a tube body having an inflatable / reducible cuff at the distal end, and a cuff tube for allowing a part of inhalation to flow through the cuff. A cuffed tube is provided, wherein an intake pressure adapter for generating a ventilation resistance is provided upstream of the intake pipe, and an introduction end of the cuff tube is connected to the upstream side of the intake pressure adapter.
In the tube with a cuff of the present invention, the intake pressure adapter may be a fixed orifice type intake pressure adapter that increases ventilation resistance without fully closing the intake pipe.
Further, the intake pressure adapter may be a variable orifice type intake pressure adapter that adjustably increases a ventilation resistance of the intake pipe without fully closing the intake pipe.
The intake pressure adapter may be a spring-loaded intake pressure adapter that creates a ventilation resistance of the intake pipe through a valve biased by a spring without fully closing the intake pipe.

The cuffed tube according to the present invention is such that the cuff swells and is airtight only in the inspiratory phase, and can obtain the minimum required cuff pressure to the extent that ventilation is not impaired. Damage to the tracheal inner wall can be reduced.
In addition, a part of the exhalation escapes to the upper airway, so that the patient can speak.
Furthermore, by using a ventilation resistor that can adjust the ventilation cross-sectional area, an appropriate cuff pressure can be applied according to the patient's condition.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 are views showing an embodiment of a cuffed tube according to the present invention. FIG. 1 shows an inspiratory phase and FIG. 2 shows an expiratory phase. In these drawings, reference numeral 1 denotes a cuffed tube. 1 and 2 show the case where the cuffed tube 1 of the present invention is applied to a tracheostomy tube, but the present invention is not limited to this, and other cuffed tubes such as a tracheal tube. Needless to say, this is applicable.

  The cuffed tube 1 is composed of a tube body 3 (in the present example, a tracheostomy tube) having a cuff 2 that can be expanded and contracted at a distal end portion, and a cuff tube 4 that circulates air through the cuff 2, and artificial respiration. Connected to the connecting pipe 8 connecting the respirator 5 and the rear end of the tube body 3 via the inspiratory pipe 6 connected to the inspiratory side 5a of the ventilator 5 and the expiratory pipe 7 connected to the expiratory side 5b. Used.

  The upstream end of the intake pipe 6 and the intake side 5a of the ventilator 5 are connected via an intake pressure adapter 9 serving as a ventilation resistor, and the introduction end 4a of the cuff tube 4 is connected to the upstream side of the intake pressure adapter 9. It is configured to connect to. The intake pressure adapter 9 has an introduction end 4a of the cuff tube 4 connected to the upstream side connected to the intake side 5a of the ventilator 5, and a narrowed portion 15 provided immediately downstream of the introduction end 4a. .

  In this example, the tube body 3 is incised in the middle of the trachea 10 and the distal end portion is inserted into the trachea 10 and fixed. Inhalation sent through the tube body 3 enters the trachea 10 and reaches the lung 11. The cuff 2 provided at the distal end of the tube main body 3 is a balloon-like thing made of a stretchable thin film. The cuff 2 expands when a part of the intake air is fed into the cuff tube 4 and shrinks when extracted. It is like that. The tube body 3 and the cuff 2 can be configured using various types of tubes and cuffs used in conventionally known tracheostomy tubes and tracheal tubes.

  As shown in FIGS. 1 and 2, the cuff tube 4 may be externally attached to the tube body 3, or may be communicated with the cuff by a lumen in the tube wall as shown in FIG. 4 (a). You may connect with a double lumen tube. It is desirable to make the cuff tube 4 as large as possible.

  As shown in FIGS. 1 and 2, the cuffed tube 1 configured as described above is configured such that the tube body 3 is inserted into the trachea 10 of the patient, and the intake pipe 6 of the connection pipe 8 is inhaled by the ventilator 5. The exhalation tube 7 is connected to the exhalation side 5b of the ventilator 5, and the ventilator 5 is driven. The cuff tube 4 is connected in advance to an intake pressure adapter 9 attached to the upstream end of the intake pipe 6.

  Inhalation supplied from the inspiratory side 5a of the ventilator 5 during the inhalation of the patient shown in FIG. 1 includes an inspiratory pressure adapter 9, an inspiratory pipe 6 (the inspiratory pipe 6 and the inspiratory pressure adapter 9 can be in this order) and a tube. It enters the patient's trachea 10 through the body 3 and is delivered to the lung 11. At this time, a part of the intake air is sent to the cuff 2 through the cuff tube 4 provided with the introduction end 4a immediately upstream of the constriction 15 of the intake pressure adapter 9, expands, contacts the inner wall 12 of the trachea, and is airtight. Is preserved. During this inspiration, the exhalation valve 14 of the ventilator 5 is closed.

  When the patient exhales as shown in FIG. 2, exhalation in the patient's lungs 11 partly flows to the exhalation tube 7 through the tube body 3, and the other part passes through the gap between the reduced cuff 2 and the tracheal inner wall 12. It flows into the upper respiratory tract and is discharged from the mouth and nose. The exhaled air flowing into the exhalation tube 7 is discharged to the atmosphere through the exhalation valve 14 of the ventilator 5. The exhaled breath that escapes to the upper airway passes through the glottis 13 on the way, so that the patient can speak.

The operation of the cuff 2 when using the cuffed tube 1 will be described with reference to FIG.
Graph of FIG. 3 is a graph showing the repetition cycle of the patient's inspiratory phase and expiratory phase, a supply pressure P _I in the cuff tube 4 ₍₌ cuff pressure P _C), the pressure variation of the tracheal pressure P _T (The vertical axis indicates pressure, and the horizontal axis indicates time t).

In the intake phase, gradually increases from the tracheal pressure P _T indicated by supply pressure P _I and the dashed line indicated by a solid line in FIG. 3, a matching end inspiratory eliminated air inlet flow. Here, the supply pressure P _I to the cuff 2, for introducing end 4a is provided on the upstream side of the narrowed portion 15 of the intake pressure adapter 9, higher than tracheal pressure P _T corresponding to a downstream side of the constriction 15 Pressure is reached (P _I = P _C > P _T ). Cuff 2, bulge by a high supply pressure _{P I} than tracheal pressure _{P T (P C> P T} ), airtightness of the intake air is held in contact with the trachea inner wall 12. The pressure difference of P _C > P _T is based on the ventilation resistance generated by the narrowed portion 15 of the intake pressure adapter 9. That is, the circuit upstream of the constriction 15 of the intake pressure adapter 9 has a larger circuit internal pressure than the downstream thereof, and the cuff 2 can be sufficiently inflated by the differential pressure. Therefore, the intake pressure adapter 9 is designed so that a differential pressure that can sufficiently inflate the cuff 2 is generated.

In the expiratory phase, the exhalation valve 14 of the ventilator 5 is opened, the intake pipe 6, connecting tube 8, the expiratory tube 7 is vented to atmosphere with a sufficiently large inner diameter, and because the capacity of the cuff is small, the cuff pressure P _C Decreases more rapidly than the intratracheal pressure P _{T of} exhaled air passing through the tube body 3 having a relatively small inner diameter (P _C <P _T ), and the cuff 2 is reduced. By the reduction of the cuff 2, the cuff 2 is separated from the tracheal inner wall 12, and exhaled air can escape to the upper airway through the gap. As a result, the invasion of the tracheal inner wall 12 due to the cuff 2 constantly pressing the tracheal inner wall 12 is reduced, and a part of the exhalation escapes to the upper airway so that the patient can speak.

  FIG. 5 shows a structure in which a check valve 18 is provided in the middle of the cuff tube 4 and an extension tube 19 is connected to the check valve 18. As a result, without using the extension tube 19, it is possible to apply a fixed cuff pressure by a syringe as usual.

  FIG. 6 is a view showing another example of the intake pressure adapter used in the cuffed tube of the present invention. In the example shown in FIGS. 1 and 2, a fixed orifice type intake pressure adapter 9 having a constricted portion 15 is used. However, instead of the intake pressure adapter 9, a variable orifice type shown in FIG. 6 is used. An intake pressure adapter 20 can also be used. This variable orifice type intake pressure adapter 20 is configured by slidably overlapping two discs each having an arcuate opening 21 formed therein. The variable orifice type intake pressure adapter 20 is provided on the downstream side of the position where the cuff tube 4 of the intake pipe 6 is connected. This variable orifice type intake pressure adapter 20 can adjust the cross-sectional area of the flow path by turning one of the disks without fully closing the intake pipe 6.

  FIG. 7 is a view showing still another example of the intake pressure adapter used in the cuffed tube of the present invention. The spring-loaded intake pressure adapter 22 used in this example is configured to generate a ventilation resistance of the intake pipe 6 through a valve biased by a spring without fully closing the intake pipe 6. The spring-loaded intake pressure adapter 22 can adjust the cuff pressure by appropriately adjusting the compression degree of the spring.

It is a block diagram of the cuffed tube which shows one Embodiment of the cuffed tube of this invention, and exists in an inhalation phase. It is a block diagram of the tube with a cuff similarly in an expiration phase. It is a graph which shows the pressure fluctuation of the inhalation phase and expiration phase of the same cuffed tube. The attachment state of a cuff and a cuff tube is shown, (a) is a cross-sectional view of the tube main body tip portion in the lumen in the tube wall, and (b) is a perspective view in the double lumen tube. It is a principal part perspective view which shows the modification of a cuff tube. It is a principal part perspective view which shows another example of the intake pressure adapter used for the tube with a cuff of this invention. It is a principal part block diagram which shows another example of the intake pressure adapter used for the tube with a cuff of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cuffed tube, 2 ... Cuff, 3 ... Tube main body, 4 ... Cuff tube, 4a ... Introducing end, 5 ... Respirator, 5a ... Inspiratory side, 5b ... Expiratory side, 6 ... Inspiratory tube, 7 ... Expiratory tube , 8 ... Connecting pipe, 9 ... Inspiratory pressure adapter (fixed orifice type inspiratory pressure adapter), 10 ... Trachea, 11 ... Lung, 12 ... Tracheal inner wall, 13 ... Glottis, 14 ... Exhalation valve, 15 ... Stenosis, 16 ... Tube Wall lumen, 17 ... opening, 18 ... check valve, 19 ... extension tube, 20 ... variable orifice intake pressure adapter, 21 ... opening, 22 ... spring loaded intake pressure adapter.

Claims (4)

It is attached to the connection pipe of the breathing circuit including an inhalation pipe for sending inhalation from the ventilator to the patient, an exhalation pipe through which the patient's exhalation passes, and a connection pipe connecting them at the patient mouth side, and the tip is attached to the patient's air In the cuffed tube inserted into the tube,
A tube main body having a cuff capable of expanding and contracting at a distal end portion thereof, and a cuff tube for allowing a part of the intake air to flow through the cuff, and an intake pressure adapter for generating a ventilation resistance upstream of the intake pipe is provided, A cuffed tube, wherein an introduction end of the cuff tube is connected to an upstream side of an intake pressure adapter. The cuffed tube according to claim 1, wherein the intake pressure adapter is a fixed orifice type intake pressure adapter that increases ventilation resistance without fully closing the intake pipe. 2. The cuffed tube according to claim 1, wherein the intake pressure adapter is a variable orifice type intake pressure adapter that adjustably increases a ventilation resistance of the intake pipe without fully closing the intake pipe. 3. The said intake pressure adapter is a spring load type intake pressure adapter which produces the ventilation resistance of an intake pipe through the valve | bulb energized by the spring, without fully closing the said intake pipe. Cuffed tube.

Images