FR2814081A1 - DEVICE FOR SECURING PERIDURAL PERFUSIONS BY PERFORMING AUTOMATIC SUCTION TESTS WITH RESISTANCE LOSS SEARCH AND ANALYSIS OF PERFUSED OR ASPIRE FLUID - Google Patents

Abstract

Device for securing epidural infusions by performing automatic aspiration tests with detection of loss of resistance and analysis of the infused or aspirated fluid. The invention comprises performing automatic aspiration tests and the possible analysis by a sensor placed on the device. the infusion line of the qualities of the fluid infused or aspirated during these aspiration tests During the aspiration tests, the pusher (1) of the infusion device pulls the plunger of the syringe and maintains this traction for a predetermined period, in search of resistance (2) to the rollback. If this disappears, an alarm (3) sounds and the infusion is stopped. An internal or external sensor (4) can be placed on the infusion line (5) so as to detect variations in the quality of the fluid circulating therein. In the event of a change in the quality of the fluid, an alarm (3) sounds and the infusion is stopped. The device according to the invention is particularly suitable for the treatment of pain by epidural route by an electric syringe pump or by an apparatus of analgesia controlled by the patient and aims to detect catheter disconnection, vascular migration thereof or intrathecal migration.

Description

The present invention relates to securing continuous infusions

  epidurally by an electric syringe pump or by a patient-controlled analgesia device (PCEA), using a device designed to detect catheter disconnection, vascular migration or intra-catheter migration -thécale. This device includes performing automatic aspiration tests and possible analysis by a sensor placed on the infusion line

  the qualities of the fluid perfused, or aspirated during the automatic suction tests.

  The administration of local anesthetics, morphine drugs and adjuvants by means of a catheter placed beforehand in the epidural space is a very effective method of preventive and curative treatment of pain, in particular during the postoperative phase. However, the spread of this analgesia method is limited by its risks and the resulting need for surveillance. For this reason, some authors do not recommend this method, however very effective, outside intensive care services. Three of the main risks of the method are exposed here: they are the target of the invention proposed here: disconnection of the catheter. It most often occurs at the connection between the catheter and the bacterial filter, on the "patient" side of it (or distal side). The longer the catheter disconnection time, the greater the risk of microbial contamination, which can induce iatrogenic meningitis, is greater. The diagnosis of disconnection must therefore be made early. It can be done either on the visual observation of disconnection, or on the loss of resistance during a suction test preceding any manual injection into the catheter, or finally and later, on the observation cie! A decrease in the efficacy of epidural analgesia; - intravenous migration: intravenous malposition of the distal end of the catheter in an epidural vein is most often done during its placement,

  a reflux of blood is then visualized in the Tuohy needle or in the catheter.

  This reflux may be spontaneous or require a manual aspiration test with the syringe.

  Some authors recommend systematically carrying out a vascular test dose, that is to say the injection of an adrenaline dilution into the catheter. If this is followed by variations in heart rate or blood pressure, the test dose is considered to be positive and requires repositioning of the catheter. The continuation of anesthesia or analgesia would expose to the risks of ineffectiveness of the technique, of neurological accidents due to the convulsive power of local anesthetics on the central nervous system, of cardiovascular accidents due to the effects -2- cardiovascular depressants local anesthetics. In some cases, the vascular break-in is delayed compared to the placement of the catheter, this is called migration of the latter. The catheter may be at full channel in or near an injured epidural vein. These secondary breaches justify that during any subsequent manual injection, an aspiration test is carried out looking for a loss of resistance and / or the visualization of a "blood return" in the catheter; - intra-thecal migration: intra-thecal migration from the distal end of the catheter is a rare possibility. As with intravenous migration, this catheter positioning anomaly most often occurs during its placement; reflux of cerebrospinal fluid is then visualized in the Tuohy needle or in the catheter. This reflux may be spontaneous or require a manual aspiration test with the syringe. Some authors recommend systematically carrying out a spinal test dose after placement of the catheter, that is to say 1 l injection of a concentrated solution of local anesthetic into the catheter in a small volume (for example 1.5 ml of lidocaine at 5%). If this is followed by spinal-anesthesia-type spinal anesthesia, the test dose is considered positive and requires withdrawal of the catheter. The continuation of anesthesia or analgesia would expose to the risks of complete spinal anesthesia including in particular: significant vasoplegia by extended sympatholysis, bulbar paralysis with cardio-respiratory arrest. In some cases the intrathecal invasion is delayed compared to the placement of the catheter, we speak then of migration of this one. The catheter may be at full channel in the injured intra-thecal space or close to it. These secondary breaches justify that during any subsequent manual injection, an aspiration test is carried out looking for a loss of resistance with

  return to the catheter of a clear liquid rich in glucose.

  According to some authors, catheter positioning anomalies can be encountered in 10% of cases. It is regrettable, however, to note that among the services, even intensive care, where this very effective technique is used, manual suction tests are almost never carried out since the injections are no longer carried out manually but by means of electrical devices. infusion: electric syringe pump or patient-controlled analgesia device. This

  therefore exposes these services to the above-described accidents.

  The device according to the invention improves the safety of these medical techniques by the automatic performance by the perfusion apparatus of 3 - automatic aspiration tests. The periodicity of these suction tests is a parameter programmable by the user who can choose: - a manual mode; - a periodic mode (hourly for example) for electric syringe pumps and contr. 5ée by the patient; - an occasional mode, i.e. the triggering of an automatic aspiration test before the infusion of each bolus carried out by an analgesia device controlled by the patient or before each bolus requested manually by the caregiver on a electric syringe;

  - or of course, a mode combining two or three of the previous choices.

  According to particular embodiments, a sensor can be placed on the infusion line (extension-filter-connector-rd-catheter) to allow analysis

  chemical or physical characteristics of the fluids circulating there.

  For these purposes, the invention relates, according to a first aspect, to a device for improving the safety of epidural infusions carried out by devices of the electric syringe pump type or devices of the patient controlled analgesia type (PCEA), device comprising means for carrying out at least one automatic aspiration test for a predetermined duration on the perfusion system, in particular the plunger of a syringe, and means for detecting the loss of resistance to this aspiration controlling means for alarm and means for stopping the perfusion system upon detection of a loss of this suction resistance, in particular due to disconnection of the catheter and / or

  vascular and / or intra-thecal invasion.

  According to various embodiments, the device is such that - the means for detecting the loss of suction resistance comprise means for direct and / or indirect measurement of the perfusion pressure; the means for detecting the loss of suction resistance comprise means for measuring the torque and / or the driving force of the motor of the perfusion system; the means for detecting the loss of resistance to suction include means for detecting movement behind the piston or its carriage following the suction test; - It includes means for performing automatic suction tests, periodically, at regular intervals programmable by the user;

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  - It includes means for carrying out automatic aspiration tests carried out systematically before each bolus carried out by an electric syringe pump or an analgesia device controlled by the patient; - it also includes an external sensor located on the epidural catheter, analyzing the physical characteristics of the fluid perfused or aspirated during automatic aspiration tests, any variation in the quality of the fluid causing an alarm and stopping the infusion; - it further includes a sensor analyzing the physical characteristics of the fluid perfused or aspirated during automatic suction tests, this single-use sensor being arranged in series between the filter and the catheter connection when the catheter is placed epidural; - It further comprises a sensor analyzing the physical characteristics of the fluid perfused or aspirated during automatic suction tests, this sensor forming an integral part of the microbial filter and becoming a "filter-sensor" assembly put in place during installation. catheter; - the sensor is an internal sensor directly analyzing the electrical and / or physical, biochemical and / or chemical characteristics of the fluid perfused or aspirated during automatic aspiration tests; - it includes an external sensor analyzing the physical characteristics of the fluid perfused or aspirated during the automatic suction tests located between the

syringe and filter.

  The invention relates, according to a second aspect, to a method for improving the safety of epidural infusions carried out by devices of the electric syringe pump type or of analgesia type controlled by the patient, characterized in that at least one automatic aspiration test for a predetermined period on the perfusion system, in particular the plunger of a syringe and in that the resistance to aspiration is detected and that, upon detection of a loss of resistance to this aspiration in particular due to a disconnection of the catheter and / or a vascular and / or intra-thecal breach, means are ordered

  alarm and means for stopping the infusion.

  According to various embodiments, the method is such that - automatic suction tests are carried out periodically, at regular intervals programmable by the user; - an aspiration test is systematically carried out before each bolus carried out by an electric syringe pump or an analgesia device controlled by

the patient.

  The accompanying drawings illustrate the invention.

  In FIG. 1, the automatic aspiration test consists of pulling, in the opposite direction to the usual infusion, by the push-button of the infusion device 1 on the plunger of the syringe 2 and maintaining this pull for a few seconds . This aspiration is accompanied by a depression in the perfusion reservoir 3 which thus prevents return to. back of the piston. This tensile strength results in a negative pressure 4 which can be recorded by the device. Any vascular or intra-thecal breach of the catheter 5 or any loss of tightness on the infusion line including the syringe 2, the extender 6, the filter 7, the catheter connector 8 and the catheter 5 will be accompanied by disappearance. or a decrease in negative pressure 4 and resistance to depression. This causes an alarm 9 and stops the infusion. Depending on the particular manufacturing methods, the loss of suction resistance can be detected: - by direct measurement of the perfusion pressure; - by indirect measurement of the perfusion pressure; - by measuring the motor torque necessary to perform the suction; - by detection of a backward movement of the piston or of the carriage consecutive to

aspiration test.

  In the embodiment according to FIG. 2, a sensor 10 is placed on the epidural catheter 5 and analyzes the quality of the fluid perfused or aspirated during the automatic suction tests. He will be able to detect the presence of blood during vascular breaches, the presence of cerebrospinal fluid during intra-thecal breaches, the presence of air during catheter disconnections. Any variation

  fluid quality triggers an alarm 9 and stops the infusion.

  In the embodiment according to FIG. 3, the sensor 10 is placed above the filter 7, on the perfusion extender 6 and can detect the passage of air during

  leakage by extension / syringe or extension / filter disconnections.

  In the embodiments according to Figures 2 and 3, the sensor is an external sensor through which passes the perfusion line without contact between the liquid and the sensor. The analysis is done through the walls of the infusion line. Properties

  studied are the physical or optical properties of the fluid.

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  In the embodiment according to FIG. 4, the sensor 11 is a single-use sensor fixed, during the placement of the epidural catheter, by two Luer-Lock latches

  between the bacterial filter 7 and the catheter connector 8.

  In the embodiment according to FIG. 5, the sensor forms an integral part of the microbial filter and becomes a sensor-filter assembly 12 for single use which is installed during the placement of the epidural catheter between the extender 6 and the connector of the

catheter 8.

  In the embodiment according to FIGS. 4 and 5, the sensor is either: - an external sensor: the analysis is carried out through the rigid plastic of the measurement chamber; - an internal sensor in contact with the fluid, directly measuring the properties

  physical, chemical or biochemical thereof.

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Claims (14)

  1. Device for improving the safety of epidural infusions carried out by devices of the electric syringe pump type or devices of the patient controlled analgesia type (PCEA) characterized in that it comprises means for carrying out at least one test of automatic aspiration for a predetermined period of time on the perfusion system, in particular the plunger of a syringe (2), and means for detecting the loss of resistance to this aspiration controlling alarm means (9) and means for shutdown of the infusion system upon detection of a loss of this suction resistance, in particular due to a   catheter disconnection and / or vascular and / or intrathecal intrusion.   2. Device according to claim 1, characterized in that the means for detecting the loss of suction resistance comprise measuring means   direct and / or indirect of the infusion pressure.   3. Device according to claim 1, characterized in that the means for detecting the loss of suction resistance comprise measuring means   the torque and / or the driving force of the motor of the infusion system.   4. Device according to claim 1, characterized in that the means for detecting the loss of suction resistance comprise means for detecting movement behind the piston or its carriage following the test suction.   5. Device according to any one of claims 1 to 4, characterized in   what it includes means for performing automatic aspiration tests,   periodically, at regular intervals programmable by the user.   6. Device according to any one of claims 1 to 5, characterized in   what it includes means for carrying out automatic aspiration tests carried out systematically before each bolus carried out by a syringe pump   or a patient-controlled analgesia device.   7. Device according to any one of claims 1 to 6, characterized in   what it further includes, an external sensor (10) located on the epidural catheter (5), analyzing the physical characteristics of the fluid perfused or aspirated during automatic suction tests, any variation in the quality of the fluid causing a   alarm (9) and stopping the infusion.   8. Device according to any one of claims 1 to 6, characterized in   what it further comprises a sensor (11) analyzing the physical characteristics of the fluid perfused or aspirated during automatic suction tests, this single-use sensor being arranged in series between the filter (7) and the fitting catheter (8) when   the placement of the epidural catheter.   9. Device according to any one of claims 1 to 6, characterized in   what it further includes, a sensor analyzing the physical characteristics of the fluid perfused or aspirated during the automatic aspiration tests, this sensor forming an integral part of the microbial filter and becoming a "filter-sensor" set   in place when placing the catheter.   10. Device according to claim 8 or 9, characterized in that the sensor is an internal sensor directly analyzing the electrical and / or physical, biochemical and / or chemical characteristics of the fluid perfused or aspirated during the tests automatic suction.   11. Device according to any one of claims 1 to 6, characterized in   what it includes an external sensor analyzing the physical characteristics of the fluid perfused or aspirated during the automatic suction tests located between the 1 5 syringe (2) and the filter (7).   12. A method for improving the safety of epidural infusions carried out by devices of the electric syringe pump type or of analgesia type controlled by the patient, characterized in that at least one automatic aspiration test is carried out for a predetermined period of time. perfusion system, in particular the plunger of a syringe and in that the resistance to aspiration is detected and that, upon detection of a loss of resistance to this aspiration in particular due to disconnection of the catheter and / or a vascular and / or intrathecal invasion, alarm means (9) and means for stopping the infusion.   13. Method according to claim 12, characterized in that the automatic suction tests are carried out periodically, at regular intervals user programmable.   14. Method according to claim 12 or 13, characterized in that a test   aspiration is carried out systematically before each bolus carried out by a pusher   electric syringe or patient-controlled analgesia device.