WO1992015355A1

WO1992015355A1 - Respirator

Info

Publication number: WO1992015355A1
Application number: PCT/EP1992/000340
Authority: WO
Inventors: Volker Lang
Original assignee: Volker Lang
Priority date: 1991-02-27
Filing date: 1992-02-18
Publication date: 1992-09-17
Also published as: CA2101647A1; DE4106098A1; DE4106098C2; EP0573468A1

Abstract

A device for producing a continuous positive pressure in the respiratory passages during spontaneous breathing is described. Respiratory gas is introduced, under overpressure with modulated pressure oscillations, through nasopharyngeal tubes (9) into the nasopharyngeal-oral cavity (16) or through a special oropharyngeal tube with pressure-measurement channels (flexible tubes) (12, 13) and a wide-lumen gas supply channel (flexible tube) and a narrow-lumen venting channel. In this way, even large leaks in the mouth region can be compensated. To ensure the constancy of the desired therapeutic positive pressures in the nasopharyngeal-oral cavity (16) and the respiratory passages and lungs, which communicate with the nasopharyngeal-oral cavity (16), continuous electrical-electronic measurements are carried out on the pressurized gas by pressure probes (11) in the nasopharyngeal-oral cavity (16), and the supply of fresh respiratory gas is regulated in function of these measurements. Obstruction of the pressure probes (11), e.g., by nasal mucus, is detected immediately by the absence of oscillating pressure signals and any differences in pressure registered by the pressure probes (14, 15), and generally cleared due to the activation of an automatic blow-through device for the probes. Only in rare cases would an alarm be triggered.

Description

AUXILIARY BREATHING DEVICE

The invention relates to a device for generating a continuous positive pressure in the airways during spontaneous breathing according to the preamble of claim 1.

Continuously positive airway pressures during spontaneous breathing have been used successfully for about two decades to treat lung instabilities and to improve oxygen absorption by the lungs in premature and newborn babies. Three different methods are used for this. All three methods have in common that a closed breathing tube system with a breathing gas reservoir and a manually adjustable pressure relief valve is used, into which an excess of the humidified, warmed, oxygen-enriched breathing fresh gas is fed. With this breathing gas, the lungs of the connected spontaneously breathing patient are inflated under a defined, as constant as possible excess pressure, and their used breathing gas exhaled into the breathing tube system is also blown out into the open via a pressure relief valve. The technical The only difference between the methods used clinically today is how the respiratory gas is supplied in order to generate the therapeutically desired, as constant as possible excess pressure in the lungs. Together with the additional clinical problems that arise, they are briefly described below.

Procedure No. 1:

It uses a tracheal tube (breathing tube), which is inserted directly into the patient's trachea, in order to supply the breathing gas directly to the bronchial system and the lungs, in order to build up and maintain the desired overpressure there. This allows very constant pressures to be achieved in the lungs.

Main problems of this procedure:

The patient has to be intubated and has a tube as a foreign body in his windpipe, which can cause permanent irritation, damage to the vocal cords and trachea as well as infections of the bronchial system and the lungs. In addition, this tube in the trachea requires continuous, intermittent artificial mucus suction to keep the airways open. In addition, this breathing tube represents a considerable flow resistance, which must be overcome by the patient during inhalation and exhalation.

Procedure No. 2:

The fresh breath gas is introduced through one or two hoses through the nose into the nasopharyngeal mouth and builds up the desired continuous overpressure there and in the airways and lungs communicating with it.

Main problems of this procedure;

Uncontrolled, large gas leaks, especially through the mouth and small over the nose. Overall, these leaks can be so great that a constant, positive pressure in the oral cavity can no longer be maintained and the overpressure in the lungs breaks down or can only be maintained at an uncontrolled, very low, possibly physiologically ineffective pressure level. In order to be able to compensate for these changing large gas leaks, large amounts of fresh gas are necessary, but di can no longer be fed into the nasopharynx-oral cavity without considerable pressure loss via the relatively narrow nasal tubes, so that the desired set in the breathing tube system with gas reservoir therapeutic pressures in the oral cavity can no longer be achieved.

Procedure No. 3:

Breathing gas is fed into the nasopharynx-mouth and the connected airways and lungs with the help of a tightly fitting mask which includes both the nose and the mouth. This means that the mouth and nose leaks disappear and the possibility of breathing gas being supplied via the nose and mouth. This would ensure good pressure consistency.

Main problems of this procedure:

Difficulty sealing (leaks) the mask on the face of the newborn, some of which cannot be remedied despite the application of dangerously high pressure on the face, skull and neck, and complications such as Pressure damage to the skin and possibly even brain bleeding. In addition, it is necessary to install a large, bulky holding device in the incubator (incubator). This results in significant disabilities and a restriction of nursing and therapeutic measures.

It is an object of the present invention to provide a ventilation device in which leak-compensated ventilation without intubation is particularly suitable for early and early childhood Newborns can be carried.

Starting from the generic state of the art, this object is achieved by a ventilation device which is further developed in accordance with the teaching of the characterizing part of the main claim. According to the invention, two nasopharyngeal tubes are used to supply fresh breathing gas, which have one or two thin pressure measurement tubes (channels) in their lumen or wall. In contrast to all the described and known methods, the fresh breathing gas fed in is not under the desired therapeutic pressure of 5 to 10 cm H2O, but under 25 to 30 cm H2O overpressure and additionally has modulated pressure oscillations. Larger leaks through the mouth are compensated for in the device according to the invention in such a way that the pressure in the nasopharyngeal mouth is continuously checked via the thin measuring probes (channels) with downstream electrical-electronic pressure measuring devices and via selective detection electronics and an electronic one Control element with metering valve controls the supply of fresh gas in such a way that an increase in the amount of the mouth leaks also causes an increased compensation gas flow in the nasopharyngeal tubes. The inevitably occurring increased pressure drop at high gas flow does not lead to a pressure drop in the mouth and the lungs as in the known methods, but can be therapeutic between breathing fresh gas feed pressure (25 to 30 cm H2O) and that in the nasopharyngeal mouth applied pressure (5 to 10 cm H2O) there is a pressure difference of at least 20 cm H2O, through which the gas supply control can be easily compensated. However, in the interest of patient safety, care must be taken with this technique that no impermissibly high pressures can occur in the mouth and thus also in the lungs, e.g. in the event of a sudden sharp reduction in gas leaks.

A first pressure limitation at an increased pressure level is given in the device according to the invention by the feed pressure of the fresh breathing gas limited to 25 to 30 cm H2O. The The second pressure limitation at a therapeutic pressure level of 5 to 10 cm H2O is carried out by the continuous exact pressure measurements in the nasopharyngeal-oral cavity and the fresh gas supply regulated as a function thereof. If pressure probe clogging due to nasal mucus occurs, a not uncommon event, then the downstream pressure measuring element, if it does not have a vent to the outside, will continue to be pressurized for a long time with the pressure in the nasal cavity just before the probe is blocked. Pharynx mouth. This would result in a potentially dangerous incorrect regulation of the fresh breathing gas feed with a build-up of high pressures up to a maximum of 30 cm H2O. In order to reliably avoid such incorrect measurements and regulations, the device according to the invention uses fresh breathing gas to which pressure vibrations are modulated. However, these pressure vibrations are only transmitted to the downstream electrical-electronic pressure element in the case of an open pressure probe, but not after it has become blocked. In this way, this blockage can be recognized very easily when evaluating the signals in special electronics. An immediate activation of the automatic probe blow-through device integrated in the device can eliminate this disturbance. If this is not possible in rare cases, the device alarm is triggered automatically and at the same time the fresh gas supply is reduced to a minimum. If the described pressure measurement and regulation of the fresh breathing gas supply are still in the form of two completely separate control loops with pressure probes, pressure measuring elements as well as selective and control control electronics, then a maximum of patient safety can be achieved with this. The only problem now is the exhalation of the patient into the nasopharynx and mouth, with the danger that the used exhaled air will accumulate there with the mouth closed and the nose misplaced and inhaled again and again by the patient. To eliminate this problem, a small, fixed leak is created outside with the help of a kink-resistant tube inserted in the mouth. With a fresh breathing gas supply always in the range of 2 to 5 1 / min. can this leak Reaching out the used exhaled air into the open.

Further details and advantages of the invention are explained with reference to the following exemplary embodiment shown in the drawing. Show it:

1 shows schematically the individual building blocks of the device according to the invention and their logical combination;

Fig. 2 in supervision the fixation aid for the nasopharynx tubes with mouth tube and

3 is a perspective view from the front and side of the special mouth and throat tube for breathing gas supply, pressure control and ventilation of the nasopharynx.

Fresh breathing gas passes from a commercially available high-pressure compressed-air-oxygen mixer 1 to the electromagnetically operated metering valve 2 with a fixed bypass (2 to 5 l / min. Purging continuous gas flow) and from here to the low-pressure regulator 3, which Pressure limited to 25 to 30 cm H2O. This regulator delivers breathing gas to the modulator 5, which modulates pressure oscillations (frequency range used 0.1 to 100 Hz, stroke 0.5 to 10 cm H2O) before the fresh gas then flows through and over a commercially available breathing gas humidification heating device 6 the connecting hose 7 reaches the Y gas distributor 8. The two special nasopharyngeal tubes 9 with their adapters 10 are inserted here and supply the schematically illustrated nasopharyngeal mouth 16 and the trachea 19 and lungs communicating with it with breathing gas under the preselected excess pressure (5 to 10 cm H 2 O). Varying gas leaks 18 across the lips are symbolized by parallel lines.

A tube inserted in the mouth (kink-proof tube) 17 serves as a fixed leak to the outside for safe flushing out of the used exhaled air from the nasopharynx-oral cavity 16 by means of fresh breathing gas flowing continuously via the regulator 3. Due to the thin pressure measuring probes 11 running in the lumen of the nasopharyngeal tubes 9, each via connecting hoses 12, 13, each with an electrical-electronic pressure measuring element 14, 15 and through a further downstream selective electronics 21 and an electronic control element 22, only the metering valve is used til 2 and pressure relief valve 4 controlled. If the thin pressure measuring probes become blocked, for example due to nasal mucus, then pressure signals are only detected by the pressure measuring elements 14, 15 without modulated pressure vibrations and can thus be recognized by the selective electronics as a blockage. This leads to a triggering of the automatic blow-by device 23, which briefly releases breathing gas under pressure into the connecting hoses 12, 13 and the associated pressure measuring probes 9 via the electromagnetic valves 24, 25 and thus generally eliminates the blockage. Since the valves 24, 25 simultaneously vent the pressure measuring elements 14, 15 during the blow-through process, an exact pressure detection is ensured after the blow-through process has ended without a great time delay despite the thin measuring probes used.

Fig. 2 shows the holding device for the nasopharynx tubes and the mouth tube. It consists of a base plate 26 made of elastic material (rubber, silicone rubber) which has openings. The openings 27, 28 serve for the clamping insertion of the nasopharyngeal tubes 9 and the opening 29 for the mouth tube 17. Rectangular punchings 30, 31 attached to the right and left serve for the attachment of retaining straps. As can be seen, the openings 24, 25 are only surrounded by a narrow sow of elastic material 32, which is connected to the base plate 26 via a respective narrow web 33, 34. When the base plate is fixed on the upper lip of the patient, these webs allow the nasopharyngeal tubes to be attached largely without pressure in a position angled by approximately 90 °. 3 shows, as an alternative device for the described breathing gas supply via nasopharynx tubes, a special mouth throat tube 35 made of soft plastic. It represents a slightly angled tube with an oval cross-section, the underside 36 on the tongue and the open end 37 thereof , in which the hoses 40, 41, 42 and 43 open about 1 cm from the end, protected from mucus, lies in the patient's pharynx (throat entrance). The plate 38 attached to the front end of the mouth and throat tube lies on the outside of the patient's lips and can be fixed there, for example, by means of the fastening slots 39. The hoses fitted in the tube lumen and fixed in a gastight manner are used for pressure measurement 40, 41 (low-volume), the breathing gas feed 42 (wide-volume) and for ventilation 43 of the nasopharyngeal-oral cavity and the airways and lungs communicating therewith.

Claims

Respirator patent claims

1. Device for generating a continuous positive pressure in the airways during spontaneous breathing with a high-pressure compressed-air oxygen mixer (1), a downstream metering and / or pressure relief valve (2; 4) and at least one nasopharyngeal tube (9 ),

marked by

a modulator (5) which modulates pressure vibrations on the breathing gas,

two pressure measuring elements (11) connected to a pressure measuring device (14, 15), which measure the current pressure in the area of the nasopharyngeal tubes (9) and

a control element (22) which corresponds to the recorded - lo -

Pressure measurement signal controls the metering and / or pressure relief valve (2,).

2. Device according to claim 1, characterized in that one or two as wide-lumen Schläu¬ che (9) are used as nasopharynx tubes and that one or two thin pressure measuring tubes (11) or channels in their lumens or in as pressure measuring elements whose walls are arranged.

3. Apparatus according to claim 1 or 2, characterized in that the pressure measuring device (14, 15) is designed in a simple or dop¬ pelter design.

4. The device according to claim 1, characterized in that a nasopharynx tube (9) for breathing fresh gas supply and a two-ter is used for pressure measurement.

5. The device according to claim 1, characterized in that for fresh gas supply and pressure measurement in the nasopharynx an insertable mouth-throat tube is used which has two pressure measuring channels and one or two wide-lumen channels or tubes for fresh gas supply and a channel for Ventilation of the oral cavity is provided outdoors.

6. The device according to claim 1, characterized in that a definable gas leak (17) which can be generated in the mouth, is preferably formed by a corresponding hose.

7. Device according to one of claims 1 to 6, characterized gekenn¬ characterized in that an elastic perforated plate (26) is used as Fixierhil¬ fe for the nasopharynx tubes, this preferably has laterally punched holes (30) for fastening tapes .

8. Device according to one of claims 1 to 7, characterized gekenn¬ characterized in that an automatic probe blowing device - II -

(23) is integrated with detection electronics, which automatically triggers a probe blowing process when pressure signals are registered without modulated vibrations.

9. Device according to claims 1, 3 and 7, characterized gekenn¬ characterized in that an alarm device is present which, in the absence of pressure signals with modulated vibrations, triggers an alarm after a probe blowing process and, at the same time, leads to a minimum of fresh gas by throttling.

10. Device according to claims 7 and 8, characterized gekennzeich¬ net that the automatic probe blowing device (23) is manually operable.

11. Device according to one of claims 1 to 10, characterized ge indicates that by means of the modulator (5) Druckschwingun¬ gene with amplitudes in a range from 0.5 to 10 cm H2O and frequencies in a range from 0.1 to 100 Hertz can be modulated.

12. Device according to claims 1 and 10, characterized gekenn¬ characterized in that the modulator (5) generates the pressure vibrations of the breathing gas by intermittent complete or incomplete interruption of the gas flow or vibrations of a membrane.