WO2014095736A1

WO2014095736A1 - Device for administering a high-flow therapy

Info

Publication number: WO2014095736A1
Application number: PCT/EP2013/076723
Authority: WO
Inventors: Gunther Weiszl
Original assignee: Linde Aktiengesellschaft
Priority date: 2012-12-17
Filing date: 2013-12-16
Publication date: 2014-06-26
Also published as: DE102012223446A1

Abstract

The present invention relates to a device for administering a breathing gas, particularly a high-flow therapy, having a supply unit (110) for providing a breathing gas and a hose unit (120), which is connected at the distal end thereof to an output of the supply unit (110), the breathing gas being supplied to a patient via the proximal end of the hose unit (120) at a predefinable pressure/first pressure, and a pressure sensor (300) being provided in the hose unit.

Description

description

Device for administering a Hiqh-flow therapy

The invention relates to a device for administering a high-flow therapy according to the preamble of patent claim 1.

State of the art

In so-called high-flow or high-flow humidification therapy (HFT), a humidified, warm breathing gas, in particular oxygen-enriched air, is administered to the patient via a nasal cannula.

The problem with such nasal cannulas is that they can easily fall off the nose of a patient, thus impairing the effectiveness of HFT therapy. In particular, in patients who are unable to re-insert the nasal cannula into the nose, for example premature babies or patients who are not conscious, this can lead to significant problems or emergencies.

The object of the invention is therefore to provide a device for administering an HFT therapy, with which problematic states or emergencies can be detected in a simple manner.

This object is achieved by a device for administering a high-flow therapy with the features of patent claim 1. With the device according to the invention, it is possible in a simple manner to detect a pressure applied in a tube unit of the device via which respiratory gas is supplied to a patient. This pressure is determined by the flow resistance of the respiratory gas in the tubing and the nasal canals and the flow resistance in the respiratory tract of the patient. This back pressure is built up against the pressure caused by the breathing gas flowing through the hose unit. This back pressure must therefore be overcome in order to ensure a flow of breathing gas to the patient. If the pressure prevailing in the hose unit pressure drops, for example, falls below a certain Pressure threshold, be concluded that the tube unit or provided at the proximal end of the tube unit cannula is no longer applied to the nose of the patient. Similarly, in the event that it is determined that the sensed pressure does not fluctuate (eg, falls below the pressure amplitude of a particular threshold), it can be concluded that a patient is not breathing. In both cases, using the device according to the invention, corresponding warning signals can be generated or countermeasures initiated. The pressure sensor for detecting the pressure prevailing in the hose unit is arranged in particular in the hose unit, in particular a lumen of the hose unit.

Furthermore, the counting of the characteristic pressure fluctuations during a certain time window can be used to calculate and display the respiratory rate. An exceeding or falling short of given limit values of the respiratory frequency can generate corresponding warning signals by taking advantage of the device according to the invention or it is possible to initiate countermeasures. However, it may also be arranged at other suitable positions of the device according to the invention, for example in a region in which the composition of the respiratory gas has already been provided in the desired manner, e.g. from individual gases, but not moistened yet.

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings. According to a particularly expedient embodiment of the device according to the invention, the pressure sensor provided according to the invention cooperates with a computing device and a device for generating an alarm signal such that when the pressure threshold value, pressure amplitude threshold value and / or pressure frequency threshold value are exceeded or undershot at least one alarm signal is issued. By presetting certain suitable threshold values, a wide variety of medical conditions can be detected in a simple manner, and corresponding alarm signals can be triggered. It is possible, for example, to trigger different alarm signals depending on the exceeded or undershot threshold value. Decisive for the calculation of the presettable threshold values are preferably the flow rate of the respiratory gas, the composition of the respiratory gas and the selected hose length diameters and types. The backpressure that results depending on the size and constitution of the patient is preferably identified by the controller.

According to a preferred embodiment of the device according to the invention, the tube unit connecting the supply unit to the patient has an inner lumen for transporting breathing gas to the patient, and an outer lumen surrounding the inner lumen for transporting the inner lumen from the environment of the patient Hose unit heat insulating gas, in particular for the transport of heated air on. The use of such a hose unit effectively prevents breathable gas transported by the inner lumen from condensing during transport through the hose assembly, and thus damaging a pressure sensor disposed in the inner lumen of the hose assembly. Also, such hose units have a greater rigidity compared to single-lumen hose units, so that the risk of damaging the pressure sensor by bending or buckling of the hose unit is significantly reduced.

Expediently, the supply unit has an oxygen supply device and an air supply device and means for mixing air and oxygen to provide a suitable respiratory gas. In this case, a breathing gas provided in this way is introduced into the hose unit, in particular the inner lumen of the hose unit.

Particularly preferred is an additional line, which is connected to the outer lumen of the hose unit, and which is arranged such that air from the air supply device is introduced into the externa ßere lumen. Likewise preferred is the provision of a heating unit for heating oxygen supplied by the oxygen supply device and / or air provided by the air supply device. The device according to the invention preferably has a moistening unit for moistening respiratory gas. The invention is illustrated schematically with reference to an embodiment in the drawing and will be described in detail below with reference to the drawing. figure description

Figure 1 shows a schematic, greatly simplified view of a preferred embodiment of the device according to the invention, Figure 2 shows a schematic side view of another preferred embodiment of the device according to the invention, and

FIG. 3 shows various pressure values in a hose unit, which are detected according to the invention during a high-flow therapy, through which breathing gas is supplied to a patient.

Detailed description of the drawing

The figures are described overarching, wherein like reference numerals represent the same or similar components.

A first preferred embodiment of the device according to the invention is shown in FIG. The device 100 has a supply unit 110 for supplying breathing gas and a hose unit 120 (corresponding to a distal end 120b of the hose unit) connected to a proximal end of the supply unit. Via the hose unit 120, a respiratory gas supplied and processed is supplied to a patient in the supply unit 1, as will be explained further below.

At its proximal end 120a, the tube unit 120 is connectable to a nasal cannula designated 190.

Further details of the supply unit 1 10 and the hose unit 120 will be discussed in more detail below with reference to FIG. In Figure 1 is only illustrated that the tube unit 120 is formed with a pressure sensor 300, by means of which pressure, which is present in the interior of the tube unit 120 during the transport of breathing gas from the supply unit 1 10 through the tube unit 120 to the patient, is detected.

The flow of gas provided by the tubing unit 120 to the patient during high-flow therapy must overcome a back pressure caused by the tubing unit 120, the proximal adjacent nasal cannula 190, and the patient's airway. As a result, slight pressure prevails in the hose unit 120 (or in its lumen). The value over time of this (over) pressure present in a high-flow therapy in the hose unit is designated by pi in FIG. The ambient pressure is designated Pamb. During the breathing of the patient connected to the tube unit 120, periodic changes in this pressure, which are detected by the sensor 300, occur. Deviations of the pressure down, which occur, for example, during an active inhalation of the patient, are indicated at 302. This lowering of the detected pressure is due to the fact that during this inhalation, the back pressure decreases. A phase of slightly increased pressure, which is caused, for example, by a passive exhalation with concomitant emptying of the lung and a corresponding increase in the back pressure, is designated 304.

If the frequency or amplitude of such pressure drops 302 or pressure ports 304 falls below a specific threshold value, it can be assumed that a patient is breathing too irregularly or not at all. In this case, the computing unit 310 connected to the pressure sensor 300 activates the alarm device 320 which outputs a corresponding alarm signal. Appropriately, in this case, a first characteristic alarm signal is output.

Likewise, if such a frequency threshold value of such pressure drops 302 is exceeded, an abnormal situation can be detected, which can be displayed on the alarm device 320. If the cannula 1 90 falls out of the patient's nose, the counterpressure inside the tube unit 120 immediately drops to a lower value, which is denoted P _{2 in} FIG. Since, in this case, the patient's respiration no longer has any influence on the pressure present in the hose unit, this value P _{2 is} constant over time. The pressure value P ₂ detectable by means of the sensor 300 is likewise evaluated by means of the arithmetic unit 310, for example by comparison with a presettable pressure threshold value. If the computing device 310 determines that the pressure P _{2 is} below this threshold value, a corresponding alarm signal, preferably a second alarm signal characteristic of this state, is output by means of the alarm device 320.

The pressures Pi, P ₂ as well as the depressurization 302 or pressure increases 304 occurring during respiration depend on the respiratory gas used, in which case flow, temperature and oxygen concentration play a role, and on the physiological conditions of an individual patient. Furthermore, environmental influences such as ambient pressure and ambient temperature can be used for the evaluation.

Especially in the context of high-flow therapy, it must be taken into account that due to the high humidity there is a high mass flow.

On the basis of all these factors, suitable threshold values are predetermined by means of the arithmetic unit. Another preferred embodiment of the invention is illustrated in FIG.

The device 100 has a supply unit 110 for supplying respiratory gas and a hose unit 1 20 (corresponding to a distal end 120b of the hose unit) connected to a proximal end of the supply unit. Via the hose unit 120, a respiratory gas supplied and processed is supplied to a patient in the supply unit 1, as will be explained further below.

At its proximal end 1 20a, the tube unit 120 can be connected to a nasal cannula, which is shown purely schematically and designated by 1 90. In the illustrated embodiment, the supply unit 110 has an oxygen supply device 150 and an air supply device 152. The oxygen supply device 150 may be, for example, a suitable oxygen pressure vessel. The air supply device 152 may also be formed as a pressure vessel, wherein particularly preferred is the combination of a suction pump with a compressor for the utilization of ambient air. Air from the air supply device 152 and oxygen from the oxygen supply device 150 is fed via respective lines 181 and 182 in a desired ratio in a line 183 in which a mixture of oxygen and air takes place. For the exact adjustment of the oxygen content in the resulting breathing gas mixture, control valves 175, 176 are respectively formed in the supply lines 181, 182 and can be controlled by a control device 101 shown schematically.

The line 183 is connected to a line 184, via which water vapor generated in a moistening unit 160 can be introduced into the line 183 for moistening the respiratory gas. The supply lines 181, 182 and / or the line 183 are formed with a heating unit 170, by means of which the oxygen supply device 150 and the air supply device 152 exiting or the line 183 flowing through gases to a desired temperature, preferably body temperature or higher, are warm.

Overall, a respiratory gas heated to body temperature and having an air humidity of up to 100% can be provided by the oxygen supply device 150, the air supply device 152, the moistening unit 160 and the heating unit 170.

The supply unit 110 is, as mentioned, coupled to the hose unit 120. This tube unit has an inner lumen 186 and a concentrically surrounding outer lumen 187 on. At the distal end of the hose unit, the inner lumen 186 is connected to the conduit 183 so that in the supply unit provided breathing gas can be transported via the tube unit 120 to the patient.

In line 181 branches off an additional line 185. In this additional line 185, a further control valve 177 is provided.

This additional line 185 is connected to the outer lumen 187 of the hose unit 120. As can be seen from FIG. 1, air heated by the heating device 170 can thus be conducted from the air supply device 152 in a controllable or controllable manner into the outer lumen 187 of the hose unit 120. With appropriate adjustment of the air temperature in the outer lumen 187, an effective heat insulation for the inner lumen with respect to the environment is provided.

By setting a suitable air temperature in the outer lumen 187, it can be ensured, in particular, that the humidified and preferably 100% air humidity-containing breathing gas does not condense in the inner lumen 186. It can thus be ensured that respiratory gas leaving the proximal end 120a of the tube unit 120 and entering the nasal cannula 190 essentially retains the temperature and humidity provided by the supply unit 110.

At the proximal end 120a of the hose unit 120, the provided air exits the outer lumen 187 into the ambient air. In order to avoid an unpleasant air flow for a patient here, for example, a sponge insert 195 is provided in the outlet region of the outer lumen 187. Instead of such a sponge insert, it would also be possible to use suitable flow flaps.

The breathing air exiting the inner lumen 186 at the proximal end 120a, as mentioned, enters the nasal cannula 190 connected to the patient. Overall, it can be ensured by means of the device according to the invention that the air entering the patient via the nasal cannula 190 has an optimum temperature (essentially body temperature) and moisture (essentially 100% atmospheric humidity). For example, according to a preferred embodiment of the invention, it is conceivable to heat the air introduced into the outer lumen 187 more strongly than the respiratory gas in the inner lumen 186. This can be used, for example, to achieve heat from the respiratory gas during transport through the inner lumen receives air flowing through the outer lumen and is thus further heated during passage through the inner lumen 186 of the hose unit 120. In this case, the temperature of the breathing gas could be chosen correspondingly lower when entering the inner lumen.

It proves to be particularly advantageous that the air for the outer lumen 187 and for the provision of the desired breathing gas in the inner lumen can be provided from the same source, namely the air supply device 152. It can thus be exploited the easy availability of ambient air, which can be provided and processed in a very inexpensive manner.

To provide an optimally processed breathing gas, it is possible to provide temperature sensors, not shown in FIG. 1, at suitable positions of the device 100 and, according to the detected temperature values, to control the control valves 175, 176, 177, the heating device 170 and / or the humidifying device 160 to make. However, it is particularly preferred to dispense with such temperature sensors for cost reasons, and to set the air flow through the outer lumen 187 accordingly conservative, ie with relatively high air temperature and / or flow. The inner and outer lumen tube unit 120 may be connected to the supply unit 110 at a suitable interface which provides respiratory gas and air in a correspondingly coaxial manner. This requires only a single compound, which is an improvement over conventional solutions using two compounds, for example for breathing gas and heated water. The angular orientation of such a connection can be chosen essentially arbitrary. A simple hose connection, such as used for single-lumen tubing, is sufficient. For example, conical connectors could be used. According to the invention, interruption of the therapy, ie the supply of breathing gas to a patient is possible in a particularly simple manner, without having to interrupt the flow of heated air through the outer lumen 187. As a result, the insulating effect can be maintained in a simple manner, wherein, for example, breathing gas remaining in the inner lumen is not subjected to excitation.

The pressure sensor 300 is disposed within the inner lumen 186 in this embodiment. By avoidable with this embodiment condensation or excitation damage to the pressure sensor 300 can be effectively avoided. Incidentally, the formation of the tube unit with an inner and an outer ßeren lumen proves to be more robust than conventional tube units with only one lumen, so that the pressure sensor is exposed to a lower load when bending or bending the hose unit. Furthermore, a pressure sensor arranged in the inner lumen is also better protected against external mechanical influences due to the double wall (wall of the inner lumen and wall of the outer lumen).

Claims

claims

1 . Device for administering a respiratory gas, in particular a high-flow therapy, with a supply unit (110) for providing a respiratory gas and a tube unit (120) which is connected at its distal end to the supply unit (110) the breathing gas is supplied to a patient via the proximal end of the tube unit (120),

characterized,

the hose unit is formed with a pressure sensor (300) for detecting a pressure present in the hose unit.

2. Apparatus according to claim 1, characterized in that the pressure sensor (300) with a computing device (310) and a device (320) for generating an alarm signal cooperates such that when exceeding or falling below at least one presettable pressure threshold, pressure amplitude Threshold or pressure frequency threshold an alarm signal is output.

3. Apparatus according to claim 2, characterized in that falls below a predetermined pressure threshold value or a Druckfrequenz- threshold an alarm signal indicating an interruption of the connection

Tube unit with the patient indicates is output.

4. Device according to one of the preceding claims, characterized in that the hose unit (120) with an inner lumen (186) for transporting breathing gas to a patient, and an outer lumen (187) surrounding the inner lumen (186) for transporting a the inner lumen (186) is formed from the environment of the hose unit heat-insulating gas, in particular for the transport of heated air.

5. Device according to one of the preceding claims, characterized in that the supply unit (1 10) comprises an oxygen supply device (150) and an air supply device (152), and means (183) for mixing air and oxygen to provide a suitable breathing gas, wherein a breathing gas thus provided is introduced into the tube unit, in particular the inner lumen (186) of the tube unit.

Device according to one of the preceding claims, characterized in that an additional line (185) is provided, which is connected to the outer lumen (187) of the hose unit, and which is arranged such that air from the air supply device (152) in the eu The second lumen (187) is introduced.

Device according to one of the preceding claims, characterized by a heating unit for heating oxygen provided by the oxygen supply device (150) and / or air provided by the air supply device (152).

Device according to one of the preceding claims, characterized by a moistening unit (160) for moistening breathing gas.