WO2008052534A1

WO2008052534A1 - Method and respirator for pressure-assisted spontaneous ventilation

Info

Publication number: WO2008052534A1
Application number: PCT/DE2007/001964
Authority: WO
Inventors: Marcelo Gama De Abreu; Thea Koch; Peter Markus Spieth
Original assignee: Technische Universität Dresden
Priority date: 2006-10-30
Filing date: 2007-10-25
Publication date: 2008-05-08
Also published as: DE112007003234A5; DE102006052572B3

Abstract

The invention relates to a method and a respirator for pressure-assisted spontanous ventilation based on a pressure support ventilation, wherein the respiration is effected by means of a respiration attachment and, connected to the latter, a computer-integrated respirator, and wherein a pressure-assisting gas transfer takes place via the respiration attachment at two different airway pressure levels, with an upper level corresponding to an airway peak pressure and a lower level corresponding to an end-expiratory airway pressure. The object is to achieve improved pressure support without taking into consideration complicated feedback between pressure or flow changes and the respirator, and to avoid rigid support of the breathing. The solution is that, during the spontaneous ventilation, a variable pressure support ventilation is carried out by means of a variation pattern of the airway pressure pVn with n = 1, 2, 3,..., m from breath to breath in the respirator (20), wherein the variation pattern of the airway pressure pVn is established according to a predefined distribution and controlled by means of a computer (24, 26), and wherein the values of the airway pressure pvn form a time-dependent, predefined mean value (8).

Description

Method and ventilation device for pressure-assisted spontaneous breathing

description

The invention relates to a method and a ventilation device for pressure-assisted spontaneous breathing on the basis of a pressure assisted ventilation, wherein the ventilation by means of a breathing connection and a computer-integrated ventilation device connected thereto and wherein a pressure-supporting gas transmission over the breathing port at two different airway pressure levels with an upper level - an atrial peak pressure - and a lower level - corresponding to a end-expiratory airway pressure - is performed. The spontaneously breathing assisting forms of ventilation can be carried out with different methods and differ from controlled forms of ventilation, which do not support spontaneous breathing.

Most of the conventional methods support the spontaneous breathing of the patient connected to the ventilator by creating a constant airway pressure. This results in a breathing pattern that behaves monotonously. Other methods of assisting spontaneous breathing in ventilated patients may adapt to the needs of the patient or defined target variables. Airway pressure or respiratory gas flow can be continuously measured. By means of an integrated controller with appropriate program-technical means, the minute volume can be kept constant, components of the lung mechanics can be optimized or the gas exchange can be improved by extensive feedback systems. Characteristic of the known forms of pressure-supported spontaneous breathing is the fact that after an adjustment phase, the breathing pattern remains constant.

There are ventilation methods in the specification Putensen C, Hering R., Muders T., Wrigge H .: Assisted breathing is better in acute respiratory failure, Curr. Opin Crit Care Med. 2005; 11; 63-8 which describe two different forms of ventilation, Airway Pressure Release Ventilation (APRV) and Biphasic Intermittent Positive Airway Pressure (BIPAP), the latter being in the form of airway pressure. p) time (t) curve is shown in Fig. 1a are used. The two ventilation methods are characterized by two different, constantly spaced airway pressure levels (CPAPs): an upper CPAP Level High (CPAP Level 1) and a lower CPAP Level Low (CPAP) 2 level. between which spontaneous breathing can take place without restriction. The degree of pressure assistance results from the duration of the existence of the two airway pressure levels 1, 2 and the tidal volume (English tidal volume) V _τ during the two ventilation methods. The tidal volume VT in turn depends on respiratory physiological conditions and the constant difference between the two airway pressure levels.

In two-phase positive airway pressure ventilation, BIPAP, airway pressure is varied between two levels - the CPAP Level High and the CPAP Level Low. As a result of the changes in the airway pressure, the tidal volume is also varied, with the two pressure levels 1, 2 exhibiting fluctuations 3 at their set level. Tidal volume per se depends on the pressure variation and mechanical properties of the respiratory system. Spontaneous breathing can be unrestricted in this mode but is not systematically supported by the ventilator in a breath-synchronous manner.

In Fig. 1b, an airway pressure (p) time (t) curve for constant pressure assist ventilation PSV with two prior art airway pressure levels is shown, with the two pressure levels 1,2 as level constant and equidistant values 5, 7 and the peak airway pressure values 5 are formed equidistantly in chronological order. Spontaneous breathing can be unrestricted in this mode, but it is systematically supported breath-synchronously by the ventilator when the patient's inspiratory effort, called trigger 4, is detected by the ventilator.

It is in the publication Putensen C, Mutz N., Putensen-Himmer G., Zinseriing J .: Spontaneous breathing during ventilatory support improves ventilation-perfusion distributes in patients with acute respiratory distress syndrome, Am. J. Respir. Crit. Care med 1999; 159; 1241-1248 a comparison between the ventilation methods: the respiratory pressure reduction ventilation APRV and the two-phase positive airway pressure ventilation BIPAP on the one hand and on the other hand the constant pressure support ventilation PSV described, the latter, as in - A -

1b, only a lower airway pressure level is used, and with each spontaneous inspiration, a higher airway pressure level of limited duration is generated, and with each inspiration measured by the ventilator, spontaneous breathing is supported, which requires synchrony between the patient and the ventilator. It is described that on the one hand the respiratory pressure reduction respiratory ventilation APRV or two-phase positive respiratory pressure ventilation BIPAP compared to the constant pressure assisted ventilation PSV with regard to the gas exchange lead to better results and on the other hand the constant pressure support ventilation PSV bring no significant advantage compared to the completely controlled ventilation should. The decoupling of spontaneous breathing and machine-generated breaths for a better ventilation / perfusion ratio in the lungs is considered necessary. It is stated in the document that generation of a negative intrathoracic pressure is required to improve venous return and lung perfusion, which would not be possible with constant pressure assisted ventilation PSV, since with constant pressure assisted ventilation PSV, each breath is relatively high positive Printing is supported.

Despite this negative assessment, Patroniti N. et al: Sigh implants gas exchange and volume in patients with acute respiratory distress syndrome undergoing pressure support ventilation, Anesthesiology 2002; 393; 788-794 describes that, as shown in FIG 2, the constant pressure assisted breathing PSV in combination with fixed sighs 6, ie with short-term increases in airway pressure beyond the upper pressure level 1 and with a longer duration, with the sighs 6 machined at fixed intervals, is quite an improvement gas exchange in the lungs in spontaneously breathing patients with acute respiratory failure. The mechanism of this improvement is best explained by the recruitment of collapsed lung areas, as an increase in venous return is not expected. Sighing 6 in combination with the constant pressure assisted ventilation PSV also causes a reduction on the respiratory frequency allows. Since the synchrony between the ventilator and the patient is improved with low respiratory drive, this circumstance could at least partially explain the positive effect of the combination.

2 shows an airway pressure (p) time (t) curve for the constant pressure assisted breathing PSV with an involved sigh 6 and two pressure constant airway pressure levels 1,2, wherein at the constant pressure assisted ventilation PSV the level of support of each individual breath adjusted to achieve the desired tidal volume. The sighs 6 may be generated by generating a peak airway pressure level 6 above the upper pressure level 1, called sigh, at a regular interval.

One problem of the methods mentioned is that they generate a respiration pattern that is generated monotonically, which means that a constancy of the flow or pressure profile results from breath to breath and thus a monotonous breathing pattern can arise. However, this monotonous breathing pattern causes a loss of the intrinsic variability of the respiratory system.

A problem of the methods, which are characterized at the same time by a comprehensive, beyond a simple respiratory recognition outgoing feedback system, is the adaptation of the ventilator in the actual state using predefined time variables, resulting in a constancy in the desired state. After the adaptation of the ventilator and the achievement of the desired state, therefore, a rigid support of the respiration takes place, i. The result is a monotonous form of ventilation. In addition, computer-aided feedback algorithms used are complex, difficult to implement, and associated with increased costs.

A device for assessing the applied air pressure in automated ventilation by positive airway pressure is described in the publication WO 00/24446, whereby the applied airway pressure varies by means of the device is set so that at least three different pressure values are set. For these pressure values, the corresponding respiratory gas flow is measured. It is judged from the relation of the measured respiratory gas flow value to one another whether the applied airway pressure is below or above an optimal pressure level or whether the applied airway pressure corresponds to the optimum pressure level. The device can be used in setting the optimal airway pressure in respiratory devices for CPAP therapy.

One problem is that the airway pressure generated by this system remains constant with the patient's needs remaining constant.

The invention has for its object to provide a method and a ventilation device for pressure-assisted spontaneous breathing, which are designed so suitable that an improved pressure support is realized without taking into account extensive feedback between pressure or flow changes and the ventilation device. So a rigid support of breathing should be avoided.

The object is solved by the features of claims 1 and 10. In the method of pressure-assisted spontaneous breathing based on pressure assist ventilation, wherein the ventilation is via a breathing port and a computer integrated ventilator connected thereto and wherein a pressure assisting gas transmission via the breathing port to two different airway pressure levels having an upper level corresponding to a peak airway pressure According to the characterizing part of claim 1, during spontaneous breathing, variable pressure assist ventilation is performed by means of a variation pattern of the airway pressure p _Vn with n = 1, 2, 3,..., breath to breath performed the respiratory device, wherein the variation pattern of the airway pressure p _{Vn is determined} according to a predetermined distribution and controlled by a computer and wherein the values of the airway pressure p _{Vn form} a time-dependent, predetermined mean value.

The end-expiratory airway pressure p _{0 of} the variable pressure-assisted ventilation can be kept constant both at p ₀ and during ventilation with Po ≠ const. = pov can be varied.

By means of program technology in the computer, a random order can be used as a given variation pattern via a random pressure value generator.

By means of programmatic means in the computer, the predetermined variation pattern can be formed fractally.

By means of programming means in the computer, the predetermined variation pattern can be formed according to an arbitrary distribution or a sequence of absolute values.

During the implementation of a variable pressure assist ventilation according to the invention, a different airway pressure Dv _n can be generated with each breath.

In a first associated variant of variable pressure assist ventilation with an internal computer alone, the airway pressure values Pv _n to be generated with n = 1, 2, 3,..., M can be queried from an internal memory or generated by the computer itself.

In variable pressure assist ventilation with an external control of the variation pattern with respect to the respirator, internal sensors of the ventilator may measure flow and airway pressure monitor, wherein based on trigger criteria within programmable means a detection is performed, when an inspiration in the form of a pressure change and / or a flow is present, to which the respirator responds with the variable pressure support ventilation.

The variable print support has the following steps:

In the first monitoring step, a pressure / flow monitoring is performed by the ventilation device, in the triggering step at least one pressure change signal and / or flow signal - an inspiration - the pressure and / or flow trigger is activated, whose / the signals are supplied to the internal or external computer, in the case of trigger stop, the monitoring of pressure and flow changes in the region of the respiratory connection is continued latently; in the query step triggering the trigger, queries are made about the next pressure assistance, from the sequence in the ventilation pattern output step the respiration variation pattern is released from an appropriate memory;

in the setting step, the signaling of the pressure support is output with the adopted ventilation variation pattern,

in the generating step, the variable pressure assistance is generated and the variable pressure assist ventilation is performed via the breathing port, the last three steps being executed in a module for providing pressure support levels, which may be assigned to either the internal computer or the external computer.

In the ventilator for pressure-assisted spontaneous breathing on the basis of a pressure support ventilation with a respiratory connection, wherein the respiration takes place by means of the respiratory connection and the computer-integrated ventilator connected thereto and wherein a pressure-assisted respiration According to the method of claim 1, according to the characterizing part of claim 10, the respirator includes a respirator at two different airway pressure levels having an upper level corresponding to a peak airway pressure and a lower level corresponding to end-expiratory airway pressure Pressure / flow generator, at least one pressure / flow sensor and a computer with at least one memory, wherein in the memory of the computer at least one variation pattern of the sub-support pressure is stored according to a predetermined distribution, and / or program-technical means are present in the computer which generate during the operation of the ventilator, the variation pattern for a variable pressure assist ventilation, wherein the associated airway pressure values pv _n with n = 1, 2,3, ..., m form a time-dependent, defined average and wherein the end-expiratory airway pressure p ₀ at a lower level with p ₀ ≠ const. = Pov variable or with po = const. is constantly adjustable.

Optionally, in an external computer which can be integrated into the respiration device, variation patterns of the support pressure can also be contained in one of its external memories, with which a second externally prepared variant of the variable pressure support ventilation can be carried out.

In the second variant with the external computer, this can be used as a so-called main computer, which constantly polls the internal computer of the ventilator after the start of a breath - a flow or a pressure difference - and delivers the heights of the airway pressure levels Pv _n to be generated.

The pressure or flow generator is responsible for generating the predetermined airway pressure p _Vn , and the pressure or flow sensors constantly monitor the variable pressure assist ventilation. Furthermore, there is at least one module for providing pressure support levels for variable pressure assist ventilation associated with either the internal or external computer.

The invention makes it possible, without extensive feedback system, i. without adjusting the ventilation pattern to the measured respiration of a patient or to a particular measurement variable or measurement parameter, to control the variation of pressure support in the ventilator, the variation being established prior to the start of the ventilation process, and the mean of the pressure support values being freely selectable ,

It supports spontaneous breathing with different airway pressure levels, but not with an extensive feedback mechanism, which allows recovery and maintenance of the variability of the breathing pattern in any situation. Spontaneous respiration can take place as described with the change of the support pressure both without pressure support as well as maximally supported.

The invention opens up the possibility that by restoring and maintaining the variation of the breathing pattern in the variable pressure assist ventilation not only an improvement in lung function, but also a faster weaning of the patient from the mechanical ventilation can be achieved, resulting in shorter ventilation times. Uneven spontaneous breathing by means of variable assist pressure values may result in an improvement in venous return and cardiac output. Excessively pressure-assisted breaths can eventually contribute to the opening of collapsed lung areas.

The invention will be explained in more detail using an exemplary embodiment by means of several drawings. Show it: 1a shows an airway pressure (p) time (t) curve with two fixed breathing pressure levels for a two-phase positive airway pressure ventilation and spontaneous breathing according to the prior art,

1 b an airway pressure (p) time (t) curve for a constant pressure assisted ventilation PSV and with two fixed airway pressure levels according to the prior art,

FIG. 2 shows an airway pressure (p) time (t) curve for a constant pressure support ventilation PSV and involved sighs with two fixed set

Airway pressure levels according to the prior art,

3 shows an airway pressure (p) time (t) curve for the method according to the invention with a variable pressure assist ventilation with multiple respiratory peak pressure levels, a fixed end expiratory airway pressure value and time-variable adjustable assist pressure values,

4 shows an airway pressure (p) -time (t) curve during the constant pressure-assisted breathing PSV and lung function parameters in the case of a respiratory insufficiency according to FIG.

5 shows an airway pressure (p) -time (t) curve during ventilation with variable pressure assist ventilation and lung function parameters in the case of a respiratory insufficiency according to FIG.

Fig. 6 is a schematic representation of the ventilation device according to the invention and

7 shows a flow chart about the method in the ventilation device. In the following, FIGS. 3 and 6 are considered together. In the method according to the invention for pressure-assisted spontaneous breathing on the basis of a pressure assist ventilation, the respiration takes place according to FIG. 6 by means of a respiratory connection 21 and a computer-integrated respiration device 20 connected thereto, wherein a pressure-supporting gas transmission via the respiratory connection 21 to two different airway pressure levels with an upper respiratory Level 1 - corresponding to a peak airway pressure - and a lower level 2 - corresponding to a end-expiratory airway pressure - is performed.

According to the invention, during spontaneous breathing, variable pressure assist ventilation is performed by means of a variation pattern of the airway pressure Pv _n with n = 1,2,3,..., M from breath to breath in the ventilator 20, the variation pattern of airway pressure pv _n is determined according to a predetermined distribution and controlled by means of a computer 24,26 as shown in FIG. 6 and wherein the values of the airway pressure pvn form a time-dependent, predetermined mean value 8.

The end-expiratory airway pressure p ₀ 2 can be used both with Po = const. kept constant as well as during ventilation with p ₀ ≠ const. = p _O v be varied.

By means of program technology in one of the computers 24, 26, a random sequence can be used as a given variation pattern via a random pressure value generator.

Also, by means of programming means in the computer 24, 26 the predetermined variation pattern can be formed fractally.

It can further be formed by means of programming means in the computer 24,26 the predetermined variation pattern according to an arbitrary distribution or a sequence of absolute values. The pattern of the airway support variation according to the invention can thus also be arbitrarily set, so that three or more support pressure levels are generated.

In Fig. 3, the airway pressure values p _Vn on three or more pressure levels of support are pvi varies Pv2, Pv3, Pvm in the pressure level, whereby the respective pressure level of support structure is in chronological order not equidistant, but depends on the trigger 4, raised and formed. Both sigh pv _m 6 with maximum support, eg with a pressure increase of, for example, 35 cmH ₂ O column, and free spontaneous breathing at the respiratory travel pressure value pv3 can be generated with largely avoided support at different time intervals from the previous pressure support level the airway pressure 2 represents the end-expiratory pressure level p ₀ . The form of the associated respiratory gas flow may be different for generating the airway pressure values. In this case, a different form of the airway pressure values, as shown in Fig. 3, train, the respective peak values pvm remain at the same level, so that therefore also different A temgasflussformen can be used.

FIG. 4 shows the airway pressure (p) time (t) curve during the prior art constant assistive pressure ventilation PSV and the pulmonary function parameters in respiratory insufficiency, where spontaneous breathing with the same pressure p _{K is} supported for each breath Comparison with the following FIG. 5.

FIG. 5 shows an airway pressure (p) time (t) curve during respiration with the variable pressure assist ventilation of the present invention and pulmonary function parameters in respiratory failure. With each breath, a different airway pressure pv _{n is} generated, wherein the mean value 8 of the assist pressure values pv _n can be compared with the airway peak pressure values of conventional ventilation methods. In order to clarify the difference between the method according to the invention for variable pressure assist ventilation and the conventional ventilation methods, FIG. 4 shows the course of the almost constant airway pressure pK recorded over approximately 35 seconds. It differs from the course of the airway pressure p _Vn during the variable pressure support ventilation according to the invention on the same model according to FIG. 5.

The mean value 8 of the support pressure in FIG. 5 and the mean support pressure 8 'in FIG. 4 are almost identical in the two ventilation methods, but the variable pressure support ventilation in FIG. 5 leads to better gas exchange and better lung mechanics Comparison between the parameters extensibility (narrow elastance) in mbar / l and resistance (engl, resistance) in mbar / l / s in the lungs of a test person shows. At the same high-set middle support Press 8 'in Figure 4 and Figure 5 are mean 8 in Figure 5 in the case of inventive variable pressure support ventilation much higher tidal volume V _τ (250ml), much lower parameter of lung compliance (elastance = 75 mbar / l) and Airway resistance (Resistance = 9mbar / l / s) possible. PaO ₂ and PaCO ₂ and the pH are blood gas values of the subject having the same values in Figs. 4 and 5, where PaO _{2 is} the arterial oxygen partial pressure and PaCO _{2 is} the arterial carbon dioxide particle pressure.

The respiration device 20 shown in FIG. 6 for pressure-assisted spontaneous breathing on the basis of a pressure assisted ventilation contains a respiratory connection 21, wherein the respiration takes place by means of the respiratory connection 21 and a computer-integrated ventilation device 20 connected thereto and wherein a pressure-assisting gas transmission via the respiration connection 21 at two different airway pressure levels with an upper level 1 - corresponding to the peak airway pressure - and a lower level 2 - according to the end-expiratory airway pressure - is performed at a support pressure.

According to the invention, the ventilation device 20 includes a pressure / flow generator 22, a pressure / flow sensor 23 and a computer 24 having at least one memory 25, wherein stored in the memory 25 of the computer 24 at least one variation pattern of the support pressure according to a predetermined distribution, and / or program-technical means are present in the computer 24, which generate during the operation of the ventilation device 20 rationsmuster for a variable pressure support ventilation, wherein the associated airway pressure values Pv _n with n = 1,2,3, ..., m is a time-dependent , and the end-expiratory airway pressure p ₀ at a lower level with p ₀ = const. const kept constant as well during ventilation with p ≠ _0. = pov is variably adjustable.

In an associated variant - variant 1 - with the internal computer 24 alone, e.g. the support pressure values according to the invention to be generated are queried from the internal memory 25 or generated by the computer 24 itself.

Likewise, in a second external computer 26 that can be integrated into the ventilation device 20, the variation patterns of the support pressure may also be contained in one of its external memories 27, with which the second variant of the variable pressure support ventilation can be performed.

In the variant with the external computer 26 - Variant 2 - this can be designed as a so-called main computer, which constantly polls the internal computer 24 of the ventilator 20 after the start of a breath and provides the amount of support pressure. The pressure generator 22 is responsible for generating the predetermined airway pressure Pv, and the pressure sensor (s) 23 is constantly monitoring / monitoring the breathing pattern.

The flowchart with step sequence shown in FIG. 7 shows the sequence of events in the context of the variable pressure assist ventilation according to the invention with an external control of the variation pattern with respect to the respiration device 20. The internal sensors 23 of the ventilation device 20 monitor the flow and airway pressure. Based on trigger criteria, it is recognized when the patient begins to inhale, that is, if there are already or still pressure change and / or flow signals, whereupon the respirator 20 responds with computer-supplied variable pressure assistance. According to variant 2, the level of the variable pressure support can be transmitted to the internal computer 24 of the ventilation device 20 with the external computer 26 and, according to variant 1, generated by the internal computer 24 or retrieved from the memory 25. The step sequence consists in the following: In the monitoring step 30, a pressure / flow monitoring by the ventilation device 20. In the triggering step 31, the breathing effort in the form of pressure change and / or flow signals is detected by the pressure or flow sensor and after exceeding the trigger threshold, a signal internal or external computer 24,26 supplied. If the trigger threshold is not exceeded, the monitoring is continued latently. In the query step 32, which is triggered by the trigger, queries are made about the next pressure assistance, from the sequence in the ventilation pattern output step 33, the ventilation pattern is released from an appropriate memory 25,27. In the setting step 34, the signaling of the variable pressure assistance with the adopted ventilation pattern is output so that the variable pressure support is generated in the generation step 35 and the variable pressure support ventilation is performed via the ventilation connection 21. The Three steps 33, 34, 35 are executed in a print support level delivery module 36, which is part of either the internal computer 24 or the external computer 26.

As a result of the invention, a reduction in mortality can be achieved by improving the respiratory function, faster weaning of the patients from mechanical ventilation, and shorter residence times of patients in the intensive care unit.

Further advantages of the invention are that the lung function with respect to the gas exchange, ie the arterial oxygenation or CO ₂ -Elimination of the mechanical properties of the lungs, for example, the resistance and the elasticity and the reduction of the work of breathing can be improved.

Reference number list

1 upper pressure level

2 lower pressure level

3 Pressure fluctuations due to spontaneous breathing 4 triggers

5 constant upper pressure value

6 sighs

7 constant lower pressure value

8 mean 8 'mean assist pressure value

20 ventilation device

21 ventilation connection

22 pressure or flow generator

23 Pressure or flow sensor (s) 24 Internal computer

25 Internal memory

26 External computer

27 External memory 30 Monitoring step 31 Triggering step

32 query step

33 Ventilation Pattern Output Step

34 fixing step

35 Generation step 36 Module for providing pressure support levels

Pv airway pressure end expiratory airway pressure pov variable end-tidal airway pressure

V _τ tidal volume

Claims

claims

A method of pressure assisted spontaneous breathing based on pressure assisted ventilation, wherein ventilation is by means of a breathing port and a computer integrated ventilator connected thereto and wherein a pressure assisting gas transmission via the breathing port to two different airway pressure levels having an upper level corresponding to a peak airway pressure. and a lower level - corresponding to a final expiratory airway pressure - characterized in that during spontaneous breathing, a variable pressure assist ventilation by means of a variation pattern of the airway pressure pv _n with n = 1,2,3, ..., m from breath to breath in the ventilation means (20) is passed through, wherein the pattern of variation of the airway pressure pv _n according to a predetermined distribution defined and by means of a computer (24,26) is controlled, and the values of the airway pressure pv _n a Time-Dep -dependent form, specified mean (8).

2. Method according to claim 1, characterized in that the end-expiratory airway pressure p ₀ (2) of the variable pressure-assisted ventilation with both p ₀ = const. kept constant as well as during ventilation with p ₀ ≠ const. = pov is varied.

3. The method of claim 1 or 2, characterized in that by means of programmatic means in the computer (24,26) is used as a predetermined variation pattern, a random order over a Zufallsdruckwertege- erator.

4. The method according to claim 1, characterized in that by means of programmatic means in the computer (24,26) the predetermined variation pattern is fractal.

5. The method according to claim 1, characterized in that by means of programming means in the computer (24,26) the predetermined variation pattern is formed according to an arbitrary distribution or a sequence of absolute values.

6. The method according to any one of the preceding claims, characterized in that during the implementation of a variable pressure assist ventilation in each breath, a different airway pressure is generated.

7. The method according to any preceding claim, characterized in that in a first associated variant of the variable pressure assist ventilation with an internal computer (24) alone the airway pressure values to be generated p _Vn with n = 1,2,3, ..., m from a internal memory (25) queried or generated by the computer (24) itself.

8. The method of claim 1 to 7, characterized in that in the variable pressure support ventilation with an external with respect to the ventilation device (20) or internal control of the variation pattern internal sensors (23) of the ventilation device (20) the airway flow and / or Monitoring airway pressure, whereby, based on triggering criteria within programming means, a recognition is carried out when an inspiration in the form of at least one change in pressure and / or flow signal, whereupon the respirator (20) responds with a computer-supplied variable pressure assisted ventilation.

9. The method according to claim 1 to 8, characterized in that the variable pressure support comprises the following steps:

In the first monitoring step (30), a pressure / flow monitoring is performed by the respiration device (20). In the triggering step (31), the pressure or flow trigger is activated by means of at least one pressure change and / or flow signal whose signals are sent to the internal or external computer (24,26) are supplied, wherein in the absence of triggering the trigger, the monitoring of pressure and flow changes in the area of the breathing port (21) is latently continued,

in the query step (32) which triggers the triggering, queries are made about the next pressure assistance, from the sequence in the ventilation pattern output step (33) the ventilation variation pattern is released from an appropriate memory (25, 27), - in the setting step (34) output the signaling of the pressure assist with the accepted ventilation variation pattern,

in the generating step (35), the variable pressure assistance is generated and the variable pressure assist ventilation is performed via the breathing port (21), the last three steps (33, 34, 35) being carried out in a module (36) for delivering the

Print support levels, which is assigned to either the internal computer (24) or the external computer (26) are processed.

10. Ventilation device for pressure-assisted spontaneous breathing on the basis of a pressure support ventilation with a respiratory connection, wherein the

Ventilation by means of the ventilation connection and the connected and wherein a pressure-assisting gas transmission is performed via the breathing port at two different airway pressure levels having an upper level corresponding to a peak airway pressure and a lower level corresponding to end-expiratory airway pressure, according to the method of claim 1, characterized the respiration device (20) contains a pressure / flow generator (22), at least one pressure / flow sensor (23) and at least one computer (24, 26) with at least one memory (25, 27)

Memory (25,27) of the computer (24,26) at least one variation pattern of the support pressure according to a predetermined distribution is stored, and / or program-technical means in the computer (24,26) are present, the during operation of the ventilation device (20) the Generate variation patterns for a variable pressure assist ventilation, wherein the associated airway pressure values pv _n with n = 1,2,3, ..., m form a time-dependent, defined mean and wherein the end-expiratory airway pressure p ₀ at a lower level with p ₀ ≠ const. = pov variable or with p ₀ = const. is constantly adjustable.

11. Ventilation device according to claim 10, characterized in that optionally in an in the ventilation device (20) integratable external computer (26) and variation patterns of the support pressure in one of its external memory (27) are included, with a second externally prepared variant the variable pressure support ventilation is feasible.

12. Ventilation device according to claim 11, characterized that in the second variant with the external computer (26) this is used as a main computer, which constantly polls the internal computer (24) of the ventilation device (20) after the start of a breath and the heights of the airway pressure levels to be generated pv _{n of} the support pressure supplies.

13. Ventilation device according to claim 10 to 12, characterized in that it is a pressure or flow generator (22), which is responsible for the generation of the predetermined airway pressure pv _n , and printing or

Contains flow sensors (23) which constantly monitor the variable pressure assist ventilation.

The ventilator of any of claims 10 to 13, characterized in that there is a module (36) for providing pressure support levels for variable pressure assist ventilation associated with either the internal computer (24) or the external computer (26).