System to support blood gas exchange through ventilation and extracorporeal blood gas exchange

Abstract

System (10) for supporting the exchange of blood gases of a patient (12) on the one hand by means of ventilation using a ventilator (14) and on the other hand by means of extracorporeal blood gas exchange using an oxygenator (16), wherein the system (10) comprises as system components at least a medical device in the form of a ventilator (14) and a medical device in the form of an oxygenator (16) for extracorporeal blood gas exchange, wherein at least a first and a second data set (26, 28) with ventilation parameters can be selected for the operation of the ventilator (14), wherein the first data set (26) is intended for the operation of the ventilator (14) without the oxygenator (16) and the second data set (28) is intended for the operation of the ventilator (14) together with the oxygenator (16), where the operation of the ventilator (14) is carried out by default with the ventilation parameters of the first data set (26) and without the oxygenator (16) and wherein, by selecting a corresponding operator, operation of the ventilator (14) together with the oxygenator (16) and with the ventilation parameters of the second data set (28) instead of the ventilation parameters of the first data set (26) can be activated, wherein at least one ventilation parameter effective during operation of the ventilator (14) together with the oxygenator (16) is automatically adjustable depending on a measured value, wherein the measured value is obtained by means of a sensor (19) a blood pressure measurement that can be recorded by a medical device (14, 16, 18) included in the system (10).

Description

[0001] The invention relates to a system for supporting blood gas exchange by means of ventilation and extracorporeal blood gas exchange. The system comprises a ventilation device in the form of a ventilator, an anesthesia machine, or the like for the mechanical ventilation of a patient's lungs, as well as a so-called ECMO device (ECMO = Extracorporeal Membrane Oxygenation; other name: Extracorporeal Life Support = ECLS) for extracorporeal blood gas exchange, namely a pumpless ECMO device (pECLA).Within the system, the ventilation device referred to below briefly, but without sacrificing broader general validity, as a ventilator, and the pECLA referred to below briefly, but also without sacrificing broader general validity, as an oxygenator, are designed and set up to automatically perform, on the one hand, mechanical respiratory support by the ventilator and, on the other hand, extracorporeal blood gas exchange by the oxygenator in a coordinated manner.

[0002] The ventilator facilitates a gas exchange of oxygen and carbon dioxide in the patient's lungs in a generally known manner. The oxygenator facilitates the extracorporeal supply of oxygen and the removal of carbon dioxide, also in a generally known manner.

[0003] US Patent 2015 / 0034082 A1 discloses a system for providing oxygenation and ventilation to a patient using a medical device. The system can simultaneously treat and / or monitor a patient with a ventilator and an ECGE system (ECGE = extracorporeal membrane gas exchange). The patent describes a ventilator-ECGE system comprising a ventilator, an oxygenation system, a user interface, a variety of sensors, a control unit, and a display unit.

[0004] From DE 10 2014 107 980 A1 a system of the type outlined above is known, comprising an ECLS device for extracorporeal blood gas exchange and a ventilation device.

[0005] The plan is for the ECLS device to specify a level of extracorporeal blood gas exchange and for the ventilation device to automatically adjust to a level of mechanical respiratory support based on the level specified by the ECLS device, for example by setting a positive end-expiratory pressure (PEEP) during the delivery of respiratory gas that correlates with a level of extracorporeal blood gas exchange.

[0006] One object of the present invention is to facilitate the combined, as well as simultaneous, use of a ventilator and an oxygenator in the ventilation of a patient.

[0007] According to the invention, this problem is solved by means of a system with the features of claim 1. Such a system comprises at least one medical device in the form of a ventilation device, hereinafter referred to as a ventilator. The system further comprises a pumpless ECMO device (pECLA), hereinafter referred to as an oxygenator. Mechanical ventilation of a patient's lung is performed by means of the ventilator in a manner known per se. Extracorporeal blood gas exchange is performed by means of the oxygenator, also in a manner known per se. The blood gas exchange by means of the oxygenator supports the blood gas exchange by means of the ventilator. At least one first and one second data set with ventilation parameters can be selected for operating the ventilator. The first data set is intended for operating the ventilator without the oxygenator.The second data set is intended for operating the ventilator together with the oxygenator (combined operation or simply combined operation). Upon selection by an operator, usually a physician, the system can activate operation of the ventilator using the ventilation parameters from the second data set.

[0008] An advantage of the invention is that the second data set includes predetermined or predefinable ventilation parameters which, when used in the operation of the ventilator, enable a combined operation of the ventilator together with the oxygenator that is favorable for the patient.

[0009] In a system according to one of the embodiments described below, the first data set is selected for operating the ventilator without the oxygenator (no combined operation) and the second data set is selected for operating the ventilator together with the oxygenator (combined operation).

[0010] Upon a corresponding selection by the operator, for example by activating an input device or an element of a graphical user interface, the ventilator is activated to operate with the ventilation parameters of the second data set. Without such a selection, the ventilator is activated and operated with the ventilation parameters of the first data set. If the operator, for example the physician, desires combined operation of the ventilator and oxygenator, only the aforementioned selection is necessary. This selection can be made after the operator has verified the availability and functionality of the oxygenator connected to the patient's bloodstream, in order to activate combined operation with the ventilator's ventilation parameters adapted for this combined operation.

[0011] In a specific embodiment, it may be provided that the aforementioned selection is not possible, or, if a selection has been made, that switching to the second data set does not occur if it is automatically detected that no oxygenator is connected. Such automatic detection is possible, for example, by means of a communication link between all medical devices belonging to the system, i.e., at least a communication link between the ventilator and the oxygenator. If no communication link to a medical device automatically identifiable as an oxygenator is possible in a given network, this is evaluated as the absence of the oxygenator in the system, and then either the aforementioned selection is not possible, or it is ensured that no switch to the second data set intended for combined operation takes place.

[0012] Advantageous embodiments of the invention are the subject of the dependent claims. References to the main claim refer to the further development of the subject matter of the main claim by the features of the respective dependent claim.

[0013] In one embodiment of the system, the first and second data sets can be loaded into the memory of a medical device included in the system, for example, the memory of the ventilator or the memory of a medical device acting as a higher-level device within the system. A computer program acting as a control program can be executed by a medical device included in the system, such as the ventilator or the higher-level device, and can be run during system operation. Under the control of the computer program, operation of the ventilator with the ventilation parameters of the first or second data set can be activated, and, under the control of the computer program, combined operation of the ventilator with the ventilation parameters of the second data set can be activated by the operator with a corresponding selection.

[0014] In one embodiment of the system according to the invention, at least one ventilation parameter effective when the ventilator is operated together with the oxygenator, i.e., a ventilation parameter effective during combined operation, is automatically adjustable based on a measured value. Such automatic adjustability allows, for example, during the patient's recovery, an automatic shift in the focus of ventilation towards ventilation via the ventilator, so that after a sufficient shift in the center of gravity, the oxygenator can be removed. Such automatic adjustment relieves the operator of the need to determine and manually enter adjusted ventilation parameters.

[0015] According to the invention, a blood pressure measurement is particularly suitable as a measured value based on which such an automatic adjustment of at least one ventilation parameter effective in combined operation can be made. In particular, a blood pressure measurement automatically and regularly recorded by a sensor of a medical device included in the system is suitable, since the blood pressure measurement is a good physiological parameter and – as will be explained in more detail below in the specific description section – a characteristic value for the effects of the combined operation of a ventilator and oxygenator. Furthermore, a blood pressure measurement is easy to record.

[0016] For example, the sensors of a medical device included in the system and functioning as a patient monitor could be considered.

[0017] Such a patient monitor is regularly used in the intensive care treatment of a patient, and consequently it can be assumed that it is already available as part of the system, which otherwise includes at least the ventilator and the oxygenator.

[0018] Alternatively or additionally, sensors on the oxygenator can be used, which allow the blood pressure to be measured directly due to the connection of the oxygenator to the patient's blood circulation.

[0019] In a further embodiment of the system, each ventilation parameter, which can be adjusted depending on a measured value, is cyclically changed by a predetermined or predefinable increment or percentage. Such automatic and cyclical adjustment results in a systematic shift in the focus of the patient's ventilation towards ventilation by the ventilator, i.e., a systematic "phasing out" of ventilation by the oxygenator, so that the oxygenator can eventually be deactivated.

[0020] The aforementioned problem can therefore also be solved by means of a control unit that operates as described here and below and includes means for its implementation. Finally, the invention is also a control unit for a medical device, a medical device, or a system comprising such a medical device.

[0021] Overall, the proposed innovation also includes the use of a system as described here and below, i.e., at least a system which comprises as system components at least one medical device in the form of a ventilator and one medical device in the form of an oxygenator for extracorporeal blood gas exchange, to support the exchange of blood gases (blood gas exchange) of a patient by means of ventilation via the ventilator by means of extracorporeal blood gas exchange via the oxygenator, wherein at least one first and one second data set with ventilation parameters can be selected for the operation of the ventilator and are selected during operation of the system.wherein the first data set is intended for the operation of the system and the ventilator included therein without the oxygenator and the second data set is intended for the operation of the system and the ventilator together with the oxygenator and wherein, upon appropriate selection by an operator, operation of the ventilator included in the system with the ventilation parameters of the second data set can be activated or is activated.

[0022] An embodiment of the invention is explained in more detail below with reference to the drawing. Corresponding objects or elements are provided with the same reference numerals in all figures.

[0023] The exemplary embodiment is not to be understood as a limitation of the invention. Rather, within the scope of the presented description, modifications and alterations are entirely possible, in particular such variants and combinations which, for example, can be deduced by a person skilled in the art with regard to the solution of the problem by combining or modifying individual features in conjunction with those described in the general or specific part of the description and contained in the claims and / or the drawing, and which lead to a new subject matter through combinable features.

[0024] They show: Fig. 1 a system for ventilating a patient, which includes at least one medical device functioning as a ventilator, Fig. 2 a memory included by the ventilator, into which a computer program functioning as a control program of the ventilator and a first and a second data set with ventilation parameters are loaded, Fig. 3. A partial functionality of the computer program illustrated in the form of a flowchart, namely a partial functionality effecting the selection of the ventilation parameters of the first or second data set for the operation of the ventilator depending on a user action, and Fig. 4. Another partial functionality of the computer program, also illustrated in the form of a flowchart, is the automatic adjustment of the ventilation parameters effective during the operation of the ventilator depending on a measured value.

[0025] The representation in Fig. Figure 1 shows – in a highly simplified schematic – a system 10 for ventilating a patient 12. The system 10 comprises at least two medical devices 14 and 16 intended for ventilating the patient 12: a first medical device 14 in the form of a ventilator for the mechanical ventilation of one of the patient's lungs 12, and a second medical device 16 in the form of a so-called pumpless ECMO device (pECLA). The pumpless ECMO device removes carbon dioxide (CO2) from the patient's blood and enriches the blood with oxygen (O2), i.e., performs extracorporeal gas exchange. In accordance with the simplification explained above, the ventilator (first medical device 14) and the pECLA (second medical device 16) will be referred to below – without sacrificing broader general applicability – as the ventilator 14 and oxygenator 16, respectively.Optionally, the system 10 also includes at least one additional medical device 18, for example, a medical device 18 in the form of a so-called patient monitor 18 or the like. This additional medical device 18 includes, for example, a sensor 19 for recording a blood pressure measurement.

[0026] The ventilator 14 is connected to the lungs of patient 12 in a manner known per se. The oxygenator 16 is also connected to the circulatory system of patient 12 in a manner known per se. The circulatory system includes a pulmonary circulation, through which oxygen passes from the lungs into the blood and CO2 passes from the blood into the lungs.

[0027] During respiratory arrest, due to the lack of lung movement by the respiratory and accessory muscles, no fresh, oxygen-rich air enters the lungs (no ventilation). During cardiac arrest, blood flow ceases (no perfusion).

[0028] For a promising cardiopulmonary resuscitation (CPR) using external ventilation and chest compressions (CPR measures), knowledge of the mutual effects of the pressure conditions in the circulatory system, especially in the heart muscle, and in the pulmonary circulation, especially the pressure conditions in the lungs and the ventilation pressures, is very essential.

[0029] A description of the relationship between resuscitation measures and ventilation pressures and their functional and temporal relationships is provided in DE 10 2012 024 672 A1.

[0030] It is shown there that even a "poor execution" of ventilation from the perspective of ventilation as a therapy for lung health can be helpful in supporting a promising cardiopulmonary resuscitation. In this context, the inspiratory and expiratory ventilation pressures (P) are considered. insp , P exsp ), in particular the end-expiratory pressure level (PEEP), is controlled in such a way that the lungs are filled with respiratory gas to such an extent that the lungs take up so much space in the chest cavity that the heart cannot escape the effects of the cardiac compressions.

[0031] During mandatory ventilation using a ventilator 14 in combination with an oxygenator 16 for extracorporeal blood gas exchange, ventilation may be "suboptimal" from the perspective of lung perfusion and ventilation, since part of the necessary life support – otherwise provided by lung perfusion and ventilation – is carried out in the extracorporeal circuit. The pressure level (PEEP) increases the intrathoracic pressure in the lungs and affects venous return to the heart, which corresponds to an increase in "internal flow resistance" in the circulatory system. This results in an increase in pressure in the pulmonary artery.

[0032] If the heart now has to pump blood to the extracorporeal circulation against external flow resistances from the oxygenator and the necessary supply lines (tubes, venous and arterial access) in addition to the body's own blood circulation, this can lead to further changes in cardiac output (CO) and thus also in mean arterial pressure (MAP = ½ * (systolic value in mmHg + diastolic value in mmHg; normal value ∼ 100 mmHg) in addition to the pressure settings on the ventilator 14, in order to compensate for the volumes in the supply lines and the aforementioned flow resistances (internal, external). This is based on the doctoral dissertation by Anne Mareike Leuchtenberg entitled "Influence of positive end-expiratory pressure on hepatic venous perfusion: Doppler sonographic examination" (Justus Liebig University Giessen).Regarding studies conducted on dogs, the text states: “Ventilation with increased end-expiratory pressure, using both intrinsic and extrinsic PEEP, leads to an increase in intrathoracic pressure, resulting in a decrease in venous return and an increase in central venous pressure (CVP). Simultaneously, pulmonary artery pressure rises and cardiac output decreases. As a result of the reduced cardiac output, mean arterial blood pressure drops.”

[0033] This can, under certain circumstances, place an unacceptable burden on the heart during long-term therapy. This is sometimes also associated with an increased heart rate, which can likewise represent an additional burden on the heart in the long run.

[0034] Therefore, during therapy in a special operating mode, settings on the ventilator 14 are possible and possibly also "permitted" and possibly also advantageous which, without parallel "ventilation" by means of the oxygenator 16, would generally lead to rather unsuitable and possibly inadequate ventilation of the lungs.

[0035] Settings which in such an operating mode (in addition to inspiratory pressure (P) insp ), expiratory pressures (P exsp , PEEP)) can be set in other ways, are - a minute volume (MV), - a respiratory rate (RR), - an inspirational / expiratory time ratio (I:E ratio) and / or - a tidal volume (VT).

[0036] These settings, in addition to the print settings (P), also affect these settings. insp , P exspPEEP settings also affect the pressure conditions in the lungs. For example, a situation known as "air trapping" can occur, in which the lungs cannot empty almost to their functional residual capacity (FRC) over a longer period. This can happen due to settings for the respiratory rate and the inspiratory / expiratory ratio, or the expiratory duration, or due to settings for the tidal volume, expiratory duration, and respiratory rate. A residual amount of exhaled gas then remains in the lungs, which can lead to a (continuous) incremental increase in the end-expiratory pressure level (PEEP), a so-called "intrinsic PEEP."

[0037] In many cases of conventional ventilation, intrinsic PEEP is accepted, taking into account specific patient situations, for the benefit of life support and the therapeutic effect of ventilation, and in exceptional cases even provoked.

[0038] An intrinsic PEEP can therefore occur even with appropriately chosen pressure settings (P insp , P exsp , PEEP) and can lead to increased stress (pressure stress) on the heart during the course of therapy.

[0039] Therefore, when using an oxygenator 16 for parallel "ventilation", it is important to avoid excessive PEEP and intrinsic PEEP in order to prevent effects on cardiac output (CO) and mean arterial pressure (MAP), so as not to place additional strain on the heart as the "engine" for the parallel "ventilation" using an oxygenator 16 (pECLA).

[0040] Because the parallel “ventilation” using an oxygenator 16 ensures part of the blood gas exchange, this also provides an opportunity to adjust the pressure settings and the other ventilation settings.

[0041] For example, to avoid intrinsic PEEP, the expiratory time can be extended by a predetermined period (e.g. 5% to 15% of the usual expiratory time without oxygenator 16) compared to a normal expiratory time in order to avoid pressure build-up.

[0042] This can also be accompanied by an increase in the respiratory rate (RR) of 10% to 20% or more (RR > 18 min). -1 ) can be combined, since a fundamentally unfavorable increased dead space ventilation due to the increase in the ventilation rate can be compensated for by the parallel "ventilation" using the oxygenator 16.

[0043] Furthermore, when administering, for example, 100% oxygen via the oxygenator 16, a reduction in the oxygen concentration at the ventilator 14 is possible. Such an adjustment ensures that the total amount of oxygen supplied to the body via the oxygenator 16 (bloodstream) and the ventilator 14 (breathing gas) remains below a threshold that would correspond to an oxygen concentration in the breathing gas above 50%. As is known, oxygen concentrations above 50% can lead to lung damage, depending on the duration of ventilation.

[0044] The following explains what has been said above using the example of an injured, but otherwise medically unproblematic, male, adult patient 12: For such a patient 12 (age 35 to 45 years, 78 to 82 kg, height approx. 1.85 m) the following results apply for pressure-controlled ventilation (MV= BP * Vt, no assisted spontaneous breathing support using PASB , Vt = approx. 0.5 liters (with Vt = approx. 4-10 ml / kg) on ​​the ventilator 14 The following are the usual settings as starting values: 1. I:E = 1.0 : 2.0, 2. P insp = 12 hPa (normal range 8 to 16 hPa), 3. PEEP = 7 hPa (normal range 5 to 8 hPa), 4. Blood pressure = 12 breaths per minute (normal range 12-15 min) -1 ), 5. Oxygen concentration 21% - 40%.

[0045] This (in itself) uncomplicated patient 12 is treated as an example with combination therapy using a ventilator 14 and an oxygenator 16, for instance, because he sustained a rib fracture in the accident. This accident brings with it the following accompanying symptoms: - that breathing is painful for patient 12 and as a result his spontaneous breathing would be rather shallow and - that, due to the accident, the space for the heart and lungs inside the thorax is restricted, for example due to swelling and / or bruising.

[0046] Therefore, when providing ventilation, it should be taken into account that a pressure build-up due to ventilation using the ventilator 14 can cause or increase pain.

[0047] The representation in Fig. Figure 2 shows the ventilator 14 according to Fig. 1 without the oxygenator 16. The ventilator 14 comprises, in a manner known per se, a processing unit 20 in the form of or similar to a microprocessor, and a memory 22 into which a computer program 24 can be loaded and into which, during operation of the ventilator 14, a computer program 24, which determines the functionality of the ventilator 14, is loaded. Other units comprised of the ventilator 14 in a manner also known per se, such as a fan, are not shown. In addition to the computer program 24, at least a first data record 26 and a second data record 28 are loaded into the memory 22.

[0048] Each data set, or at least the first and second data sets 26, 28, includes ventilation parameters, for example predefined or predefinable values ​​for 1. an inspiration / expiration time ratio (I:E ratio), 2. an inspiratory pressure P insp , 3. an end-expiratory pressure PEEP, 4. a ventilation rate RR, 5. and an oxygen concentration.

[0049] The first data set 26, for example, includes the values ​​mentioned above, namely 1. I:E = 1.0 : 2.0, 2. P insp = 12 hPa, 3. PEEP = 7 hPa, 4. RR = 12 min -1 , 5. Oxygen concentration 21% - 40%.

[0050] The first data set 26 and its values ​​are used (at least as starting values) under the control of the computer program 24 during the operation of the ventilator 14 when the ventilation of the patient 12 is carried out only by means of the ventilator 14, i.e. without an oxygenator 16 combined with the ventilator 14.

[0051] The second data set 28 and its values ​​are used (at least as starting values) under the control of the computer program 24 during the operation of the ventilator 14 when the patient 12 is ventilated by means of the ventilator 14 and by means of the oxygenator 16 combined with the ventilator 14.

[0052] The second data set 28, for example, includes the following values: 1. I:E = 1.0 : 2.5, 2. P insp = 8 hPa, 3. PEEP = 5 hPa, 4. RR = 15 breaths per minute and 5. Oxygen concentration 21% - 40%.

[0053] The second data set 28 does not need to include a value for every parameter. If a value is missing, it can be provided that the corresponding value from the first data set 26 is used. Thus, if the second data set 28 does not include a value for the oxygen concentration, for example, the oxygen concentration specified in the first data set 26 is used.

[0054] In the second data set 28, instead of absolute values, ratios, ratio values, differences or difference values ​​to the first data set 26 can also be stored.

[0055] To select the coordinated operation of ventilator 14 and oxygenator 16, i.e., to select ventilation of the patient 12 by means of the ventilator 14 and simultaneously by means of the oxygenator 16 (combined operation), an input device 30 is provided for operation by an operator, i.e., for example, a doctor.

[0056] The input device 30 can be – as schematically simplified – a button or the like. Likewise, an element of a graphical user interface can also serve as the input device 30.

[0057] Actuating or activating the input device 30 causes the second data set 28 to be used instead of the first data set 26 when operating the ventilator 14. By actuating or activating the input device 30, the respective operator indicates, on the one hand, a connected oxygenator 16 and, on the other hand, the desire for combined operation of the ventilator 14 and oxygenator 16, i.e., the desire for coordinated ventilation of the patient 12 by means of the ventilator 14 and by means of the oxygenator 16, using the ventilation parameters adapted for such combined operation in the second data set 28.

[0058] The representation in Fig. Figure 3 shows this procedure schematically simplified in the form of a flowchart. The flowchart represents part of the functionality of the computer program 24, which determines the functionality of the ventilator 14. According to the representation in Fig. 3. A case distinction 32 checks whether the input device 30 is actuated or activated. If so, the program branches to a program section 34 in which the second data record 28 and the values ​​it contains are selected for the operation of the ventilator 14 (accordingly, program section 34 can also be referred to as the combined operation selection program section 34). The ventilator 14 is then operated with ventilation parameters that are designed for the coordinated operation of the ventilator 14 and the oxygenator 16. If, on the other hand, case distinction 32 shows that the input device 30 is not actuated or activated, the program branches to a program section 36 in which the first data record 26 and the values ​​it contains are selected for the operation of the ventilator 14.The ventilator 14 is then operated with ventilation parameters that are set for individual operation of the ventilator 14. Program section 36 can accordingly be referred to as normal operation selection program section 36. The representation in . Fig. The three steps described are executed automatically during operation of the ventilator 14. A cyclical or similar design ensures that actuation or activation of the input device 30 is detected even at different times during operation of the ventilator 14.

[0059] The continuation of computer program 24 immediately following program sections 34 and 36 is not important. What is essential, however, is that, based on the selection described, at a later time and under the control of computer program 24, program section 38 (ventilation program section 38) is executed with computer program instructions that cause the ventilation of patient 12 by means of the ventilator 14 with the ventilation parameters selected in one of program sections 34 or 36.

[0060] Using the values ​​from the second data set 28 (examples) given above, the pressure level in the thoracic cavity decreases. Patient 12's lungs can "relax" during expiration. Intrinsic PEEP is avoided, and the essentially rapid and shallow ventilation prevents pain.

[0061] Once the consequences of the accident (swelling, bruising) or similar have partially healed, it is advisable to readjust the settings, for example, by gradually reversing the adjustments made by activating the ventilation parameters of the second data set 28 instead of the ventilation parameters of the first data set 26. Such a reversal of the initial adjustment made by activating the second data set 28 can be performed automatically.

[0062] The representation in Fig. Figure 4 shows an optional functionality of the ventilator 14 and thus an excerpt from a computer program 24 executed by the ventilator 14 during operation, which includes this optional functionality.

[0063] The in Fig. Functionality shown in section 4, for example, belongs to program section 38, whose computer program instructions effect the ventilation of patient 12 with the ventilation parameters. In any case, when the program starts, the following occurs: Fig. 4. The functionality shown assumes that usable ventilation parameters are available, in particular in the form of the first or second data set 26, 28.

[0064] At the in Fig. 4. The optional functionality of the ventilator 14 shown provides for an automatic adjustment of at least one ventilation parameter effective during the operation of the ventilator 14, depending on a measured value recorded in the system 10 or on the patient 12, for example a blood pressure measurement.

[0065] For a blood pressure measurement – ​​the following applies accordingly to other measured values ​​– a case distinction 40 is used to check whether a currently determined blood pressure measurement (pA) is less than a specified or predeterminable blood pressure set point (pA). Soll ) is: pA < pA Soll ?

[0066] If this condition is met, the program branches to section 42, in which at least one of the existing ventilation parameters is adjusted (accordingly, section 42 can also be referred to as the ventilation parameter adjustment program section). If, however, this condition is not met, section 42, in which at least one of the existing ventilation parameters is adjusted, is skipped. Subsequently, i.e., after the adjustment of at least one ventilation parameter or after skipping such an adjustment, section 38, for example, is executed. The computer program instructions in this section cause the patient 12 to be ventilated by the ventilator 14 using the currently valid (i.e., the adjusted or the existing) ventilation parameters. Then, for the purpose of cyclical execution, the following can be performed: Fig. The functionality shown in section 4 can be used, for example, by means of a case distinction 44 to check whether a criterion for terminating ventilation (termination criterion) is present. If this is not the case, at the beginning of the procedure described in section 44, the following steps are performed: Fig. The functionality shown in section 4 branches out. In the resulting cyclical or at least regular execution, whenever the blood pressure measurement meets the condition tested in case distinction 40, a readjustment (i.e., an incremental adjustment overall and over several cycles) of at least one ventilation parameter occurs.

[0067] The adjustment of ventilation parameters, either by adjusting at least one ventilation parameter or by simultaneously adjusting several ventilation parameters, is carried out, for example, by decreasing (or increasing) one or more ventilation parameters by a predetermined or predetermined increment.

[0068] The following adjustment can be cited as an example of such an adjustment of ventilation parameters: PEEP:=PEEP−ΔPEEP, Pinsp:=Pinsp−ΔPinsp, where ΔPEEP and ΔP insp The increments used can be predetermined or predefinable absolute values, or alternatively, predetermined or predefinable percentage values, so that in the latter case the respective ventilation parameter is reduced step by step by a predetermined or predefinable percentage, for example by 5% each time.

[0069] The exemplary adjustment of the ventilation parameters described above is thus an example of the functionality of program section 42, in which the previously valid ventilation parameters are adjusted and new, current ventilation parameters result from the adjustment.

[0070] The adjustment of at least one ventilation parameter described above is a simplified representation. Preferably, before making an adjustment, it is checked whether the adjustment will result in the ventilation parameter exceeding or falling below a (predefined or predefinable) limit value. This monitoring ensures that the adjustment cannot push a ventilation parameter into an unacceptable range.

[0071] The blood pressure measurement pA, and thus the decisive influencing factor for the automatic adjustment of at least one ventilation parameter, is measured, for example, by means of a patient monitor 18 ( Fig. 1) The blood pressure is recorded by a functioning medical device 18 and one of its sensors 19, for example as the mean value MAP = ½ * ( systolic value in mmHg + diastolic value in mmHg). Alternatively, the blood pressure measurement pA is recorded, for example, by means of a sensor (not shown) of the oxygenator 16 connected to the patient's circulatory system 12.

[0072] The described optional adjustment of at least one ventilation parameter depending on a measured value, in particular a blood pressure reading, can optionally be activated by means of an operating action on the ventilator 14 or on a device functioning as a higher-level device in the system 10. Activation is usually carried out by a physician, or at least by medically trained personnel.

[0073] Activation causes a "phase-out" of ventilation via the oxygenator 16. By adjusting at least one ventilation parameter, the focus of ventilation gradually shifts to the ventilator 14, so that after some time of adjusting at least one ventilation parameter, the coordinated operation of ventilator 14 and oxygenator 16 can be terminated and the oxygenator 16 can be removed.

[0074] Optionally, it is provided that the described optional adjustment of at least one ventilation parameter depending on a measured value, in particular a blood pressure measurement, only takes place at predetermined or predeterminable times or at predetermined or predeterminable time intervals, so that the phase-out of ventilation by means of the oxygenator 16 takes place over a longer period of time, in particular a period that can be influenced by specifying the times and / or the time intervals.

[0075] The most important aspects of the description submitted here can be summarized as follows: A system 10 is specified which includes as system components at least a medical device 14 functioning as a ventilator 14 and a medical device 16 functioning as an oxygenator 16 and facilitates the combined operation of ventilator 14 and oxygenator 16.

[0076] For the operation of the ventilator 14, at least one first and one second data set 26, 28 can be selected, each comprising ventilation parameters. The first data set 26 is intended for the operation of the ventilator 14 without the oxygenator 16.

[0077] The second data set 28 is intended for the operation of the ventilator 14 together with the oxygenator 16.

[0078] Upon appropriate selection of an operator, operation of the ventilator 14 with the ventilation parameters of the second data set 28 can be activated and the ventilation of the patient 12 by means of the ventilator 14 takes place with the ventilation parameters of the second data set 28. REFERENCE MARK LIST 10 System (to support blood gas exchange by means of ventilation and extracorporeal blood gas exchange) 12 patients 14 Medical device, ventilator 16 Medical device, oxygenator 18 Medical device, patient monitor 19 Sensors 20 processing units 22 storage 24 Computer program 26 first data set 28 second data set 30 Input device 32 Case distinction 34 Program section (of the computer program), combined mode selection program section 36 Program section (of the computer program), Normal operation selection program section 38 Program section (of the computer program), ventilation program section 40 Case distinction 42 Program section (of the computer program), ventilation parameter adjustment program section 44 Case distinction

Claims

System (10) for supporting the exchange of blood gases in a patient (12) on the one hand by means of ventilation using a ventilator (14) and on the other hand by means of extracorporeal blood gas exchange using an oxygenator (16), wherein the system (10) comprises as system components at least one medical device in the form of a ventilator (14) and one medical device in the form of an oxygenator (16) for extracorporeal blood gas exchange, wherein at least one first and one second data set (26, 28) with ventilation parameters can be selected for the operation of the ventilator (14), wherein the first data set (26) is intended for the operation of the ventilator (14) without the oxygenator (16) and the second data set (28) is intended for the operation of the ventilator (14) together with the oxygenator (16),wherein the ventilator (14) is operated by default with the ventilation parameters of the first data set (26) and without the oxygenator (16), and wherein, upon appropriate selection by an operator, operation of the ventilator (14) together with the oxygenator (16) and with the ventilation parameters of the second data set (28) instead of the ventilation parameters of the first data set (26) can be activated, wherein at least one ventilation parameter effective when operating the ventilator (14) together with the oxygenator (16) is automatically adjustable depending on a measured value, wherein the measured value is a blood pressure measurement that can be recorded by means of a sensor (19) of a medical device (14, 16, 18) included in the system (10). System (10) according to claim 1, wherein the blood pressure measurement value is recorded by means of a sensor (19) of a medical device (18) comprising the system (10) and functioning as a patient monitor (18). System (10) according to one of the preceding claims, wherein the or each ventilation parameter that can be adjusted depending on a measured value can be cyclically changed by a predetermined or predeterminable increment or by a predetermined or predeterminable percentage.

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