Device for the enteral absorption of co2, and corresponding set

Abstract

The invention relates to a device for the controlled in vivo absorption of CO2, comprising a catheter which has a gas-permeable membrane and a CO2-absorbing carrier medium. The invention additionally relates to a set comprising said device and to the device or set for use in the prophylaxis or treatment of diseases of the respiratory system or for use in the induction of hypercapnia in a patient.

Description

In the context of the present invention, a "catheter" is understood to be a flexible device that can be inserted into the body via a body opening and has connections for introducing and removing a preferably liquid carrier medium. The catheter is designed for use with the CO2-absorbing carrier medium in that it is filled with the CO2-absorbing carrier medium during therapeutic use and allows CO2-containing carrier medium to be exchanged for fresh carrier medium via the inlet and outlet. In one embodiment, the catheter is filled with the CO2-absorbing carrier medium. The catheter according to the invention is intended for use in the intestinal tract and is therefore designed in terms of size and composition for the intestinal tract. It is inserted rectally through the anus and positioned in the lumen of the intestine. It is preferably positioned in the descending colon and / or sigmoid colon, i.e., between the left colic flexure and the rectum. The intestinal environment is understood to be the environment surrounding the catheter positioned in the intestinal tract. This includes the lumen of the intestinal tract and, in the case of a catheter that contacts the intestinal wall (even if only temporarily) with at least part of the membrane, also the intestinal wall as CO2-containing tissue. The invention has several advantages over the prior art. The catheter with the enveloping membrane allows large quantities of CO2-absorbing carrier medium to be provided in the body. In conjunction with the large surface area of the end / large intestine, this allows relevant amounts of CO2 to be removed from the body very quickly, which makes the catheter particularly suitable for the treatment of intensive care and high-risk patients. The complete enveloping with the membrane provides a closed and secure coating, so that a wide range of CO2-absorbing carrier media can be used and even media associated with side effects can be used safely. By combining several parameters, such as the choice of CO2 carrier medium, its concentration, and the flow rate, the skilled person can adapt the device according to the invention specifically to the respective therapeutic application. In addition, changing the flow rate of the carrier medium allows for targeted adaptation to the patient's needs and can also be carried out within a single treatment session. The catheter design is suitable for large-scale production. Due to its enteral administration, the present device with the catheter can be widely used for the treatment of respiratory diseases without impairing or burdening the respiratory tract. This results in an innovative therapy option with few side effects that can be used particularly for intensive care patients or high-risk patients. The invention in detail According to the invention, the catheter has an inlet and an outlet for a CO2-absorbing carrier medium. In one embodiment, there are two separate access points. In an alternative embodiment, the inlet can also function as an outlet. In this embodiment, the CO2-absorbing carrier medium can be introduced into the catheter through the inlet in a first step and then, after absorbing CO2, be removed from the catheter through the same inlet. Advantageously, the device according to the invention may be designed such that the gas-permeable membrane is impermeable to water and / or has a molecular weight cutoff (MWCO) of less than 200 daltons. A water-impermeable membrane prevents the diffusion of water molecules from the intestine into the catheter and vice versa from the catheter into the intestine, thereby maintaining the water balance of the intestine and preventing possible constipation or diarrhea. In one embodiment, the gas-permeable membrane is also impermeable to water vapor. When using a liquid carrier medium, which is preferred, it is not necessary to moisten the carrier medium. The term "water impermeability" is synonymous with the term "watertight" in the context of this application. The so-called waterproofness of the gas-permeable membrane is measured by the water column under which the material begins to allow water to pass through. According to DIN standard EN 343:2019-06, a membrane is water impermeable from a value of 1,300 mm upwards. In a preferred embodiment, the gas-permeable membrane of the catheter is designed in such a way that it essentially prevents the release of the CO2-absorbing carrier medium or the CO2-absorber during in vivo use. Here, "essentially" means that during in vivo use of the catheter, a maximum of 5 wt.%, preferably a maximum of 4 wt.%, more preferably a maximum of 3 wt.%, and even more preferably a maximum of 1 wt.% of the CO2-absorbing carrier medium or CO2 absorber is released from the catheter. Many CO2-absorbing carrier media or CO2 absorbers cause undesirable side effects when released in the gastrointestinal tract. In the case of calcium hydroxide as a strong base, release would lead to a sharp increase in pH. In the case of magnesium hydroxide, excessive release could be accompanied by muscle weakness and diarrhea. P0751AU The CO2-absorbing catheter according to the invention is a device that serves exclusively to absorb CO2 from the organism. A release of the CO2-absorbing carrier medium or CO2 absorber, whether as a CO2free reactant or a CO2 containing product, should be prevented as far as possible. In this sense, the gas-permeable membrane of the catheter is a semi-permeable or selectively permeable barrier that permits the passage of CO2 from the organism to allow absorption by the CO2 absorber inside the catheter, but is impermeable to the CO2 absorber and preferably also impermeable to its absorption product(s). Accordingly, the gas-permeable membrane of the catheter is impermeable to the CO2-absorbing carrier medium or CO2 absorber and preferably to its absorption product(s), even during in vivo use. In an alternative preferred embodiment, the gas-permeable membrane of the catheter is designed in such a way that, during in vivo use, it prevents the release of the CO2-absorbing carrier medium or the CO2 absorber in the gastrointestinal tract during in vivo use to such an extent that the concentration of the CO2-absorbing carrier medium or the CO2 absorber in the intestinal lumen is less than 1 mM, preferably less than 100 pM, more preferably less than 10 pM, and particularly preferably less than 1 pM. This minimized release can also be determined by means of an in vitro test. Both the European Pharmacopoeia (Ph.Eur.) and the United States Pharmacopeia (USP) define precise procedures and equipment for in vitro drug release tests. The European Pharmacopoeia specifies the equipment according to the dosage form. For example, Chapter 2.9.3 "Drug Release from Solid Dosage Forms" lists the following defined equipment: rotating basket apparatus (USP); rotating paddle apparatus (USP); or flowthrough cell (USP). The specialist is familiar with reaction temperatures and buffers that simulate the release of the CO2-absorbing carrier medium or CO2 absorber in the gastrointestinal tract. How the test is to be carried out depends on the release of the active ingredient from the dosage form, and here he will select delayed release. The present formulation has a selectively permeable membrane, whereby the selective permeability consists in the fact that the membrane is permeable to CO2 (allowing CO2 from the gastrointestinal tract to pass through the membrane to the CO2 absorbing carrier medium or CO2 absorber, where it can be bound) and impermeable to the CO2-absorbing carrier medium or CO2 absorber (whether as a CO2-free reactant or a CO2-containing product). The selective permeability of the present membrane remains during the catheter's stay in the gastrointestinal tract. A physiologically effective amount of CO2 is removed from the human gastrointestinal tract. The catheter with its gas-permeable membrane of any embodiment of the invention is preferably sufficiently robust to persist in the environment of use, for example, to persist in the GI tract or a representative in vitro assay for pharmaceutical applications without such a catheter being significantly degraded and / or preferably without the physical characteristics and / or performance characteristics of the catheter being significantly impaired. In preferred embodiments, the gas-permeable membrane is essentially not degraded and / or has physical characteristics and / or performance characteristics that are essentially not degraded under physiological conditions of the GI tract (or in vitro representations or mimics thereof) during a period of time for remaining in the environment of interest, such as in the gastrointestinal tract. Preferably, the CO2-absorbing carrier medium or CO2 absorber binds the CO2 and retains the CO2 for a significant period of time in the environment of interest. For example, in applications involving the binding of CO2 in the gastrointestinal tract, the catheter can bind CO2 in areas of the gastrointestinal tract that have a relatively high concentration of CO2. Such bound CO2 preferably remains bound to the CO2-absorbing carrier medium or CO2 absorber and is excreted from the body in a sufficient amount to produce a therapeutically beneficial effect. From an alternative perspective, the catheter does not release the bound CO2 in the area of interest, for example in the gastrointestinal tract, in a significant manner before a desired therapeutic effect is achieved. The catheters described herein can retain a significant amount of CO2. The term "significant amount" as used herein is not intended to mean that the entire amount of bound CO2is retained. It is preferred that at least a substantial portion of the bound CO2 is retained so that a therapeutically relevant effect occurs. The retention period is generally preferably during the time that the catheter is used in the area of interest. For applications involving the binding of CO2 in the gastrointestinal tract, for example, this time is a period sufficient for a therapeutically beneficial effect. In the embodiment in which catheters are used to bind CO2 and remove it from the gastrointestinal tract, the retention period may generally be the dwell time of the composition in the gastrointestinal tract and, more preferably, the average dwell time in the small intestine and large intestine. Advantageously, the permeable selectivity of the catheter of the invention is sufficiently durable to produce a useful effect, for example, treatment of a disease of the respiratory system. The durable selectivity (for example, the durable selective permeability) of the catheter membrane is particularly advantageous for binding CO2 in the gastrointestinal tract. The catheters of the invention are preferably sufficiently robust to remain intact in the environment of their intended use. In one application, the catheters with their gas-permeable membrane are, for example, sufficiently robust to remain in the gastrointestinal system (or to survive in a representative in vitro assay) without such a catheter or its membrane being significantly degraded. In preferred embodiments, the gas-permeable membrane of the CO2 absorber is substantially robust under physiological conditions of the gastrointestinal tract (or in in vitro representations or simulations thereof) during a period of residence in the gastrointestinal tract (e.g., it is not degraded, perforated, or separated and / or delaminated). For example, the CO2 absorber and membrane are essentially not degraded under in vitro conditions, wherein these conditions are preferably selected from the group consisting of (ii) an aqueous solution with a pH of (approximately) 8 over a period of (approximately) 10 hours, (iii) an aqueous solution with a pH of (approximately) 6 over a period of (approximately) 20 hours, and combinations thereof, each at a temperature of (approximately) 37°C with stirring. In some embodiments, the CO2 absorbing carrier medium or, preferably, the particulate CO2 absorber may be robust in terms of other aspects in addition to not decomposing, for example, including in terms of physical characteristics and / or performance characteristics. Physical characteristics may include particle size, particle size distribution, and / or surface properties, for example, as visually assessed using microscopes, for example, electron microscopes and / or confocal microscopes. Performance characteristics may include specific binding capacity, selectivity (e.g., selective permeability), and durability or persistence. Some preferred in vitro assays that can be used in connection with determining robustness, for example for the purposes of modifying or optimizing a catheter in this regard, include the aforementioned in vitro drug release studies, whereby the CO2 absorbing carrier medium or CO2 absorber should not be released as an "active ingredient." In some embodiments, the membrane may impart other properties related to robustness, such as sufficient strength to withstand mechanical forces or stresses associated with pressurized fluid filling in connection with therapeutic use. In embodiments of the invention, the membrane may protect the CO2-absorbing carrier medium or the CO2 absorber from the external environment, for example, the gastrointestinal tract. Advantageously, the invention may provide that the CO2-absorbing carrier medium is a liquid, i.e., the carrier medium is in the liquid state during operation (under standard conditions). Due to the use of a liquid as the carrier medium, the removal and transport of substances can be carried out in a much more controlled and efficient manner. Due to the use of a liquid as the CO2-absorbing carrier medium, the membrane of the device is a membrane suitable for liquids, i.e., configured and designed for the exchange of substances between two liquids. Even though such a membrane could or can achieve an exchange of substances between a liquid and a gas to a certain extent, the overall configuration of the membrane, in particular the intended contact surface and / or mechanical stability, means that in one embodiment it is not designed for use with a gaseous carrier medium. By using suitable carrier liquids and increasing the supply of this liquid, higher CO2 absorption by the membrane can be achieved and the required membrane surface area can be reduced, which leads to a reduced pressure difference in the catheter and thus also enables a reduction in the size of the delivery device. In a preferred embodiment, the CO2-absorbing carrier medium is selected from the group consisting of: (a) a carrier fluid in which CO2 is soluble, wherein the CO2 solubility at 20 °C and 1 atm is at least 85 ml CO2 / 100 ml carrier fluid; (b) a liquid in which a CO2-adsorbing material is dissolved or dispersed; (c)   a liquid in which a CO2-absorbing material is dissolved or dispersed; (d) a liquid in which a CO2-reacting enzyme such as carbonic anhydrase is dissolved. In one embodiment, the carrier liquid itself can serve as a CO2-absorbing carrier medium, insofar as it is a carrier liquid in which CO2 is soluble, and wherein the CO2 solubility at 20°C and 1 atm is at least 85 ml CO2 / 100 ml carrier liquid. The CO2 solubility at 20°C and 1 atm can be at least 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, or 250 ml CO2 / 100 ml carrier fluid. The carrier fluid with CO2 solubility involves physical absorption. The term "absorption" describes the process of absorbing or "dissolving" carbon dioxide in another phase. This does not involve attachment to the surface (adsorption), but rather absorption into the free volume of the absorbing phase. In physical absorption, the carbon dioxide is dissolved as a gas in a solvent. Mixing takes place without a chemical reaction. The absorption capacity for CO2 in the blood is approximately 20 ml / 100 ml. Carbon dioxide is present in the blood in two forms: a smaller portion is physically dissolved in the blood plasma as free CO2. The larger part is dissolved in the plasma and erythrocytes as hydrogen carbonate (bicarbonate), or occurs in the erythrocytes bound to hemoglobin (so-called carbaminohemoglobin). In an alternative embodiment, the CO2-absorbing carrier medium is a liquid in which a CO2-adsorbing material is dissolved or dispersed. In this context, "adsorption" refers to the accumulation of carbon dioxide on the surface of a solid. In the device, it may be advantageous to provide that the CO2-adsorbing material is selected from the group consisting of activated carbon, a molecular sieve such as zeolite, silica, and metal-organic frameworks (MOFs). Activated carbon is a fine-grained carbon with a large internal surface area, which can be between 300 and 2000 m2 / g of carbon. The term "molecular sieve" is the functional designation for natural and synthetic zeolites or other substances that have a high adsorption capacity for carbon dioxide gas. In addition to zeolites, there are also carbon molecular sieves (or "molecular sieving carbon"). Molecular sieves have a large internal surface area (600-700 m2 / g) and uniform pore diameters that are on the order of the diameters of molecules. Metal-organic frameworks (MOFs) are defined in this application as microporous materials composed of inorganic building units (IBUs) and organic molecules as linkers between the inorganic building units. MOFs are coordination networks with an open framework containing pores. After synthesis, the pores of the threedimensional structures are usually filled with guest molecules (e.g., solvents or unreacted linkers). By removing the guest molecules (e.g., by baking, in a vacuum, or by a combination of both), the pores can be made accessible again for the absorption of gases such as CO2. In a further embodiment, the CO2-absorbing carrier medium is a liquid in which a CO2-absorbing substance is dissolved or dispersed. Absorption in this context refers to chemical absorption, in which the carbon dioxide undergoes a chemical reaction with the "solvent" or absorbent to form a product substance. For example, the CO2 can react with an inorganic hydroxide compound such as calcium hydroxide to form calcium carbonate according to the following reaction equation (I). Water is produced as a by-product of the reaction: (I)    :--11:,-                       Il,-,:: In an alternative embodiment, the CO2-absorbing carrier medium is a liquid in which a CO2-converting enzyme such as carbonic anhydrase is dissolved. This enzyme can convert the gaseous CO2 diffusing through the membrane into bicarbonate and hydrogen ions according to the following reaction equation (II): (II) C02 + 2 H20 - h2co3 + h2o ~ h3o+ + hco3- In humans, there are more than 10 different isoforms of a-carbonic anhydrase, which are systematically numbered with Roman numerals (CA-I, CA-II, CA-III, etc.). The zinc ion is responsible for the actual activity of the enzyme as the active center. It is bound to three imidazole residues derived from histidine in the protein framework. The fourth coordination site is occupied by a hydroxy ligand (OH-). The zinc in carbonic anhydrases is therefore tetracoordinated. In the immediate vicinity is a pocket for the uptake of CO2. The invention may provide that the CO2-absorbing substance is an inorganic hydroxide compound. As hydroxide compounds, they can react with the carbon dioxide to form the corresponding carbonates. The hydroxide compound is preferably selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, and magnesium hydroxide, or mixtures thereof. The use of magnesium hydroxide is particularly preferred. According to one embodiment, the CO2-absorbing substance consists essentially of calcium hydroxide. The calcium hydroxide reacts with the carbon dioxide to form pharmaceutically acceptable calcium carbonate. Here, "essentially" means that the CO2-absorbing substance contains at most 5 wt%, preferably at most 4 wt%, more preferably at most 3 wt%, and even more preferably at most 1 wt% of other components. In an advantageous embodiment, the calcium hydroxide-containing CO2-absorbing material is essentially free of sodium and potassium hydroxide. Here, "essentially" means that the CO2-absorbing material contains at most 4 wt%, preferably at most 2 wt%, more preferably at most 1 wt%, further preferably 0.5 wt% sodium hydroxide and potassium hydroxide, and particularly preferably no sodium hydroxide and potassium hydroxide. According to a particularly preferred embodiment, the CO2-absorbing material consists essentially of magnesium hydroxide. Magnesium hydroxide has the advantage that, due to its lower basicity, it does not cause any significant side effects even if the catheter ruptures and material leaks out. The magnesium hydroxide reacts with the carbon dioxide to form pharmaceutically safe magnesium carbonate. Here, "essentially" means that the CO2-absorbing material contains at most 5 wt%, preferably at most 4 wt%, more preferably at most 3 wt%, and even more preferably at most 1 wt% of other components. In an advantageous embodiment, the magnesium hydroxide-containing CO2-absorbing material is essentially free of sodium and potassium hydroxide. Here, "substantially" means that the CO2-absorbing material contains at most 4 wt%, preferably at most 2 wt%, more preferably at most 1 wt%, further preferably 0.5 wt% sodium and potassium hydroxide, and particularly preferably no sodium and potassium hydroxide. Advantageously, the invention may provide that the CO2-dissolving liquid is selected from the group consisting of strongly eutectic solvent, ionic liquid, and perfluorocarbon. Perfluorocarbons (PFCs) are synthetic, fully halogenated carbon compounds. In most cases, the hydrogen atoms are replaced by fluorine, but other halogens such as bromine or chlorine also occur. They can absorb and release large amounts of gases such as oxygen or carbon dioxide. Due to the very high carbon-fluorine bond energy, PFCs are chemically and metabolically inert, i.e., they do not form toxic metabolites. PFCs are neither hydrophilic nor lipophilic and are immiscible with aqueous liquids such as blood. Compared to blood, PFCs have a ten times higher absorption capacity for CO2 than blood, making them a highly efficient carrier fluid for CO2. Furthermore, PFCs have low surface tension and spread very easily on surfaces due to their high spreading coefficient. These properties make these fluids particularly suitable for use with hollow fiber membranes. In a preferred embodiment, the perfluorocarbon is selected from the group consisting of perfluorodecalin, perfluoro-decyl bromide, perfluorooctyl bromide, perfluorodichlorooctane, perfluoroisobutylcyclohexane, perfluorotributylamine, and perfluoromethylcyclohexylpiperidine. A strong eutectic solvent can also be used as a CO2 -dissolving liquid. In the context of the present application, strong eutectic solvents (DES) are defined as multicomponent eutectic salt melts whose melting point, like that of ionic liquids, is close to or below room temperature. Examples of eutectic solvents are based on a mixture of a quaternary ammonium compound with hydrogen bond donors (e.g., amine) and a carboxylic acid. Ionic liquids (IL) are salts with a melting point below 100 °C. Preferably, their melting temperature is below 37°C, and even more preferably below room temperature (then referred to as "room temperature ionic liquids" (RTIL)), so that they can be used in liquid form in the catheter. Like all salts, they consist of anions and cations. By varying these, the physicochemical properties of an ionic liquid can be varied within wide limits and optimized to meet technical requirements. Ionic liquids are mainly used as solvents and, due to their structural diversity, are also referred to as "designer solvents." One example of a CO2-absorbing ionic liquid is 1-butyl-3-propylaminoimidazolium tetrafluoroborate, which, according to the following reaction scheme (III), can bind equimolar amounts of CO2 as a task-specific ionic liquid (TS-IL): (III) Another example of a CO2-storing ionic liquid is 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM PF6). With a melting point of 12°C, BMIM PF6 is a room temperature ionic liquid (RTIL). In one embodiment of the invention, the CO2-absorbing carrier medium may be a gas or gas mixture, preferably having a CO2 partial pressure of less than 40 mm Hg. For example, nitrogen or air may be introduced into the catheter as a gas mixture. Based on the preferred use of a carrier liquid as the carrier medium, the gas-permeable membrane of the catheter is a membrane suitable for liquids, i.e., configured and designed for the exchange of substances between two liquids. Depending on the application, i.e., in particular depending on the substance to be exchanged and thus also depending on the carrier fluid, the design, material, and structure of the membrane can be adapted accordingly. Suitable materials include, for example, hydrophilic or hydrophilized copolymers and hydrophilic polymer mixtures. Specifically, mixtures with one or more components from a group consisting of poly(organo)siloxane, polyethylene such as high-density polyethylene (HDPE) or low-density polyethylene (LDPE), polypropylene, thermoplastic polyurethane, polyester; polybutylene succinate; polybutylene adipate terephthalate (PBAT), polyethersulfone (PES), polyarylethersulfone, polyacrylethersulfone (PAES), polyvinylpyrrolidone (PVP), polymethyl methacrylate (PMMA), polymethyl pentene (PMP), polyamide (PA), polyacrylonitrile (PAN), polytetrafluoroethylene, ethylene vinyl alcohol copolymer (EVOH), cellulose, cellulose triacetate (CTA), cellulose nitrate, and silicone-coated polypropylene can be used as membrane materials. In one embodiment, the membrane may be a composite of a microporous PE outer layer, a PU intermediate layer, and a microporous PE inner layer. Preferably, the gas-permeable membrane comprises poly(organo)siloxane, for example in the form of a coating such as a PE film coated with silicone rubber, or, more preferably, the membrane consists of poly(organo)siloxane. The pore size of the gas-permeable membrane can be between 0.01 pm and 0.1 pm. A pharmaceutically acceptable material, preferably a polymer, is suitably used as the membrane. This enables in vivo application with few or no side effects. According to a further embodiment, the membrane may have one of the following properties to provide a sliding catheter: (a) the membrane consists of a lubricious polymer; (b) the membrane has a coating of a lubricating substance, such as water-soluble lubricating gel, PTFE, or poly(organo)siloxane; (c) the membrane is coated with a lubricant before rectal insertion. The design as a lubricated catheter facilitates rectal application and positioning in the intestinal tract and also allows the use of larger catheters. Advantageously, the invention may provide that the total surface area of the gas-permeable membrane, which forms the contact surface for gas absorption or gas exchange, is at least 0.1 m2. The contact surface may be at least 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0 m2. Advantageously, the invention may provide that the gas-permeable membrane is designed as a hollow fiber membrane, wherein the inner surface of the hollow fiber membrane is in contact with the carrier medium and the outer surface of the hollow fiber membrane is in contact with the intestinal tract. A particularly large contact area in a small space can be achieved if the membrane is a hollow fiber membrane. The actual contact area is formed by the walls of the hollow fibers or capillaries. A hollow fiber membrane can comprise up to 20,000 individual capillaries or hollow fibers. The diameter of the individual hollow fibers is between 0.01 mm and 1 mm, in particular between 0.1 and 0.5 mm. The total surface area of the membrane, which forms the contact surface for the exchange of substances, is between 0.1 and up to 10 m2, preferably between 0.2 and 1 m2. The material from which the hollow fibers are formed may consist of one or more of the above-mentioned polymers, with polymethylpentene or poly(organo)siloxane being preferred. In connection with the application according to the invention and, if necessary, the promotion of intestinal fluid during operation through the catheter, the filigree hollow fibers of the membrane can be housed in a protective catheter sheath. The invention may provide that the catheter has a plurality of hollow fibers, each fiber being connected to the inlet by a first connection and to the outlet by a second connection, the hollow fibers preferably being present as a bundle of hollow fibers and the hollow fibers being arranged for the most part substantially parallel to a longitudinal extension of the catheter. According to a further embodiment, the gas-permeable membrane may be designed as an elongated hollow body with a proximal and a distal end, wherein the inner surface of the membrane is in contact with the carrier medium and an outer surface of the membrane is in contact with the intestinal tract. The elongated hollow body design allows the catheter to adapt to the shape of the intestine and enables CO2 absorption without seriously disrupting intestinal activity. The hollow body may preferably have a diameter of 3 to 8 cm during operation, and more preferably 5 to 7 cm. Use during operation means use after positioning the catheter and increasing its volume by supplying the carrier medium. The skilled person will select the diameter here depending on the diameter of the intestine, whereby it is preferable that the catheter predominantly or even completely fills the cross-section of the intestine during use, so that maximum gas diffusion is possible due to the small distance or, in extreme cases, due to the close contact between the catheter and the intestinal wall. Advantageously, the invention may provide that the inlet is located at the distal end and the outlet at the proximal end of the elongated hollow body, so that they preferably define the longest possible flow path. In this case, the CO2-absorbing carrier medium enters the hollow body at the distal end through the inlet, passes through the entire length of the hollow body, and leaves the hollow body again at the proximal end through the outlet. The invention may provide that the elongated hollow body has an axial length of 3 to 100 cm, preferably an axial length of 20 to 50 cm, and particularly preferably an axial length of 30 to 50 cm or 10 to 20 cm. The skilled person can select a suitable length for the catheter hollow body according to the desired uptake rate and the size of the patient. According to a further embodiment, it may be provided that the elongated hollow body has one of the following shapes: (a) a tube-shaped hollow body with a circular or oval cross-section; (b) a hollow body with longitudinal, essentially parallel fold or crease lines; (c) a tubular hollow body with an inner tube surrounded by an outer tube, wherein the two tubes have such different diameters that a substantially cylindrical passage is formed between the tubes, through which the CO2-absorbing carrier medium can flow longitudinally; (d) a flat body with two outer membrane surfaces which, together with intermediate walls, form channels for the CO2-absorbing carrier medium, so that the membrane surfaces are in contact with the intestinal tract and the membrane is designed in such a way that it allows the diffusion of gas from the intestinal tract into the CO2-absorbing carrier medium circulating in the channels; or (e) a tubular hollow body that is helically wound to form a helix, wherein the helix preferably forms an inner channel for transporting the digestive pulp. In a design as a tubular hollow body with a circular or oval cross-section, the catheter has a shape that is easy to implement and corresponds to the elongated intestine. Preferably, the tubular hollow body has an internal continuous channel for transporting the digestive pulp. Alternatively, the hollow body may be provided with longitudinal, essentially parallel fold or crease lines, whereby the contact surface can be significantly increased. In a further embodiment, the tubular hollow body may be designed with an inner tube, wherein the inner tube is surrounded by an outer tube, and wherein the two tubes have such different diameters that a substantially cylindrical passage is formed between the tubes, through which the CO2-absorbing carrier medium can flow through the passage along its longitudinal direction. This ensures that the carrier medium flows in a preferably laminar flow close to the outer membrane and can thereby absorb CO2 in an optimal manner. In one embodiment, the hollow body is designed as a flat body with two outer membrane surfaces which, together with intermediate walls, form channels for the CO2-absorbing carrier medium, so that the membrane surfaces are in contact with the intestinal environment and the membrane is designed in such a way that it allows the diffusion of gas from the intestinal environment into the CO2-absorbing carrier medium circulating in the channels. The flat design provides a large contact surface. The respective channel routing allows the carrier medium to be passed through the hollow body in a variety of ways, thus also allowing the path length to be variably adjusted. For example, a meandering channel routing can be used to achieve a very long path length while making optimum use of the available contact surface. Advantageously, the invention may provide that the catheter is movably designed in one of the following forms to increase gas diffusion: a) Rotation around the longitudinal axis; b) Alternating twisting of a hollow fiber bundle; c) Pulsating volume change. According to one embodiment, the catheter may be designed to be expandable or dilatable so that it can undergo a cross-sectional enlargement after insertion into the intestinal tract. For example, it can be easily inserted rectally and positioned in the intestine in a folded or rolled-up form and then expanded or dilated to its final size. This is preferably achieved by supplying the carrier medium into the catheter. Advantageously, the invention may provide that the inlet and outlet are connected as a double-lumen tube with the gas-permeable membrane. In this case, the tube leading to the inlet and the tube leading to the outlet may be adjacent to each other with a semicircular cross-section in a side-by-side configuration of a larger tube or may be welded together to form a pair of tubes. In an alternative design, the two tube lumens are arranged coaxially. According to a further embodiment, it may be provided that the CO2-absorbing carrier medium is enriched with oxygen before entering the catheter, thus allowing CO2 / O2gas exchange in the intestinal tract. When using a CO2-absorbing carrier medium that also stores oxygen, the catheter can also be used for CO2 / O2 gas exchange. In this case, the CO2-absorbing carrier medium must be enriched with oxygen before entering the catheter and can then absorb CO2 and release O2 in the intestinal tract. This allows both hypercapnia and hypoxia to be treated. The invention may provide that the catheter additionally has a sensor selected from the group consisting of a CO2 sensor, an oxygen sensor, and a pH sensor. Numerous designs for a CO2 sensor and also for an oxygen sensor or pH sensor are known to those skilled in the art. By measuring the CO2content, the absorption rate of the catheter can be adjusted, for example by increasing or decreasing the delivery rate. When using metal hydroxides, the extent of the pH change is a measure of the CO2 absorption rate, so that this can be easily determined by measuring the pH value. The invention may provide that the catheter additionally has a flushing tube with an outlet opening into the intestinal tract, the outlet opening preferably being located at or near the proximal end. This allows the intestine to be flushed during treatment, thereby optimizing gas exchange. In a preferred embodiment, the catheter is designed as a disposable item. In this case, it is advantageous if the catheter consists of a closed hollow body and is discarded after therapeutic use as a single-use product. Advantageously, the invention may provide that the inlet is fluidly connected to a container for the CO2-absorbing carrier fluid and to a pump for transporting the CO2-absorbing carrier fluid from the container to the catheter, and that the outlet is preferably fluidly connected to a collection container for receiving the CO2-absorbing carrier. In this simplest delivery configuration, the CO2-absorbing liquid present in a container serving as a reservoir is pumped by means of a pump through a first liquid line and the inlet into the catheter and, after CO2 absorption, is conducted on the outlet side through a second liquid line into the collection container. According to a further embodiment, the catheter may be connected to an extracorporeal exchange device to form a circulation system, wherein the circulation system has a pump for conveying the carrier medium, and preferably a first switching device is additionally provided in the circulation system, with the aid of which the carrier medium flowing out of the catheter can be selectively returned to the catheter or fed to the collection container. In this configuration, there are therefore two fluid paths side by side. First, a unidirectional path according to the previous configuration and, second, a circulation system, whereby the two fluid paths can be fed alternatively by a switching device. This allows the carrier medium to circulate in the circulation system until the desired amount of CO2 has been absorbed (possibly even up to CO2 saturation), before being diverted to the collection container and then feeding the catheter with new carrier medium. A flexible hose, hereinafter also referred to as a hose line, is suitably used as the fluid line. Those skilled in the art are familiar with pumps in the field of catheters, which they can select in a suitable manner in accordance with the delivery volume and delivery rate. The invention may provide that the pump is selected from the group consisting of a hose pump, a pulsation pump, a centrifugal pump, a diaphragm pump, and a piston pump, whereby a hose pump or a centrifugal pump is preferred. Advantageously, the invention may provide that the device is additionally equipped with a control device that controls the supply or circulation of the CO2-absorbing carrier medium in the catheter, preferably based on the CO2 absorption rate of the carrier medium. According to a further embodiment, the device may additionally comprise an insertion aid for rectal insertion of the catheter into the intestinal tract. For example, a sleeve with a cavity may be used, wherein the cavity is suitable for receiving the catheter. After inserting the sleeve and positioning it at the desired section of the intestine, the sleeve can be withdrawn and the catheter remains at the target location. In this case, the catheter is preferably in an empty or folded configuration and is brought to its final size after positioning by filling it with the carrier medium. Alternatively, the device may also have a guide wire that is permanently or reversibly detachable from the catheter. In a further embodiment, the device may also comprise a receptacle for an endoscope as an insertion aid. In a second aspect, the invention relates to a kit comprising the catheter according to the invention, a pump, an exchange device, and a tube connected to the catheter and the pump or exchange device for transporting a carrier fluid between the catheter and the pump or exchange device. In a third aspect, the invention relates to the device according to the invention device or kit according to the invention for use in the prophylaxis or treatment of diseases of the respiratory system, such as acute or chronic respiratory diseases or lung diseases; cardiovascular diseases, metabolic disorders such as ketoacidosis, or infectious diseases or respiratory disorders following severe courses of disease. In the prophylaxis or treatment of diseases of the respiratory system, the patient subgroup of patients with diverticulosis can also be treated advantageously. In diverticulosis, one or more balloon-like protrusions (diverticula) are present, usually in the large intestine (colon). Since the catheter according to the invention is safely positioned as a single device in the intestinal lumen, patients with diverticulosis do not represent a contraindication for treatment according to the third aspect of the invention, and this patient subgroup can be safely and effectively treated with the device according to the invention. This is particularly important in emergency treatment, as no differential diagnosis for the presence of diverticula needs to be made in advance. Advantageously, the invention may provide that the disease of the respiratory system is selected from the list consisting of: (a) chronic obstructive pulmonary disease; (b) Asthma; (c) Cystic fibrosis; (d) Acute respiratory failure; (e) Hypercapnia; (f) Pneumonia; (g) Lung carcinoma; (h) Pulmonary fibrosis; (i) Respiratory diseases following medical procedures according to ICD-10 J95; (j) Respiratory insufficiency according to ICD-10 J96; (k)   Other respiratory diseases according to ICD-10 J97; (l) Respiratory diseases in diseases classified elsewhere according to ICD-10, J99; or (m) immature lungs. In the prophylaxis or treatment of diseases of the respiratory system according to points (a) to (m), the patient subgroup of patients with diverticulosis can also be treated, as described above. In a further aspect, the invention relates to the device or kit according to the invention for use in inducing hypocapnia in a patient. When inducing hypercapnia in a patient, the subgroup of patients with diverticulosis can also be treated, as described above. The invention may provide that the use comprises the following steps: (a) optional chemical or mechanical partial degradation of the mucosal barrier of the intestine to increase gas diffusion through the intestinal epithelium and / or emptying of the intestine by means of a gravity enema; (b) rectal insertion of the catheter according to the invention for positioning in the lumen of the intestinal tract, preferably in the descending colon; (c) extracorporeal supply of CO2-absorbing carrier medium into the lumen of the catheter for absorption of CO2 from the intestinal tract; (d) optional circulation of the CO2-absorbing carrier medium in a circulation system with an extracorporeal exchange device until the carrier medium, as a spent carrier medium, has a predetermined CO2 content; (e) Discharge of the spent carrier medium from the catheter into a collection container. During use, the CO2 absorbing carrier medium in step (c) and / or step (d) can preferably be passed through the catheter at a flow rate of 1 to 5 L / min. It is advantageous for the CO2 absorbing carrier medium to contain a pH indicator. When using metal hydroxides, the extent of the pH change is a measure of the CO2 absorption rate, so that the absorption rate can be easily determined by measuring the pH value. Definitions In this document, the term "polymer" refers to a group of chemically uniform macromolecules that differ in terms of degree of polymerization, molar mass, and chain length, which have been produced by a polyreaction (polymerization, polyaddition, polycondensation). The term also covers derivatives of such a group of macromolecules from polyreactions, i.e., compounds obtained by reactions such as additions or substitutions of functional groups on given macromolecules, which may be chemically uniform or chemically non-uniform. The term also includes copolymers and so-called prepolymers, i.e., reactive oligomeric pre-adducts whose functional groups are involved in the formation of macromolecules. In this document, the term "copolymer" refers to a polymer composed of two or more different monomer units. This distinguishes copolymers from homopolymers, which are composed of only one (real or imaginary) type of monomer and therefore have only one repeating unit. Copolymers can be divided into five classes, namely 1.) statistical copolymers, in which the distribution of the two monomers in the chain follows a statistical distribution, 2.) Gradient copolymers, which are similar in principle to statistical copolymers, but in which the proportion of one monomer increases and the other decreases along the chain. 3.) alternating copolymers, in which the two monomers alternate, 4.) block copolymers and segment copolymers, which consist of longer sequences or blocks of each monomer, and 5.) Graft copolymers, in which blocks of one monomer are grafted onto the backbone of another monomer. In this document, the term "solvent" refers to compounds listed as organic solvents in CD Rompp Chemie Lexikon, 9th edition, version 1.0, Georg Thieme Verlag, Stuttgart 1995. The polyols used in the invention are not covered by this definition, although they act as solvents for the monomers and also for the low-molecular-weight polymer produced by radical polymerization. In this document, "liquid" refers to substances that can be deformed and are flowable, including highly viscous and pasty substances. The term hypercapnia as used in the present invention describes an increase in arterial CO2 partial pressure above 45 mm Hg, and thus indicates a pathologically elevated CO2 concentration in the blood. The causes of an increase in carbon dioxide partial pressure are generally attributable to the failure of the respiratory pump, as can be seen, for example, in the case of respiratory insufficiency with hypoventilation and the resulting respiratory acidosis. Classic examples include blocked airways due to a fallen tongue and breathing impeded by mucus and blood. Other causes of hypercapnia include the effects of medication (excessive muscle relaxants, opiates, hypnotics), disturbances in respiratory mechanics due to pneumothorax, or disturbances in gas exchange due to pulmonary edema. Symptoms of hypercapnia primarily include impaired consciousness and possibly coma (in cases of a sharp increase, this is also referred to as "carbon dioxide narcosis"). The term "hypocapnia" describes the opposite of hypercapnia, i.e., a decrease in arterial CO2 partial pressure or a decreased CO2 concentration, e.g., caused by hyperventilation. This results in respiratory alkalosis. Furthermore, hypocapnia can also occur as a result of respiratory compensation for metabolic alkalosis. Cardio-circulatory effects of hypocapnia include an increase in peripheral vascular resistance, a decrease in cardiac output, an increase in coronary resistance, and a decrease in coronary blood flow. It should be expressly noted that, in the context of this patent application, indefinite articles and indefinite numerical values such as "one...", "two..." etc. are generally to be understood as minimum values, i.e. as "at least one...", "at least two..." etc., unless it is clear from the context or the specific text of a particular passage that only "exactly one...", "exactly two..." etc. is meant. Furthermore, all numerical data and information on process parameters and / or device parameters are to be understood in a technical sense, i.e., as subject to the usual tolerances. Even if the explicit restriction "at least" or "minimum" or similar is used, it cannot be concluded that the simple use of "one", i.e. without the specification of "at least" or similar, means "exactly one". Unless otherwise stated, the percentages given in this document are weight percentages. The embodiments shown here are only examples of the present invention and should therefore not be understood as limiting. Alternative embodiments considered by those skilled in the art are equally covered by the scope of protection of the present invention. Examples of embodiments Various embodiments of the invention are described below with reference to the figures. It shows: Fig. 1 Schematic representation of a catheter according to the invention designed as a hollow body Fig. Schematic representation of a catheter according to the invention designed as a hollow body in sectional view with proximal inlet and distal inlet Fig. Schematic representation of a catheter according to the invention featuring a hollow fiber membrane Fig. Schematic representation of a catheter according to the invention in crosssectional view with meandering channels; and Fig. 5    schematic hand-drawn representation of a catheter and Fig. 6 its use in the intestinal tract. Figure 1 shows the device 10 with the catheter 20 as an essential component, which is cylindrical in shape and enclosed by the gas-permeable membrane 60. The catheter has an inlet 30 at the lower end for supplying the CO2-absorbing carrier medium and an outlet 40 at the upper end for removing the CO2-absorbing carrier medium after it has absorbed CO2 from the intestinal environment. Figure 2 shows a further embodiment of a catheter 20 according to the invention in crosssection, in which the gas-permeable membrane 60 forms an elongated hollow body with rounded ends, and the membrane has a first side 90 in contact with the carrier medium located in the lumen 70 and a second side 80 of the membrane in contact with the intestinal environment, thereby allowing the diffusion of gas from the intestinal tract into the CO2-absorbing carrier medium. The catheter has an inlet 30 at the upper end for supplying the CO2-absorbing carrier medium and an outlet 40 at the lower end for removing the CO2-absorbing carrier medium after it has absorbed the CO2 from the intestinal environment. Figure 3 shows the device 10 with the catheter 20 as an essential component, which has a plurality of hollow fiber membranes 60a that can be flowed through with carrier medium on the inside and are in contact with the intestinal environment on the outside of the hollow fibers. The catheter has an inlet 30 at the lower end for supplying the CO2-absorbing carrier medium and an outlet 40 at the upper end for removing the CO2-absorbing carrier medium after it has absorbed CO2 from the intestinal environment. Figure 4 shows the device with the catheter 20 as an essential component, which is designed as a flat body and is enveloped by the gas-permeable membrane 60 at least on the flat sides. The flat body has meandering channels 100 through which the carrier medium is conducted. The catheter has an inlet 30 at the lower left end for supplying the CO2-absorbing carrier medium and an outlet at the lower right end for removing the CO2-absorbing carrier medium after it has absorbed CO2 from the intestinal environment. Figure 5 shows a cross-sectional view of an embodiment of a catheter 20 according to the invention, in which the gas-permeable membrane 60 forms an elongated bag-shaped hollow body and the membrane is in contact with the carrier medium located in the lumen 70 with a first side 90, and a second side 80 of the membrane is in contact with the intestinal environment, thereby allowing the diffusion of gas from the intestinal tract into the CO2-absorbing carrier medium located in the lumen. The catheter is fluidically connected at the distal lower end to a first supply tube 110, which has a proximal inlet 30 located at the upper end of the catheter for supplying the CO2-absorbing carrier medium. The catheter is also connected to a second discharge tube 120 at the distal lower end, which has a distal outlet 40 in the catheter, i.e., located at the lower end, for removing the CO2-absorbing carrier medium after it has absorbed CO2 from the intestinal environment. Figure 6 shows a schematic representation of the therapeutic application of the catheter shown in Figure 5. After rectal insertion, the catheter is positioned in the colon and rectum 130 and is connected via the supply tube 110 to a pump with a reservoir for the CO2-absorbing carrier medium (not shown). The catheter is also connected via the discharge tube 120 to a disposal container as a collection container (not shown). During therapeutic use, the pump transports the CO2-absorbing carrier medium via the supply tube 110 into the catheter, where it enters the catheter at the proximal inlet and absorbs carbon dioxide via the membrane as it flows through the membrane bag. The CO2-enriched carrier medium leaves the catheter at the proximal end via the outlet and is disposed of in the collection container via the discharge hose 120. List of reference symbols Device Catheter Inlet Outlet Carrier medium Gas-permeable membrane Gas-permeable hollow fiber membrane Lumen Outer surface of the membrane - contact with intestinal environment Inside of the membrane - contact with carrier medium Meandering channels Supply hose Drain hose Large intestine and rectum

Claims

1. Device for enteral absorption of CO2, comprising a catheter for use in the intestinaltract,wherein the catheter comprises5 -   an inlet and -  an outlet for a CO2 -absorbing carrier medium, and -  a gas-permeable membrane, wherein o the membrane defines a lumen for receiving the CO2 -absorbing carrier medium, 10 o wherein a first, inner side of the membrane faces the lumen so that it is in contact with the carrier medium when the lumen is filled with the CO2-absorbing carrier medium, and o a second, outer side of the membrane faces an environment so that, when positioned in an intestine, it is in contact with the intestinal 15 environment,o wherein the membrane has gas permeability from the outer side to the inner side such that when positioned in the intestinal environment, the membrane allows diffusion of gas from the intestinal tract into the CO2-absorbing carrier medium20          and wherein the catheter is filled with the CO2-absorbing carrier medium,wherein the CO2-absorbing carrier medium is a liquid in which a CO2-absorbing substance is dispersed, andwherein the inlet and an outlet are two separate access points.

2. Device according to claim 1, characterized in that the gas-permeable membrane25          is impermeable to water and / or has a molecular weight cutoff (MWCO) of less than200 Daltons.2024372605   15 Jun 20263.     Device according to claim 1 or 2, characterized in that the CO2-absorbingsubstance comprises an inorganic hydroxide compound, which is selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, and magnesium hydroxide or mixtures thereof.5   4.     Device according to one of the preceding claims, characterized in that the gas-permeable membrane comprises a polymer selected from the group consisting of poly(organo)siloxane, polyethylene such as high-density polyethylene (HDPE) or low-density polyethylene (LDPE), polypropylene, thermoplastic polyurethane, polyester; polybutylene succinate; polybutylene adipate terephthalate (PBAT),10          polyethersulfone (PES), polyarylethersulfone, polyacrylethersulfone (PAES),polyvinylpyrrolidone (PVP), polymethyl methacrylate (PMMA), polyamide (PA), polyacrylonitrile (PAN), ethylene vinyl alcohol copolymer (EVOH), polytetrafluoroethylene, cellulose, cellulose triacetate (CTA), polymethyl pentene (PMP), cellulose nitrate, and silicone-coated polypropylene and mixtures thereof.15   5.     Device according to one of the preceding claims, characterized in that for providinga sliding catheter the gas-permeable membrane has one of the following properties: (a) the membrane consists of or comprises a lubricious polymer;(b) the membrane has a coating of a lubricating substance, such as petroleum jelly, water-soluble lubricating gel, PTFE, or poly(organo)siloxane; or20           (c) the membrane is provided with a lubricant for rectal insertion.

6. Device according to one of the preceding claims, characterized in that the totalsurface area of the gas-permeable membrane, which forms the contact surface for gas absorption or gas exchange, is at least 0.1 m2.

7. Device according to one of the preceding claims, characterized in that the gas-25         permeable membrane is designed as a hollow fiber membrane, wherein the innersurface of the hollow fiber membrane is in contact with the carrier medium and the outer surface of the hollow fiber membrane is in contact with the intestinal tract.

8. Device according to claim 7, characterized in that the catheter has a plurality ofhollow fibers, wherein the fibers are each connected with a first connection to the30           inlet and a second connection to the outlet.

9. Device according to any one of claims 1 to 6, characterized in that the gas-permeable membrane is designed as an elongated hollow body with a proximal and2024372605   15 Jun 2026a distal end, wherein the inner surface of the membrane is in contact with the carrier medium and an outer surface of the membrane is in contact with the intestinal tract.

10. Device according to claim 9, characterized in that in the elongated hollow body, the inlet is located at the distal end and the outlet is located at the proximal end, so5           that they define a flow path.

11. Device according to one of claims 9 or 10, characterized in that the elongated hollow body has an axial length of 3 to 100 cm.

12. Device according to one of claims 1 to 6 or 10 to 11, characterized in that the catheter designed as an elongated hollow body has one of the following shapes:10(a) a tubular hollow body with a circular or oval cross-section; wherein this tubular hollow body has an internal continuous channel for transporting a digestive pulp;(b)   a hollow body with longitudinal, essentially parallel fold or crease lines;(c)   a tubular hollow body with an inner tube surrounded by an outer tube, wherein15                 the two tubes have such different diameters that a substantially cylindricalpassage is formed between the tubes, through which the CO2-absorbing carrier medium can flow longitudinally;(d) a flat body with two outer membrane surfaces which, together with intermediate walls, form channels for the CO2-absorbing carrier medium, so 20                that the membrane surfaces are in contact with the intestinal environment andthe membrane is designed in such a way that it allows the diffusion of gas from the intestinal environment into the CO2-absorbing carrier medium circulating in the channels; or(e) a tubular hollow body that is helically wound to form a helix, wherein the helix25                 has an inner channel for transporting the digestive pulp.

13. Device according to one of the preceding claims, characterized in that the catheter is movably designed in one of the following forms to increase gas diffusion:(a) Rotation about the longitudinal axis;(b) alternating twisting of a hollow fiber bundle;2024372605   15 Jun 2026(c) pulsating volume change.

14. Device according to one of the preceding claims, characterized in that the catheter is designed to be expandable or dilatable so that it can undergo a cross-sectional enlargement after insertion into the intestinal tract.5   15. Device according to one of the preceding claims, characterized in that the inlet andoutlet are connected as a double-lumen tube with the gas-permeable membrane.

16. Device according to one of the preceding claims, characterized in that the CO2-absorbing carrier medium is enriched with oxygen before entering the catheter, thus allowing CO2 / O2 gas exchange in the intestinal tract.10   17. Device according to one of the preceding claims, characterized in that the catheteradditionally has one or more sensors selected from the group consisting of a CO2 sensor, an oxygen sensor, and a pH sensor.

18. Device according to one of the preceding claims, characterized in that the catheter additionally has a flushing tube with an outlet opening into the intestinal tract, 15          wherein the outlet opening is located at the proximal end or near the proximal end.

19. Device according to one of the preceding claims, characterized in that the catheter is designed as a disposable article.

20. Device according to one of the preceding claims, characterized in that the inlet is fluidly connected to a container for the CO2-absorbing carrier medium and to a pump20          for transporting the CO2-absorbing carrier medium from the container to the catheter,and the outlet is connected to a collection container for receiving the CO2-absorbing carrier medium.

21. Device according to one of the preceding claims, characterized in that the catheter is connected to an extracorporeal exchange device for forming a circulation system, 25          wherein the circulation system has a pump for conveying the carrier medium.

22. Device according to one of claims 20 or 21, characterized in that the pump is selected from the group consisting of a hose pump, a pulsation pump, a centrifugal pump, a diaphragm pump, and a piston pump.2024372605   15 Jun 202623. Device according to one of claims 20 to 22, characterized in that the device is additionally equipped with a control or regulating device which controls or regulates the supply or circulation of the CO2-absorbing carrier medium in the catheter.

24. Device according to one of the preceding claims, characterized in that the device 5           additionally has an insertion aid for rectal insertion of the catheter into the intestinaltract, which is one of the following:(a) a sleeve for receiving the catheter in the cavity of the sleeve;(b) a guide wire that is permanently or reversibly detachably connected to the catheter; or10          (c) a receptacle for an endoscope.

25. Kit comprising a device according to one of claims 20 to 24 and a tube connected to the catheter and the pump or exchange device for transporting a carrier fluid between the catheter and the pump or exchange device.

26. Device according to claims 1 to 24 or a kit according to claim 25 for use in the 15          prophylaxis or treatment of diseases of the respiratory system such as acute orchronic respiratory diseases or lung diseases; of cardiovascular diseases, metabolic disorders such as ketoacidosis, or of infectious diseases or respiratory disorders following severe courses of disease.27.202530Device for use according to claim 26, characterized in that the disease of the respiratory system is selected from the list consisting of: (a) chronic obstructive pulmonary disease;(b)   asthma;(c)   cystic fibrosis;(d)   acute lung failure;(e)   hypercapnia;(f)   Pneumonia;(g)  Lung carcinoma;(h)   Pulmonary fibrosis;(i) Respiratory diseases following medical procedures according to ICD-10 J95;(j)    respiratory insufficiency according to ICD-10 J96;(k)   other respiratory diseases according to ICD-10 J97;(l) Respiratory diseases in diseases classified elsewhere according to ICD-10,J99;2024372605   15 Jun 2026(m) immature lungs.

28. Device according to claims 1 to 24 or kit according to claim 25 for use in inducing hypocapnia in a patient.

29. Device for use according to any of claims 26 to 28, characterized in that the use5          comprises the following steps:(a) optional chemical or mechanical partial degradation of the mucosal barrier of the intestine to increase gas diffusion through the intestinal epithelium and / or emptying of the intestine by means of a gravity enema;(b) rectal insertion of a catheter according to one of claims 1 to 24 for positioning in10               the lumen of the intestinal tract;(c) extracorporeal supply of CO2-absorbing carrier medium into the lumen of the catheter for absorption of CO2 from the intestinal tract;(d) optional circulation of the CO2-absorbing carrier medium in a circulation system with an extracorporeal exchange device until the carrier medium, as a spent15             carrier medium, has a predetermined CO2 content;(e) Discharge of the spent carrier medium from the catheter into a collection container.

30. Device for use according to claim 29, characterized in that in step (c) and / or step (d), the CO2-absorbing carrier medium is passed through the catheter at a flow rate 20           of 1 to 5 L / min.

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