LOCKING ELEMENT

Description

[0001] The invention relates to a barrier element for suppressing the ingress and accumulation of respiratory air in the stomach during artificial, non-invasive ventilation, in particular nasal CPAP ventilation.

[0002] The medical background for the invention is the need to treat respiratory distress syndrome in newborns. This respiratory distress syndrome, also called surfactant deficiency syndrome, occurs predominantly in premature infants, and the more premature the infants are, the more frequent and severe the symptoms. Surfactant is necessary for normal lung function. Surfactant is a surface-active substance that reduces and modulates the surface tension of the alveoli. It is produced by type II pneumocytes and forms a film over the surface of the alveoli. Surfactant enables the lungs to fill with air at normal pressures, prevents end-expiratory collapse of the alveoli, and thus maintains a sufficient functional residual volume. Due to the modulation of surface tension, surfactant also prevents an abnormal distribution of air within the lungs, which would otherwise exhibit areas of collapsed and overinflated sections. Surfactant is generally not administered until the 34th week of life.Surfactant is sufficiently produced by the 14th week of pregnancy. Therefore, premature infants are more frequently affected by respiratory distress syndrome due to surfactant deficiency. However, more mature infants can also develop the condition through secondary inactivation.

[0003] Treatment of respiratory distress syndrome (RRS) typically requires some form of ventilation or respiratory support. A distinction is made between invasive and non-invasive ventilation methods. In invasive procedures, a tube is usually inserted endotracheally into the trachea through the mouth or nose. Gas exchange is facilitated by a connected ventilator, which, like a medical air pump, delivers an air-oxygen mixture into the lungs under positive pressure. Exhalation occurs either passively or, as with high-frequency ventilation, actively through the application of negative pressure. In addition to achieving sufficient gas exchange, it is crucial to apply continuous distending pressure (positive end-expiratory pressure, PEEP). This keeps the alveoli open at the end of expiration and ensures the functional residual volume that is essential for survival.This ensures that even in premature infants, the exchange of oxygen and carbon dioxide takes place during the relatively longer expiration. However, for several years now, it has also been known that invasive ventilation is not always necessary, and that non-invasive respiratory support is perfectly sufficient for many children. In non-invasive ventilation, the air-oxygen mixture is delivered at a specific pressure into the nasopharynx via a nasal cannula or mask. If spontaneous breathing is maintained, this pressure and gas flow continue intrapulmonarily, facilitating inspiration and the maintenance of functional residual volume. This form of ventilation is called CPAP ("continuous positive airway pressure"), and the most important parameter here is, once again, the previously mentioned PEEP. Many studies have now shown that non-invasive CPAP ventilation is equivalent to, and in some aspects superior to, invasive ventilation.In industrialized countries, more than 50% of very premature infants are now treated exclusively with CPAP. However, in practice, CPAP use can lead to side effects that may be clinically significant or limiting. In very premature infants, the development of a so-called "CPAP belly" poses a problem.

[0004] Air enters the pharynx through both the nose and mouth. The pharynx contains not only the trachea, into which the air is meant to pass, but also the esophageal inlet. With non-invasive CPAP ventilation using a mask, a problem arises: the pressurized air passes not only through the trachea into the lungs but also through the esophagus into the stomach. This causes the stomach to continuously inflate, which is undesirable. In particular, an inflated stomach presses against the lungs from below, reducing functional residual capacity. This also makes inhalation and exhalation more difficult. Furthermore, this abnormal air delivery can lead to intolerances of enterally administered nutrition, affecting gastrointestinal function.This can lead to a reduction in nutritional intake, which in turn requires longer-lasting parenteral nutrition and can therefore result not only in insufficient growth but also in a higher sepsis rate. Overall, the unintentional introduction of air into the gastrointestinal tract via CPAP is a problem of significant clinical importance.

[0005] From WO2017 / 036846, a gastric tube with a cuff positioned in the esophagus is known. This gastric tube has a suction section located in the patient's pharynx to remove saliva or secretions and prevent them from entering the trachea. The saliva is therefore drained via the suction section before it reaches the trachea. However, if a patient is being ventilated with positive pressure through the pharynx, a suction section located in the pharynx is completely unsuitable.

[0006] Based on this, the invention aims to create a barrier element that effectively prevents pressurized breathing air from entering the stomach from the nasal and pharyngeal cavity, without hindering the patient's ability to eat and at the same time preventing the patient from choking on saliva accumulated in the esophagus.

[0007] The locking element with the features of claim 1 solves this problem in an inventive manner. The dependent claims describe partly advantageous and partly inventive further developments of this invention.

[0008] The invention is based on the fundamental principle of sealing the esophagus to prevent the entry of inhaled air with PEEP overpressure into the stomach. To still allow the patient to be fed, the sealing element consists of a gastric tube, formed from a thin tube, that passes through the esophagus. This gastric tube is flanked on its outer surface by an inflatable cuff. Such a cuff is also referred to as a "cuff." When inflated, the cuff forms a balloon-shaped plug in the esophagus. In its inflated state, the balloon-shaped plug completely seals the esophagus, its outer wall resting against the inner walls of the esophagus. Due to the compressibility of air, the balloon-shaped cuff can conform to the inner walls of the esophagus.

[0009] As already explained, the tube-shaped gastric tube is guided through the cuff to feed the patient.

[0010] However, this arrangement has the problem that the inflated cuff not only prevents the passage of the PEEP-pressurized air but also the normal flow of saliva from the throat, through the esophagus, and into the stomach. This obstructed saliva flow to the stomach then causes a backup of saliva above the inflated cuff. In extreme cases, so much saliva accumulates that it flows back from the inflated cuff into the throat and, in extreme cases, enters the trachea.

[0011] To prevent such a backflow of saliva, the inventive blocking element includes a device for removing saliva entering the esophagus. With such a device, the saliva accumulating in the esophagus can be removed either continuously or in certain cycles.

[0012] According to the invention, the inventive locking element includes a further suction probe as a device for removing the saliva. This suction probe, like the gastric tube, is tubular in shape. Its free end terminates above the cuff. In the region of its free end located above the cuff, the suction probe has a plurality of suction openings in its tubular sheath to collect and remove the saliva that is retained by the cuff. The plurality of suction openings also prevents the outer wall of the suction probe from adhering to or becoming suctioned to the inner wall of the esophagus.

[0013] An additional spacer or cage can be positioned in the area of ​​these suction openings, its outer wall resting against the inner wall of the esophagus. This spacer or cage keeps the esophageal lining and the suction openings at a distance, ensuring the suction openings remain unobstructed and functional.

[0014] In one embodiment of this device, the inflatable cuff, positioned in the esophagus and sealing it when inflated, is designed to intermittently fill with air and deflate at specific intervals. The balloon-like cuff is thus filled with air at predefined intervals and then deflated again. The deflation intervals are quite short compared to the inflation intervals. However, they are sufficient to allow the collected saliva to flow past the outer walls of the cuff and directly into the stomach. When the cuff is deflated, the PEEP pressure effectively forces the saliva past the outer walls of the cuff and into the stomach.

[0015] In another embodiment of the invention, the two aforementioned devices for saliva removal are combined. In addition to the cuff, which is intermittently filled and emptied with air, a suction probe is provided in this embodiment. The following description refers both to each embodiment on its own and to the combined device.

[0016] In an advantageous embodiment of the invention, the cuff is arranged in the region of the cardia at the end of the esophagus. In this embodiment, both the gastric tube and the suction tube completely penetrate the esophagus. The balloon-like cuff thus seals the stomach at its cardia. This arrangement has the advantage that any residual accumulation of saliva in the area of ​​the cuff occurs away from the pharynx, so that unwanted entry of saliva into the trachea is virtually impossible.

[0017] In another alternative embodiment, the cuff is positioned in the upper mediastinum of the esophagus. This ensures that the suction probe does not draw saliva from the pharynx or from the cervical portion of the esophagus located above the mediastinum. The pharynx and cervical portion of the esophagus should ideally be supplied with saliva to prevent the pharynx from drying out. Drying of the pharynx could lead to involuntary coughing fits or other undesirable reactions in the patient, especially a newborn.

[0018] Furthermore, the preferred arrangement of the cuff in the upper mediastinum has the advantage that the suction path through the suction probe is comparatively short.

[0019] Alternatively, the cuff can also be positioned in the posterior mediastinum below the superior mediastinum. This arrangement avoids excessively long suction paths for the suction probe and ensures sufficient distance between the cuff and the pharynx.

[0020] A collection vessel is provided at the end of the suction tube furthest from the free end. The aspirated saliva is temporarily stored in this vessel and then introduced into the gastric tube via a multi-way stopcock connected to the tube, from where it is delivered into the stomach. This introduction of the collected saliva has the advantage that almost the entire amount of saliva produced by the body is available for the digestive process in the stomach.

[0021] The invention is explained in more detail with reference to the embodiment shown in the drawing:

[0022] The diagram schematically depicts a section of the esophagus 1. The inflated cuff 2 lies within the esophagus 1. The balloon-like cuff 2 rests with its outer walls against the inner walls of the esophagus 1, thus sealing it off. The gastric tube 3 is guided through the cuff 2. The gastric tube 3 terminates in the schematically indicated stomach 4. The cardia 5 is also indicated in the diagram. The diagram thus shows a cuff 2 located in the posterior mediastinum.

[0023] The free end of the suction probe 6 terminates above the cuff 2. Suction openings 7 are incorporated into the hose sheath of the suction probe 6 in the area of ​​this free end. Saliva that has accumulated at the cuff 2 can be suctioned out via these suction openings 7 and another opening in the free end of the suction probe 6.

[0024] In this embodiment, the aspirated saliva is introduced into the collection vessel 8 via the suction probe 6. From the collection vessel 8, the saliva collected in the vessel 8 can be introduced into the gastric tube 3 via a multi-way stopcock 9. Through the gastric tube 3, the saliva can be introduced through the cuff 2 into the stomach 4.

[0025] The drawing shows a combined supply and exhaust air duct 10. At its end, the supply and exhaust air duct 10 is connected to a compressor 11. The compressor 11 supplies air to inflate the cuff 2. A valve 12, also located in the supply and exhaust air duct, allows the air collected in the cuff 2 to be released from the system. By alternately activating the compressor 11 and the valve 12, intermittent operation of the cuff 2 can be achieved. The cuff 2 is inflated to close off the esophagus 1. The flow of saliva through the esophagus 1 into the stomach 4 is then blocked or inhibited. When the air is released from the cuff 2 through the valve 12, saliva can flow past the outer walls of the cuff 2 through the esophagus 1 and into the stomach 4.

[0026] In this way, it is effectively prevented from penetrating the trachea, which runs alongside the esophagus 1 and is not shown in the drawings. Reference symbol list

[0027] 1 Esophagus 2 Cuff 3 Gastric tube 4 Stomach 5 Cardia 6 Suction tube 7 Suction port 8 Collection vessel 9 Multi-way stopcock 10 Intake and exhaust line 11 Compressor 12 Valve Summary

Claims

1. Blocking element for suppressing the ingress and accumulation of respiratory air in the stomach (4), with a gastric probe (3) formed by a tube which extends through the oesophagus (1), with a cuff (2) which can be inflated with air and which closes the oesophagus (1) in the inflated state, and with a device for removing saliva penetrating into the oesophagus (1), characterized in that the device comprises a suction probe (6) for saliva penetrating into the oesophagus (1) and constructed as a suction tube which protrudes into the oesophagus (1) and with its free end terminating at the cuff (2), with suction openings (7) in the regions of the tube sheath located in the oesophagus (1), and characterized by a collecting vessel (8) for the saliva aspirated with the suction probe (6) at the probe outlet facing away from the free end of the suction probe (6) and by a selector valve (9) which is conductively connected to the gastric probe (3) for introducing the saliva collected in the collecting vessel (8) into the stomach (4) through the gastric probe (3).

2. Blocking element as claimed in claim 1, characterized in that the cuff (2) is constructed to be intermittently emptied and subsequently refilled in order to serve as a combined device for removing saliva penetrating into the oesophagus.

3. System as claimed in claim 1 or claim 2, characterized in that the cuff (2) is disposed in the region of the cardia (5) at the end of the oesophagus (1).

4. System as claimed in claim 1, claim 2 or claim 3, characterized in that the cuff (2) is disposed in the superior mediastinum.