MXPA05012239A - Tracheal ventilation device - Google Patents

Abstract

Tracheal ventilation device, in particular tracheal tube, which seals the trachea in as air-tight a manner as possible. Said device comprises a cuff that blocks the trachea below the glottis and is traversed by a ventilation cannula. The cuff is larger in its filled, freely displaceable, unrestricted state than in its filled state positioned in the trachea. The cuff consists of a flexible soft film material and lies against the trachea by means of its folds. The device (1) is adapted to the morphology of a child's larynx and is available in finely graded sizes.

Description

TRAQUEAL BREATHING DEVICE The invention relates to a tracheal breathing device, in particular to a tracheal tube, which, for a pediatric patient to breathe, closes the trache as compatible as possible with the tissue, with a bubble cuff blocking the trachea by below the glottis, through which passes a breathing cannula, consisting of the bubble cuff of a flexible material of soft leaves and in a full state, of unfolding free without delimitation, is greater than in full state being placed in the trachea and the cuff bubble with its folds being in contact with the trachea. In the German patent DE 198 45 415 Al a tracheal breathing device is described in which the bubble cuff (cuff) consists of a flexible material of soft sheets of smaller wall thickness. A bubble cuff of this type is well suited for numerous applications in intubation and mechanical breathing of patients. Also German Patent DE 196 38 935 Cl describes a similar tracheal breathing device, which can be used in general cases. An area that remains problematic for the use of cuff breathing tubes is the tracheal intubation of newborns and children. Thus, breathing tubes with cuff for children are considered by patients as especially risky, since the filling of the cuff bubble always causes damage to the trachea and larynx. In general, the lesions are caused by the direct action of cuff filling pressure on the blood supply of the supplying vessels in the tissues in contact with the cuff. The reduced supply, infarction and death of the tissue and structures in question can lead to extremely serious life-long affectations or the death of the child. In this context, breathing tubes with so-called low volume / high pressure cuffs are especially problematic. In its free unfolding state, its bubble cuff has a smaller diameter than that of the trachea to be closed. Therefore, for tracheal sealing, the cuff wall should usually expand under elevated pressure. The expansion pressures that then act on the adjacent tissue always produce a complete interruption of the supply of the vessels and, even after a short time, the degeneration of the structures in contact with the cuff. In the tracheal tubes that are currently used, in the conformation of the cuff bubble, preferably thin sheets are used which, in their dimensions, are configured with residual volume, called high volume / low pressure cuffs. In these tubes, the bubble cuff has a diameter considerably greater than the diameter of the trachea to be intubated in the state of free, untubed splitting (with a sufficient safety tolerance of, typically, approximately 50%). Due to the fold of the cuff envelope that is generated by filling in the trachea (block) with a cuff like the previous one, of larger diameter, in the tracheal seal with cuffs of great volume / low pressure, an expansion of the wrap of the cuff under pressure values of risk for the fabric, as usual with the cuff bubbles of low volume / high pressure. Therefore, in the tracheal seal with high volume / low pressure cuffs, the bubble wrap of the bubble, produced consciously, allows filling pressure values compatible with perfusion and, in the end, guarantees for the user that The barometric pressure measured in the cuff bubble largely matches the pressure transferred to the tissue transmurally. In adult intubation, with the use of this type of large-volume cuff bubbles with cuff envelope deployed in situ, serious tracheal or laryngeal damage could be reduced to a very small extent even in the case of long-term intubation. However, in breathing tubes for intubation of premature babies and newborns and children and young children, the use of the principle of high volume / low pressure accredited for adults remains problematic. With the current cuff materials, such as PVC, latex and silicone, it is not possible to manufacture cuff bubbles of residual volume that fit and meet the special requirements for the intubation of children's respiratory tract and that behave in a manner reliable atraumatic mainly also in the case of long-term intubation. Thus, using conventional materials in principle would be technically feasible a geometric conformation of the ball necessary to ensure low pressure behavior, however, due to the specific properties of the material, these cuff bubbles are inadequate for pediatric breathing. The corresponding PVC cuff bubbles are usually manufactured with wall thicknesses of 50 to 100 micrometers, or, in the case of silicone and latex, of 100 to 200 micrometers. The PVC processing limit for obtaining cuff bubbles suitable for respiration (usually by extrusion molding and in-line blow molding) is located at a critical lower wall thickness of about 40 to 50 microns. If the PVC cuffs are made with considerably thinner walls, there is a risk of a focal bulging of the cuff wall (herniation), even under low pressure loads (from 20 to 30 mbar usual in tracheal intubation). ), which, in the most unfavorable case, can produce a displacement of the distal opening of the breathing tube due to the hernia that is formed and, thus, the dreaded valve effect on respiration. The same applies in the processing of latex to obtain balloons with residual volume of less than 100 micrometers of wall thickness. Since the latex-based cuff bubbles are produced by the immersion process, the manufacture of thin-walled balloons of less than 100 microns is, on the one hand, technically difficult, and on the other, these balloons often show a insufficient mechanical resistance under breathing conditions. Also, due to their potential allergenicity, latex components are currently considered inadequate. Silicone balloons are also produced by the immersion process and, when they present a geometry of residual characteristics in the range of wall thickness less than 100 micrometers, they can only be used for the same reasons under certain conditions in breathing tubes for children . The minimum wall thicknesses mentioned for PVC and silicone, when forming a cuff with sufficiently residual characteristics or a cuff of suitable geometry, always produce a mechanical, or a stiffness of the bubble cuff that largely excludes it from being used in a atraumatic in children's tracheal tubes. By correspondingly making a cuff with conventional materials, the special cuff bubble design criteria necessary for atraumatic infant intubation, such as small spokes in the heel of the cuff, residual diameters, bubble-like conformation of the cuff bubble with a small length In total of the cylinder (cuff), they involve multiple risks for the pediatric patient. Thus, a correspondingly shaped cuff of conventional materials, with dimensions suitable for high volume / low pressure characteristics and cylindrical shape, always appears prominent in the evacuated state, or, unlocked, rests on the tube stem when folded and , therefore, it involves a mechanical obstacle both in the intubation (introduction of the tube in the trachea) and in the extubation (extraction of the tube). The consequences can be irritations that trigger a reflex (laryngospasm) of the larynx and the vocal cords (glottis) due to the cuffed cuff envelope that rests in the stem fold. In many cases also, the conventional cuffs form in the evacuated state folds of sharp edges oriented towards the mucosa, which can produce both in the intubation and in the extubation of the cuff cutting lesions in the mucosa or even cutting penetrations of deeper structures. In children's cuffs of conventional construction, due to the wall thickness of the material and the resulting rigidity, in the locked tracheal state in many cases a homogeneous pressure distribution of the cuff bubble in the tracheal mucosa is not guaranteed. In the formation of the in situ crease, the rigidity of the cuff envelope often results in crushing and congestion (bleeding) of the mucosa in the wedge-shaped entrance area of the cuff wall cuff oriented to the cuff wall. tracheal wall In addition, in many cases transmural action pressure maxima are formed within the sections of the balloon, which have a convex shape with respect to the trachea between the fold inversion zones, and can produce critical focal pressure values, considerably greater than the filling pressure itself of the cuff, on the adjacent tissue with the consequence of the corresponding reduction of blood circulation in the adjacent mucosa (infarction). The filling pressures required for the in situ deployment of this type of conventional construction cuffs are already close to the critical values of the blood supply. Due to the lack of softness of the cuff envelope, the fold pattern in the trachea of a bubble cuff with the corresponding shape and conventional materials is usually coarse and only inefficient in its sealing performance against gas in the direction pulmonary (tracheo-bronchial) and secretion in the direction of the pharynx. This is problematic mainly when the tracheo-bronchial breathing pressure acting on the cuff briefly exceeds the filling pressure thereof (peak pressures). To achieve a certain sealing, the conventional construction cuff, formed with residual volume, must usually be filled with critical pressures of limit values, or it exceeds them considerably. Therefore, at present, children's breathing tubes with bubble cuff based on conventional materials can only be made with an insufficient and potentially traumatic operation. Due to the difficult or impossible adaptation of conventional cuff materials with a low pressure geometry or conformation thereof, the cuff bubbles of many children's breathing tubes are currently formed in a non-residual or not sufficiently residual way ( cuff of low volume / high pressure). In other cases, to reduce the ridge due to rigidity, with irritating or traumatizing effects on the rod in the evacuated state, differs in length from the length expansion of an anatomically and physiologically compatible cuff. To avoid a flange such as this, which involves a particular stiffness mainly in the area of the heel of the cuff, an approximately spindle shape is often given as an outlet. Although it has a sufficiently residual diameter in its central section, given the conditions, the spindle-shaped expansion section which is located proximally and distally of the central portion always produces a potentially traumatizing overhang of the cuff. In many cases, the proximal portion of these cuffs arrives in situ to the subglottic larynx especially sensitive to pressure, which is located below the vocal cords (glottis). In the case of inadequate intubation (too high placement of the cuff in the trachea), or, if inadequately constructed tracheal tubes (excessive length cuff) are used, injuries occur in this area of the respiratory tract of children. more serious and complicated. Therefore, in the design of pediatric breathing tubes with cuff, the subglottic larynx should be considered as a particular risk source. The high total risk of using children's tubes with conventional cuffs means that the vast majority of users still today totally renounce the cuff as a sealing element. In this case, the child breathing tubes that do not have a sealing cuff are provided with an external diameter such that the sealing of the respiratory tract against the positive breathing pressure is carried out essentially by the rod of the tube itself. In the foregoing, the diameter of the latter is chosen in such a way that it largely agrees with the diameter of the physiological anatomical narrowing of the respiratory tract of children, the so-called cricoid cartilage. Usually, the user tolerates a small air leak, or looks for it as a safety factor to avoid risky peak pressures in the lungs of children. However, the child tracheal tube without bubble cuff of obturation is in many cases disadvantageous in breathing. Problems are mainly surgical interventions that require a very constant supply of narcosis (volume of minutes of stable breathing), or constant values of the gases in the blood, as it may be the case, for example, in intraoperative cardio-surgical breathing or neurosurgical In the course of intensive breathing spontaneous changes of support of the child can occur with very variable air leaks and, in the case of high vigilance, make stable breathing impossible. In interventions with heavy bleeding in the head area or in the intraoperative antiseptic rinse of the oral and pharyngeal cavity, due to insufficient filling of a tube without a cuff in some cases a cuffed tube is also preferred. Otherwise, the blood, rinses and secretions of the pharynx arrive largely unimpeded to the distal airways and can considerably complicate the course of breathing as well as the course during and after extubation. The invention is based on the task of providing a tracheal tube with a cuff bubble of tracheal filling, which is suitable for long-term use and in a manner compatible with the respiratory tract in children and which prevents or decisively reduces the known trauma risks for the usual children's tracheal tubes to date, equipped with a cuff. The achievement of the proposed task is achieved with the features of claim 1. In a tracheal breathing device of the type cited at the beginning, the tracheal tube of embodiment according to the invention is endowed and manufactured for a respective age class and of development of the child's breathing physiology, with a cuff that is characterized by a specific combination of cuff wall material and thickness, as well as by the dimensions and placement in the tube stem. The tracheal tube according to the invention guarantees an atraumatic alternative, safe in its application, for the principle of obturation of the airways preferred until now in the intubation of children, at the height of the physiological narrowing of the respiratory tract ( cricoid cartilage) by means of a rod of adapted tube in its diameter. Sealing against breathing gas or secretions that accumulate above the cricoid cartilage is done instead of the above by a bubble cuff placed tracheally. In the tracheal tube according to the invention, the bubble cuff is ideally located in the region of the transition from the third distal to the middle of the trachea and there, thanks to its particular characteristics of material and dimensions, ensures a seal of the trachea with fill pressure values of the cuff (5 to 15 mbar) that are clearly below the pressure values of the tissue blood flow (30 to 35 mbar). The tube according to the invention therefore avoids, with great probability, the lesions in the adjacent mucosa due to cuff pressure (crushing, infarction), as is known to be problematic in conventional cuff breathing tubes with cuffs., not only in the area of the trachea, but also in the zone of subglottic and glottic larynx that is especially problematic in terms of late consequences.

Thanks to the embodiment with micro thin wall of the bubble cuff, the tube according to the invention allows an evacuation of the cuff almost free of flange and thus avoids irritations or even cutting injuries in the intubation and extubation. Furthermore, the tube according to the invention would be able to sufficiently seal against the secretions and reliably against the gas with a blockage in the proposed low pressure range (5 to 15 mbar). Guarantee a reliable air seal (self-sealing), among other things, with tracheo-bronchial action pressure values (peak and plateau pressures) that exceed the adjusted cuff filling pressure. The tube according to the invention is designed in such a way in its selection of material and in its specific dimensions, as in the choice of the size of the tube, which in the case of the breathing tubes is generally oriented according to the diameter of the tube. In this case, the user, starting from the magnitudes calculated with the usual formulas, can optionally be decided by the smaller diameter of the next rod, that is, 0.5 mm narrower. To achieve tracheal filling under standard breathing conditions (breathing pressure &cuff fill pressure) and cuff self-sealing against breathing pressures that exceed cuff filling pressure, also with optionally larger stem size small, the cuff filling pressures that do not affect the perfusion described above are sufficient. Through the optional choice of a smaller stem diameter, the potential traumatizing effect of a tube tube chosen too large can be reduced (relative movements with tissue damage between the cricoid cartilage and the rod, with the consequence of the risky swelling of the tube. irritated tissue), which offers the user additional security of use. The preferred sheet material of the bubble cuff is a polyurethane or a polyurethane compound. Alternatively, materials which, on the one hand, can be processed in the range of wall thickness according to the invention, and on the other hand, have a pressure-volume expansion mechanics in the intended filling pressure range. that agrees with that of polyurethane. The wall thickness of the sheet used is 0. 015 to 0.005 mm. A wall thickness less than or equal to 0.010 mm and greater than or equal to 0.005 mm is preferred. A wall thickness of approximately 0.007 mm has proven to be ideal for atraumatic sealing according to the invention. In the foregoing, the wall thicknesses within the balloon sheet are preferably formed in such a way that in the area of the heel that abuts the tube stem is wider than in the cylindrical section directly adjacent to the tracheal ucosity. The technical embodiment of the cuff according to the invention is illustrated below based on characteristic relationships of certain parameters that describe the cuff and its placement. For the corresponding description are used: the diameter of the free unfolding cuff, not placed in the trachea (D-CUFF), the lower radius (Rl) and the upper radius (R2) in the heel portion of the free unfolding cuff, not placed in the rod of the tube, the distance between the two points of transition from Rl to R2 (L2), the distance of the mounting points of the cuff on the rod of the tube (MD_MP), the distance of the tip of the tube and the proximal mount point of the cuff on the rod (SP_MP), the distance of the tip of the tube and the distal mounting point of the cuff on the rod (SP_MD), the internal diameter of the rod of the tube (ID), the distance of the tip of the tube to the glottal depth mark (SP_GM) The described magnitude relationships apply for children's tracheal tubes with internal rod diameters of 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5 and 7.0 mm. This distribution of magnitudes covers the age and development classes from newborns to the young adult of approximately 15 years. The diameters of the bubble cuff are staggered so that the diameter of the cuff (D_CUFF) goes from 8 to 22 mm. In order to ensure a tracheally compatible long-term trachea filling, which does not affect perfusion under standard breathing conditions, in addition to the appropriate choice of material and the realization of the same with the correct wall thickness, for the tube According to the invention, the following two relationships are decisive: a) The ratio of the cuff diameter (D-Cuff) to the distance of the cuff mounting point on the tube stem (MD_MP), whose projection of the hyperbolic curve is can describe in all magnitudes approximately with the straight function D_CUFF (mm) = 0.75 x MD_MP + 4.00. b) The ratio of the tip of the tube to the distal mounting point (SP_DM) to the internal diameter of the tube stem (ID), which is also represented hyperbolically and can be characterized approximately in all magnitudes with the straight function SP_DM (mm) = 2.36 x ID -0.86. In the dimensions of the tracheal tube according to the invention it is taken into account in particular that the axial expansion of the length of the cuff mounted on the rod, is chosen, on the one hand, as small as possible in order to maximize the distance between the proximal end of the cuff and glottis, or, the glottic positioning mark (reduction of the risk of traumatization of the subglottic larynx sensitive to pressure by a passage to the dislocated cuff glottis), but on the other side as large as it is necessary to achieve the sealing of the respiratory tract according to the invention, compatible with the trachea, with the described combination of material, wall thickness and other dimensions of the cuff. With the realization of the material, the dimensions and the positioning of the cuff on the rod according to the invention, the pressure in the bubble cuff is adjusted in such a way that in the filling interval of 5 to 20 mbar and, preferably, of 10 to 15 mbar, produce a reliable air seal, compatible with the mucosa, which remains effective even when the pressure generated in the distal airways (tracheo-bronchial) under the cuff briefly exceeds the filling pressure of the cuff , for example, in the plateau phase or peak pressure of a respiratory cycle. This behavior, known as self-sealing, is possible thanks to a specific conformation of the cuff. The diameter of the cuff is to such a residual extent (ie, greater than the diameter of the trachea to be sealed), which may cause an annular rim-like conformation extending proximally and distally of the filled cuff (between the rod) to occur in situ. of the tube and wall of the trachea) (see Figure 4a). If the breathing pressure exceeds the filling pressure of the cuff, the cuff's rim of distal convexity passes into the proximal concavity (see Figure 4b). Due to the reduced volume expansion behavior of the cuff envelope with the respiratory pressure values to be expected (usually <; 30 mbar), in this situation, in which the breathing pressure acting on the cuff goes to the filling pressure thereof, no significant deformation of the proximal flange of the cuff occurs. Rather, the forces that were provisionally generated in the cuff are transferred to the lateral wall (cylindrical portion) thereof, or to the trachea in direct contact with the lateral wall. The cuff sticks in its cylindrical portion to the tracheal wall with a force that agrees with the breathing pressure acting momentarily, which at a higher breathing pressure (20 to 30 mbar) always occurs with a gauge jump of the trachea in the area adjacent to the cuff. To achieve the self-sealing behavior in breathing situations in which the breathing pressure intermittently exceeds the cuff filling pressure, the tracheal tube according to the invention presented the combination of two additional characteristic relationships, which allow the inclined in situ conformation of its distal and proximal heel portion decisive for the self-obturation effect of the cuff. a) Ratio of the distance between the mounting points of the cuff (MD_MP) to the length of the cuff of the component of the free, not mounted, which is located in the ratio MD_MP = L2 - 2. b) Ratio of D_CUFF to the radius Rl (Rl describes the radius of the lower transition in the form of an arc from the rod of the tube to the heel of the cuff) characterized approximately by the ratio Rl (mm) = 0.19 x D_CUFF + 0.39. The micro-thin embodiment of the cuff envelope provides the cuff full with the necessary dynamics and the mechanical properties to adhere to the trachea in the shortest time, under changing pressure conditions acting on the cuff, in a self-sealing manner with change of shape , without being elastically deformed (for example, in the case of transient respiration pressure> cuff pressure), between the wall of the trachea and the cuff can escape breathing gas in large quantities. In the case of a cuff made in accordance with the invention, in the tracheal blocking state, neither tracheal mucosal entrapments occur in the cuff fold inversion area nor infarctions caused by local peak pressures in the region of the cuff. contact of cuff and mucosa. In the micro-thin balloon sheets, the wedge-shaped entrance area of the fold of the residual envelope of the cuff has such a small surface area, that it can hardly lodge tissue nor damage it by tightening between the folded sheet parts. Similarly, in cuff bubble sections that are located between the inversion zones, with the cuff blocked, no inhomogeneities are observed in the distribution of forces that act on the wall of the trachea, that is to say, there are no peaks of local pressures that possibly produce infarctions. In the same way, almost thanks to the micro-thin wall thicknesses of the cuff, the smoothness that results from its wrapping and the almost total tightness of the evacuated cuff, sharp cuts of the mucous membrane are excluded when inserting and removing the tube. Beyond the tracheal tubes, the design according to the invention of the cuff can also be applied to pediatric tracheostomy tubes. An exemplary embodiment of a tracheal tube with bubble cuff placed therein is shown in the accompanying drawings. They show: Figure 1, a tracheal tube in side view. Figure 2, the shape of a cuff bubble of free deployment, not assembled, in section. Figure 3, a bubble cuff mounted on the rod, in section.

Figure 4a, the placement of the tracheal tube in the trachea, in section. Figure 4b, the schematic representation of the self-sealing function. Figures 5a-d, the reproduction of graphic description of the relations of the parameters according to the invention. Figure 1 shows a tracheal tube 1 in view. The breathing cannula 2 has the bubble cuff 3. Through a line 4 arranged in the wall of the cannula 2, the bubble cuff 3 is inflated (blocked) and the introduced air is let out (unblocks). For this, line 4 carries the valve 5 at its end leaving the cannula 2. The tracheal tube 1 is formed in such a way in its selection and the arrangement of its components, that in all breathing situations that are to be expected A tracheal filling compatible with the tissue is guaranteed. In order to optimally fulfill this task, the tracheal tube 1 is made in several staggered sizes. The bubble cuff 3 preferably consists of polyurethane, for example, of the Pellethane 2363 material from Dow Chemical Inc. It is a polyurethane of high strength and chemical resistance. The wall thickness of the bubble cuff is 0.015 to 0.005 mm. Preferably, the wall thickness is made less than or equal to 0.010 mm. The wall thickness of the bubble cuff ideally amounts to approximately 0.007 mm. The volume expansion of the cuff envelope of the unfolded, unpulsed, unpressurized state, with the filling pressure being located slightly above the ambient pressure, at a filling pressure of approximately 30 mbar, is approximately 15%, but preferably not more than 10%. The bubble cuff 3 is individually shaped for the staggered sizes and fixed to the cannula 2 in a typical single position or manner. The selection of the material and the wall thickness of the bubble cuff 3, in combination with the respective geometric conformation thereof, allow the atraumatic obturation of the trachea according to the invention, the bubble cuff 3 being fitted to the trachea organically compatible, with a very low filling pressure, which does not affect the blood flow of the tissue. The cannula 2 (preferably PVC) is made with internal diameters (ID) of 3 to 7 mm (+/- 0.2 mm). The staggering of the sizes of the internal diameters is preferably carried out in steps of 0.5 mm. The external diameters of the cannula 2 conform to the ID internal diameters and ideally amount to 4.1 to 9.3 mm (+/- 0.2 mm). In Figure 2, the cuff bubble of free deployment, not yet mounted on the rod of the tube, is shown as a free component. In the slightly inflated state (slightly above the surrounding pressure) the following magnitudes are available in each tube size. The radial expansion of the freely unfurled bubble cuff 3 (D_CUFF) is 10 to 20 mm. The axial expansion of the cuff bubble is determined by the distance (L2) between the transition points of Rl and R2 in the heel of the distal and proximal cuff. L2 is 10 to 22 mm. Rl expresses the radius of the arc-shaped transition of the portion of the rod (S) of the bubble cuff to the heel thereof and ascends to 2.55 to 3.45 mm. R2 indicates the arc-shaped transition from the heel of the cluff (S) to the cylindrical portion (Z) adjacent to the tracheal wall. The variations of the magnitudes are explained in each case mainly by the variations due to the manufacture in the processing of the polymer or of the elastomer. Figure 3 shows the cuff mounted on the rod of the tube, in a schematic longitudinal section. The bubble cuff 3 is preferably fixed by adhesion or welding on the cannula 2 in the area of the rod portions (S) of the bubble cuff. MD describes the distal mounting point of the bubble cuff on the cannula. The point of assembly is defined by the point of transition of the portion of the rod (S) at the radius Rl, or, the location of said point in the cannula of tube 2. MP correspondingly describes the proximal mounting point of the bubble cuff. MD_MP designates the distance between the two mounting points on the cannula 2. MD_MP is 8 to 20 mm (+/- 1.5 mm). The variation width of the assembly magnitudes is mainly explained by variations in the assembly of the bubble cuff 3 on the cannula 2. Figure 4a shows the tracheal tube placed in the trachea. Cuff bubble 3 is placed in the transition zone of the tracheal third distal to the middle. The glottic marking (GM) on the rod of the tube (2) describes the correct placement of the tube compared to the orientation point that is normally used in the intubation, the vocal cords (SL). SG indicates the so-called subglottic larynx (subglottis), which is known as especially vulnerable to pressure. Therefore, in the area of the subglottic larynx, mechanical irritations of the tissue should be reduced as much as possible. Since with the changes of support or the spontaneous movements of the child it is possible that to some extent dislocations of the tube or the cuff to proximal bubble occur, the tracheal tube according to the invention integrates a safety zone (SB), or Well, place the cuff as far as possible from the subglottic larynx. In spite of the cuff bubble minimized in its length expansion, thanks to its specific shape and the composition of the material, the sealing properties of the tube according to the invention are guaranteed. In the tracheal block of the residual volume cuff, the envelope with residual dimensions of the bubble cuff is arranged in longitudinal projection folds. In addition, in its heel areas, the cuff forms annular ridges (R) that extend proximally and distally. Figure 4b describes the self-sealing mechanism of a cuff tracheal bubble according to the invention placed in breathing situations in which the breathing pressure briefly exceeds the fill pressure of the cuff. While the distal annular ridge (dR) goes from convex (Figure 4a) to concave (Figure 4b), the proximal ridge (pR) does not change in its (convex) orientation or in its shape (due to the low volume expansion of the wrap of the cuff). The development of the pressure that remains synchronous inside the cuff leads instead to a moderate bulging of the cylindrical portion of the cuff envelope towards the tracheal wall and is thus responsible for a sealing maintained to a great extent even in situations of peak pressure. Figure 5a describes the relationship of D-CUFF with respect to the distance between the mounting points MD_MP of the cuff on the rod of the tube. The central line (ideal) reproduces the approximate ratio of D CUFF = 0.75 x MD MP + 4.00 which applies for all tube size ranges (internal diameter of 3.0 to 7.0 mm). For tubes of sizes with an internal diameter of 3.0 to 3.5, D_CUFF is defined by a range of values whose upper limit is described by the line resulting from D__CUFF = 0.75 x MD_MP + 5.00, and whose lower limit is defined by the line D__CUFF = 0.75 x MD_MP + 3. 25. For pipes of size 4.0 to 5.5, for D_CUFF a corresponding range of values with the same upper limit D_CUFF = 0.75 x MD_MP + 5.20 and the lower limit D_CUFF = 0.75 x MD_MP + 2.50 results. In the case of tubes of sizes from 6.0 to 7. 0, C_CUFF results as a range of values between the upper limit D_CUFF = 0.75 x MD_MP + 5.50 and the lower limit D_CUFF = 0.75 x MD_MP + 2.50. In the above, for MD_MP a tolerance is assumed due to the assembly of approximately +/- 1.5 mm, which applies to all tube sizes. Figure 5b shows the ratio of the internal diameter of the rod ID and the distal mounting point SP_MD, which can be described approximately with the straight line (ideal) SP_DM = 2.36 x ID - 0.86 and applies to all tube sizes. For tubes of sizes with an ID of 3.0 to 3.5, SP_DM is defined in its upper limit by the line that results from SP_DM = 2.36 x ID - 0.11, at its lower limit by the line SP_DM = 2.36 x ID - 1.86. For pipes of size 4.0 to 5.5, the upper limit for SP_DM results from SP_DM = 2.36 x ID + 0.34, the lower limit of SP_DM = 2.36 x ID - 2.16. In the case of tubes of sizes 6.0 to 7.0, the upper limit is SP_DM = 2.36 x ID + 0.64 and the lower limit of SP_DM = 2.36 x ID - 2.46. Figure 5c describes the relationship between the distance of the mounting points of the cuff (MD_MP) with respect to the length of the cuff of the cuff component not assembled, freely deployed (L2). The ratio can be described approximately for all pipe sizes by MD_MP = L2 - 2. The upper limit of variation is equivalent for all the sizes to a line of MD_MP = L2 - 0.5, the lower of MD_MP = L2 - 3.5. Figure 5d reproduces the ratio of the radius Rl to the diameter D_CUFF for all tube sizes, with the approximation Rl = 0.19 x D_CUFF + 0.39. The upper limit of variation is equivalent in all sizes to a line Rl = 0.19 x D CUFF + 0.69, the lower limit to Rl = 0.19 x D CUFF + 0.09.

Claims (19)

1. A tracheal breathing device, in particular a tracheal tube, which, for a pediatric patient to breathe, closes the trache as airtight as possible, with a bubble cuff blocking the trachea below the glottis, through the which passes a breathing cannula, consisting of the bubble cuff of a flexible material of soft leaves and that in a full state, of unfolding freely without delimitation, is greater than in a full state placed in the trachea and the bubble cuff being with its folds in contact with the trachea, characterized because for the tracheal tubes with internal diameters of the rod (ID) of 3.0 to 7.0 mm, for the freely deployed cuff diameter (D__CUFF) a relation according to D_CUFF = 0.75 x MD_MP + 4.0 is given, as well as for the distance of the tube tip and the distal mounting point of the tube. cuff on the rod (SP_MD), an SP_MD = 2.36 x ID - 0.86, where MD_MP is the distance of the mounting points of the cuff on the rod of the tube.

2. A tracheal breathing device according to claim 1, characterized in that for tracheal tubes with an internal diameter (ID) of 3.0 to 3.5 mm, the D_CUFF is a range of values that lies between the lines D CUFF = 0.75 x MD MP + 5.00 and D_CUFF = 0.75 x MD_MP + 3.50, as well as with an SP_MD that is a range of values between the lines SP_DM = 2.36 x ID -0.11 and SP_DM = 2.36 x ID - 1.86.

3. A tracheal breathing device according to claim 1, characterized in that for tracheal tubes with an internal diameter (ID) of 4.0 to 5.5 mm, the D_CUFF is a range of values that lies between the straight lines D_CUFF = 0.75 x MD_MP + 5.20 and D_CUFF = 0.75 x MD_MP + 2.50, as well as with an SP_MD that is a range of values between the lines SP_DM = 2.36 x ID -0.34 and SP_DM = 2.36 x ID - 2.16.

4. A tracheal breathing device according to claim 1, characterized in that for tracheal tubes with an internal diameter (ID) of 6.0 to 7.0 mm, the D_CUFF is a range of values that lies between the straight lines D_CUFF = 0.75 x MD_MP + 5.50 and D_CUFF = 0.75 x MD_MP + 2.50, as well as "with an SP_MD that is a range of values between the lines SP_DM = 2.36 x ID -0.64 and SP_DM = 2.36 x ID - 2.46

5. A tracheal breathing device according to any of claims 1 to 4, characterized in that for the tracheal tubes with internal rod diameters (ID) of 3.0 to 7.0 mm, for the MD_MP approximately a ratio of MD_MP = L2-2 is given, with L2 being the distance between the two transition points of the radii Rl and R2 in the heel portion of the freely deployed cuff

6. A tracheal breathing device according to any of claims 1 to 5, characterized in that MD_MP is in a range of values between the lines MD_MP = L2 - 0.5 and MD_MP = L2 - 3.5.

7. A tracheal breathing device according to any of claims 1 to 4, characterized in that for tracheal tubes with internal rod diameters of 3.0 to 7.0 mm, for Rl a ratio of Rl = 0.19 x D_CUFF + 0.39 is given.

8. A tracheal breathing device according to any of claims 1 to 4, characterized in that for the tracheal tubes with internal diameters of the stem of 3.0 to 7.0 mm, a range of values that lies between the straight lines R1 is given for R1. = 0.19 x D_CUFF + 0.69 and Rl = 0.19 x D_CUFF + 0.0

9. 9. A tracheal breathing device according to any of claims 1 to 4, characterized in that for the tracheal tubes with internal rod diameters of 3.0 to 7.0 mm, MD_MP is given a ratio of MD_MP = L2-2, as well as for Rl a ratio of Rl = 0.19 x D_CUFF + 0.39.

10. A tracheal breathing device according to any of claims 1 to 4, characterized in that for tracheal tubes with internal rod diameters of 3.0 to 7.0 mm, a range of values is given for MD_MP between the lines MD_MP = L2 - 0.5 and MD_MP = L2 - 3.5, as well as for Rl, a range of values between the lines Rl = 0.19 x D_CUFF + 0.69 and Rl = 0.19 x D_CUFF + 0.09.

11. A tracheal breathing device according to any of claims 1 to 10, characterized in that the wall thickness (D) of the blade (7) is 0.015 to 0.005 mm.

12. A tracheal breathing device according to any of claims 1 to 11, characterized in that the wall thickness (D) of the blade (7) is less than or equal to 0.01 mm.

13. A tracheal breathing device according to any of claims 1 to 12, characterized in that the wall thickness (D) of the sheet (7) in the area of the fold is thinner than in the free area of folds oriented towards the cannula (2).

14. A tracheal breathing device according to any of claims 1 to 13, characterized in that the blade (7) of the bubble cuff (3) consists of a polyurethane.

15. A tracheal breathing device according to any of claims 1 to 14, characterized in that the cannula (2) is made with stepped internal diameters (ID) of 3 to 7 mm.

16. A tracheal breathing device according to claim 15, characterized in that the stepping of the internal diameters (ID) is 0.05 mm.

17. A tracheal breathing device according to any of claims 1 to 16, characterized "in that the external diameters (OD) of the cannula (2), adjusting to its internal diameter (ID), are from 4.1 to 9.3 mm.

18. A tracheal breathing device according to any of claims 17, characterized in that the bubble cuff (3) has external diameters (M) staggered from 10 to 20 mm

19. A tracheal breathing device in accordance with the claim 18, characterized in that the stepping of the external diameter (M) of the bubble cuff (3) is carried out in two equal steps in each case: a tracheal breathing device according to any of claims 1 to 19, characterized in that the length The axial (N) of the bubble cuff (3) is 16 to 32 mm 21. A tracheal breathing device according to any of claims 1 to 20, characterized in that the surface and external effective cuff bubble (3) adjacent to the larynx, has an axial length (L2) of 10 to 22 mm. 22. A tracheal breathing device according to any of claims 1 to 21, characterized in that the stepping of the axial length (L2) is carried out in two equal steps in each case. 23. A tracheal breathing device according to any of claims 1 to 22, characterized in that the end (6) of the breathing cannula protruding from the bubble cuff (3) is from 4 to 11 mm. 24. A tracheal breathing device according to any of claims 1 to 23, characterized in that in the cannula (2) there is a mark (8) that indicates the distance from the upper edge of the bubble cuff (3) to the vocal cord . 25. A tracheal breathing device according to any of claims 1 to 24, characterized in that the pressure in the bubble cuff (3) is in the range of 5 to 20 mbar, preferably in the range of 10 to 15 mbar .