ENTERAL FEEDING TUBE ASSEMBLY AND SUCTION TUBE THEREFOR

Abstract: A suction tube (16) is adapted to receive an enteral feeding catheter (11) through its lumen and has a longitudinally splittable wall to allow the suction tube (16) to be removed from a patient whilst leaving the feeding catheter (11) in place. In a modified embodiment the suction tube (16) has a longitudinally extending lumen (23) in the wall thereof which may be used for air bleed, sample aspiration and delivery of medication

Description: This invention relates to a suction tube for use with an enteral feeding catheter, and to an enteral feeding tube assembly. Enteral feeding is the medical procedure whereby food is delivered directly to the intestine following, for example, a stomach operation. A liquid feed is usually supplied through a catheter inserted into the intestine through the patient's nose and alimentary canal. A suction tube is often necessary to remove unwanted liquids and gases from the region of the operation. The feeding catheter and suction tube may be inserted one through each nostril, but this has the disadvantage that both nostrils are blocked which is uncomfortable and unnatural for the patient. An alternative ′duplex′ construction is disclosed in Japanese Patent Publication 222067/1985 in which a single tube has feeding and suction lumens. An enteral feeding catheter normally has a relatively small diameter compared with the suction tube. Following an operation the suction tube can usually be removed after several days whereas the feeding catheter may remain in-situ for a comparatively long period. The ′duplex′ type feeding tube has the disadvantage that although only one nostril is blocked, the patient must endure pain from the relatively large bore suction tube long after the need for suction has passed. It has also been proposed to provide a feeding catheter within a suction tube and to withdraw the suction tube when the need for suction has passed. However, the suction tube cannot be removed from the feeding catheter and consequently the catheter must be at least twice the length of suction tube to accommodate the suction tube outside the patient. It is also extremely difficult to slide the suction tube along the catheter to a position wholly outside the patient. Furthermore the long feeding catheter restricts the flow rate of food by approximately 50% over a conventional catheter since for small diameter pipes flow rate is inversely proportional to pipe length (Poiseuilles law). Finally the excess feeding catheter length must be secured to the patient or to other apparatus and this is awkward and can be dangerous. It is an object of the present invention to provide a suction tube assembly which overcomes the disadvantages of prior art proposals whilst being generally more convenient and acceptable to the patient. According to the invention there is provided an enteral feeding and suction tube assembly for insertion into the nasal gastric passageway of a patient, the assembly comprising an enteral feeding catheter having a lumen extending therethrough between proximal and distal ends, a means at the proximal end thereof for connecting the lumen to a source of feeding liquid, and holes at said distal end thereof for discharging said feeding liquid from said lumen; a suction tube having proximal and distal ends for substantially encasing said catheter, characterised in that the suction tube has a lumen substantially larger than and generally spaced apart from the lumen of the catheter, said catheter extending from the proximal end to the distal end of said suction tube, a connection means at said proximal end of said suction tube for connecting the lumen of said suction tube to a source of suction, suction openings in said distal end of said suction tube and said suction tube includes an incompatible material in the wall thereof which facilitates longitudinal splitting of the tube and removal of said suction tube from said catheter. The suction tube used in the present invention has the advantage that it accommodates a feeding tube in the bore thereof, so having the advantages of a ′duplex′ tube, and yet is removable from the patient without requiring an excessively long feeding catheter. The feeding catheter is of the usual length and thus has a flow rate commensurate with prior art separate feeding catheter. In a preferred embodiment the tube has two longitudinally extending lines of incompatible material. The tube is therefore splittable into two sections, one each to be gripped in the practitioners hands for removal. Alternatively a single line of incompatible material may be provided or the incompatible material may be mixed with the suction tube material before extrusion in such a way as to provide longitudinal splitting. In an alternative embodiment of the invention the suction tube has a longitudinally extending lumen in the wall thereof which can be used to relieve excess suction in the alimentary canal and to provide an air bleed. The lumen may also be used to aspirate a sample from the distal end of the suction tube or to pass medication to the alimentary canal. The suction tube may have a connector at the proximal end thereof which has an opening to receive an enteral feeding catheter in sliding sealing engagement, and a branch pipe for connection to a suction source. Other features of the invention will be apparent from the following description of two preferred embodiments shown by way of example only in the accompanying drawings in which: Figure 1 is a plan view of a feeding tube assembly according to the invention and partially sectioned along its axis; Figure 2 is a plan view corresponding to Figure 1 of an alternative embodiment; and Figure 3 is a transverse section on line A-A of Figure 2. With reference to Figure 1 there is shown an enteral feeding catheter 11 having the usual proximal connector 12, feeding eyes 13 and weighted tip 14. The catheter 11 passes through a suction tube 16 which has a plurality of suction holes 17 at the distal end thereof. The feeding catheter and suction tube are made of materials which will not be affected by intestinal juices but which are sufficiently flexible to pass easily through the nose and the alimentary canal. Suitable materials are PVC and polyethylene. The inner surface of suction tube 16 has a matte finish to promote free sliding on the feeding catheter 11. The distal end of the suction tube is open but rounded as shown to avoid damage to body tissue. A connector 18 is inserted into the proximal end of the suction tube and is closed about the feeding catheter by a cap 19. The connector 18 has a branch pipe 21 for connection to a suction source. The tube 16, connector 18 and cap 19 are secured together sufficient to resist suction applied to the branch pipe 21; the parts may be in sealing frictional engagement for example. The suction tube includes two longitudinal lines of incompatible material 22 (Figure 3) which extend from the proximal to distal end. The lines 22 may comprise a filler material which bonds sufficiently strongly to the suction tube wall to permit insertion and use of the tube but which separates freely with the fingers to allow the suction tube to-be removed from the feeding tube. Alternatively the filler material may be mixed with the suction tube so as to give free splitting in a longitudinal direction. The feeding catheter and/or suction tube may be provided with depth graduation marks to allow the insertion length of the catheter to be adjusted relative to the suction tube. In use the relative lengths of tube 16 and catheter 11 are adjusted and the assembly inserted through one nostril of the patient and through the. alimentary canal to the stomach region. The catheter and tube are connected to respective food and suction sources and used in a conventional manner. One nostril of the patient is free to provide an airway. When the need for suction has passed the branch connector 18 is disconnected from the suction tube, and the proximal end of the suction tube is split; the user holds one half of the tube in each hand and pulls the tube out of the patient, splitting the tube as it is removed. A modification of the feeding tube assembly is shown in Figure 2 which carries corresponding reference numerals. The suction tube includes a lumen 23 in the wall thereof which is open to the interior of the suction tube at the distal end and has a radial opening 26 and an axial opening 27 at the proximal end. A removable tube 24 may be inserted through the radial opening 26 as shown. The lumen 23 has several uses. When the tube 24 is removed it may act as a vent to relieve suction in the alimentary canal and thereby avoid damage to the mucosa which may occur if the wall of the alimentary canal is sucked against the suction tube. When the tube 24 is in place the axial opening 27 of the lumen 23 is blocked. In this condition the tube 24 may be used to aspirate a sample from the distal end of the suction tube or alternatively to irrigate the alimentary canal. The tube 24 may also be used to administer a medicinal preparation. Other variations are possible and it is intended that the invention be limited only by the scope of the claims appended hereto.

Claims: 1. An enteral feeding and suction tube assembly for insertion into the nasal gastric passageway of a patient, the assembly comprising an enteral feeding catheter (11) having a lumen extending therethrough between proximal and distal ends, a means (12) at the proximal end thereof for connecting the lumen to a source of feeding liquid, and holes (13) at said distal end thereof for discharging said feeding liquid from said lumen; a suction tube (16) having proximal and distal ends for substantially encasing said catheter (11), characterised in that the suction tube (16) has a lumen substantially larger than and generally spaced apart from the lumen of the catheter (11), said catheter (11) extending from the proximal end to the distal end of said suction tube (16), a connection means (18) at said proximal end of said suction tube (16) for connecting the lumen of said suction tube to a source of suction, suction openings (17) in said distal end of said suction tube (16) and said suction tube (16) includes an incompatible material in the wall thereof which facilitates longitudinal splitting of the tube and removal of said suction tube (16) from said catheter (11). 2. An assembly according to claim 1, characterised in that said incompatible material for facilitating longitudinal splitting is in the form of two longitudinally extending lines (22) of said suction tube (16) extending the length thereof. 3. An assembly according to claim 1, characterised in that a second longitudinally extending lumen (23) is provided in a wall of said suction tube (16), said lumen having an opening at the distal end thereof opening into said suction tube (16) and an opening (27) at the proximal end thereof external to said suction tube (16). 4. An assembly according to claim 2, characterised in that a second longitudinally extending lumen (23) is provided in a wall of said suction tube (16) spaced apart from said weakened portions (22), said lumen (23) having an opening at the distal end thereof opening into said suction tube (16) and an opening (27) at the proximal end thereof external to said suction tube (16). 5. An assembly according to any one of the preceding claims, characterised in that said means for connecting the lumen of said suction tube (16) to a source of suction is in the form of a tubular body (18) mounted at the proximal end of said suction tube (16), said body (18) having one end adapted for fluid connection to the lumen of said suction tube and another end closed by a cap (19), said cap (19) having an aperture therein adapted to receive said enteral feeding catheter (11) in sliding sealing engagement, said body (18) further including a branch pipe (21) adapted for connection to a source of suction. 6. An assembly according to anyone of the preceding claims, characterised in that the lumen of said suction tube (16) has axial opening at the distal end thereof that is at least as large as the outside diameter of the portion of the catheter (11) extending proximally thereof and in that the distal end of said catheter (11) adjustably extends beyond the distal end of said suction tube (16) by slidable movement of said catheter relative to the distal end of said suction tube (16).

Inventors: KURIMOTO, MUNEHITO
Applicants: SHERWOOD MEDICAL COMPANY
Application year: 1987
Main classification: A61M25
IPC codes: A61M25, A61M1, A61M39, A61J15