Patent Publication Number: US-2020297904-A1

Title: Suction catheter assemblies

Description:
This invention relates to suction catheter assemblies of the kind including a suction catheter having a first lumen for suctioning and the assembly including a second lumen for supplying irrigating liquid to the patient end of the assembly. 
     Suction catheter assemblies may be used to remove secretions from within a tracheal tube or the respiratory passages of a patient. They are also used in other applications. Suction catheter assemblies may be of the closed-system kind in which the catheter is enclosed within a flexible envelope. Such assemblies have a manifold at the patient end with a sliding seal through which a suction catheter can be advanced and withdrawn. The flexible envelope is joined at one end to the manifold and encloses the catheter along its length. The other end of the envelope and the catheter are joined with a rear end housing including a suction control valve and a connector. The connector connects the catheter to a suction source; the valve enables the clinician to control the suction applied by the catheter. In some suction catheter assemblies the catheter has two lumens, one being used for suctioning and the other being used to supply irrigating or lavage liquid along the catheter to its patient end to aid in removing secretions from the tracheal tube. 
     Examples of closed-system suction catheter assemblies are described in U.S. Pat. Nos. 5,269,768, 5,300,043, 4,569,344, 4,638,539, 4,872,579, 5,167,622, 5,779,687, 5,325,850, 5,490,503, 5,419,769, 5,460,613, 5,349,950, GB2394761, GB2400160, U.S. Pat. Nos. 6,109,259, 6,227,197, EP801577B, WO96/09082, EP1239907B, EP1478424B, U.S. Pat. No. 6,588,427, EP1620148B, US2004/0221852, EP1911482A, EP1795217A, US2007/0282250, WO2007/143502, US2008/0188833, U.S. Pat. Nos. 6,227,200, 6,543,451, EP1239909B, U.S. Pat. No. 6,602,219, EP1347798, WO02/49680, U.S. Pat. No. 6,609,520, WO/055143, U.S. Pat. Nos. 6,805,125, 6,923,184, 7,021,313, 7,191,782, WO2004/101045, U.S. Pat. No. 7,263,997, WO2004/103448, WO00/15276, EP637257B, EP1113835B, EP1210957A, EP1237612B, U.S. Pat. No. 7,152,603, EP1267957B, U.S. Pat. No. 6,978,783, US2004/0007236, US2005/0211253, US2005/0211245, US2005/0235987, U.S. Pat. No. 7,059,322, WO2004/032817, US2008/0135051, U.S. Pat. Nos. 4,836,199, 4,850,350, 4,967,743, 5,025,806, 5,083,561, 5,220,916, 5,215,522, 5,255,676, 5,277,177, 5,309,902, 5,333,606, 5,343,857, 5,487,381, 5,513,628, 5,791,337, EP1343552A, WO02/49699, U.S. Pat. No. 6,612,304, EP1322371A, WO02/28463, U.S. Pat. No. 6,629,530, WO02/051485, U.S. Pat. No. 6,769,430, EP1330284, WO02/36191, U.S. Pat. No. 6,886,561, WO2004/034946, U.S. Pat. No. 7,188,623, WO2006/014431, U.S. Pat. No. 7,341,059, WO2005/094925, WO2006/103233, WO2007/030388, WO2009/003135, U.S. Pat. Nos. 4,838,255, 5,107,829, 5,133,345, 5,642,726, 6,702,789, 7,458,955, 7,273,473, 5,139,018, 4,327,723, 4,515,592, 6,099,519, EP695556B, U.S. Pat. Nos. 5,065,754, 5,730,123, 5,207,220, 5,309,903, 7,086,402, 7,597,686, 7,726,315, WO11020985 and GB2468946. Closed system suction catheters are available from various manufacturers including Smiths Medical, Kimberley Clark, Covidien and Viasys. 
     One problem with conventional dual-lumen catheter assemblies is that the arrangement of the suction control valve and the irrigation port to which the source of lavage fluid is connected are difficult to be used single-handed. Usually, the clinician holds the suction control valve in one hand and manipulates the suction catheter with his or her other hand while an assistant connects a lavage saline phial to the irrigation port and squeezes the phial to administer the lavage fluid. The small size of the rear end housing makes it difficult for the clinician and assistant both to grip and manipulate the housing at the same time, making the procedure awkward. It is important to control the amount of lavage liquid that is dispensed carefully because, if too much is given too quickly it might not all be removed by the suctioning and could flow down the tracheal tube into the respiratory passages. In effect, washing secretions from the tube into the lungs. 
     It is an object of the present invention to provide an alternative suction catheter assembly. 
     According to the present invention there is provided a suction catheter assembly of the above-specified kind, characterised in that the assembly includes a handpiece towards its machine end having a first port for connection with a source of suction and a second port for connection with a source of irrigating liquid, that the handpiece includes a suction control for enabling or restricting suction applied to the first lumen and that the handpiece is arranged such that the user can both actuate the suction control and control the flow of irrigating liquid to the assembly using the same hand as holds the handpiece. 
     Both the first and second lumens preferably extend along the suction catheter. The handpiece may include an irrigating liquid control on the hand piece that can be actuated by the same hand as holds the handpiece. The source of suction and the source of irrigating liquid may both be external of the handpiece. The handpiece preferably has a pistol grip shape with a main body portion that is gripped between the palm and fingers and an upper part on which the user can place his thumb, the suction control being actuable by the thumb on the upper part and the irrigating liquid control being actuable by the fingers of the same hand on the main body portion. The irrigating liquid control may be in the form of a pump actuator arranged to pump liquid from a liquid reservoir to the second port. Alternatively, the irrigating liquid control may be in the form of a valve arranged to control flow of irrigating liquid from a source of liquid at pressure to the second port. The source of irrigating liquid may include a compressible reservoir mounted on the handpiece such that flow of irrigating liquid to the second port can be controlled by compressing the reservoir with the same hand as holds the handpiece. The assembly may include a hinged lever extending along the compressible reservoir such that the reservoir can be compressed to dispense irrigating liquid from the reservoir by squeezing the lever. The assembly preferably includes a patient fitting including a wiper seal through which the patient end of the catheter can be extended and retracted, and that the assembly includes a flexible sleeve extending along the outside of the catheter and attached at one end with the patient end fitting and at its opposite end with the handpiece so that the catheter can be manipulated through the sleeve. 
    
    
     
       Three examples of suction catheter assemblies according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a partly sectional side elevation view of a first form of assembly; 
         FIG. 2  is a partly sectional side elevation view of a second form of assembly; 
         FIG. 3  is a partly sectional side elevation view of a third form of assembly; and 
         FIG. 4  shows a modification of the assembly of  FIG. 3 . 
     
    
    
     With reference first to  FIG. 1  there is shown a first form of closed-system suction catheter assembly including a suction catheter  1  attached at its machine end with a handpiece  2 . The suction catheter  1  is of the dual-lumen kind, having a suction lumen  10  and an irrigating lumen  11  extending along its length and opening at both the patient end  12  of the catheter and at its machine end  13 . The catheter  1  is enclosed along its length in a flexible, transparent plastics sleeve or envelope  3  through which the catheter can be gripped and manipulated. The sleeve  3  is sealed at its machine end with the handpiece  2  and at its opposite, patient end with the rear, machine end of a patient fitting in the form of a manifold  4 . The manifold  4  has a cross-shape configuration with a patient end port  40  adapted to fit onto a 15 mm coupling at the machine end of a tracheal tube (not shown), two side ports  41  and  42  adapted to be connected with a breathing system, and the machine end port  43  to which the envelope  3  is sealed. The machine end port  43  includes a wiper seal  44  through which the patient end of the catheter  1  can be advanced and retracted. As so far described the assembly is conventional. 
     The assembly differs from conventional assemblies in that its handpiece  2  is arranged such that the user can control both suction and the flow of irrigating liquid to the catheter using the same hand as holds the handpiece. The handpiece  2  has an outer housing  20  of a moulded plastics that is shaped into a pistol grip with a main body portion  21  that can be gripped between the palm and four fingers of the hand in a generally upright position and allowing the user&#39;s thumb to be placed on the upper part  22  of the housing. The machine end  13  of the suction catheter  1  is located inside the housing  20  of the handpiece which has a suction flow path  23  and an irrigating flow path  24 , both of which can be provided by respective lengths of tubing. 
     The suction flow path  23  extends at one end from the suction lumen  10  at the machine end  13  of the suction catheter  1  to a suction port  25  projecting from the outside of the housing  20  on the opposite side from the suction catheter. The suction port  25  is tapered and ribbed so that one end of flexible suction tubing  26  can be pushed and retained on the port. The opposite end of the suction tubing  26  connects with a suction source, external of the handpiece  2 , indicated generally by the numeral  27 , which can be of any general kind, such as including a suction drainage bottle connected with a hospital suction supply and including conventional filters and overfill prevention valves or the like. The suction flow path  23  also includes a flow control valve  28  positioned along it that is normally closed, preventing suction being applied to the catheter  1 , but can be manually opened to enable flow along the suction flow path. The suction control valve  28  is coupled with a manually displaceable rod  29  projecting through the upper side  22  of the housing  20  and terminated by an enlarged thumb pad  30 . The rod  29  is urged upwardly and outwardly by a spring  31  in the housing  20 . When the user presses down with his thumb on the pad  30  the rod  29  is pressed down and in against the action of the spring  31 , thereby actuating the valve  28  to cause it to open and connect the suction source  27  with the suction catheter  1 , This allows aspirated material to flow through the catheter  1 , along the suction flow path  23  and valve  28  in the housing  20  and through the suction tubing  26  to the suction source  27 . When the user releases his thumb the suction valve actuator rod  29  is moved up by the spring  31  to its outer, neutral or rest position. 
     The irrigating flow path  24  extends from the irrigating lumen  11  of the catheter  1  at one side of the housing  20  to a second, irrigating liquid port  35  projecting from the outside of the housing  20  on the opposite side from the suction catheter just below the suction port  25 . The irrigating port  35  is tapered and ribbed so that one end of flexible, irrigating tubing  36  can be pushed and retained on the port. The irrigating tubing  36  extends to a source  37  of irrigating liquid, external of the handpiece  2 , such as a suspended bag of saline. Alternative irrigating liquid sources are described later. The irrigating flow path  24  includes a second flow control valve  38  positioned along the length of the flow path. The irrigating flow control valve  38  is normally closed to prevent flow of irrigating liquid along the flow path  24  to the irrigating lumen  11  of the catheter  1 . The irrigating flow control valve  38  is coupled with a manually-displaceable rod  39  projecting through the left-hand, forward side of the main body portion  21  of the housing  20  and is terminated by an enlarged trigger pad  50 . The rod  39  is urged outwardly by a spring  51  in the housing  20 . When the user places his index or middle finger on the trigger pad  50  and presses this inwardly against the action of the spring  51  it moves the rod  39  inwardly and actuates the irrigating valve  38 . This causes the irrigating valve  38  to open and allow irrigating liquid to flow from the irrigating source  37  to the irrigating lumen  11  of the catheter  1 . 
     The arrangement of this assembly enables the handpiece  2  to be gripped by the user in one hand. Suction can be controlled easily simply by pressing the suction pad  30  down with the thumb. Irrigation can also be controlled easily simply by squeezing the irrigating trigger  50  with the fingers of the same hand. In this way suction and irrigation can be controlled at the same time enabling just suction, or just irrigation, or both suction and irrigation to be applied by the catheter  1 . As only one hand is needed to control suction and irrigation the user can use his other hand to manipulate the suction catheter  1  into the tracheal tube, advancing it or retracting it to ensure effective removal of any secretions. 
     Instead of connecting the handpiece of the assembly to a remote source of irrigating liquid via tubing, as described with reference to  FIG. 1 , it would be possible to mount the source of irrigating liquid directly on the assembly and supported by the handpiece itself. Arrangements for doing this are shown in  FIGS. 2, 3 and 4 . 
     In the arrangement shown in  FIG. 2  the source of irrigating liquid  237  is provided by a bottle  238  of irrigating liquid and the handpiece  202  has a housing  203  that is open at its lower end  204  so that the open upper end of the bottle  238  can be fitted into the handpiece. In place of the valve described in relation to the embodiment of  FIG. 1 , this arrangement includes a mechanical pump  240  having an inlet wand  241  depending from the pump down into the bottle  238  close to its lower, closed end. The wand  241  provides the second, irrigating port of the handpiece  202 . The pump  240  has an outlet  242  at its upper end connected by a tube  243  to the machine end of the irrigation lumen in the suction catheter. The pump  240  is driven by an actuating rod  244  extending from the pump through the front wall of the hand piece  202  and terminated in a trigger pad  245 . The rod  244  is urged outwardly by a spring  246  in the housing  203 . To operate the pump, and hence cause irrigating liquid to flow from the bottle  238  to the irrigating lumen  11  in the catheter  1 , the trigger pad  245  is squeezed inwardly by the user&#39;s forefinger against the action of the spring  246  and is then released. This causes a measured bolus of liquid to flow along the irrigation lumen  11  of the catheter  1 . The user can squeeze and release the trigger  245  repeatedly to dispense as much irrigation fluid as is needed. 
     The arrangement shown in  FIG. 3  is similar to that shown in  FIG. 2  in that the source of irrigating liquid is supported by the handpiece  302  but differs in that it lacks any pumping mechanism. Instead, the irrigating liquid is contained within a cylindrical phial  303  of a resilient material. The phial  303  is open at its upper end  304  and is connected to a port  305  within the handpiece  302 . A tube  306  extends from the irrigating fluid port  305  to the irrigating lumen  11  of the suction catheter  1 . The body of the handpiece  302  is modified to have an open, skeletal form where the phial  303  is supported by a narrow vertical rib  308  extending down half the length of the phial on the side remote from the suction catheter. A narrow ring formation  309  at the lower end of the rib  308  embraces the phial  303  midway along its length. The remaining surface of the phial  303  is exposed either side of the ring  309  so that it can be squeezed by gripping with the fingers so as to compress the phial and squeeze out some of its contents into the irrigating lumen  11  of the suction catheter  1 . 
     Instead of the user directly contacting and squeezing the phial  303  with his fingers it would be possible to use a modified assembly of the kind shown in  FIG. 4 , which includes a lever  400  by which the phial can be squeezed indirectly. The lever  400  has an L-shape with a long arm  401  and a shorter arm  402  extending at right angles to the long arm at its upper end. The long arm  401  extends down along the front side of the phial  303  and has a protrusion  403  towards its lower end projecting towards the front side of the phial  303  where this extends below the ring  309 . The short arm  402  extends rearwardly a short distance at the upper end of the phial  303  towards the suction inlet  325 . The lever  400  is pivotally mounted on the handpiece  302  at the upper end of the phial  303  at a location along the short arm  402 . A coil spring  404  or other resilient member is mounted between the lever  400  and the handpiece  302  to urge the lever in a clockwise sense so that the long arm  401  is urged away from the phial  303  in its natural state. When irrigation is needed the user simply squeezes the long arm  401  of the lever  400  against the action of the spring  404  to rotate the lever through a small angle anticlockwise and force the protrusion  403  against the side of the phial  303 . This squeezes the phial  303  and dispenses the irrigation liquid. The lever  400  ensures that the pressure is always applied to the phial  303  at the same location regardless of where the user squeezes the lever. This may make it easier for someone with small hands to operate the assembly. 
     The arrangements of  FIGS. 2, 3 and 4  have the advantage of avoiding the need for suction tubing to be attached to the handpiece, making the assemblies easier to manipulate without tangling. The disadvantage of these arrangements, however, is that the weight of the irrigating liquid adds to the total weight of the handpiece and the quantity of irrigating fluid is more limited, which may require replacement of the bottle or phial. 
     The invention is not confined to closed-system suction catheters with an outer protective envelope but could be used with exposed suction catheters. The suction catheter assemblies are not confined to those for use in tracheal tubes but could be used in other applications where both suction and irrigation is needed. The source of irrigating liquid could be provided by any conventional means, such as, for example, an elastomeric pump or a liquid container in which the liquid is forced out by gas pressure within the container. The suction catheter need not have two lumens since it could just have a suction lumen and the irrigating lumen be provided in a separate tube opening in the machine end fitting. This still enables the catheter to be irrigated when it is withdrawn but allows the outer diameter of the suction catheter to be minimised, which is especially important in paediatric applications.