Patent Application
20090320853
Ventilators or respirators are used for mechanical ventilation of the lungs of a patient in a medical setting. The ventilator unit is connected to a hose set; the ventilation tubing or tubing circuit, delivering the ventilation gas to the patient. At the patient end, the ventilation tubing is typically connected to a tracheal ventilation catheter or tube, granting direct and secure access to the lower airways of a patient. Tracheal catheters are equipped with an inflated sealing balloon element, or “cuff”, creating a seal between the tracheal wall and tracheal ventilation tube shaft, permitting positive pressure ventilation of the lungs.
One type of tracheal catheter, an endotracheal tube (ET tube), inserted through the mouth, is generally used for a number of days before a decision is made to switch a patient to a tracheostomy tube, inserted directly into the trachea through a stoma in the tracheal wall. Endotracheal tubes have been linked in some studies to an increased rate of ventilator acquired pneumonia (VAP) and so tracheostomy operations are becoming increasingly common and are being performed earlier in the patient's hospital stay in order to reduce the occurrence of VAP.
A tracheostomy procedure involves making a small horizontal incision in the skin of the neck to grant access to the trachea. Because of the uniquely flexible and elastic nature of the trachea, it has been found that healing is much faster if only a small hole is made in the tracheal wall and the hole dilated, rather than cutting the tracheal wall. After the trachea has been dilated, a tracheostomy or “trach” tube is inserted through the stoma, the balloon cuff inflated and the trach tube connected to a ventilator.
The amount of force needed to insert a trach tube into the trachea can cause the tubes to kink and collapse. Great care is needed to avoid this problem, lengthening the time necessary to perform this procedure.
There remains a need for a device that can more quickly and safely allow for the successful placement of a tracheostomy tube.
There is provided a novel tracheostomy tube that largely overcomes the problem of trach tube collapse. The tube has a variable flexibility which may be provided in a number of ways. The tube is flexible at its distal portion so as to pose less of a problem for the posterior wall of the trachea should it contact it. It is less flexible at its proximal portion where the greatest amount of force is generally applied during a tracheostomy procedure and after placement due to the tracheal rings. The upper or proximal portion is as much as two thirds of the length of the tube between the flange and the start of the sealing cuff. The lower or distal portion is the balance of the tube between the start of the sealing cuff and the distal end.
Tracheostomy is a lifesaving procedure to allow a patient to be ventilated directly through the trachea. Tracheostomy is also believed by many to prevent or delay the onset of ventilator acquired pneumonia (VAP). This lifesaving procedure, unfortunately, is relatively time consuming and current technology requires a large number of steps and pieces of equipment that must remain sterile and functioning properly in order to arrive at a successful conclusion. The tracheostomy procedure may be greatly improved using tapered dilators and trach tube loading catheters or obturators.
Dilators are instruments or substances for enlarging a canal, cavity, blood vessel or opening, according to the American Heritage Stedman's Medical dictionary 2001. Once a dilator is used to enlarge the stoma in the trachea for placement of the trach tube, the tube is inserted to the point at which the flange 70 touches the skin of the patient.
The tracheostomy tube is shown in
In order to place a trach tube in the trachea of a patient, a loading catheter 50 is desirably slid into the tracheostomy tube 26 (
The tracheostomy tube 26 with the loading catheter 50 inside (
The loading catheter 50 may be removed from the trach tube by disengaging the detachably attached handle 52 from the proximal end of the tracheostomy tube 26 and pulling the handle 52 away from the tube 26. One way of accomplishing this disengagement is by twisting the loading catheter handle 52. This twisting action cams the loading catheter handle 52 off the proximal end of the trach tube 26, overcoming any static friction that may exist in the system and defeating the tabs 62 and slots 64 locking the loading catheter handle 52 to the tube 26. This action allows the user to pull all the loading components out through the inner lumen of the trach tube 26, leaving only the tube 26 in place. Clearly the optionally dilator tip 12 must be sized so that its largest diameter is slightly less than that of the tracheostomy tube 26 that it is intended to pass through. Once the trach tube 26 is in place, the tube cuff 30 is inflated and the tube 26 is connected to a ventilator (not shown) and placed in service (
The trach tube 26 has a balloon cuff 30 around its circumference on a lower (distal) portion of the tube that serves to block the normal air flow in the trachea so that (assisted) breathing takes place through the trach tube using a ventilator. The cuff is desirably made from a soft, pliable polymer such as polyurethane (PU), polyethylene teraphihalate (PETP), low-density polyethylene (LDPE), polyvinyl chloride (PVC), or elastomeric-based polyolefins. It should be very thin; on the order of 25 microns or less, e.g. 20 microns, 15 microns, 10 microns or even as low as 5 microns in thickness. The cuff should also desirably be a low pressure cuff operating at about 30 mmH2O or less, such as 25 mmH2O, 20 mmH2O, 15 mmH2O or less. Such a cuff is described in U.S. Pat. No. 6,802,317 which describes a cuff for obturating a patient's trachea as hermetically as possible, comprising a cuffed balloon which blocks the trachea below a patient's glottis, an air tube, the cuffed balloon being attached to the air tube and being sized to be larger than a tracheal diameter when in a fully inflated state and being made of a soft, flexible foil material that forms at least one draped fold in the cuffed balloon when inflated in the patient's trachea, wherein the foil has a wall thickness below or equal to 0.01 mm and the at least one draped fold has a loop found at a dead end of the at least one draped fold, that loop having a small diameter which inhibits a free flow of secretions through the loop of the at least one draped fold. Another description of such a cuff is in U.S. Pat. No. 6,526,977 which teaches a dilator for obturating a patient's trachea as hermetically as possible, comprising a cuffed balloon which blocks the trachea below a patient's glottis, an air tube, the cuffed balloon being attached to the air tube and being sized to be larger than a tracheal diameter when in a fully inflated state and being made of a sufficiently soft, flexible foil material that forms at least one draped fold in the cuffed balloon when fully inflated in the patient's trachea, wherein the at least one draped fold formed has a capillary size which arrests free flow of secretions across the balloon by virtue of capillary forces formed within the fold to prevent aspiration of the secretions and subsequent infections related to secretion aspiration.
There is a flange 70 on the trach tube 26 on the proximal end that is used to attach the trach tube to a patient's throat. The flange 70 extends on either side of the tube 26 near the proximal end where the ventilator connection 72 is located. The flange 70 is flexible and non-irritating and can be sutured onto the throat of a patient to anchor the tube 26. The size of the flange will vary depending on the size and needs of the patient.
The trach tube 26 also may be used with disposable cannulas 80 (
The flange 70 may desirably be of a width between 6 and 12 cm and height of 1 to 6 cm, more particularly between 7 and 10 cm and 2 and 5 cm respectively or still more particularly between 8 and 9 cm and 2 and 4 cm respectively. The distance from the flange 70 to the distal tip 31 of the trach tube 26 may be an arched distance of between 70 and 100 mm, desirably between about 75 and 95 mm and more desirably between 80 and 90 mm. The angle of the trach tube from the flange to the distal end is between 85 and 120 degrees, desirably between 95 and 115 degrees, more desirably between 100 and 110 degrees. Materials that are suitable for making a trach tube and flange include polyurethanes, polyvinyl chlorides, nylons, polyolefins and other biocompatible polymers. Depending on the polymer chosen, the trach tube and flange may be transparent, translucent or opaque.
One way of enhancing the strength of the upper portion of the trach tube shaft 74 is to make the shaft of materials of different hardnesses. One suitable measurement of hardness known to those skilled in the art is the Durometer ASTM D2240 hardness test. The upper portion of the shaft may be made, for example, of a relatively harder polymer than the lower portion of the shaft. The use of the same type of material, e.g., polyurethane, allows the polymers to be fashioned into a tube in the same manner and at nearly the same conditions, and helps ensure a strong and seamless transition. The upper portion of the shaft may be made, for example, by injection molding a 55 D Shore hardness polyurethane while the lower portion is injection molded, simultaneously in the same mold, of an 80 A Shore hardness polyurethane. The resulting shaft will vary in flexibility.
Rather than making the upper and lower portion of the trach tube from different hardness polymers, a variable blend of polymers may be used with a greater proportion of a harder polymer in the upper portion, gradually tapering to a much lower amount in the lower portion of the tube. Again, this may be accomplished by using an injection molding procedure as is known to those skilled in the art.
Another way to enhance the strength of the tube is by winding wire 100 about the tube (
Plastic wire reinforcement may be provided on the exterior shaft surface but in such a position may make it more difficult to insert the tube as it may catch on the edge of the tracheal stoma as the tube is being inserted. Suitable plastics include polytetrafluoroethylene (PTFE) or fluoroethylene propylene (FEP) and other relatively high melt temperature materials. The use of wire reinforcement, of any type, would permit the tube shaft 74 to be made of only one uniform type of material. A prefabricated wire may be slid over the trach tube after fabrication. Alternatively the wire could be installed in the trach tube mold prior to injection so that it becomes imbedded in the tube as it is produced. Wire reinforcement may be added to the upper portion of the shaft using between 3 and 20 windings per inch (1.2 to 8 windings per cm), desirably between 5 and 10 windings per inch (2 and 4 windings per cm).
Another way to enhance the strength of a tracheostomy tube is to place reinforcing rods 101 along the sides of the tube (
Yet another way to enhance the strength of the tube is to install concentric rings 102 around the tube (
This application is one of a group of commonly assigned patent application which are being filed on the same day. The group includes application serial no.:______ (attorney docket no. 64375503US01) in the name of Brian J. Cuevas and is entitled “Easy Grip Tapered Dilator”; application serial no.: ______ (attorney docket no. 64375503US02) in the name of Brian J. Cuevas and is entitled “Method of Performing a Tracheostomy”; application serial no.: ______ (attorney docket no. 64375504US01) in the name of Brian J. Cuevas and is entitled “Dilator Loading Catheter”; application serial no.: ______ (attorney docket no. 64392563US01) in the name of Brian J. Cuevas and is entitled “Tracheostomy Tube Butterfly Flange”; application serial no.: ______ (attorney docket no 64482359US01) in the name of James Schumacher and is entitled “Tracheostomy Tube”; design application no. ______ (attorney docket no. 64392563US02) in the name of Brian J. Cuevas and is entitled “Butterfly Flange”; design application serial no. ______ (attorney docket no. 64375503US03) in the name of Brian J. Cuevas and is entitled “Tapered Dilator Handle”; design application ______ (attorney docket no. 64392563US03) in the name of Brian J. Cuevas and is entitled “Stoma Pad”. The subject matter of these applications is hereby incorporated by reference.
As will be appreciated by those skilled in the art, changes and variations to the invention are considered to be within the ability of those skilled in the art. Such changes and variations are intended by the inventors to be within the scope of the invention. It is also to be understood that the scope of the present invention is not to be interpreted as limited to the specific embodiments disclosed herein, but only in accordance with the appended claims when read in light of the foregoing disclosure.
