Method and apparatus for providing artificial ventilation to a trachea of a patient

Abstract

An airway catheter (“AEC”) includes a catheter lube having proximal and distal tube end faces in fluid communication with a tube lumen. The distal lube end face and a portion of the tube wall collectively form a distal tube end region. A plurality of side holes extend laterally through the tube wall. An inflatable cuff is secured to the outer tube wall surface with an inner cuff volume in fluid communication with the tube lumen via the side holes. A resistor plug has proximal and distal plug end faces in fluid communication with a plug lumen and is defined laterally by a plug wall. The resistor plug is maintained within at least a portion of the tube lumen in the distal tube end region with an outer plug wall surface being at least partially in compressive contact with the inner tube wall surface.

Having described the invention, we claim: 
     
         1 . A method of providing artificial ventilation to a trachea of a patient, the trachea having a longitudinally oriented trachea lumen defined by a trachea wall, the method comprising the steps of:
 providing an airway catheter (“AEC”) including
 an elongate, flexible catheter tube having longitudinally spaced proximal and distal tube end faces in fluid communication with a tube lumen extending longitudinally through the tube and defined laterally by a tube wall extending between the proximal and distal tube end faces, the tube wall having laterally spaced inner and outer tube wall surfaces, the distal tube end face and a minority portion of the tube wall directly longitudinally adjacent to the distal tube end face collectively forming a distal tube end region, 
 a plurality of side holes extending laterally through the tube wall between the inner and outer tube wall surfaces, all of the side holes being located in the distal tube end region, 
 an inflatable cuff secured to the outer tube wall surface at two longitudinally spaced circumferences of the outer tube wall surface in the distal tube end region such that an inner volume of the cuff is in fluid communication with the tube lumen via all of the plurality of side holes, the inflatable cuff being configured for selective adjustment between inflated and deflated conditions, and 
 a reduced-diameter resistor plug having laterally spaced proximal and distal plug end faces in fluid communication with a plug lumen extending longitudinally through the resistor plug and defined laterally by a plug wall extending between the proximal and distal plug end faces, the plug lumen having a substantially smaller inner diameter than an inner diameter of the tube lumen in the distal tube end region, the plug wall having laterally spaced inner and outer plug wall surfaces, the resistor plug being maintained within at least a portion of the tube lumen in the distal tube end region with an outer plug wall surface being at least partially in compressive contact with the inner tube wall surface; 
 providing a ventilation fluid source having a selectively adjustable ventilation fluid flow pressure and direction; 
 operatively placing the ventilation fluid source in fluid communication with the proximal tube end; 
 arranging at least a distal portion of the AC within the trachea lumen; 
 directing ventilation fluid from the ventilation fluid source flows in a first, distally oriented direction through the tube lumen; 
 by the diameter of the plug lumen being smaller than the diameter of the tube lumen, causing a first elevated ventilation fluid pressure in a portion of the tube lumen longitudinally coincident with at least a portion of the distal tube end region by resisting passage of the ventilation fluid through the plug lumen; and 
 with the first elevated ventilation fluid pressure, urging at least a portion of the ventilation fluid through at least one side hole and into the inflatable cuff to urge the inflatable cuff toward the inflated condition. 
   
     
     
         2 . The method of  claim 1 , wherein the step of urging at least a portion of the ventilation fluid through at least one side hole and into the inflatable cuff to urge the inflatable cuff toward the inflated condition includes the step of bringing at least a portion of an outer circumference of the inflatable cuff into lateral contact with at least a portion of the trachea wall. 
     
     
         3 . The method of  claim 2 , wherein the step of bringing at least a portion of an outer circumference of the inflatable cuff into lateral contact with at least a portion of the trachea wall includes the step of placing substantially an entirety of the outer circumference of the inflatable cuff into lateral contact with at least a portion of the trachea wall to block fluid flow longitudinally past the inflatable cuff through the trachea lumen. 
     
     
         4 . The method of  claim 1 , including the steps of:
 directing ventilation fluid from the ventilation fluid source to flows in a first, distally oriented direction through the tube lumen;
 accepting, with the inflatable cuff, a predetermined volume of ventilation fluid from the plurality of side holes; 
 when the inflatable cuff has achieved the inflated condition through presence of the ventilation fluid within the inflatable cuff, resisting flow through the side holes of ventilation fluid in excess of the predetermined volume of ventilation fluid; 
 causing, with the flow resistance of the inflatable cuff, a second elevated ventilation fluid pressure, higher than the first elevated ventilation fluid pressure, in a portion of the tube lumen longitudinally coincident with at least a portion of the distal tube end region; 
 urging, with the second elevated ventilation fluid pressure, ventilation fluid distally through the plug lumen and out of the AC from the distal tube and plug end faces. 
   
     
     
         5 . The method of  claim 4 , including the steps of:
 raising, with the ventilation fluid urged distally through the plug lumen and out of the AC from the distal tube and plug end faces, an ambient fluid pressure in an ambient space distally located with respect to the AEC.   
     
     
         6 . The method of  claim 5 , including the steps of:
 selectively adjusting the fluid pressure within the tube lumen to have a lower pressure than the ambient fluid pressure in the ambient space distally located with respect to the AEC;   with the lower pressure within the tube lumen, causing ventilation fluid to be drawn through the side holes from the inflatable cuff; and   
       urging the inflatable cuff toward the deflated condition. 
     
     
         7 . The method of  claim 6 , including the step of cooperatively urging, via the at least partial deflation of the inflatable cuff and the ambient fluid pressure, ventilation fluid from the ambient space to flow through the trachea lumen in a second, proximally oriented direction between the outer tube wall and the trachea wall. 
     
     
         8 . The method of  claim 6 , including the step of urging, via at least the ambient fluid pressure, ventilation fluid from the ambient space to flow through the tube lumen in a second, proximally oriented direction. 
     
     
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