TRACHEAL MUCUS VELOCITY REMAINS NORMAL IN HEALTHY SHEEP INTUBATED WITH A NEW ENDOTRACHEAL-TUBE WITH A NOVEL LARYNGEAL SEAL

Background: Tracheal mucus velocity (TMV), an index of mucociliary cle arance, is reduced markedly in patients intubated with standard endotr acheal tubes (ETTs) with high-compliance low-pressure (hi-lo) cuffs. T he authors developed a new ultra-thin walled ETT in which the inflatab le cuff is replaced with a no-pressure seal, positioned at the level o f the larynx. The seal consists of 12 to 20 toroidal layers of thin po lyurethane film (''gills'') at the level of the vocal cords and preven ts both air leak and fluid aspiration, The authors hypothesized that E TTs with the new laryngeal seal may impair TMV less than ETTs with inf lated hi-lo cuffs do. Methods: The TMV was measured in seven healthy f emale sheep by radiographically tracking the motion of small discs of tantalum inserted into the trachea through a bronchoscope, The TMV was measured in spontaneously breathing sheep before intubation (baseline ) and after intubation with either a hi-lo ETT (control group) or afte r intubation with a new ETT with gills (study group). Four to six week s later, the studies were repeated, but the sheep that were previously in the control group served as the study group, and those in the stud y group served as controls. Results: Baseline TMV did not differ in th e two groups, In the control group, TMV decreased significantly (by 67 %) from baseline. In the study group, TMV did not differ significantly from baseline and remained steady during 3 h of intubation. Conclusio ns: The TMV does not change in sheep intubated with new ETTs with gill s, The new ETTs may help promote a normal mucociliary clearance in pat ients who require ventilation.