Pneumonia andIncidence of Endotracheal TubeOcclusion

pneumonia (VAP) andtherateofendotracheal tubeocclusion. Methods: Thisreport describes a prospective, randomized trial of280consecutive trauma patients ina 20-bed traumaICU(TICU). Allintubated patients notventilated elsewhere inthe medical centerprior totheir TICUadmission were randomized toeither an in-line HMEF or a H-wHinthebreathing circuit. Ventilator circuits were changed routinely every 7days, andclosed system suction catheters were changed every 3days. HMEFs were changed every 24h, or more frequently ifnecessary. A specific endotracheal tubesuction andlavage protocol was not employed. Patients were dropped fromtheHMEF groupifthefilter was changed more than three times aday or thepatient was placed on aregimen ofultra high-frequency ventilation. The CentersforDisease Control andPrevention (CDC) criteria fordiagnosis ofpneumonia were used; early-onset, community-acquired pneumonia was defined ifCDC criteria were metin^3 days, andlate-onset, hospital-acquired pneumonia was defined ifcriteria were metin>3days. Laboratory andchestradiograph interpretation were blinded. Results: Thepatient agesranged from15to95years intheHMEF groupand16to87years in theH-wHgroup(p=not significant), with a mean ageof46years and48years, respectively. The maletofemale ratioranged between 78to82%/22to18%,respectively, and55%ofall admissions were related toblunt trauma, 40%secondary topenetrating trauma, and5% tomajor burns. There was no difference inInjury Severity Score(ISS) between thetwogroups. Moreover, there was no significant difference inmean ISSamongthose whodidnotdevelop pneumonia andthose patients whodeveloped either early-onset, community-acquired or late-onset, hospital-acquired pneumonia. TheHMEF nosocomial VAP ratewas 6% compared to16%fortheH-wH group (p<0.05), andtotal ventilator circuit costs(per group) were reduced. There were no differences induration ofventilation (mean±SD) ifthepatient didnotdevelop pneumonia or ifthepatient developed an early-onset, community-acquired or a late-onset, hospital-acquired pneumonia. Moreover, total TICUdays were reduced intheHMEF group. Inaddition, theincidence of partial endotracheal tubeocclusion was notsignificantly different between theH-wH andthe HMEF groups. Conclusions: TheHMEF usedinthisstudy reduced theincidence oflate-onset, hospital-acquired VAP, butnotearly-onset, community-acquired VAP,compared totheconventional H-wHcircuit. This was associated with a significant reduction intotal ICUstay. Disposable ventilator circuit costsintheHMEF group were reduced compared totheH-wHgroup inwhomcircuit changes occurred at7-day intervals. Clinical implications: Theuse oftheHMEF isa cost-effective clinical practice associated with fewerlate-onset, hospital-acquired VAPs, andshould result inimproved resource allocation and utilization. (CHEST 1997; 112:1055-59)