Cost analysis and clinical impact of weekly ventilator circuit changes in patients in intensive care unit

Background: The introduction of heated circuits and sealed, single-use humidifiers has prompted some investigators to question the traditional recommendations for changing vertilator circuits. We studied the clinical and cost impact of extending the circuit change interval from 72 hours to 7 days in our two intensive care units with 17 beds. Methods: With standard surveillance definitions from the Centers for Disease Control and Prevention and the National Nosocomial Infections Surveillance System, baseline pneumonia rates were established for a 3-month period. After the institution of weekly circuit changes, daily surveillance of intubated patients was performed during 18 of 22 weeks from May through September 1993. Standard microbiologic methods were used for the identification of patient and environmental isolates. Results: Ventilator-associated pneumonia for the 72-hour circuit change group was 9.1% or 1.29 per 100 ventilator days. After the institution of weekly changes, pneumonia occurred in 9 of 146 patients (6.2% or 0.74 per 100 ventilator days χ2= 0.33, P = 0.44). No common bacterial isolates were recovered as judged by phenotype, biochemical, or antimicrobial susceptibility patterns. Weekly changes reduced the number of circuits used from a predicted 469 to 214. Estimating $26.46 per circuit change, annualized cost savings were $20,246.90. Conclusions: Weekly circuited changes in patients undergoing ventilation therapy in the intensive care unit are cost-effective and do not contribute to increased rates of nosocomial pneumonia.