Mechanical ventilation with or without 7-day circuit changes. A randomized controlled trial.

Abstract

To determine whether a practice of not routinely changing ventilator circuits in patients who require prolonged mechanical ventilation is associated with an increased incidence of nosocomial pneumonia. Randomized controlled trial. Intensive care units in two university-affiliated teaching hospitals. 300 patients admitted to an intensive care unit who required mechanical ventilation for more than 5 days. Patients were randomly assigned to receive either no routine ventilator circuit changes or circuit changes every 7 days. The primary outcome measure was the incidence of ventilator-associated pneumonia. Other outcome measures included duration of mechanical ventilation, length of hospital stay, and hospital mortality. 147 patients were randomly assigned to receive no routine ventilator circuit changes, and 153 patients were randomly assigned to receive circuit changes every 7 days. The two groups were similar at the time of randomization with regard to demographic characteristics, intensive care unit admission diagnoses, and severity of illness. Ventilator-associated pneumonia was seen in 36 patients (24.5%) receiving no routine changes and in 44 patients (28.8%) receiving changes every 7 days (relative risk, 0.85 [95% CI, 0.55 to 1.17]). No statistically significant differences for hospital mortality, intensive care unit mortality, death during mechanical ventilation, death in patients with ventilator-associated pneumonia, or mortality directly attributed to ventilator-associated pneumonia were found between the two treatment groups (P > or = 0.11). Patients receiving changes every 7 days had 247 circuit changes costing a total of $7410; patients receiving no routine changes had a total of 11 circuit changes costing $330. The elimination of routine ventilator circuit changes can reduce medical care costs without increasing the incidence of nosocomial pneumonia in patients who require prolonged mechanical ventilation.