Higher PEEP, Fewer Events: An Institutional Initiative to Reduce Ventilator-Associated Complications

Introduction: The CDC has outlined a surveillance framework to capture a range of complications from mechanical ventilation called ventilator-associated events (VAEs), which are defined by sustained increases in ventilator settings after a period of stability and categorized into three nested tiers: ventilator-associated conditions (VAC), infection-related ventilator-associated complications (IVAC), and possible ventilator-associated pneumonia (PVAP). Because mechanical ventilation reduces functional residual capacity (FRC), often leading to atelectasis, and PEEP is a key determinant of FRC, we hypothesized that a higher baseline PEEP would reduce VACs. We also observed that many PEEP changes triggering surveillance were not due to clinically relevant complications. We therefore further hypothesized that raising baseline PEEP would reduce false-positive triggers and improve detection specificity.


Methods: In August 2021, a new PEEP protocol was implemented across seven ICUs at an urban academic hospital campus. All newly ventilated patients were initiated at a baseline PEEP of 8 cm H₂O instead of 5 cm H₂O. Respiratory therapists, nurses, and intensivists received targeted education, and unit-based champions supported adherence. Spontaneous breathing trials and weaning continued per institutional protocols. We compared rates of VAEs - including VAC, IVAC, and PVAP - over 27-months before and 39-months after implementation.


Results: A total of 35,199 ventilator days occurred in the pre-intervention period and 48,299 post-intervention. The average VAC rate declined from 7.95 to 3.08 events per 1,000 ventilator days, a 61.3% relative reduction (p < 0.001). IVAC and PVAP rates declined from 5.07 to 2.33 events per 1,000 ventilator days, a 54.1% reduction (p < 0.001).


Conclusions: Initiating mechanical ventilation with higher baseline PEEP appears to reduce VAE and IVAC/PVAP rates. These benefits may stem from improved alveolar recruitment and the mechanical stenting effect of PEEP, which limits secretion migration and microaspiration—a key contributor to ventilator-associated pneumonias. Additional effects of PEEP on atelectasis, pulmonary edema, or ventilator-induced lung injury may also play a role. This protocol may enhance surveillance specificity by reducing insignificant VAE triggers.