(1150) Specific Driving Pressure Orders in Initial Ventilator Settings May Improve Outcomes

Introduction: Identifying factors leading to lung injury during ventilation is crucial. Recent literature reports that driving pressure (DP) of less than 15 cmH2O significantly decreased the mortality of ARDS patients. In our study, we assess the need to put orders for driving pressure of less than 15 cmH2O in the initial ventilator orders.

Methods: This cross-sectional study of mechanically ventilated ICU patients at a large healthcare system with tertiary and 7 sister hospitals. Mechanically ventilated patients were identified utilizing the electronic health record system (EPIC). DP was calculated using the formula plateau airway pressure minus positive end-expiratory pressure (PEEP) or by dividing tidal volume with the static lung compliance. 2 independent authors collected the data after IRB exemption as a safety project. No patient-identifying data was preserved in any manner. Patients with insufficient data for DP calculation were excluded from the study. Patients who underwent tracheostomy were excluded as well as they may be on collar trial.

Results: Of 119 driving pressures obtained, 75/119 (63.0%) were found to be less than or equal to 15 cmH2O - followed by 44/119 (36.9%) patients with DP more than 15 cmH2O. We performed the binomial test as we were looking for a particular outcome between DP > or < 15 without any specific order. To determine the probability that particular outcome (K = DP above 15) across a certain number of trials (n =119) will occur, we use the formula z = ((K - np) ± 0.5) / √npq, where n is the total observation, K = occasions where DP violated ideal situation, (i.e., < 15) which was designated as 1. Our calculated q was zero. Our one-tailed probability pwas p < .000001, which means without specific orders, there is a statistically significant chance that DP will be > 15. Data collection was halted for 2 weeks in middle to ascertain washout and avoid duplication. Study was limited by its short cross-sectional design, small sample size, single healthcare system, no outcome data collection, and only EMR based data. This may have included patients on spontaneous breathing trials.

Conclusions: Study highlights the need to include DP in initial ventilator settings in order to allow for more effective lung protective strategies. More than 1/3rd patients were subjected to higher DP.