A55-51 Driving Pressure Limited Ventilation In Acute Hypoxemic Respiratory Failure; A Meta-analysis Of Randomized Controlled Trials

Rationale

Driving pressure (DP) is associated with ventilator induced lung injury and mortality in patients with acute hypoxemic respiratory failure. Most current evidence is observational with lack of powered prospective randomized data to confirm causality. Therefore, we conducted this meta-analysis to evaluate the evidence and potential benefit of implementing DP limited strategy in patients with acute hypoxemic respiratory failure.

Methods

We systematically searched multiple databases using pre-defined search terms. We included only randomized controlled trials directly or indirectly implementing DP limited strategy in ventilating patients with acute hypoxemic respiratory failure. Primary outcome of interest was all-cause mortality. Secondary outcomes were ventilator-free days, ICU length of stay (LOS), and hospital LOS. We calculated odd ratios (OR), and mean differences (MD), using random-effects model via RevMan 5.4 software.

Results

We included 5 randomized trials with a total of 982 patients and a median follow-up of 28 days. 1-5 Two trials investigated ultra-limited tidal volume (TV) ventilation, 4,5 one with the facilitation of extra-corporeal CO2 removal. 5 All trials adhered to lung protective ventilation and allowed neuromuscular blockade and pronning as indicated. The patients mean age was 62±16 years, 35% identified as female. Community acquired pneumonia was the etiology in 59% of patients, and 39% were due to COVID-19 pneumonia. Mean PAO2:FiO2 at enrollment was 138±81, TV 6.5±1.3 ml/Kg predicted bodyweight, DP 14±5.0 cm H2O, and respiratory rate 25±6.0 breath/min. All trials used positive end expiratory pressure (PEEP) of 10±2 cm H2O, except one trial, used 6.0±1.0 cm H2O. 3 Our study found that compared to the conventional arm; DP limited strategy had statistically significant lower DP, [MD -1.33, 95% CI (-2.04, -0.62), P < 0.001]. There was no statistically significant difference in all-cause mortality rate, ICU LOS, nor Hospital LOS [OR 1.15, 95% CI (0.89,1.48), P = 0.29], [MD 0.03, 95% CI (-2.50,2.56), P = 0.98], [MD 1.08, 95% CI (-1.74,3.91), P = 0.45] respectively. DP limited strategy showed less favorable Ventilator-free days compared to conventional arm [MD -1.82, 95% CI (-3.13, -0.51), P = 0.006].

Conclusion

In patients with acute hypoxemic respiratory failure requiring mechanical ventilation, implementing DP limited strategy did not show any difference in mortality, ICU or hospital length of stay.

This abstract is funded by: None