Acute respiratory distress syndrome (ARDS) remains a formidable sequela, complication, and mortality risk in patients with large burns with or without inhalation injury. Alveolar recruitment using higher Positive End Expiratory Pressures (PEEP) after the onset of ARDS has been tried with varying success. Studies have identified benefits for several rescue maneuvers in ARDS patients with refractory hypoxemia. A prophylactic strategy utilizing an early recruitment maneuver, however, has not, to our knowledge, been explored in ventilated burn patients. This study was designed to evaluate the natural progression and clinical outcomes of ARDS severity (mild, moderate, and severe) using Berlin criteria in ventilated burn patients treated with an early high-PEEP ventilator strategy.
A single-center retrospective review of burn patients who were mechanically ventilated for greater than 48 hours utilizing an early high-PEEP >10 mmHg (10.36) ventilator strategy was performed at our Level 1 trauma and regional burn center. ARDS severity was defined according to the Berlin criteria and then compared to published results of ARDS severity, clinical outcomes, and mortality. Demographic data, as well as respiratory and clinical outcomes were evaluated.
Eighty-three patients met inclusion criteria and were evaluated. Utilizing the Berlin definition as a benchmark, 42.1% of patients met ARDS criteria on admission and most patients (85.5%) developed ARDS within the first seven days: 28 (34%) mild, 32 (38.6%) moderate, and 11 (13.3%) severe ARDS. The mean percent total body surface area (%TBSA) was 24.6 + 22.1, with 68.7% of patients diagnosed with inhalation injury. The highest incidence of ARDS was 57.8% on day 2 of admission. Most cases remained in the mild to moderate ARDS category with severe ARDS (2.4%) being less common by hospital day 7. Overall, 30-day in-hospital and inhalation injury mortality rates were 9.6% and 15.8%, respectively. No correlation was observed between plateau pressures (22.8), mean arterial pressures (84.4), or vasopressor requirements; and oxygen requirements down trended quickly over the first 24-48 hours.
In our study, implementing prophylactic, immediate high-PEEP in mechanically ventilated burn patients was associated with trends toward decreased severity and rapid resolution of ARDS in the first week following burn injury. This correlated with low 30-day in-hospital mortality in this population. This short and less severe course suggests that early high-PEEP support may be a viable protective strategy in the treatment of ventilated burn patients with ARDS.