Controlled airway pressure therapy, nitric oxide inhalation, prone position, and extracorporeal membrane oxygenation (ECMO) as components of an integrated approach to ARDS

Abstract

Background: Recent years have seen the introduction of innovative additive therapies for acute respiratory distress syndrome. However, because there are no reliable predictors of response to a particular therapy, potential responders to a specific therapeutic intervention may be lost. Therefore, the authors evaluated the effect of a combined therapeutic approach on the survival of patients with acute respiratory distress syndrome, when treated according to a strict algorithm. Methods: During a 2.5-yr period, 84 patients with acute respiratory distress syndrome were assigned to a standardized treatment protocol. Data analysis was performed by retrospective review of patient charts. Patients were treated using a stepwise treatment algorithm of pressure-controlled ventilation (peak airway pressure < 35 cm H2O), positive end-expiratory pressure (PEEP; 12-15 cm H2O), permissive hypercapnia, inhaled nitric oxide (5-20 ppm), and prone positioning. These interventions were termed 'conventional therapy.' Response to treatment was defined as a more than 20% increase in arterial oxygen tension (Pa(O2)). Nonresponders were triaged to extracorporeal membrane oxygenation. Results: The overall survival rate was 80%. All patients received conventional therapy up to 96 h; 71 responded to conventional therapy and 59 survived (83%). Thirteen patients (15%) did not respond to conventional therapy and underwent extracorporeal membrane oxygenation; 8 of these patients (62%) survived. For the group, the mean admission lung injury score was 3.3 ± 0.5, the Pa(O2)/fractional inspired oxygen tension (Fi(O2)) ratio was 96 ± 45, and the Acute Physiology and Chronic Health Evaluation (APACHE) II score was 18 ± 6. Conclusions: The 80% overall survival rate achieved in this group of patients with severe acute respiratory distress syndrome may in part reflect the additive beneficial effects of combined treatment methods, such as airway pressure control, nitric oxide inhalation, prone position, and early triage of nonresponders to extracorporeal membrane oxygenation.