Therapeutic Optimization Including Inhaled Nitric Oxide in Adult Respiratory Distress Syndrome in a Polyvalent Intensive Care Unit

Abstract

To investigate the effects of inhaled nitric oxide (NO) in adult respiratory distress syndrome (ARDS) associated with a therapeutic optimization strategy on oxygen parameters, barotrauma, and evolution in a medical and surgical intensive care unit. Prospective study. Twenty consecutive patients with ARDS were studied (Murray score 3.6 +/- 0.2). Eleven were surgical patients and nine were medical patients. All fulfilled the extracorporeal membrane oxygenation entry criteria. The APACHE II score predicted mortality was 39%. All were ventilated with FiO2 1 with positive end-expiratory pressure (PEEP) of 11 +/- 1 cm H2O. Therapeutic optimization included permissive hypercapnia, tracheal gas insufflation, prone position, continuous hemofiltration, treatment of infection, and pleural drainage. We used NO continuously inhaled at a concentration ranging from 5 to 10 ppm. After 1 hour, inhaled NO improved PaO2 in all patients except one (78 +/- 11 to 130 +/- 25 mm Hg) (p < 0.05), allowing a reduction of FiO2 and PEEP. After 24 hours, mean pulmonary arterial pressure decreased from 31 +/- 3 to 25 +/- 2 mm Hg (p < 0.05). Systemic hemodynamics were unaffected. Oxygen delivery increased from 531 +/- 135 to 603 +/- 125 mL/minute/m-2 (p < 0.05). Barotraumatic lesions were present in only one patient. Reversal of ARDS was obtained in 16 patients, of whom 14 (70%) were discharged. This study was shorter to demonstrate an improvement in the survival rate. Nevertheless, these preliminary results are encouraging. Because of its safety, effectiveness, and easy use, inhaled NO should be used as a part of a therapeutic optimization protocol before considering more invasive and expensive procedures, such as extracorporeal respiratory support or intravascular oxygenation.