Category: Critical Care
Keywords: ARDS, Nitric Oxide, acute respiratory failure, mechanical ventilation (PubMed Search)
Posted: 3/23/2014 by John Greenwood, MD
(Updated: 3/26/2014)
Click here to contact John Greenwood, MD
Nitric Oxide appears to have NO role in ARDS
Background: The use of inhaled nitric oxide (iNO) in acute respiratory distress syndrome (ARDS) & severe hypoxemic respiratory failure has been thought to potentially improve oxygenation and clinical outcomes. It is estimated that iNO is used in up to 14% of patients, despite a lack of evidence to show improved outcomes.
Mechanism: Inhaled NO works as a selective pulmonary vasodilator which has been found to improve PaO2/FiO2 by 5-13%, but is costly ($1,500 - $3,000 per day) and increases risk of renal failure in the critically ill.
Study: A recent systematic review analyzed 9 different RCTs (N=1142) and compared mortality between those with severe (PaO2/FiO2 < 100) and less severe (PaO2/FiO2 > 100) ARDS and found that iNO does not reduce mortality in patients with ARDS, regardless of the severity of hypoxemia.
Bottom Line: Inhaled NO is an intriguing option for the treatment of refractory hypoxemic respiratory failure, however there does not appear to be a mortality benefit to justify it's high cost and potentially negative side effects. In the ED, it is important to focus on appropriate lung protective ventilation strategies (TV: 6-8 cc/kg IBW) and maintaining plateau pressures < 30 cm H2O in the initial stages of ARDS to prevent ventilator induced lung injury while awaiting ICU admission.
Reference
Adhikari NK, Dellinger RP, Lundin S, et al. Inhaled nitric oxide does not reduce mortality in patients with acute respiratory distress syndrome regardless of severity: systematic review and meta-analysis. Crit Care Med. 2014;42(2):404-12. [PMID: 24132038]
Follow me on Twitter (@JohnGreenwoodMD)
