Inhaled nitric oxide for acute chest syndrome in people with sickle cell disease

Abstract

Background: Acute chest syndrome has been defined as a new infiltrate visible on chest radiograph associated with one or more symptoms, such as fever, cough, sputum production, tachypnea, dyspnea, or new-onset hypoxia. Symptoms and complications of this syndrome, whether of infectious or non-infectious origin, vary quite widely in people with sickle cell disease. Lung infection tends to predominate in children, whilst infarction appears more common in adults. However, these are often interrelated and may occur concurrently. The differences in clinical course and severity are suggestive of multiple causes for acute chest syndrome. Successful treatment depends principally on high-quality supportive care. The syndrome and its treatment have been extensively studied, but the response to antibiotics, anticoagulants, and other conventional therapies remains disappointing. The potential of inhaled nitric oxide as a treatment option has more recently provoked considerable interest. Nitric oxide appears to play a major role in both the regulation of vascular muscle tone at the cellular level and in platelet aggregation (clumping). Much of the pathophysiology of sickle cell disease is consistent with a mechanism of nitric oxide depletion and although there has been extensive research on the pathophysiology of acute chest syndrome, the possible therapeutic role of inhaled nitric oxide for acute chest syndrome in sickle cell disease is still to be determined.

Objectives: To assess the effectiveness of inhaled nitric oxide for treating acute chest syndrome by comparing improvement in symptoms and clinical outcomes against standard care.

Search strategy: We searched The Group's Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. In July 2007 the following clinical trials registers were searched: ClinicalTrials.gov (www.clinicaltrials.gov/); the WHO International Clinical Trials Registry Platform (www.who.int/trialsearch/); Current Controlled Trials (www.controlled-trials.com/) and CLINICALTRIALS.COM (www.clinicaltrials.com/). Most recent search of the Trials Register: November 2007.

Selection criteria: All randomised or quasi-randomised controlled trials of people with sickle cell disease suffering from acute chest syndrome, comparing the use of inhaled nitric oxide to placebo or standard care for any single or multiple treatment and over any time period.

Data collection and analysis: No studies identified were eligible for inclusion.

Main results: No studies identified were eligible for inclusion.

Authors' conclusions: There is a need for well-designed, adequately-powered randomised controlled trial to assess the benefits and risks of this form of treatment as an adjunct to established therapies.