Nitric oxide has little effect on acute pulmonary hypertension and right ventricular function during acute respiratory distress syndrome.

OBJECTIVE

To evaluate the effect of nitric oxide (NO) on acute pulmonary hypertension and right ventricular function in patients with acute respiratory distress syndrome.

DESIGN

A prospective clinical study.

PATIENTS

Ten patients in the respiratory and surgical intensive care units were used. They met the criteria for acute respiratory distress syndrome and were significantly hypoxic. They were all ventilator-dependent at the time of the study.

INTERVENTION

NO was delivered to the patients in 5, 10, 20 and 30 ppm doses for 30 minutes at each concentration. The dosing was not randomised.

MEASUREMENTS AND RESULTS

The general and central haemodynamics were measured. Right ventricular function and interaction with the pulmonary artery impedance (Ea) were quantified with the ratio of right ventricular stroke work index/Ea. NO did not decrease the raised pulmonary artery pressure found in all of the patients. Right ventricular coupling to the circulation did not improve during the administration of NO.

CONCLUSION

NO did not relieve the acute pulmonary artery hypertension associated with acute respiratory distress syndrome. As a consequence of this, right ventricular function failed to improve during the administration of NO.