For patients with severe acute respiratory syndrome (SARS), inhaling nitric oxide leads to improved oxygenation and less need for mechanical ventilation, according to a new report.

Nitric oxide or NO (not to be confused with nitrous oxide “laughing gas, NO2) has dilating properties, and is sometimes used to help babies with breathing problems, for example.

Dr. Goran Hedenstierna, at Uppsala University in Sweden, and associates in China studied 14 patients with SARS treated in hospitals in Beijing in 2003. Six were treated with NO and the remaining eight served as “controls.”

All the patients were also treated with inhaled oxygen, an antiviral drug and steroids, along with antibiotic or antifungal drugs as needed.

During NO treatment, the amount of oxygen the patients needed was reduced by two-thirds, while the level of oxygen in the blood increased, the team reports in the medical journal Clinical Infectious Diseases.

Only in the NO group was ventilation support reduced during the 10-day study period and then discontinued, with no decrease in blood oxygen saturation.

Chest X-rays showed lung improvements in five of the patients given nitric oxide.

One patient in the NO group and two in the control group died. For the remaining patients, discharge from the hospital took place after an average of 4.4 weeks in the NO group and 6.2 weeks in the control group.

The improvements seen with nitric oxide “can hardly be explained” just by the dilating properties of the gas, Hedenstierna’s team believes. They therefore suggest that the treatment had an effect on the disease itself, perhaps by directly inhibiting the SARS virus.

SOURCE: Clinical Infectious Diseases, November 15, 2004.