Patients undergoing heart surgery may be able to avoid kidney injury through the use of nitric oxide gas. The study, conducted in China, looked at the use of the gas on patients who were undergoing heart valve replacement.  Patients were relatively young and their heart problems were the result of rheumatic fever.

Heart valve replacement surgery requires a patient to be hooked up to a device called a cardiopulmonary bypass for approximately 90 minutes. The process can cause disruption to the red blood cells and cause them to release hemoglobin which can later cause kidney injury. It was theorized giving the patient the nitric oxide during and 24 hours after the procedure would prevent this damage.

This is because nitric oxide is normally produced by the cells lining the blood vessels and would render the hemoglobin inert. The study found:

• The group who received the nitric oxide were 50% less likely to develop kidney injury. This was down from 64% in patients who received the placebo.

• The risk of progressing to more serious kidney disease went down to 21% in the group who received the gas versus 33% in those who received the placebo.

• Only 18% of the gas group had serious kidney injury a year after surgery. In the placebo group, however, 31% had serious kidney disease a year later.

• Overall mortality went down to 3% in the gas group versus 6% in the placebo group after one year. In this case, the study noted the decrease was not considered significant because of the small number of people involved.

Previously, doctors have tried to use drugs, though they proved to be ineffective.

The results are currently only applicable in the cases of these cardiopulmonary cases. Still, researchers are excited as this could mean this procedure could help older such patients who undergo similar procedures. A similar trial is currently being undertaken at Massachusetts General Hospital in response to the China Study.