Prediction of peri-operative adverse respiratory events in children: the role of exhaled nitric oxide

Increased levels of exhaled nitric oxide (eNO) may be a more objective predictor in identifying children at higher risk of peri-operative adverse respiratory events than the presence of risk factors such as recent cold or wheeze. Children with either none or >= 2 risk factors had eNO measured before surgery and any peri-operative adverse respiratory events were recorded. We found that an elevated eNO level was only predictive of adverse respiratory events in children with >= 2 risk factors (OR 2.96 (95% CI 1.48-5.93), p = 0.002). The presence of risk factors had a better predictive capability than a raised eNO level (OR 3.83 (95% CI 1.85-7.95), p < 0.001). The combination of both predictors did not improve the predictive capability for adverse respiratory events (OR 1.93 (95% CI 1.44-2.59), p < 0.001). We conclude that measuring eNO levels does not lead to improved prediction of adverse respiratory events and that, in routine clinical practice, an accurate history of risk factors remains the most appropriate tool for successfully identifying children at risk of peri-operative adverse respiratory events.