Predictors of oxygen desaturation in patients undergoing diagnostic bronchoscopy

Oxygen desaturation is not uncommon during bronchoscopy. We sought to identify factors predictive of desaturation during flexible bronchoscopy.

Over eight months, we enrolled 137 randomly selected patients who were undergoing fiberoptic bronchoscopy at our medical center. The patients' oxygen saturation was monitored on their arrival and during the procedure by finger pulse oximetry. Desaturation was defined as an overall saturation nadir of < 90% or an episode of decreased saturation of 5% from the baseline regardless of whether the patient was receiving supplemental oxygen.

The need for oxygen supplementation before the procedure was predictive of a higher rate of desaturation episodes (73.9% vs. 50%, p = 0.036). Although all interventional procedures or their complications can cause desaturation, the specific type of procedure was the most important predictor of desaturation (lavage, 88.9%; washing, 43.8%; brushing, 15.2%; biopsy, 10%). A low peak expiratory flow rate before the procedure seemed to be predictive of a high desaturation rate in patients undergoing lavage or washing during bronchoscopy.

Our study suggested that age, sex and baseline oxygen saturation were not predictors of desaturation. We should be reminded of the possibility of desaturation during every procedure, especially in patients who need supplemental oxygen before bronchoscopy.