Comparison of oxygenation among different supplemental oxygen methods during flexible bronchoscopy in infants

BackgroundSupplemental oxygen (O2) is mandatory during flexible bronchoscopy (FB) in infants, but there are limited studies that deal with the efficacy of different O2 delivery methods. This study aims to compare the oxyhemoglobin saturation in infants during FB among three different O2 delivery methods, as measured by pulse oximeter (SpO2).MethodsA prospective study enrolled infants with two criteria: (1) less than 2 years old; and (2) needing FB examination. All infants received intravenous sedation and topical anesthesia. They were randomly placed into the following three groups: (1) nasal cannula (NC; 0.5 L/kg/min); (2) nasal prongs with continuous positive airway pressure (NP-CPAP; 5–10 L/min, pressure 5 cmH2O); and (3) nasopharyngeal catheter (NPC; 0.3–0.5 L/kg/min). SpO2, heart rate, blood pressure and respiratory rate were measured and compared at different stages: (1) prior to the FB (baseline); the FB tip at (2) the nose tip; (3) the pharynx; (4) the carina and (5) 30 minutes after the FB.ResultsA total of 75 infants, with 25 infants per group, were enrolled during a 2-year period. There were no significant differences in basic characteristics and baseline SpO2. After the designated O2 was delivered, SpO2 decreased significantly (p < 0.05) when the FB tip was advanced from the nostril to the pharynx, and further decreased (p < 0.01) when at the carina in all groups, especially in the NC group. After FB, SpO2 returned to baseline levels in all three groups. The NC group had the lowest SpO2 at the pharynx (p < 0.01) and carina (p < 0.01). The NP-CPAP and NPC groups had better SpO2.ConclusionSupplemental O2 via NPC is a simple and cost-effective method to maintain good SpO2 during FB examination of infants.