The role of capnography in endoscopy patients undergoing nurse-administered propofol sedation: a randomized study

OBJECTIVE. Standard benzodiazepine/opioid cocktail has proven inferior to propofol sedation during complicated endoscopic procedures and in low-tolerance patients. Propofol is a short-acting hypnotic with a potential risk of respiratory depression at levels of moderate to deep sedation. The existing literature on capnography for endoscopy patients sedated with nurse-administered propofol sedation (NAPS) is limited. Can the addition of capnography to standard monitoring during endoscopy with NAPS reduce the number, duration, and level of hypoxia. MATERIALS AND METHODS. This study was a randomized controlled trial with an intervention group (capnography) and a control group (without capnography). Eligible subjects were consecutive patients for endoscopy at Gentofte Hospital compliant with the criteria of NAPS. RESULTS. Five hundred and forty patients, 263 with capnography and 277 without capnography, were included in the analysis. The number and total duration of hypoxia was reduced by 39.3% and 21.1% in the intervention group compared to the control group (p > 0.05). No differences in actions taken against insufficient respiration were found. Changes in end-tidal carbon dioxide (R = 0.177, p-value < 0.001) and respiratory rate (R = 0.092, p-value < 0.001) were correlated to oxygen saturation (SpO2) up to 36 s prior to changes in SpO2. CONCLUSIONS. Capnography seems to reduce the number and duration of hypoxia in NAPS patients (p > 0.05). Capnography is able to detect insufficient respiration that may lead to hypoxia prior to changes in pulse oximetry. However, due to a limited clinical benefit and additional costs associated with capnography, we do not find capnography necessary during the use of NAPS.