అనస్థీషియా & క్లినికల్ రీసెర్చ్
అందరికి ప్రవేశం

నైరూప్య

Evaluation of Transcutaneous and End-Tidal Carbon Dioxide During Intravenous Sedation in Volunteers

Kenichi Satoh DDS, Hitoshi Miura, Miho Kumagai, Masahito Satoh, Akiyoshi Kuji and Shigeharu Joh

Objective: During intravenous sedation, end-tidal carbon dioxide (ETCO2) is usually measured with a nasal cannula or mouth-nose cannula. We compared the measurement accuracy of ETCO2 between these two devices and TC-CO2 and assessed which device is more useful during intravenous sedation in volunteers.

Methods: Eight male volunteers aged 25 to 35 years were evaluated in this single-institution blinded observational trial. After they lay quietly for 5 min without supplemental oxygen, the volunteers received supplemental oxygen by means of each device at a flow rate of 3 L/min for 15 min. Next, midazolam (0.05 mg/kg) was intravenously injected, flumazenil (20 mg) was injected 30 min later, and the ETCO2 and TC-CO2 waveform were recorded.

Results: The differences between ETCO2 and TC-CO2 significantly increased after midazolam injection and decreased after flumazenil injection. The difference between ETCO2 and TC-CO2 using the nasal cannula was greater than that using the mouth-nose cannula. The mean difference between TC-CO2 and ETCO2 ranged from 3 to 9 mmHg after midazolam injection using a nasal mask, and the mean difference ranged from 3 to 6 mmHg after midazolam injection using a mouth-nose cannula.

Conclusions: The difference between ETCO2 and TC-CO2 against TC-CO2 was within the clinically acceptable range. Both the nasal and mouth-nose cannula were useful for ETCO2 measurement with supplemental oxygen by means of each device at flow rate of 3 L/min during intravenous sedation in volunteers.