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Capnography During Deep Sedation with Propofol by Nonanesthesiologists: A Randomized Controlled Trial

van Loon, Kim MD*; van Rheineck Leyssius, Aart T. MD*; van Zaane, Bas MD, PhD*; Denteneer, Mirjam MD; Kalkman, Cor J. MD, PhD*

doi: 10.1213/ANE.0b013e3182a1f0a2
Ambulatory Anesthesiology: Research Report

BACKGROUND: Propofol, a short-acting hypnotic drug, is increasingly administered by a diverse group of specialists (e.g., cardiologists, gastroenterologists) during diagnostic and therapeutic procedures. Standard monitoring during sedation comprises continuous pulse oximetry with visual assessment of the patient’s breathing pattern. Because undetected hypoventilation is a common pathway for complications, capnographic monitoring of exhaled carbon dioxide has been advocated. We examined whether the use of capnography reduces the incidence of hypoxemia during nonanesthesiologist-administered propofol sedation in patients who did not receive supplemental oxygen routinely.

METHODS: An open, stratified, randomized controlled trial was conducted in 427 healthy adult women during minor gynecology procedures in an outpatient clinic in the Netherlands. Patients were randomly assigned to receive either standard respiratory monitoring (standard care) or standard respiratory monitoring combined with capnography (capnography group). To replicate usual clinical practice, capnography monitoring was performed by the same medical team that provided sedation. The primary end point was the incidence of hypoxemia, defined as oxygen saturations <91%.

RESULTS: From April 2010 to January 2011, 427 patients were enrolled. In the capnography group, 206 patients and in the standard care group, 209 patients were analyzed. The percentage of patients with a hypoxemic episode was 25.7% (53 of 206) in the capnography group and 24.9% (52 of 209) in the standard care group, resulting in an absolute difference of 0.8% (−7.5 to 9.2%).

CONCLUSIONS: We were unable to confirm an additive role for capnography in preventing hypoxemia during elective nonanesthesiologist-administered propofol (monotherapy) sedation in healthy women in whom supplemental oxygen is not routinely administered. Based on the confidence interval, the benefit of adding capnography is at most an absolute hypoxemia reduction of 7.5%, suggesting that adding it in this practice setting to the routine monitoring strategy does not necessarily improve patient safety in daily practice.

Published ahead of print May 16, 2014

From the *Department of Anesthesiology, Division of Anesthesiology Intensive Care and Emergency Medicine, University Medical Center Utrecht, Utrecht; and Casa Clinics Leiden, CASA Netherlands, the Netherlands.

Accepted for publication June 9, 2013.

Published ahead of print May 16, 2014

Funding: This trial was entirely funded by the regular state funding to universities. No external funding was obtained. No manufacturer of capnographic equipment was involved in the design or execution of the study.

This report was previously presented, in part, at the Dutch Anesthesiologist meeting “NVA Wetenschapsdag” and as a poster presentation at the ASA meeting in Washington, 2012.

The authors declare no conflicts of interest.

Reprints will not be available from the authors.

Address correspondence to Kim van Loon, MD, Division of Anesthesiology Intensive Care and Emergency Medicine, University Medical Center Utrecht, F 06.149, P.O. Box 85500, 3508 GA Utrecht, the Netherlands. Address e-mail to

© 2014 International Anesthesia Research Society