From the *Department of Anesthesia and Pain Management, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada; and †Institute of Social and Preventive Medicine (IUMSP), Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
Accepted for publication October 10, 2013.
Address correspondence to: Richard Brull, MD, FRCPC, Department of Anesthesia and Pain Management, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8 (e-mail: Richard.Brull@uhn.ca).
Dr Eric Albrecht has received grants from the Swiss Academy for Anaesthesia Research (SACAR), Lausanne, Switzerland (no grant numbers attributed). Dr Vincent Chan receives equipment support for research from BK Medical, Philips Healthcare, and SonoSite.
The other authors declare no conflict of interest.
This work was funded by the Merit Award Program, Department of Anesthesia, University of Toronto, in support of Dr Richard Brull.
This work was presented in part at the 38th Annual Spring Meeting and Workshops of the American Society of Regional Anesthesia and Pain Medicine (ASRA), Boston, MA, May 2–5, 2013.
E.A. and K.R.K. were responsible for the study design, performing intervention, and primary manuscript preparation; P.T., statistical analysis; R.V.W.E., study design, performing intervention, and manuscript editing; V.W.S.C., study design and manuscript editing; C.T., patient recruitment and data collection; and R.B., study design and manuscript preparation.