[1] IWK Hlth, Dept Womens & Obstet Anesthesia, Halifax, NS, Canada
[2] Dalhousie Univ, Dept Anesthesia Pain Management & Perioperat Med, Halifax, NS, Canada
[3] Dalhousie Univ, Ctr Learning & Teaching, Halifax, NS, Canada
[4] IWK Hlth, Ctr Res Family Hlth, Halifax, NS, Canada
[5] Univ Toronto, Dept Anesthesiol & Pain Med, Toronto, ON, Canada
[6] Univ Hlth Network, Toronto Western Hosp, Dept Anesthesia & Pain Management, Toronto, ON, Canada
[7] Univ Toronto, Dept Anesthesiol & Pain Med, Toronto, ON, Canada
[8] Univ Ottawa, Childrens Hosp Eastern Ontario, Dept Anesthesiol & Pain Med, Ottawa, ON, Canada