///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Complications associated with anesthetic care in obstetrical patients: A population-based study in Canada

Abstract Number: T1I-479
Abstract Type: Original Research

Leyla Baghirzada MD, MPH1 ; David Archer MD2; Andrew Walker PhD3; Mrinalini Balki MD4

Background: Complications associated with anesthetic care in obstetrics in high-income countries are rare (~1/1000 anesthetic interventions).1This rate is too low to be informative for practitioners. We provide a population-based summary of the frequency of anesthesia-related complications in obstetrical patients in Canada.

Method: We analyzed the database of the Canadian Institutes of Health Information for women hospitalized during pregnancy, delivery or puerperium (gestation ≥ 20 weeks) in all provinces of Canada except Quebec from Apr 2004 to Mar 2017. Complications were identified by ICD-10-CA codes. We used univariate and multivariate regression to model medical and obstetrical conditions and procedures independently associated with anesthesia-related complications.

Result: 12,318 anesthesia related adverse events occurred among 2,601,034 hospitalizations over 12 year period (Table 1). The most common adverse events were spinal and epidural anesthesia induced headache. The event rate for difficult/failed intubations and pulmonary complications was low. Of the 11,841 women who suffered an event, two died (fatality rate: 16.9/100,000 interventions; 95% CI 4.2-68/100,000). The deaths were unrelated to anesthesia interventions. The frequency of anesthesia related events per year varied from 304 to 513/100,000 interventions (P < 0.001). There was significant variation in the incidence among Canadian provinces (206 to 803/100,000 interventions (P < 0.001). Women ≤ 25 yrs old were significantly less likely to suffer an anesthetic event (adjusted OR 0.90; 95% CI 0.85-0.95). Anesthesia related events were more likely in those who had a cesarean delivery (adjusted OR 1.17; 95% CI 1.12-1.23). Use of general anesthesia for an intervention was significantly associated with an anesthetic event (adjusted OR 3.17; 95% CI 2.99-3.36). Noteworthy associations between cardiomyopathy (adjusted OR 6.24; 95% CI 2.70-14.43), obstructive sleep apnea (adjusted OR 2.31; 95% CI 1.25-4.25) and an anesthetic event were found. Postpartum hemorrhage and preeclampsia were the most common conditions associated with an anesthetic event.

Conclusion: The incidence of anesthesia related events in obstetric patients in Canada is rare and declining. However, anesthesiologists should be prepared to manage them, especially in women undergoing cesarean delivery under general anesthesia, or having preexisting medical conditions.


1. Anesth Analg 2009;109:1174 –81

SOAP 2019