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Anesthesia-related adverse events in obstetric patients: a population-based study in Canada

Les événements indésirables liés à l’anesthésie chez les patientes obstétricales : une étude de population au Canada

Abstract

Background

Anesthesia-related complications in obstetric patients could be catastrophic and impact the lives of both the parturient and the neonate. The objective of this study was to determine the frequency, temporal trend, and risk factors of anesthesia-related adverse events during hospitalization for delivery in Canada.

Methods

This retrospective population-based study utilized the hospitalization database of the Canadian Institute for Health Information for all parturients (gestation ≥ 20 weeks) in Canada (except Quebec) hospitalized for childbirth from April 2004 to March 2017. Complications were identified by the enhanced Canadian version of the tenth revision of the International Statistical Classification of Diseases and Related Health Problems codes. Data were summarized with descriptive statistics. Associations between hospitalizations with an anesthesia-related adverse event and patient characteristics, delivery method, and modality of anesthesia were assessed using multivariate logistic regression.

Results

Among 2,601,034 hospitalizations (3,194,875 interventions), 8,361 anesthesia-related adverse events occurred over a 13-year period (262 per 100,000 interventions; 95% confidence interval [CI], 256 to 267), with a significant decline over time (P < 0.001). These were two-fold and seven-fold higher per 100,000 interventions with general (488; 95% CI, 438 to 542) and general plus neuraxial (1,476; 95% CI, 1,284 to 1,689) anesthesia compared with neuraxial anesthesia alone (225; 95% CI, 219 to 230). Serious adverse events constituted 9% of all adverse events. The most common adverse event was spinal and epidural anesthesia-induced headache (6,908/8,361; 83%); the overall rate of failed or difficult intubations was low (201/8,361; 2%). Anesthesia-related events were more likely in those who had a Cesarean delivery compared with vaginal delivery (odds ratio [OR], 1.12; 95% CI, 1.06 to 1.18) and general anesthesia compared with neuraxial anesthesia (OR, 1.71; 95% CI, 1.53 to 1.93). Noteworthy associations were found between any anesthesia-related adverse events and cardiomyopathy (OR, 8.34; 95% CI, 2.59 to 26.83), eclampsia (OR, 3.11; 95% CI, 1.95 to 4.97), and obstructive sleep apnea (OR, 1.91; 95% CI, 1.66 to 2.19).

Conclusion

The incidence of anesthesia-related adverse events in obstetric patients in Canada is low and declining. High vigilance is required in parturients undergoing Cesarean delivery, receiving general anesthesia, and those with pre-existing medical conditions.

Résumé

Contexte

Les complications liées à l’anesthésie chez les patientes obstétricales pourraient être catastrophiques et avoir un impact tant sur la vie de la parturiente que sur celle du nouveau-né. L’objectif de cette étude était de déterminer la fréquence, la tendance temporelle et les facteurs de risque d’événements indésirables liés à l’anesthésie pendant l’hospitalisation pour accouchement au Canada.

Méthode

Cette étude rétrospective basée sur la population a utilisé la base de données sur les hospitalisations de l’Institut canadien d'information sur la santé pour analyser les dossiers de toutes les parturientes (≥ 20 semaines de gestation) au Canada (à l’exception du Québec) hospitalisées pour accouchement entre les mois d’avril 2004 et mars 2017. Les complications ont été identifiées en suivant la version canadienne améliorée de la dixième révision des codes de la Classification statistique internationale des maladies et des problèmes de santé connexes. Les données ont été résumées à l’aide de statistiques descriptives. Les associations entre les hospitalisations comportant un événement indésirable lié à l’anesthésie et les caractéristiques de la patiente, la méthode d’accouchement et les modalités anesthésiques ont été évaluées à l’aide d’une régression logistique multivariée.

Résultats

Parmi les 2 601 034 hospitalisations (3 194 875 interventions), 8361 événements indésirables liés à l’anesthésie se sont produits sur une période de 13 ans (262 par 100 000 interventions; intervalle de confiance [IC] à 95 %, 256 à 267), avec une baisse significative au fil du temps (P < 0,001). Celles-ci étaient deux et sept fois plus élevées par 100 000 interventions avec une anesthésie générale (488; IC 95 %, 438 à 542) et avec une anesthésie générale plus neuraxiale (1476; IC 95 %, 1284 à 1689), respectivement, par rapport à une anesthésie neuraxiale seule (225; IC 95 %, 219 à 230). Les événements indésirables graves constituaient 9 % de tous les événements indésirables. L’événement indésirable le plus fréquent était les céphalées consécutives à l’anesthésie rachidienne et péridurale (6908/8361; 83 %); le taux global d’échecs d’intubation ou d’intubations difficiles était faible (201/8361; 2 %). Les événements liés à l’anesthésie étaient plus probables chez les parturientes ayant subi un accouchement par césarienne par rapport à un accouchement vaginal (rapport de cotes [RC], 1,12; IC 95 %, 1,06 à 1,18) et une anesthésie générale par rapport à une anesthésie neuraxiale (RC, 1,71; IC 95 %, 1,53 à 1,93). Des associations remarquables ont été notées entre tout événement indésirable lié à l’anesthésie et la cardiomyopathie (RC, 8,34; IC 95 %, 2,59 à 26,83), l’éclampsie (RC, 3,11; IC 95 %, 1,95 à 4,97) et l’apnée obstructive du sommeil (RC, 1,91; IC 95 %, 1,66 à 2,19).

Conclusion

Au Canada, l’incidence d’événements indésirables liés à l’anesthésie chez les patientes obstétricales est faible et en baisse. Une vigilance élevée est de mise lors de la prise en charge de parturientes accouchant par césarienne, recevant une anesthésie générale et pour celles souffrant de conditions médicales préexistantes.

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Author contributions

Leyla Baghirzada and Andrew Walker contributed to all aspects of this manuscript, including study conception and design; acquisition, analysis, and interpretation of data; and drafting the article. David Archer contributed to all aspects of this manuscript, including study conception and design and acquisition, analysis, and interpretation of data. Mrinalini Balki contributed to all aspects of this manuscript, including study conception and design, interpretation of data, and drafting the article.

Acknowledgements

The authors wish to sincerely thank and recognize the Information Technology Team at the University of Calgary, Cumming School of Medicine, Calgary, Alberta, specifically Will Fiebelkorn, Eric Anhorn, and Marcel Seguin. Without their assistance, our study would not have been possible.

Disclosures

None.

Funding statement

Support was provided by the grant from Anesthesia Academic Council, Department of Anesthesiology, Perioperative and Pain Medicine, University of Calgary

Editorial responsibility

This submission was handled by Dr. Alana Flexman, Associate Editor, Canadian Journal of Anesthesia/Journal canadien d’anesthésie.

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Correspondence to Leyla Baghirzada MD, MPH.

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This article is accompanied by an editorial. Please see Can J Anesth 2022 this issue.

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Baghirzada, L., Archer, D., Walker, A. et al. Anesthesia-related adverse events in obstetric patients: a population-based study in Canada. Can J Anesth/J Can Anesth (2021). https://doi.org/10.1007/s12630-021-02101-3

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Keywords

  • Anesthesia-related adverse events
  • Obstetric anesthesia
  • Epidemiology