Intravenous Sedation Without Intubation and the Risk of Anesthesia Complications for Obese and Non-Obese Women Undergoing Surgical Abortion: A Retrospective Cohort Study

Anesth Analg. 2016 Jun;122(6):1957-62. doi: 10.1213/ANE.0000000000001335.

Abstract

Background: The primary objective of this study was to assess the risk of perioperative anesthesia-related complications in a cohort of obese and non-obese women undergoing outpatient surgical abortion under IV sedation without tracheal intubation.

Methods: We performed a retrospective cohort study of all surgical abortions through 22 6/7 weeks' gestation at an outpatient clinic from 2012 to 2013. Women receiving IV sedation were included. Obesity status was defined by the World Health Organization criteria. The primary outcome was the rate of perioperative anesthesia complications defined as tracheal intubation, pulmonary aspiration, hospital transfer for an anesthesia indication, or anesthesia-related adverse events (persistent hypoxemia and allergic reaction). The use of opioid reversal (naloxone) was assessed as a secondary outcome measure. Multivariate analysis for the secondary outcome measure was performed with adjustment for confounding factors.

Results: During the study period, 9348 abortions were performed. Of the 5579 patients who received IV sedation, 1438 (25.8%) were obese, 1707 (30.6%) were in the second trimester, and 851 (15.3%) were ≥17 weeks' gestation. No patients experienced a primary outcome measure. Based on the upper 95% confidence interval (CI) for the sample size, the maximal risk of an anesthesia-related complication is 1 in 1860 procedures. Naloxone use occurred in 13 (0.2%) patients and was not more frequent among obese patients (0.14% vs 0.27%; 95% CI of odds ratio [OR], 0.12-2.36; P = 0.54) or procedures at ≥17 weeks' gestation (0.47% vs 0.19%; 95% CI of OR, 0.76-8.06; P = 0.12). These negative findings should be interpreted with caution, given the limitations of the sample size to assess these secondary outcome measures. Naloxone use was associated with fentanyl doses >200 μg (0.82% vs 0.13%; P = 0.002), an association that remained significant when we controlled for confounding factors (adjusted OR, 5.51; 95% CI, 1.61-18.91). Further analysis revealed that fentanyl dose >200 μg was associated with naloxone use for procedures in the first trimester (incident rate ratio, 9.02; 95% CI, 3.73-21.80) but not in the second trimester (incident rate ratio, 0.92; 95% CI, 0.23-3.70).

Conclusions: Among women receiving IV sedation without tracheal intubation for surgical abortion, anesthesia complications are rare and may not be greater for obese women or procedures at gestational age ≥17 weeks. IV sedation without tracheal intubation may be considered for women undergoing first- and second-trimester surgical abortion; however, the rarity of anesthesia-related complications in our cohort precludes a definitive conclusion regarding the overall safety of IV sedation without tracheal intubation.

Publication types

  • Comparative Study

MeSH terms

  • Abortion, Induced / adverse effects*
  • Abortion, Induced / methods
  • Adolescent
  • Adult
  • Ambulatory Surgical Procedures / adverse effects*
  • Ambulatory Surgical Procedures / methods
  • Anesthesia, Intravenous / adverse effects*
  • Anesthesia, Intravenous / methods
  • Anesthetics, Intravenous / administration & dosage
  • Anesthetics, Intravenous / adverse effects*
  • Chi-Square Distribution
  • Female
  • Humans
  • Intubation, Intratracheal
  • Logistic Models
  • Multivariate Analysis
  • Naloxone / administration & dosage
  • Narcotic Antagonists / administration & dosage
  • Obesity / complications*
  • Obesity / diagnosis
  • Odds Ratio
  • Ohio
  • Postoperative Complications / diagnosis
  • Postoperative Complications / etiology*
  • Postoperative Complications / therapy
  • Pregnancy
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Treatment Outcome
  • Young Adult

Substances

  • Anesthetics, Intravenous
  • Narcotic Antagonists
  • Naloxone