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

Obstetric Comorbidity Index (OB-CMI) as a predictor for general anesthesia in women undergoing cesarean delivery.

Abstract Number: T1H-452
Abstract Type: Original Research

Shubhangi Singh MBBS 1 ; Sarah Rae Easter MD, MS2; Kara G Fields MS3; Michaela K Farber MD, MS4; Brian T Bateman MD, MSC5; Lawrence C Tsen MD6

Background: Neuraxial anesthesia (NA) is preferred over general anesthesia (GA) for cesarean delivery (CD), but certain maternal and fetal conditions such as fetal bradycardia, hemodynamically unstable hemorrhage, or maternal coagulopathy necessitate GA. Increasing maternal morbidity may increase the risk for GA during CD. The OB comorbidity Index (OB-CMI) is a tool to identify pregnant patients at risk for morbidity, intensive care unit (ICU) admission, and mortality that has been validated in multiple populations (1, 2). Maternal comorbidities identifiable on admission to Labor and Delivery (weighed by the strength of association with maternal morbidity) are assigned points that sum into a single score. The objective of this study was to evaluate OB-CMI as a predictor of GA requirement during CD.

Methods: In this single center prospective cohort study, mode of anesthesia and OB-CMI for all women at or beyond 23 weeks of gestation undergoing CD between 2/14/2018 and 7/31/2018 were recorded. OB-CMI was calculated by the primary nurse at the time of admission to L & D and updated every 12 hours until delivery. In emergent cases where OB-CMI before CD was not available (n=161), OB-CMI documented closest to the time of delivery was abstracted. Univariable logistic regression was used to investigate the association between OB-CMI and GA.

Results: Of 935 women who underwent CD, 28 (3%) received GA. The NA and GA groups were comparable in terms of demographics, gravidity and parity. The median OB-CMI for patients who required GA was 5 (IQR 2-6.5) as compared to 2 (IQR1-4, P<0.001) for those who received NA. A 1-point increase in OB-CMI was associated with 1.33 (95% CI: 1.18, 1.51) times increased odds of receiving GA for CD. The C-statistic for the association between the OB-CMI and GA was 0.728 (95% CI 0.632-0.823) (Figure) indicating good discrimination.

Conclusions: A higher OB-CMI score was associated with increased risk of receiving GA. Although it needs to be further evaluated, OB-CMI may help predict GA requirement in women undergoing CD. A high OB-CMI score can prompt the anesthesiologist to establish a plan for potential airway or fasting management in advance of delivery or indicate mechanisms for earlier epidural placement.


1. Obstet Gynecol. 2013 Nov;122(5):957-65.

2. BJOG. 2015 Dec; 122(13): 1756.

SOAP 2019