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

Dosing of Intrathecal Bupivacaine in Super Obese Patients Undergoing Cesarean Delivery: A Retrospective Review

Abstract Number: T2D-499
Abstract Type: Original Research

Ryan M Militana DO1 ; Corinne C Weinstein MD2; Jacqueline M Galvan MD3; Heather C Nixon MD4

Introduction: It has been theorized that obese parturients require a reduction in intrathecal local anesthetic dose compared to non-obese counterparts during cesarean delivery (CD). Publications examining intrathecal bupivacaine dosing in obese patients are limited to subject populations with BMIs less than 40kg/m2 and fail to demonstrate a clear need to lower dosages. However, no data exists regarding intrathecal dose requirements in super obese parturients with BMIs > 50kg/m2. This retrospective study examines the sensory levels in super morbidly obese patients receiving either high or low dose hyperbaric bupivacaine.

Methods: Following IRB approval, the University of Illinois Obstetrics QI Cesarean Delivery Database was queried to identify patients with a BMI of 50kg/m2 or higher who underwent CD from 10/1/12-1/25/19. Each patient’s chart was hand searched to verify BMI, the use of intrathecal hyperbaric bupivacaine for CD and identify exclusion criteria (< 34 wks GA, < 148cm height, fetal wt > 4500gm, multiple gestations). Intrathecal bupivacaine doses were categorized as low dose LD (≤ 9 mg) or high dose HD (> 10mg) and sensory levels were categorized as inadequate (T7 or below), adequate (T4-T6), or high (T3 or above).

Results: A total of 230 subjects were identified and 130 were excluded due to alternative anesthetic technique (129) or missing data (1). Of the 100 pts who received intrathecal anesthesia with hyperbaric bupivacaine, 78 met inclusion criteria (16 low dose, 62 high dose). In the study group (Table 1), 23.29% had high levels (0 LD, 17 HD), 76.71% had adequate levels (15 LD, 41 HD), and 6.41% had inadequate levels (1 LD, 4 HD). High dose bupivacaine doses were associated with high sensory levels via Chi-square analysis (p-value 0.017). In the high dose group, one patient had a high spinal that required respiratory support.

Discussion: Our study demonstrates that HD intrathecal bupivacaine is associated with a high sensory levels (above T3) in super obese pts. There were no differences in the rates of inadequate levels between the high and low dose groups. Limitations of this study include the retrospective nature of the data and the small LD group size. Future prospective studies are needed to define ideal dosing in this population, but low dose intrathecal administration (7.5-9.0mg) may be a reasonable approach in combination with a CSE technique in this population.

Ref: Carvalho, et al.(2011).Anesthesiology,114(3),529-535

SOAP 2019