///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47+00:00

How far is too far? Tales of the Tuohy

Abstract Number: S-27
Abstract Type: Original Research

Roneisha Mclendon MD1 ; Brianne Bordes MD2; Allison Clark MD3

Introduction: The obesity pandemic remains a significant public health concern in the United States, with Louisiana leading this trend (1). In the 1980s and 1990s the mean depth to the epidural space was demonstrated to be 4.2-4.9 centimeters (cm)(2). In 2007, Clinkscales et al demonstrated a mean depth of 5.3 cm in Michigan patients paralleling the explosion in the obesity pandemic (3). Anecdotally, we have noted greater average depth to the epidural space and a higher rate of patients with loss of resistance greater than 8 cm depth than previously reported (2-4). We sought to determine the rates of obesity in our obstetric population, as well as the depth to the epidural space and correlate these results with body mass index (BMI) at term gestation, and to quantify the number of parturients with >8cm depth.

Methods: After Institutional Review Board approval, a retrospective chart review was conducted for patients admitted to Ochsner Medical Center for delivery between November 1, 2012 and October 31, 2013. BMI (measured at the initial and final prenatal visits), anesthesia type, depth to the epidural space (in the sitting position), and delivery mode were recorded. Obesity rates, as well as depth to the epidural space in relation to BMI were measured. These end points were then stratified by delivery mode to determine if differences between groups could be demonstrated.

Results: Data from 608 parturients has been analyzed to date. Mean BMI at presentation and term gestation was 28.5 ± 7.8 kg/m2 and 32.4 ± 7.6 kg/m2, respectively. Antepartum rates of class I, II, and III obesity were 15%, 9%, and 10%. Mean depth to the epidural space was 6.2 cm ± 1.4 cm. BMI positively correlated with depth to the epidural space (Table 1). Ten percent of parturients had loss of resistance at greater than 8 cm depth.

Conclusion: The rise in obesity during pregnancy continues, with an increase in average depth to the epidural space by approximately 1 cm since the latest published data (2). The notion that the epidural space is rarely encountered at greater than 8cm no longer holds true, as 10% of our patient population exceeds this measure.


1.CDC. Available at: http://www.cdc.gov/obesity. Feb 2014.

2.Meiklejohn B. Reg Anesth 1990; 15: 134–6.

3.Clinkscales C et al. Int J Obstet Anesth 2007;16:323–327.

4.Hamza J et al. J Clin Anaesth 1995; 7:1–4.

SOAP 2014