MORBID OBESITY IN AN OBSTETRIC ANESTHESIA PRACTICE: SIX YEAR REVIEW
Abstract Number: 54
Abstract Type: Original Research
Obesity, a major cause of preventable morbidity and mortality affects 25% of US women and over 1/3 of reproductive age. The WHO estimated that in 2005 there were >400 million obese people worldwide and predicted that by 2015 this number will double. Obesity is associated with an estimated 18% of obstetric-related maternal deaths and 80% of anesthesia-related deaths.1Morbid obesity in pregnancy is associated with increased risk for diabetes, hypertension, preeclampsia, need for operative delivery and post partum hemorrhage, all of which increase the need for anesthesia management. Obesity is defined by a BMI ≥ 30, morbid obesity ≥ 35 and severe obesity ≥40. The demographics for our region, the southeastern US, suggest a greater incidence of obesity (>30%) relative to the country as a whole. This retrospective review of deliveries at our institution expands on our earlier analysis of the demographics and impact of obesity on obstetric anesthesia service.2
Method. After obtaining IRB approval, anesthesia records were identified for delivery between October 2003 and December 2009. 15,124 records contained the following data - age, weight, height, anesthetic technique, mode of delivery, Mallampatti (MP) score, Cormack view if general anesthesia used, incidence of difficult intubation, presence of diabetes, pre eclampsia, fetal anomaly, and the incidence of epidural failure for labor and cesarean delivery. Data was sorted according to patient BMI under the following categories normal <30, obese ≥30, morbidly obese≥35 and severely obese ≥ 40. Data was analyzed with Chi square.
Results. The incidence of obesity in our population was 53.3%, morbid obesity 26.6%, and severely obese 12.8%. We were able to demonstrate a higher incidence of cesarean delivery, MP score >2, failed epidural, diabetes and pre eclampsia with increasing BMI. The use of general anesthesia was low across all subgroups (n=431), with no significant difference in use, Cormack view, nor difficulty with intubation noted. The incidence of cesarean delivery increased markedly with increasing BMI: 34.8% (BMI<30), 47.8% (BMI≥ 30), 52.0% (BMI≥ 35) and 55.2% (BMI≥ 40).
Discussion: A prior comprehensive review of anesthetic implications of morbid obesity in pregnancy revealed an increase in the need for cesarean delivery and despite overall increase in cesarean section rates we confirmed this to be true. However in this review we were unable to demonstrate the difficulties observed in the earlier study with airway management (35vs2.6%) or epidural failure (42vs5%). These findings are likely complementary as more effective epidural anesthesia can lead to better triage of the need for airway intervention.
1. Hall L, Neubert A. Obstet Gynecol Survey 2005;60:253-60.
2. Muir HA and Peterson-Layne CL. ASA Abst. 2007, A-771
3. Hood D, Dewan D Anesthesiology 1993;79:1210-1218.