When BMIs Reach Triple Digits: The Anesthetic Management of a Pregnant Woman with Super Morbid Obesity
Abstract Number: T 63
Abstract Type: Case Report/Case Series
Intro: As the incidence of super morbid obesity continues to dramatically increase, obstetric anesthesiologists are often faced with the challenges of managing patients affected by the combined physiologic implications of obesity and pregnancy. We present and review anesthetic considerations when managing a pregnant patient with super morbid obesity (BMI 115.3).
Case: A 34 year old G1P0 with pre-pregnancy weight of 630 pounds presented at 11 4/7 weeks with a chief complaint of profound dyspnea and pregnancy. The patient’s past medical history was notable for chronic hypertension, obstructive sleep apnea, asthma and GERD in addition to her super morbid obesity, for which she was taking medication prescribed from a physician supervised weight loss clinic. Because weight loss medications have been linked with valvular disease, the patient’s initial testing included echocardiography which revealed an ejection fraction of 60-65% and mild concentric left ventricular hypertrophy. Pulmonary function testing was unable to be obtained due to the patient’s size, but she received CPAP at night for her sleep apnea. As her pregnancy progressed, the patient gained 138 pounds despite intensive nutritional counseling. This led to decreased mobility causing difficulty in completion of activities of daily living and making transportation to the hospital challenging. The patient was admitted at 33 weeks gestation for inpatient management secondary to these issues. She was delivered at 36 6/7 weeks via cesarean section under epidural anesthesia with delivery of a neonate weighing 3209 grams (APGARs 9/9). An IUD was placed prior to uterine closure, epidural was removed without complication 6 hours post-operatively and anticoagulation was restarted. The patient was discharged home on post-operative day 7.
Discussion: Every organ system is affected by increases in BMI. Redundant tissue and edema in the upper airway create a hostile environment for intubation while increased truncal girth makes neuraxial anesthesia challenging, as evidenced by a sevenfold increase in initial epidural failure rate in obese women. The increased oxygen consumption and disproportionate decrease in FRC due to abdominal mass in super morbidly obese patients cause decreased time to desaturation during a rapid sequence induction. The prevalence of obstructive sleep apnea also makes postoperative pain control challenging as administration of opioids can result in a fifty percent increase in apnea events. These patients also have a higher incidence of hypertension and diabetes and are more likely to have pregnancy-induced hypertension, preeclampsia, gestational diabetes and thromboembolism. Obesity itself is a risk factor for anesthesia related maternal-mortality. With the increasing incidence of obesity around the world, anesthesia providers must be prepared to manage the many comorbidities that challenge safe administration of anesthesia.