Recent Advances in Anesthetic Management of a Morbidly Obese Parturient

Abstract

Many of the effects of pregnancy and obesity on major organs are additive and can lead to decreased physiologic reserve and thus significant functional impairment. The obese parturient is at increased risk for diabetes, ischemic heart disease, stroke, hypertension, hypercoagulability, osteoarthritis, and gall bladder disease and pregnancy-associated complications. General anesthesia and anesthesiarelated complications are much higher in the morbidly obese parturient. There are a number of features that increase the risk of hypoxia, morbidity and mortality during induction of anesthesia, intrapartum, emergence and postpartum period in these patients.The urgency of the obstetric situation must be weighed against the risk of general anesthesia. If general anesthesia is necessary, additional experienced personnel and difficult airway equipment must be available. An anesthesiology consultation should be obtained early in the third trimester to ensure proper evaluation and development of an anesthetic plan. All obstetric units should develop protocols for the management of morbidly obese women. These should include pre-assessment procedures, special community, ward and theatre equipment such as large sphygmomanometer cuffs, hoists, beds and operating tables and long regional block needles. Obesity is often associated with obstructive sleep apnea (OSA). The physiological changes associated with pregnancy may increase the severity of OSA with a higher risk of maternal and fetal morbidity. The early diagnosis of OSA in parturients is essential to minimize complications during the peripartum period.Definitive diagnosis is made by polysomnography. A recent systematic review on the screening of OSA has described that the STOP-Bang and Berlin questionnaires were found to have the highest sensitivity and specificity, respectively, in predicting moderate or severe OSA in a non-obstetric surgical population. Further studies are warranted to assess the validity of these screening questionnaires in obese parturients. Early placement of a neuraxial catheter during labor should be encouraged to allow ample time for this potentially difficult procedure. A functional epidural during labor avoids the risks of general anesthesia and tracheal intubation should any urgent operative intervention be required. Frequent evaluation of the quality of the labor epidural block in these patients is vital because of the high risk of epidural failure in obese patients. Any