P004: MATERNAL OBESITY AND THE MIGRATING CATHETER
Spencer Hyde, Anthony Cometa; University of Florida
Introduction: Maternal obesity is known to increase the rate of maternal obstetric complications, adverse neonatal outcomes and anesthetic difficulty. Of particular import is the ability to provide successful labor epidural analgesia with extension to surgical anesthesia given that higher rates of cesarean delivery are observed in obese pregnant women. With the increasing prevalence of obesity, anesthesiologists are routinely challenged to provide effective neuraxial analgesia that is often technically challenging and time consuming. Our case report highlights a unique consideration for evaluation and management of a non-functioning labor epidural.
Case Report: 33 year old G1P0 parturient at 38 weeks gestation with a past medical history of chronic hypertension, asthma, and class III obesity (BMI 80) presented for scheduled induction of labor. Labor was augmented with oxytocin and the patient requested an anesthesiology consultation for labor analgesia. A labor epidural was placed at the L4-L5 level using ultrasound guidance for landmark identification. Utilizing a 15 cm Tuohy epidural needle, the achieved loss of resistance was 13 cm and the neuraxial catheter was advanced to a depth beyond 20 cm. Appropriate labor analgesia was obtained and was analgesia was maintained via a continuous infusion of 0.1% bupivacaine at 8 ml/hr with intermittent patient-controlled epidural analgesic (PCEA) boluses. Twelve hours after epidural placement, the patient endorsed increasing levels of pain without relief following PCEA bolus. The anesthesiology team suspected the epidural catheter to have migrated to an ineffective location and the catheter was withdrawn 4-5 cm to the 20 cm mark. Ensuring all appropriate monitoring was in place, a 3 mL bolus of 2% lidocaine with epinephrine was administered; abrupt cessation of pain resulted and it was determined that the epidural catheter was located in the intrathecal space. A low dose infusion of 0.1% bupivacaine was started at 2 mL/hr. The patient remained hemodynamically stable and the patient maintained adequate analgesia to facilitate a successful and safe vaginal delivery.
Discussion: When evaluating an ineffective epidural, it is important to understand the potential causes of failure and possible remedies. Our case reinforces the challenges associated with safely performing and managing neuraxial anesthesia in the super morbidly obese parturient. It is clear that the patient initially had good analgesic coverage and we believe that the original placement of the epidural catheter was indeed located in the epidural space. What is interesting about this particular case is that after withdrawing the epidural catheter we noted return of CSF. Therefore, we believe the original placement of the epidural catheter resulted in an anterior epidural space location; withdrawal of the catheter resulted in settlement within the subarachnoid space. As such, with each movement of the neuraxial catheter, it is important that reevaluation of the potential catheter location be performed via test dose as management of an epidural vs subarachnoid catheter differ significantly.