Post Operative Pain Control Using Ropivacaine and the ON-Q System in the Adult Pectus Excavatum Patient

Overview

Pectus excavatum (PE) is a common chest wall deformity where the sternum is displaced posteriorly. In severe cases, surgery is performed to correct the defect. In recent years, minimally invasive surgery with the placement of stainless steel support bars has been increasingly performed in patients over the age of 17 years. Because of the decreased malleability and tremendous pressure required to hold the chest wall in the corrected position, post-operative pain control has been a significant problem in this patient population. Thoracic epidurals are commonly employed however mean hospitalizations of up to 7 days have been required before adequate pain control on oral analgesics is obtained and patients are suitable for discharge. It is hypothesized that using the ON-Q system (I-Flow Corporation, Lake Forest CA) with bilateral intercostal catheter infusion would provide adequate post operative pain control with a significantly shorter hospital length-of-stay than thoracic epidural. Total use of narcotics for 1 week following surgery would also be less with the ON-Q system versus epidural.

Subjects meeting eligibility criteria were randomized to one of two arms for postoperative pain control: the On-Q system versus epidural. All subjects had additional pain management as per standardized protocol including subject controlled intravenous analgesia with morphine equivalent narcotics for a maximum of 48 hours at which time the subject was transitioned to oral pain medications. Subjects using less than 5 mg of Morphine in the first 24 hours after surgery were transitioned to oral pain medications at 24 hours. After transition to oral analgesia, subjects with continued pain assessment greater than 5 were administered intravenous morphine equivalents by nursing staff until pain assessments were less than 5. ON-Q catheters could have been maintained for up to 6 days. Discharge of subjects with catheters in place was planned. The catheter was removed in the out-patient clinic if the subject was discharged before the 6th day. Subjects with epidural had their epidural discontinued at 72 hours. Data was recorded for each subject by site personnel while the subjects remained hospitalized, but were recorded in a journal by subjects after discharge up to postoperative day 7.