Elastomeric pump malfunction resulting in over-infusion of local anesthetic.

A 70 year-old female patient presented for a right humeral head replacement. Preoperatively an interscalene catheter was placed and postoperatively connected to an elastomeric pump for continuous infusion at 8 mL/h of Ropivacaine 0.2% with an additional 5 mL patient activated bolus available every 30 min. About 17 h after the elastomeric pump was connected to the catheter, the 550 mL reservoir was found to be empty, indicating the pump's infusion rate was more than 32 mL/h despite the pump still being set at an infusion rate of 8 mL/h with a possible 5 mL bolus every 30 min. There was no visible damage or leak in the pump system, and the insertion site was dry. The patient denied any changes to the pump settings. She was alert and oriented and denied any signs of local anesthetic toxicity. The catheter was immediately pulled and the manufacturer notified. The manufacturer found a red tab broken inside the patient-controlled bolus remote resulting in the over-infusion. Despite the dependability of elastomeric pumps, healthcare providers must be aware of their possible complications and malfunctions.

Ultrasound-Guided Interscalene Catheter Complicated by Persistent Phrenic Nerve Palsy.

A 76-year-old male presented for reverse total shoulder arthroplasty (TSA) in the beach chair position. A preoperative interscalene nerve catheter was placed under direct ultrasound-guidance utilizing a posterior in-plane approach. On POD 2, the catheter was removed. Three weeks postoperatively, the patient reported worsening dyspnea with a subsequent chest X-ray demonstrating an elevated right hemidiaphragm. Pulmonary function testing revealed worsening deficit from presurgical values consistent with phrenic nerve palsy. The patient decided to continue conservative management and declined further invasive testing or treatment. He was followed for one year postoperatively with moderate improvement of his exertional dyspnea over that period of time. The close proximity of the phrenic nerve to the brachial plexus in combination with its frequent anatomical variation can lead to unintentional mechanical trauma, intraneural injection, or chemical injury during performance of ISB. The only previously identified risk factor for PPNP is cervical degenerative disc disease. Although PPNP has been reported following TSA in the beach chair position without the presence of a nerve block, it is typically presumed as a complication of the interscalene block. Previously published case reports and case series of PPNP complicating ISBs all describe nerve blocks performed with either paresthesia technique or localization with nerve stimulation. We report a case of a patient experiencing PPNP following an ultrasound-guided placement of an interscalene nerve catheter.

Pain Management in Abdominal Wall Reconstruction.

BACKGROUND: In abdominal wall reconstruction, adequate pain control and minimization of narcotic consumption are essential to improving patient outcomes and satisfaction. Previous studies have examined the role of individual strategies, such as neuraxial analgesia and multimodal analgesia. However, there has not been a study that examined all potential determinants of postoperative narcotic requirements, including intraoperative strategies. METHODS: Consecutive patients who underwent abdominal wall reconstruction were reviewed. Preoperative factors (chronic preoperative narcotic usage, indication for abdominal wall reconstruction, administration of neuraxial analgesia), intraoperative factors (intraoperative narcotics administered, method of mesh fixation), and postoperative factors (multimodal analgesia, complications) were collected. The main outcomes were daily amount of opioids used and length of hospital stay. RESULTS: Ninety-three patients were included in the study. Patients who had an epidural required lower doses of opioids postoperatively, while those on chronic preoperative opioids, those whose mesh was fixated using transfascial sutures, and those who received large doses of opioids intraoperatively required higher doses of postoperative opioids. Hospital length of stay was longer in patients who received transfascially sutured mesh and those on chronic opioids preoperatively. CONCLUSIONS: This study provides potential strategies to improve pain control and minimize narcotic consumption postoperatively in patients undergoing abdominal wall reconstruction. Intraoperative administration of opioids should be minimized to avoid the development of tolerance. Epidural analgesia reduces postoperative narcotic requirement and may be especially beneficial in patients at highest risk for postoperative pain, including those on chronic opioids, and those in whom transfascial sutures are used for mesh fixation.