Opiate Intoxication Caused by Epidural Infusion of Morphine: A Case Report of a Near Fatal Medication Error.

INTRODUCTION: Epidural infusion of local anesthetics with opioids is widely used for pain control during the perioperative-and peripartum-periods. Selection of the opioid, appropriate dosing, and follow-up by the acute pain service are critical in providing safe postoperative epidural analgesia. CASE REPORT SUMMARY: A 71-year-old man was scheduled for a parastomal hernia repair with midline laparotomy. The parastomal hernia was a complication from a previously performed colectomy for ulcerative colitis. Preoperatively, the patient received a lower thoracic epidural catheter. The epidural infusate (0.2% ropivacaine with 0.5 µg/mL sufentanil) was prepared and double-checked by holding area nurses. The fact that the right prescription medication label partially covered a morphine label went unnoticed. The intraoperative phase was characterized by stable parameters. Postoperatively, it was not possible to demonstrate an epidural nerve block. No pain was reported, and the patient could be transferred to the ward. The patient developed coma and delayed respiratory depression after discharge to the surgical ward, requiring intensive care unit admission and naloxone administration. Analysis of the syringe content revealed the presence of morphine (1 mg/mL). DISCUSSION: Color-coded prefilled syringes combined with the use of an epidural specific syringe connector to prevent cross-connections should become standard practice. In addition, delayed respiratory depression should be considered after epidural administration of morphine.

A brain symmetry index (BSI) for online EEG monitoring in carotid endarterectomy.

INTRODUCTION: Carotid endarterectomy is a common procedure as a secondary prevention of stroke, and one of the early controversies in carotid surgery is centered around whether a shunt should be used during this procedure. Although various EEG parameters have been proposed to determine if the brain is at risk during carotid artery clamping, the common procedure is still the visual assessment of the EEG. We propose a brain symmetry index (BSI), that has been implemented as an on-line quantitative EEG parameter, as an additional criterion for shunt need in carotid endarterectomy. METHODS: The BSI captures a particular asymmetry in spectral power between the two cerebral hemispheres, and is normalized between 0 (perfect symmetry) and 1 (maximal asymmetry). The index was evaluated retrospectively in a group of 57 operations in which the EEG and the transcranial Doppler were used as criteria for shunt insertion. In addition, after online implementation of the algorithm, several patients have been evaluated prospectively. RESULTS: If no visual EEG changes were detected, it was found that the change in BSI from baseline, DeltaBSIor=0.06. In this group, one patient suffered from intraoperative stroke and one patient died, most likely from a hyperperfusion syndrome. CONCLUSIONS: The BSI may assist in the visual EEG analysis during carotid endarterectomy and provides a quantitative measure for electroencephalographic asymmetry due to cerebral hypo-perfusion. In patients with a change in the BSI (DeltaBSI) smaller than 0.03 during test clamping, visual EEG analysis showed no changes, whereas if visual EEG analysis did warrant shunting, it was found that DeltaBSI>or=0.06.