Intraoperative Transcranial Motor-evoked Potential Stimulation Does Not Seem to Cause Seizures.

BACKGROUND: Intraoperative neurophysiological monitoring is of critical importance in evaluating the functional integrity of the central nervous system during surgery of the central or peripheral nervous system. In a large recent study, transcranial motor-evoked potentials (TcMEPs) were found to be associated with a 0.7% risk of inducing a seizure as diagnosed by clinical observation and electromyography in patients having general anesthesia with intravenous anesthetics. The gold standard for seizure diagnosis, however, is electroencephalography (EEG). The aim of this single-institution retrospective study is to ascertain the risk of intraoperative seizures detected using EEG during surgeries in adult patients undergoing intraoperative monitoring with TcMEPs. METHODS: The authors retrospectively reviewed the intraoperative EEG records of 1175 patients anesthetized with a variety of anesthetic agents, including volatile and intravenous anesthetics, to ascertain the rate of EEG-diagnosed seizures attributable to TcMEPs. RESULT: Our analysis did not reveal a single seizure event attributable to TcMEPs in 1175 patients. CONCLUSION: The intraoperative use of TcMEPs does not seem to cause seizures.

Occult pneumothoraces in patients with penetrating trauma: Does mechanism matter?

BACKGROUND: Supine anteroposterior (AP) chest radiography is an insensitive test for detecting posttraumatic pneumothoraces (PTXs). Computed tomography (CT) often identifies occult pneumothoraces (OPTXs) not diagnosed by chest radiography. All previous literature describes the epidemiology of OPTX in patients with blunt polytrauma. Our goal was to identify the frequency of OPTXs in patients with penetrating trauma. METHODS: All patients with penetrating trauma admitted over a 10-year period to Grady Memorial Hospital with a PTX were identified. We reviewed patients' thoracoabdominal CT scans and corresponding chest radiographs. RESULTS: Records for 1121 (20%) patients with a PTX (penetrating mechanism) were audited; CT imaging was available for 146 (13%) patients. Of these, 127 (87%) had undergone upright chest radiography. The remainder (19 patients) had a supine AP chest radiograph. Fifteen (79%) of the PTXs detected on supine AP chest radiographs were occult. Only 10 (8%) were occult when an upright chest radiograph was used (p < 0.001). Posttraumatic PTXs were occult on chest radiographs in 17% (25/146) of patients. Fourteen (56%) patients with OPTXs underwent tube thoracostomy, compared with 95% (115/121) of patients with overt PTXs (p < 0.001). CONCLUSION: Up to 17% of all PTXs in patients injured by penetrating mechanisms will be missed by standard trauma chest radiographs. This increases to nearly 80% with supine AP chest radiographs. Upright chest radiography detects 92% of all PTXs and is available to most patients without spinal trauma. The frequency of tube thoracostomy use in patients with overt PTXs is significantly higher than for OPTXs in blunt and penetrating trauma.

Pulmonary vein edema in a patient undergoing coronary artery bypass graft surgery and concomitant radiofrequency ablation for chronic atrial fibrillation.

The syndrome of pulmonary vein stenosis characterized by pulmonary hypertension, dyspnea on exertion, and right heart failure, is a well-described complication of percutaneous ablation approaches, but has not been described with surgical approaches. We describe the case of a patient who developed localized edema at the pulmonary vein-left atrial junction after undergoing intraoperative radiofrequency ablation for chronic atrial fibrillation as part of CABG for severe triple vessel disease. The pulmonary vein edema resolved within 10 months suggesting that it may be a clinically silent and self-resolving phenomenon.