Electromyographic monitoring of facial nerve under different levels of neuromuscular blockade during middle ear microsurgery

Background The evoked electromyography （EMG） is frequently used to identify facial nerve in order to prevent its damage during surgeries. Partial neuromuscular blockade （NMB） has been suggested to favor EMG activity and insure patients＇ safety. The aim of this study was to determine an adequate level of NMB correspondent to sensible facial nerve identification by evaluating the relationship between facial EMG responses and peripheral NMB levels during the middle ear surgeries. Methods Facial nerve evoked EMG and NMB monitoring were performed simultaneously in 40 patients who underwent tympanoplasty. Facial electromyographic responses were recorded by insertion of needle electrodes into the orbicularis otis and orbicularis oculi muscles after electrical stimulation on facial nerve. The NMB was observed objectively with the hypothenar muscle＇s twitching after electrical stimulation of ulnar nerve, and the intensity of blockade was adjusted at levels of 0, 25%, 50%, 75%, 90%, and 100% respectively with increased intravenous infusion of Rocuronium （muscle relaxant）. Results All of the patients had detectable EMG responses at the levels of NMB 〈50%. Four out of forty patients had no EMG response at the levels of NMB 〉75%. A significant linear positive correlation was present between stimulation thresholds and NMB levels while a linear negative correlation was present between EMG amplitudes and NMB levels. Conclusions The facial nerve monitoring via facial electromyographic responses can be obtained when an intraoperative partial neuromuscular blockade is induced to provide an adequate immobilization of the patient. The 50% NMB should be considered as the choice of anesthetic management for facial nerve monitoring in otologic microsurgery based on the relationship of correlation.

A Time Series Observation of Chinese Children Undergoing Rigid Bronchoscopy for an Inhaled Foreign Body： 3149 Cases in 1991-2010

Background：In China,tracheobronchial foreign body （TFB） aspiration,a major cause of emergency episode and accident death in children,remains a challenge for anesthetic management.Here,we share our experience and discuss the anesthetic consideration and management of patients with TFB aspiration.Methods：This was a single-institution retrospective study in children with an inhaled foreign body between 1991 and 2010 that focused on the complications following rigid bronchoscopy （RB）.Data including the clinical characteristics of patients and TFB,anesthetic method,and postoperative severe complications were analyzed by different periods.Results：During the 20-year study period,the charts of 3149 patients who underwent RB for suspected inhaled TFB were reviewed.There were 2079 male and 1070 female patients （1.94：1）.A nut （84％） was the most commonly inhaled object.The study revealed a 9％ （n =284） overall rate of severe postoperative complications related to severe hypoxemia,laryngeal edema,complete laryngospasm,pneumothorax,total segmental atelectasis,and death with incidences of 3.2％,0.9％,1.3％,0.3％,0.3％,and 0.1％,respectively.The rates of preoperative airway impairment,negative findings of TFB,and adverse postoperative events have been on the rise in the past 5 years.Conclusions：The survey results confirmed that hypoxemia remains the most common postoperative complication in different periods.Both controlled ventilation and spontaneous ventilation were effective during the RB extraction of the foreign body at our hospital in the modern technique period.An active respiratory symptom was commonly seen in the groups with negative findings.