The Influence of Patient Controlled Analgesia on the Recovery of Muscle Power and Respiratory Function following Intraoperative Muscle Relaxants / 대한마취과학회지

BACKGROUND: Residual muscle paralysis after anesthesia is reduced with the advent of intermediate-acting neuromuscular blocking drugs, yet the incidence is as high as about 10 percent. Opioids in patient-controlled analgesia (PCA) may cause respiratory depression and other problems after anesthesia. The purpose of this study is to evaluate the influence of PCA on the SPO2, TOF ratio, head-lift and tongue protrusion during recovery room stay following intraoperative muscle relaxants. METHODS: 120 patients aged from 20 to 65 in ASA class I and II were divided into control or PCA groups. All patients received rocuronium (0.9 mg/kg) or atracurium (0.5 mg/kg) for tracheal intubation, and maintenance of relaxation was done with atracurium 0.2 mg/kg/hr during inhalation anesthesia. Reversal of block was done with pyridostigmine 0.15 mg/kg and glycopyrrolate 0.2 mg. SpO2, TOF ratio, 5 sec-head lift, tongue protrusion tests were evaluated in the recovery room. RESULTS: IV-PCA did not influence the incidence of residual block, SPO2, TOF ratio during recovery room stay for 20 minutes, but influenced negatively 5 sec-head lift test, tongue protrusion test only immediately after arrival at the recovery room. CONCLUSIONS: Since IV-PCA decreased the ability to perform head-lift and tongue protrusion early postoperatively, it is recommended that patients with IV-PCA should be carefully managed against the risk of aspiration or upper respiratory obstruction during their early recovery room stay.

Extraction of Parameters for the Depth of Anesthesia Using Frequency Analysis Method / 대한마취과학회지

BACKGROUND: General anesthesia alters autonomic nervous system activity. Evaluation of the autonomic nervous system activity using heart rate variability and so, evaluating the anesthetic depth was tried. METHODS: In thirty patients undergoing gynecological surgery under general inhalational anesthesia with enflurane, a 10-minute EKG was perioperatively acquired during main incidents. The heart rate variability was analyzed and expressed as 5-minute signals. RESULTS: In an analysis of the frequency area adopting the heart rate variability, both low and high frequencies represented the effects of the autonomic nervous system, but the low and high frequencies, their ratio and 1/f noise were not valuable in estimating the depth of anesthesia before, during and after the operation. The detrended fluctuation analysis also proved unsuitable for the estimation of the anesthetic depth during an operation. CONCLUSIONS: The signal using heart rate variability reflects the parameter of the autonomic nervous system during operations.

Inadvertent Epidural Administration of Atracurium and Lidocaine Mixture: A case report / 대한마취과학회지

Epidural administration of opioid and/or local anesthetics during general anesthesia is widespread method for postoperative pain control. Despite of its availability, inadvertent administration of non-epidural medications into epidural space can be associated with serious neurologic sequelae. We report a case of accidental epidural atracurium injection.