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Brachial plexus block, axillary approach appears to be a safe and reliable technique for upper extremity surgery from shoulder to hand. However, the maximum dose of lidocaine that is recommended by the manufactured is 4 mg per kg (approximately 300 mg) regardless of the injection site. The maximum recommended dose for lidocaine with epinephrine is 7 mg per kg (approximately 500 mg). These maximum recommended amounts are insufficient for brachial plexus block. We question the logic behind these recommended dosages and may exceed them. The aim of this study was to determine whether commonly acceptable dosages used in brachial plexus block within a safe range. The time courses of the plasma concentration were observed in 20 healthy patients to whom were axillary injected with 1.5% lidocaine mixed 1: 200,000 epinephrine. The plasma concentrations were measured by immunofluororesence assay at the intervals of 5, 10, 20, 30 and 60 minutes. The values of plasma concentration were 2.65±75, 4.29±2.75, 5.95 ±2.02, 4.76±1.91 and 4.48±1.90 pg/ml in group 1, and 3.71±1.68, 4.76±1.91, 6.68±3.43, 5.57±3.08 and 5.56±2.86 ug/ml in group 2, and 2.86±1.82, 5.08±3.74, 5.92±3.84, 6.82±3.84 and 5.49±3.29 ug/ml in group 3 (Mean+SD). The peak plasma concentration was 5.95±2.02 and 6.68±3.43 ug/ml at 20 minutes in group 1 and 2 respectively and 6.82±3.84 ug/ml at 30 minutes in group 3. These results indicated that the lidocaine 750 mg with epinephrine (5 ug/ml) in brachial plexus block is considered to be safe because plasma concentration dose not exceed the toxic level.

Thirty (19-58yr) patients received halothane, enflurane and isoflurane with Ohmeda, Cyprane and Narcomed vaporizer for maintenance of anesthesia during controlled ventilation. End-tidal fractional concentrations(FE) of the volatile anesthetic agents were measured for 40 minutes after induction. Inspired oxygen fractional concentrations during anesthesia in the three groups were slightly decreased from minimal 33.1±2.3% to maximal 49.3±1.7%. End-tidal carbon dioxide concentrations during anesthesia in the three groups were within normal lirnit ranged from minimal 24.5±3.2 mmHg to maximal 35.2±3.4 mrnHg. When vaporizer''s dial was fixed at 1% halothane, average measured FE/FI ratio were gradually increased from 5 minutes to 40 minute in the three groups. But FE/FI ratios were lower than dial setting, except after 40 minutes in the Narcomed vaporizer. When vaporizer''s dial were fixed at 1% isoflurane and enflurane, average measured FE/PI ratios in the three groups were nearly equal but lower than dial setting. These results suggest that the actual gas concentrations of used(2-3yr) vaporizers were measured slightly lower than dial setting and we need to continuously monitoring of respiratory gas and end-tidal anesthetic gases.

The direct effects of thiobarbiturates on helical strips of aortas from spontaneously hypertensive (SH) rats were compared with those from Wistar-Kyoto (WKY) rats. At 5-6 wk of age, the arterial pressure of SH and WKY rats did not differ, and the effects of thiobarbiturates on aortic strips from SH and WKY rats were similar. By contrast, at the age of 10-12 or 20-21 wk arterial pressure was higher in SH than in WKY rats, and responses to thiobarbiturates differed in aortic strips from SH and WKY rats: contractile responses were greater in WKY than in SH rats, and relaxing effects were greater in SH than in WKY rats. Responses to sodium nitroprusside did not differ in the aortas of SH and WKY rats, but the effects of nifedipine were greater in strips from SH rats than from WKY rats at the age of 10-12 wk. Ca2(+)-induced contractions of strips exposed to Ca2(+)-free media and depolarized by high K+ were inhibited by treatment with thiamylal; the inhibition was greater in SH than in WKY rats. The increase in smooth-muscle relaxation induced by thiobarbiturates in strips from SH rats may be due to increased sensitivity to the Ca2(+)-channel blocking action of thiobarbiturates.

The aim of this investigation was to determine whether epidural analgesia has any effect on the uterine activity. Uterine activity was checked by an intermal tocometer and calculated in uterine activity units (UAU) which were expressed as Montevideo units. Twenty two gravidas who had the term pregnancy in labor without any obstertical complications were selected and epidural analgesia was performed in 17 of these patients. Plain lidocaine was used in 10 of them, lidocaine mixed with epinephrine (200,000:1) was used in another 7 gravidas and 5 gravidas were chosen as a control group. The results were as follows: The uterine actvity of the continuous epidural anesthesia group did not differ from that of the control group. The uterine activity changes were not statistically significant between the plain Iidocaine group and the epinephrine mixed group.

The changes of the serum calcium, sodium and potassium concentrations after use of succinylcholine, d-tubocurarine and pancuronium were compared before anesthesia with during anesthesia in 60 surgical patients. In succinylcholine administration group, potassium concentration was significantly increased at 20 and 30 minutes and calcium concentration was slightly decreased at 10, 20 and 30 minutes and sodium concentration was decreased at 10 munutes and increased at 20 minutes slightly. In d-tubocuratine administration group, sodium concentration was significantly decreased at 10 and 20 minutes, but calcium and potassium concentration were not changed during anesthesia. In pancuronium administration group, calcium, sodium and potassium concentration were not changed during anesthesia.

Temperature changes during general anesthesia were studied in relation to age, the duration and type of operative procedure(gastrectomy versus tympanoplasty) and the type of anesthetic (halothane versus enflurane) in 41 patients undergoing surgery in our centrally air-conditioned operating room. Body temperatures were recorded every 15 minutes after intubation by measuring the esophageal temperature in adults and the nasopharyngeal temperature in children. A comparison of temperature changes between adults and children showed a significant temperature decrease in adults during general anesthesia(-0.6℃, p

After the establis banent for the necessity of denitrogenation in rebreathing anesthesia circuits some decades ago, many techniques were recommended for venilation with oxygen before induction of anestesia for the purpose of maintaining arterial oxygenation during laryngoscopy and tracheal intubation. For this point of view, we compared PaO2, MAP, PaCO2, pH of non-preoxygenation group (oxygen was given after succinylcholine was injected) with those of preoxygenation group (oxygen was given after thiopental sodium was injected). The cases were selected randomly ASA class I or II (without cardiopulmonary abnormalities) and ages between 27 years and 66 years old. Before induction of general anesthesia, we cannulated the radial artery after Allen's test and sampled arterial blood before anesthesia, after thiopenthal and succinylcholine were injected respectively, and when tracheal intubation was done in the two groups and measured PaO2, PaCO2, MAP, pH respectively. PaCO2, MAP, pH changes in the two groups were not significant and of no clinical significance. PaO2 after tracheal intubation showed a marked increase in the preoxygenation group compared to the non-preoxygenation group but the mean PaO2, remained within normal range in the non-preoxygenation group with the apneic period of taecheal intubation. We found that non-preoxygenated patients also had a normal range of PaO2 during the whole process of induction of anesthesia. But we think preoxygenation technique of any method can reserve more time and will do more effeclively, especially when time consuming events of difficult intubation of any reason occur.