BACKGROUND: The electroencephalogram(EEG) has long been used to study the effects of anesthetic drugs on central nervous system function. This study was designed to evaluate the accuracy of two EEG parameters for assessing anesthetic depth during inhalation of 1.5 MAC three inhalation anesthetics (halothane, enflurane, and isoflurane) with 50%-N2O in rats. METHODS: Total 15 rats weighing between 300~350 g, with 5 rats for each anesthetic group were tested for investigation the anesthetic depth. EEG spectrum analysis was evaluated for three inhalation anesthetics which all were added with 50%-N2O. The spectral edge frequency(SEF), median power frequency(MPF) were obtained from the EEG spectrum analysis of raw EEG via fast Fourier transform(FFT). RESULTS: Raw EEG of halothane demonstrated sigmoidal shaped EEG, enflurane abundant spike waves, and isoflurane burst suppression. When 50%-N2O was added to each anesthetic group, the characteristics of the raw EEG were disappeared. EEG spectrum analysis enabled to distinguish the effects of each anesthetic on the anesthetic depth. EEG spectrum analysis demonstrated after 50%-N2O was added that the values of MPF and SEF were significantly decresed as 2.5 Hz and 6.5 Hz from 5.2 Hz and 14.2 Hz respectively. CONCLUSIONS: It is speculated that SEF and MPF was decreased due to the suppression of cerebral electrical activity. The decreases of SEF and MPF from analysis of EEG spectra confirm that the addition of 50%-N2O to each inhalation anesthetics enabled the deeper anesthetic depth.
Anesthetics ; Anesthetics, Inhalation* ; Animals ; Central Nervous System ; Colon, Sigmoid ; Electroencephalography* ; Enflurane ; Halothane ; Inhalation* ; Isoflurane ; Rats* ; Spectrum Analysis

Background: It is well known that the addition of CO2 gas during cardiopulmonary bypass (CPB) can increase cerebral blood flow (CBF). In this study, we tried to find whether the increase of CBF by CO2 gas could be expressed on the measurement of body temperatures. Methods: This study included 22 adult patients who underwent CPB with moderate hypothermia and were assigned randomly to two groups by adding CO2 gas (CO2 group and Air group). We measured each tympanic (TM), nasopharyngeal (NP), oral, forehead, finger, rectal and CPB arterial line temperatures of CPB circuit for 20 times during cooling in every one minute for 20 minutes and during rewarming every two minutes for 40 minutes. Results: During cooling and rewarming, the TM, NP and oral temperatures changed more rapidly than the rectal and finger temperatures. In TM temperature, as time changed, the percent changes of temperature varied more prominently in the CO2 gas group than in the Air group. The statistical differences were significant especially during 13 minutes to 20 minutes in cooling and 8 minutes to 20 minutes during rewarming. Conclusion: From this data, we can postulate the effect of CO2 gas on CBF indirectly by measuring several sites of body temperatures.
Adult ; Body Temperature* ; Carbon Dioxide ; Cardiopulmonary Bypass* ; Fingers ; Forehead ; Humans ; Hypothermia ; Rewarming* ; Vascular Access Devices

No abstract available
Hemodynamics*

BACKGROUND: Biodegradable microspheres are a useful method of drug delivery because they are both injectable and biodegradable. Previous work in our group has characterized implantable preparations of local anesthetics in pellets for prolonged regional anesthesia. In this paper we evaluated injectable suspensions of lidocaine-polymer microspheres for extended period of percutaneous sciatic nerve blockade in rats. METHODS: Microspheres were prepared using poly (lactide-co-glycolide) loaded with 50 wt% lidocaine by a solvent evaporation method. In vitro release rate of lidocaine from microspheres was determined by high performance liquid chromatography (HPLC). Percutaneous blockade of the rat sciatic nerve was performed, and sensory blockade of the nerve was assessed using an analgesiometer. RESULTS: Lidocaine was released in a controlled manner in vitro. In general 60% of the drug released in the first day, 80% in two days. Sciatic nerve blockade duration ranged from 8 to 12 hours. Incorporation of dexamethasone 0.05 wt% into the microspheres resulted in significant prolongation of block. CONCLUSION: Prolonged percutaneous blockade of peripheral nerve is achieved using biodegradable polymeric lidocaine microspheres.
Anesthesia, Conduction* ; Anesthetics, Local ; Animals ; Chromatography, Liquid ; Dexamethasone ; Lidocaine* ; Microspheres* ; Peripheral Nerves ; Polymers* ; Rats ; Sciatic Nerve ; Suspensions

Adductor contraction from obturator nerve stimulation occurs frequently in certain situations during transurethral operations. Bladder perforation is a common result. A simple and safe technique involving use of a nerve stimulator for accurate obturator blockade and psoas compartment block are described. Only one of seven cases has obturator nerve stimulation after psoas compartment block. But there were no adductor contractions in more than seventeen transurethral resections during one year interval. There were no complications from the block itself or use of the nerve stimulator. Herein we introduce these safe methods for prevention of obturator nerve stimulation during transurethral resection.
Obturator Nerve* ; Reflex* ; Urinary Bladder Neoplasms* ; Urinary Bladder*

This study was undertaken to determine the incidence of the endotrcheal tube contamination by malignant cells in patients with upper respiratory tract cancer undergoing general anesthesia. In 17 patients endotracheal intubation was done and the tube was extubated after completion of the excision of the tumor mass. Following the procedures the outide of the endotracheal tube was swabbed by the cotten tip applicators and the specimens examined cytologically. Two positive cytologic specimens were obtained, they were class III and laryngeal carcinoma in both. This study provides evidence that contamination of the outside of the endotracheal tube can occur when it is passed directly over a carcinoma of the larynx.
Anesthesia, General ; Humans ; Incidence ; Intubation, Intratracheal ; Larynx ; Respiratory System*

BACKGROUND: This study investigated the effect of topical analgesic effects of a liposome encapsulated mixture of local anesthetics (lipo-MLA) compared with EMLA. METHODS: 3% lipo-MLA (0.5% tetracaine base, 2.5% lidocaine base) and 5% lipo-MLA (1% tetracaine base, 4% lidocaine base) were encapsulated into liposomal vesicles made with egg yolk phosphatidylcholine, cholesterol and phosphatidyldioleoyl. 3% lipo-MLA and EMLA were applied to volunteers' forearms bilaterally with and without an occlusive dressing. The topical anesthetic effects of the lipo-MLA and EMLA as a control were evaluated by the pinprick test in 28 adult volunteers after 60 minutes of application. The analgesic influence of the concentration of local anesthetics was also compared with 3% and 5% lipo-MLA under a non-occlusive dressing. RESULTS: Analgesic effects of the 3% lipo-MLA were similar with EMLA under an occlusive dressing for 60 minutes. In addition, analgesic effects of the 3% lipo-MLA under a non-occlusive dressing were more potent than EMLA. Lipo-MLA under a non-occlusive dressing showed more potent analgesic effect than lipo-MLA under an occlusive dressing. 5% lipo-MLA was more potent than 3% lipo-MLA under a non-occlusive dressing. CONCLUSIONS: Lipo-MLA has more potent analgesic effects than EMLA without an occlusive dressing and 5% lipo-MLA is more potent than 3% lipo-MLA. Therefore, lipo-MLA appeared to be an improved topical analgesic formulation which provides a more potent and convenient topical application.
Adult ; Anesthetics* ; Anesthetics, Local* ; Bandages ; Cholesterol ; Egg Yolk ; Forearm ; Humans ; Lidocaine ; Liposomes* ; Occlusive Dressings ; Phosphatidylcholines ; Tetracaine ; Volunteers

Thirty patients who had elective general anesthesia at Kyungpook National University Hospital from April to August 1986 were studied for intraocular pressure(lOP) changes after intravenous lidocaine administration. The resultg were as follows. The 30 patients comprised three groups of each 10, placebo group and lidocaine 1 mng/kg and 2mg/kg Pretreatment group. In lidocaine 1 mg/kg administration group, the IOP of 1 minute and 2 minutes after intubation were 21.8+/-3.8 mmHg, 21.3+/-2.6 mmHg and showed significant(p<0.01) increase compared with the control value. In lidocaine 2 mg/kg pretre-atment group, the IOP of I minute after intubation was 22.7+/-3.9 mmHg and showed significant(p70.05) increase, but the IOP of 2 minute after intubation was 20.2+/-3.2mmHg which not showed significant increase compared with the control value. The IOP of 2 minute after incubation in lidocaine 1 mg/kg administration group(p<0.05) and lidocaine 2 mg/kg administration group(p<0.01) showed significant decrease compared with placebo group. The incidence of coughing and arrhythmia stowed decreasing tendency according to doses of lidocaine, but not statistically significant.
Anesthesia, General ; Arrhythmias, Cardiac ; Cough ; Gyeongsangbuk-do ; Humans ; Incidence ; Intubation ; Lidocaine

The purposes of this study were to investigate the changes of plasma ADH and beta-endo-rphin levels during general anesthesia. Tweleve patients, who had surgery at Krungpook National University Hospital, were selected without specific hepatic, renal and other endocrinologic disorders. The patients were anesthetized with thiopental sodium and succinylcholine chloride followed by O2-N2O-ha1othane(4 cases), anti O2-N2O-enflurane(8 cases) , The plasma ADH and beta endorphin levels were chocked before anesthesia(control group), 20 minutes after endotracheal intubation, 20 minutes after surgical incision and at recovery roam when the patients responded to the pain. The plasma ADH levels were 5.69+/-2.19, 12.72+/-14.90. 11.47+/-9.62 and 24.42+/-23.23 ru/ml, respectively. It were progressively incresed and significantly incresed at recovery room (P<0.05). The Plasma beta endorphin levels were 4.1+/-3.54, 6.44+/-3.75, 6.68+/-3.90 and 17.88 +/-12.08 Pmol/l, resPectiTely. Plasma beta endorphin levels at 20 minutes after endotracheal intubation and 20 minutes after surgical incision were significantly increased(p<0.05) and it was very significantly increased at recovery room(P<0.01) . Albo serum electrrolytes(Na+, K+, Cl-, CO2-) were evaluated, but statistically or clinically not significant. Urine electrolytes(Na+, K+) and osmolality were evaluated before, during and after ane Sthesia, but statistically not significant. From the view of inhalation anesthetics, there were no diffrences between halothane and enflurane in plasma ADH and beta endorphin levels.
Anesthesia, General* ; Anesthetics, Inhalation ; beta-Endorphin* ; Enflurane ; Halothane ; Humans ; Intubation, Intratracheal ; Osmolar Concentration ; Plasma* ; Recovery Room ; Succinylcholine ; Thiopental

The changes of onset and duration of caudal epidural anesthesia had been compared in 54 patients schedulled for perianal surgery at kyungpook National University HospitoL The patients were divided into 3 groups of 18: lidocaine group received 2% lidocaine 20 ml, mixture group received 2% lidocaine 10 ml and 0.5% bupivacaine 10 ml and bupivcaaine group received 0.5% bupivacaine 20 ml. The onsets were as follows. The onsets wiere 3.11+/-0.63 in lidocaine group, 4.83+/-4.17 in mixture group and 8.13+/-3.49 min in bupivacaine group. The onset of bupivacaine group was slower than lidocaine group(p<0.01) and late compared with mixture group(p<0.5). The duration of caudal anesthesia were 192.00+/-62.49 in lidocaine group, 326.72+/-145.28 in mixture group and 419.22+/-125.37min in bupivacaine group. Significant differences were observed between mixture-lidocaine group(p<0.01), bupivacaine-lidocaine group(p<0.01) and bupivacaine-mixture group(p<0.05). Urinary catheteiized patients were 8 in longest duration group of bupivacaine. It is suggested from the above'results that the mixture of lidocaine and bupivacaine during caudal epidural anesthesia can produce rapid onset and long duration.
Anesthesia, Caudal* ; Anesthesia, Epidural ; Anesthetics, Local* ; Bupivacaine ; Gyeongsangbuk-do ; Humans ; Lidocaine