BACKGROUND: The nature of operation alters the volume of distribution at steady state (Vdss) of drug. The hepatic extraction ratio of midazolam (0.3~0.7) could be influenced by hepatic blood flow (HBF), and hepatic enzyme activity. The pharmacokinetics of intravenous midazolam were determined in patients undergoing lung surgery. METHODS: Midazolam, 0.2 mg/kg, was administered to five patients undergoing lung surgery at 30 minutes after induction of anesthesia. Anesthesia was maintained with O2-enflurane for one lung ventilation. Blood samples from artery were drawn at increasing intervals for 12 h. Plasma midazolam concentrations were measured by gas chromatography. Computer simulations of the times required for 20%, 50%, and 80% decreases in midazolam concentrations were performed. RESULTS: A three compartment model best described the concentration versus time data. The volume of the central compartment (Vc) and volume of distribution at steady state (Vdss) were 4.3 2.8 l and 59.9 20.1 l, respectively. The elimination half-life was 3.4 2.2 h. Simulations indicate that under all the situations, the concentrations would decrease more rapidly in our patients in spite of similar Vdss and elimination half-life of patients undergoing minor gynecological surgery. CONCLUSION: The elimination half-life was in the range of previously reported values. The shorter recovery time is apparently due to relatively faster redistrubution, and relatively greater capacity for redistribution.
Anesthesia ; Arteries ; Chromatography, Gas ; Computer Simulation ; Female ; Gynecologic Surgical Procedures ; Half-Life ; Humans ; Lung* ; Midazolam* ; One-Lung Ventilation ; Pharmacokinetics* ; Plasma

BACKGROUND: High dose fentanyl for cardiac surgery in neonates, infants and children can cause severe bradycardia and chest wall rigidity that result in decreased cardiac output and oxygen desaturation due to fixed stroke volume in pediatric patients. To ameliorate the effects of fentanyl, it is common to administer neuromuscular blocking drugs with wanted cardiovascular side effects. This study was designed to compare the cardiovascular variables and oxygen saturation among different muscular relaxants in high dose fentanyl anesthesia. METHODS: Thirty pediatric cardiac patients were allocated randomly into three muscle relaxant groups treated with 0.2 mg/kg pancuronium (n=10), 0.2 mg/kg vecuronium (n=10) or 0.2 mg/kg pipecuronium (n=10) after receiving an initial bolus dose of 25 g/kg of fentanyl. Changes of heart rate (HR), mean arterial blood pressure (MAP), rate-pressure-product (RPP) and oxygen saturation (SpO2) were observed. The same cardiovascular variables were also observed 1 and 2 minutes after the second bolus dose of 25 g/kg fentanyl and compared to the results among muscle relaxants. RESULTS: HR, MAP and RPP decreased significantly (p<0.05) 1 and 2 minutes after injection of the 1st fentanyl, which returned to levels above the control value after administration of pancuronium, vecuronium or pipecuronium. Among muscle relaxants, pancuronium caused the most rapid and significantly high level compared to the control value in HR and MAP. Next was pipecuronium and then vecuronium. In clinical setting, SpO2 was decreased after the 1st fentanyl injection and increased after the injection of muscle relaxants, but not significant statistically. CONCLUSION: In view of hemodynamic changes, pancuronium is most efficient and rapid in returning the hemodynamic variables that was decreased after high dose fentanyl anesthesia in neonates, infants and children whose cardiac output was dependent on HR due to relatively fixed stroke volume.
Anesthesia* ; Arterial Pressure ; Bradycardia ; Cardiac Output ; Child* ; Fentanyl* ; Heart Rate ; Hemodynamics ; Humans ; Infant* ; Infant, Newborn* ; Neuromuscular Blockade ; Oxygen ; Pancuronium* ; Pipecuronium* ; Stroke Volume ; Thoracic Surgery ; Thoracic Wall ; Vecuronium Bromide*

BACKGROUND: Sore throat is one of the most common complications of intubation. There are many factors that affect the incidence of sore throat and the succinylcholine-induced myalgia. Our study is to reveal the influences of these factors on the postoperative sore throat and the succinylcholine-induced myalgia. METHODS: One thousand and seven patients in ASA class I or II undergoing elective surgery under general anesthesia were studied, except patients undergoing brain surgery, open heart surgery, operation in oro-, naso-pharynx and larynx, and uncooperated psychiatric. We checked age, sex, patient controlled analgesia and nasogastric tube, size and kind of tube, operation position, duration of intubation and anesthetic agent. At 24~38 hours after operation, the patients were questioned about pre- and postoperative sore throat, or myalgia. RESULTS: Sore throat after endotracheal intubation developed more frequently in woman (32.8%) than man (25.9%). The older the patients, the lower the incidence of sore throat (p<0.05). The longer the anesthesia duration, the lower the incidence of sore throat (p<0.05). Succinylcholine, patient controlled analgesia, nasogastric tube, endotracheal tube, operation position, maintenance anesthetic agents and the amount of smoking did not affect the incidence of sore throat. The incidence of succinylcholine-induced myalgia was lower in elderly or patients who were administered nondepolarizing muscle relaxant. CONCLUSIONS: The incidences of sore throat and myalgia were 29% and 15%, respectively. There were significant differences in incidence of sore throat and myalgia depending on the gender, age, duration of operation, but the controllable factors which reduce the incidence of sore throat were not found. Nondepolarizing muscle relaxants could reduce the occurrence of postoperative myalgia.
Aged ; Analgesia, Patient-Controlled ; Anesthesia ; Anesthesia, General ; Anesthetics ; Brain ; Female ; Humans ; Incidence* ; Intubation* ; Intubation, Intratracheal ; Larynx ; Myalgia ; Pharyngitis* ; Smoke ; Smoking ; Succinylcholine ; Thoracic Surgery

BACKGROUND: This study is to demonstrate that the estimates of effective concentration (EC) inferred by logit, probit, and sigmoid Emax can be declared to be similar. METHODS: The estimates of EC (5, 25, 50, 75, 95 [%]) of 24 vecuronium concentration-single twitch response data were obtained with three pharmacodynamic methods. A paired t-test with Bonferroni's correction was used. RESULTS: The distribution of estimates by probit were narrower than that of those by logit and sigmoid Emax. The estimates of logit and sigmoid Emax were closely similar. CONCLUSIONS: It suggests that the EC estimates of other paper analysed by the different pharmacodynamic method could be lower or higher.
Colon, Sigmoid* ; Vecuronium Bromide

BACKGROUND: The present study was performed to elicit what effect nalbuphine would have on isoflurane MAC (minimum alveolar concentration) in the patients undergoing lower abdominal surgery. METHODS: Sixty-two women were randomly allocated to one of five study groups to receive an intravenous injection of no nalbuphine (group I), 0.25 mg/kg (group II), 0.5 mg/kg (group III), 1.0 mg/kg (group IV), 1.5 mg/kg (group V). Anesthesia and tracheal intubation were induced with propofol 2 mg/kg, succinylcholine 1 mg/kg. Patients were inhaled at a preset end-tidal concentration of isoflurane, which was maintained for 20 min. Response to skin incision, movement or no movement, was determined 30 minutes after nalbuphine injection. The isoflurane concentration of the next patient in the same group moved up or down in steps of 0.1~0.3%, according to the previous patient's response. MAC was determined using the "up-down" method and logistic regression. RESULTS: The MAC's of isoflurane were 1.09 vol% end-tidal in the control group, 0.89 vol% in group II, 0.65 vol% in group III, 0.55 vol% in group IV, and 0.51 vol% in group V. CONCLUSIONS: It would be suggested that nalbuphine dose-dependently reduce the isoflurane MAC, and have ceiling effect on the reduction of isoflurane MAC.
Anesthesia ; Female ; Humans ; Injections, Intravenous ; Intubation ; Isoflurane* ; Logistic Models ; Nalbuphine* ; Propofol ; Skin ; Succinylcholine

BACKGROUND: Calcium disturbance may clinically produce diaphragmatic weakness. Extracellular calcium is necessary for diaphragmatic contraction, suggesting that the diaphragm behaves more like cardiac muscle. The effect of extracellular Ca2 concentrations on the relaxation action of vecuronium was studied in rat hemidiaphragm-phrenic nerve preparations. METHODS: Hemidiaphragm-phrenic nerve preparations were obtained from male Sprague-Dawley rats (200 300 g). Preparations were bathed in Kreb's solution of (mM): NaCl 118, KCl 5, CaCl2 2.5, NaHCO3 30, KH2PO4 1, MgCl2 1 and glucose 11, then maitained at 37oC when aspirated with a mixture of 95% O2 and 5% CO2. Isometric forces generated in response to 0.1 Hz, 2 Hz for 2 seconds and, 50 Hz for 2 seconds with supramaximal electrical stimulation (0.2 msec, rectangular) to the phrenic nerve, were measured with a force transducer. Single twitch tension and peak tetanic tension were calculated as a percentage of control. TOF fade was calculated as (1-(T4/T1))x100. Each preparation was exposed to the alterations in calcium concentrations of the Kreb's solution (3.75, 3.125, 1.5, 1.25, 0.625, 0.3125 (mM)), and the adequate volume of vecuronium stock solution was added to the tissue bath for desired bath concentration. The effects of calcium and vecuronium were allowed to reach a steady state before measurement of tension parameters was done. Single twitch tensions or peak tetanic tensions, which were measured at each calcium concentration, were compared respectively. EC5, EC25, EC50, EC75, and EC95 of vecuronium for a single twitch tension, TOF fade, and peak tetanic tension at each calcium concentration, were calculated using a sigmoid Emax model. We compared the EC50 of vecuronium according to calcium concentrations. Data was compared by the Kruskal-Wallis test with a post hoc Wilcoxon rank sum test. A p-value of below 0.05 was considered significant. RESULTS: The range of calcium concentration studied didn't produce differences among single or tetanictensions respectively. The EC50's of vecuronium decreased as calcium concentration decreased. CONCLUSIONS: The reduction of calcium concentration can augment the action of vecuronium on the diaphragm.
Animals ; Baths ; Calcium* ; Colon, Sigmoid ; Diaphragm ; Electric Stimulation ; Glucose ; Humans ; Magnesium Chloride ; Male ; Myocardium ; Neuromuscular Agents* ; Paralysis ; Phrenic Nerve ; Rats* ; Rats, Sprague-Dawley ; Relaxation ; Transducers ; Vecuronium Bromide*

BACKGROUND: When appropriate premedication is required for pediatric patients, the route of drug administration and the patient's age may affect the drug response. This study was designed to evaluate the premedicative effects of intranasal, oral, and rectal midazolam in preschool (1~6 year) and school (6.1~10 year) ages. METHODS: One hundred fourteen children aged 1~10 years were randomly allocated into three groups to receive midazolam via intranasal (0.3 mg/kg), oral (1.0 mg/kg), or rectal (1.0 mg/kg) route. Sedation scores were evaluated at the arrival in preanesthetic room, drug administration, 5, 10, 20 and 30 min after drug administration, separation from parent, mask application, and induction with inhalational agent. Time to sedation scores of 3 and 4 and time to complete recovery from general anesthesia were recorded. RESULTS: At the drug administration, the incidence of crying was significantly higher in nasal group than in oral and rectal groups, especially in pre-school age group (87.5, 23.5. 40.9% for nasal, oral and rectal groups, respectively). At 5, 10 and 20 min after drug administration, sedation scores were significantly higher in nasal and rectal groups than in oral group. At separation, mask application and inhalational induction, sedation scores were significantly higher in oral and rectal groups than in nasal group. Time to sedation score of 3 and time to complete recovery were significantly longer in oral group than in nasal and rectal groups. CONCLUSIONS: In pre-school age, almost all the children cried at drug administration in nasal group, and onset and recovery were prolonged in oral group, so rectal route was suitable. In school age, nasal route was appropriate because of the lower frequency of crying at the drug administration and rapid onset and recovery. In overall age, rectal route was better because of the lower frequency of crying and rapid onset and recovery. This study suggests that administration route should be considered according to the age of pediatric patient to obtain appropriate premedication for pediatric patients.
Anesthesia, General ; Child* ; Crying ; Humans ; Incidence ; Masks ; Midazolam* ; Parents ; Premedication*

BACKGROUND: Although pain after cholecystectomy was reduced significantly since the advent of laparoscopic surgery, many patients still complain of moderate pain after the surgery. Recently intraperitoneal instillation of local anesthetics is known as safe, simple, and effective method of treatment for pain after laparoscopic cholecystectomy. METHODS: Three groups are randomized; group I (normal saline 80 ml), group II (0.5% lidocaine 80 ml+1:400,000 epinephrine) and group III (0.125% bupivacaine 80 ml+1:400,000 epinephrine). Local anesthetics are instilled via subdiaphragmatic trocar hole just after creation of carboperitoneum. Visual analogue scale (VAS), total used analgesics amount, time to first analgesics request, time to out of first flatus and complications are compared. Lidocaine blood concentrations are checked in five cases of the patients after lidocaine instillation. RESULTS: The VAS was insignificant among groups except 3 hr, 6 hr postoperatively. Time to first analgesics request are prolonged in lidocaine and bupivacaine group. Used analgesics amount are significantly less in lidocaine group than control group. Time to out of first flatus was significantly shorter in bupivacaine group. No significant complications were noted. The blood concentration of lidocaine were variable and the highest concentration in five of one case was 1.8 microgram/ml. CONCLUSIONS: Although intraperitoneal instillation of local anesthetics is simple, safe method for controlling pain after laparoscopic cholecystectomy, it is not so much effective because of dilution with irrigating saline and suctioning intraoperatively and postoperative scavenging by evacuator.
Analgesics ; Anesthetics, Local* ; Bupivacaine ; Cholecystectomy ; Cholecystectomy, Laparoscopic* ; Flatulence ; Humans ; Laparoscopy ; Lidocaine ; Pain, Postoperative* ; Suction ; Surgical Instruments

BACKGROUND: We evaluated the efficacy and safety of positive pressure ventilation (PPV) with a ProSeal laryngeal mask airway (PLMA), as compared with an endotracheal tube (ETT) and with a classic laryngeal mask airway (LMA) during laparoscopic cholecystectomy. METHODS: One hundred, ASA 1, 2 adults scheduled for elective laparoscopic cholecystectomy were randomly assigned to ETT, LMA or PLMA. Anesthesia was induced with fentanyl 2 microgram/kg, lidocaine 0.5 mg/kg and propofol 2 mg/kg and maintained with a continous infusion of propofol 6-12 mg/kg/h in 67% N2O, atracurium and fentanyl. ETT, LMA or PLMA was placed with atracurium 0.5 mg/kg. Respiratory and hemodynamic parameters were measured before and after intraabdominal CO2 insufflation. The surgeon assessed the degree of gastric distension change using a laparoscope. RESULTS: Oxygen saturation, end tidal CO2, inspiratory pressure, expiratory tidal volume and compliance of the respiratory system were similar in the three groups. Blood pressure and heart rate were lower in the PLMA and LMA groups than in the ETT group 5 min after induction (P < 0.05). Audible gas leakage occurred more so in the LMA group (48.5%) than in the PLMA group (8.8%). Because of inadequate ventilation, endotracheal intubation was changed in one case in the LMA group. The degrees of gastric distension change were similar in the three groups. The PLMA and LMA resulted in less coughing after removal than ETT (P < 0.05). A postoperative sore throat and dysphagia were similar in the three groups, but dysphonia was more frequent in the ETT group. CONCLUSION: During laparoscopic cholecystectomy, PPV with PLMA provide more effective pulmonary ventilation than LMA and fewer side effects than ETT.
Adult ; Anesthesia ; Atracurium ; Blood Pressure ; Cholecystectomy, Laparoscopic* ; Compliance ; Cough ; Deglutition Disorders ; Dysphonia ; Fentanyl ; Heart Rate ; Hemodynamics ; Humans ; Insufflation ; Intubation, Intratracheal ; Laparoscopes ; Laryngeal Masks* ; Lidocaine ; Oxygen ; Pharyngitis ; Positive-Pressure Respiration* ; Propofol ; Pulmonary Ventilation ; Respiratory System ; Tidal Volume ; Ventilation

Aneurysmal subarachnoid hemorrhage in a pregnant woman is a rare catastrophic situation that places both the mother and fetus at high risk. When this situation arises, numerous relevant issues must be individualized in the effort to reduce hazards threatening both the mother and fetus. A 29 year old woman who was 39 weeks pregnant presented with a subarachnoid hemorrhage, secondary to a ruptured left ophthalmic artery aneurysm. Following initial full recovery, the simultaneous sequence of cesarean section followed by aneurysmal clipping was electively underwent. Successful maternal and perinatal outcome was achieved. The anesthetic management of the case is described and discussed.
Adult ; Anesthesia ; Aneurysm* ; Cesarean Section* ; Female ; Fetus ; Humans ; Intracranial Aneurysm* ; Mothers ; Ophthalmic Artery ; Pregnancy ; Pregnant Women ; Subarachnoid Hemorrhage