Studies of Interaction between Hexamethonium and Lidocaine, alpha-Bungarotoxin or Decamethonium in Vitro / 대한마취과학회지

BACKGROUND: Interactions of neuromuscular blocking agents are antagonistic in a combination of depolarizing and nondepolarizing agents, additive in a combination of relative two compounds or synergistic in a combination of different two nondepolarizing agents. However, the interactions of neuromuscular blocking agents with a different site of action from each other have not been studied clearly. This study was designed to examine the interaction between hexamethonium and lidocaine, alpha-bungarotoxin or decamethonium with markedly different pre and postsynaptic sites of action. METHODS: Square wave, 0.1 Hz supramaximal stimuli or 2 Hz, 0.2 ms train of four (TOF) stimuli, was applied to the rat phrenic nerve-hemidiaphragm preparation, and the twitch height response was recorded mechanomyographically. The cumulative concentration effect and TOF ratio at each point of twitch depression after hexamethonium, lidocaine, alpha-bungarotoxin or decamethonium given were measured. The EC50 and EC95 of hexamethonium, lidocaine, alpha-bungarotoxin and decamethonium were calculated using an inhibitory sigmoid Emax model. In the experiment of each combination of two drugs, three points of the isobole for hexamethonium-lidocaine, hexamethonium-alpha-bungarotoxin and hexamethonium-decamethonium were established using ratios of 1 : 3, 1 : 1 and 3 : 1 of their EC50. Points on the line of theoretical additivity and 95% confidence intervals were calculated according to Tallarida et al. TOF ratios were observed at 75, 50 and 25% of the control twitch height value during each combination ratio of their EC50. RESULTS: Significant deviations of points on the isobole from the line of additivity to the left were found at all EC50 ratios of hexamethonium-lidocaine (P < 0.05 respectively), that to the right was found at all EC50 ratios of a hexamethonium-alpha-bungarotoxin and hexamethonium-decamethonium (P < 0.05 respectively). The magnitude of TOF fade depended upon the mixed ratios for their EC50. CONCLUSIONS: The interaction was found to be synergistic in the combination of hexamethonium- lidocaine, and antagonistic in the combination of hexamethonium-alpha-bungarotoxin and hexamethonium- decamethonium.

Effect of Etomidate and Thiopental on Intraocular Pressure associatedwith Induction of Anesthesia and Tracheal Intubation(Facilitated with Succinylcholine) / 대한마취과학회지

BACKGROUND: Good control of intraocular pressure (IOP) during induction and maintenance of anesthesia is essential for the success of intraocular surgery. Etomidate produces a significant and somewhat greater reduction in IOP than thiopental. This study was designed to compare the effects of etomidate on IOP with those of thiopental in patients receiving succinylcholine, and in whom tracheal intubation was performed. METHODS: Forty ASA physical status I or II patients undergoing elective surgery were divided into thiopental group (n = 20) or etomidate group (n = 20). Intraocular pressure was measured before induction, 1, 2, and 3 minutes after administration of an intravenous induction agent, after administration of succinylcholne, immediately after intubation and 2 minutes after intubation. Systolic blood pressure and heart rate were recorded simultaneously. RESULTS: Both agents produced significant decreases in IOP after administration. At 3 minutes after administration of an agent and after administration of succinylcholine, the IOP of the etomidate group was significantly lower than that of the thiopental group (P< 0.05), but there were no significant differences between the groups in IOP at other stages. CONCLUSIONS: Etomidate is not a more effective intravenous induction agent to control the increase of intraocular pressure following tracheal intubation with succinylcholine than thiopental.

The Effects of Propofol Anesthesia or Prophylactic Droperidol on Postoperative Nausea and Vomiting in Patients Undergoing a Gynecologic Laparoscopy / 대한마취과학회지

BACKGROUND: Postoperative nausea and vomiting (PONV) is a common complication of a gynecologic laparoscopy. This study was designed to assess the effect of prophylactic droperidol 1 mg or propofol as the induction and maintenance anesthetic agent for prophylaxis of PONV in women undergoing a gynecologic laparoscopy. METHODS: Eighty ASA physical status 1, 2 patients undergoing an elective gynecologic laparoscopy were randomly allocated into four groups. Group 1 (n = 20) recieved an intravenous placebo of noraml saline 1 ml prior to induction of anesthesia and N2O-enflurane general anesthesia. Group 2 (n = 20) recieved an intravenous placebo of noraml saline 1 ml prior to induction of anesthesia and N2O-propofol general anesthesia. Group 3 (n = 20) recieved intravenous prophylactic droperidol 1 mg prior to induction of anesthesia and N2O-enflurane general anesthesia. Group 4 (n = 20) recieved intravenous prophylactic droperidol 1 mg prior to induction of anesthesia and N2O-propofol general anesthesia. RESULTS: The incidence and severity of PONV and sedation scores were assessed at 0, 30 min, 1, 3, 6, 24 and 48 hours postoperatively. The incidence of PONV was 75% in group 1, 10% in group 2, 30% in group 3 and 20% in group 4. The incidence of PONV during the first 6 hours postoperatively was 70% in group 1, 0% in group 2, 10% in group 3 and 5% in group 4 and there were no statistical differences among the four groups in the 6 to 24 hour postoperative period. Sedation scores were significantly higher in group 3 and 4 than in 1 and 2 in the 3 to 6 hour postoperative period. CONCLUSIONS: Propofol anesthesia, prophylactic droperidol 1 mg and a combination to prevent PONV were highly effective during the first 6 hours postoperatively.

The Effect of Lidocaine on the Onset Time of Rocuronium-induced Neuromuscular Blockade in Adults / 대한마취과학회지

BACKGROUND: Rapid-sequence intubation is a common technique to reduce anesthetic complication. Due to side effects of succinylcholine, nondepolarizing muscle relaxants have been tried. Rocuronium is a new nondepolarizing muscle relaxant with a brief onset of action, but devoid of the adverse reaction associated with succinylcholine. Most local anesthetics decrease neuromuscular transmission and pontentiate neuromuscular blocks of muscle relaxants. The purpose of this study was to examine the effect of lidocaine on the onset time of rocuronium-induced neuromuscular blockade in adults. METHODS: Fourty five patients, ASA physical status I or II, were randomly divided into three groups. Anesthetic induction with thiopental 5 mg/kg was made. Succinylcholine (1.0 mg/kg) was administered intravenously in group 1. Rocuronium (0.6 mg/kg) was given in group 2, additional lidocaine (1.0 mg/kg) was given intravenously 1 minute prior to the administration of rocuronium in group 3. Neuromuscular blockade was assessed by train-of-four at the adductor pollicis muscle with supramaximal stimulation of the ulnar nerve (2 Hz, 0.2 msec) every 10 seconds. The condition of intubation, the appearance of arrhythmias, side effects of drugs, and the changes of mean arterial pressure and heart rate were checked and compared in peri-induction periods. RESULTS: The onset time of group 1 (55.1 14.9 sec) was faster than that of group 2 (137.8 46.0 sec) and group 3 (139.3 41.0 sec), but there was no difference between the onset time of group 2 and that of group 3. Intubating conditions were good or excellent in all groups, but group 1 and 3 were better than group 2. There was no difference between the three groups in hemodynamics. More adverse effects were observed in group 1, that of group 2 and 3 were observed in only one case. CONCLUSIONS: The authors concluded that lidocaine is not effective on the onset time of rocuronium, but improves the intubating condition. Rocuronium is devoid of side effects of succinylcholine, but not a alternative to succinylcholine because its onset time is too slow when compared with succinylcholine.

The Effect of Lidocaine on the Onset Time of Rocuronium-induced Neuromuscular Blockade in Adults / 대한마취과학회지

BACKGROUND: Rapid-sequence intubation is a common technique to reduce anesthetic complication. Due to side effects of succinylcholine, nondepolarizing muscle relaxants have been tried. Rocuronium is a new nondepolarizing muscle relaxant with a brief onset of action, but devoid of the adverse reaction associated with succinylcholine. Most local anesthetics decrease neuromuscular transmission and pontentiate neuromuscular blocks of muscle relaxants. The purpose of this study was to examine the effect of lidocaine on the onset time of rocuronium-induced neuromuscular blockade in adults. METHODS: Fourty five patients, ASA physical status I or II, were randomly divided into three groups. Anesthetic induction with thiopental 5 mg/kg was made. Succinylcholine (1.0 mg/kg) was administered intravenously in group 1. Rocuronium (0.6 mg/kg) was given in group 2, additional lidocaine (1.0 mg/kg) was given intravenously 1 minute prior to the administration of rocuronium in group 3. Neuromuscular blockade was assessed by train-of-four at the adductor pollicis muscle with supramaximal stimulation of the ulnar nerve (2 Hz, 0.2 msec) every 10 seconds. The condition of intubation, the appearance of arrhythmias, side effects of drugs, and the changes of mean arterial pressure and heart rate were checked and compared in peri-induction periods. RESULTS: The onset time of group 1 (55.1 14.9 sec) was faster than that of group 2 (137.8 46.0 sec) and group 3 (139.3 41.0 sec), but there was no difference between the onset time of group 2 and that of group 3. Intubating conditions were good or excellent in all groups, but group 1 and 3 were better than group 2. There was no difference between the three groups in hemodynamics. More adverse effects were observed in group 1, that of group 2 and 3 were observed in only one case. CONCLUSIONS: The authors concluded that lidocaine is not effective on the onset time of rocuronium, but improves the intubating condition. Rocuronium is devoid of side effects of succinylcholine, but not a alternative to succinylcholine because its onset time is too slow when compared with succinylcholine.

The Effect of Midazolam, Fentanyl and a Small Dose of Etomidate for Prevention of Myoclonus during Induction of Anesthesia with Etomidate / 대한마취과학회지

BACKGROUND: The hypothesis that subcortical disinhibition is the reason for etomidate-induced myoclonus suggest that drugs acting on the subcortical area may reduce myoclonus. To verify the hypothesis, premedication with placebo, etomidate of a small dosage, midazolam and fentanyl were compared. METHODS: Sixty ASA physical status I or II patients undergoing elective surgery were allocated into four groups. All groups were induced with etomidate 0.3 mg/kg and vercuronium 0.1 mg/kg and maintained with 50% N2O and 1.5-2% enflurane. Group I (n = 15) received normal saline 3 ml 5 minutes before the etomidate 0.3 mg/kg administration, group II (n = 15) received 0.05 mg/kg etomidate 50 seconds before the etomidate 0.3 mg/kg administration, group III received midazolam 0.05 mg/kg 5 minutes before the etomidate 0.3 mg/kg and group IV received 2 microgram/kg fentanyl 5 minutes before the etomidate 0.3 mg/kg. In all patients, the grade, starting time, maintenance time of myoclonus and vital signs were checked and compared between the four groups. RESULTS: In group IV, myoclonus did not develope except in one patient and there were no differences in the incidence of myoclonus between the others. All premedicating drugs do not affect vital signs. CONCLUSIONS: We find that fentanyl reduces the incidence of etomidate-induced myoclonus but midazolam and a small dose of etomidate are not effective.

The Comparison of Epidural Morphine and Epidural Morphine-Ketamine for Postoperative Pain Relief after Subtotal Gastrectomy / 대한마취과학회지

BACKGROUND: Epidural narcotics are now widely used for postoperative pain relief, but their side effects are problematic. Thus, this study was undertaken to evaluate the analgesic effects and to minimize the side effects of the combination of epidural morphine and ketamine versus epidural morphine alone in pateints with postoperative pain. METHODS: The value of using a combined infusion of morphine with a variable dose of ketamine for postoperative analgesia following subtotal gastrectomy was assessed in a double-blind randomised study of 30 patients. Three groups of 10 patients received an infusion of morphine at 2 mg/day, either alone, or combined with ketamine at a rate of 0.4 or 0.6 mg/kg/day. RESULTS: Postoperative anlagesia, sedation, and side effects were not statistically significantly different between groups I and II. Postoperative sedation, and side effects were not statistically significantly different between groups I and III. VAS of group III at 1-2 h was lower than in group I. CONCLUSION: The addition of ketamine to a continuous infusion of morphine dose not significantly improve postoperative analgesia. In addition, increasing the dose of ketamine does not significantly improve postoperative analgesia, Nor does it increase sedation, or side effects.

The Effects of Mivacurium on Isolated Rat Tracheal Muscle / 대한마취과학회지

BACKGROUND: Neuromuscular blocking drugs are designed to specifically block nicotinic cholinergic receptors at the neuromuscular junction, but many bind to muscarinic cholinergic receptors on ganglia, nerve endings, and smooth muscles, thereby altering parasymphathetically mediated airway caliber and heart rate. METHODS: We studied the effects of mivacurium on the tension of tracheal smooth muscle by using an isolated rat tracheal preparation. We studied the cumulative effect of acetylcholine after pretreating the tracheal smooth muscle with mivacurium at different concentrations, as well as the effect of L-NAME and propranolol on the tension of tracheal smooth muscle after pretreating with mivacurium. RESULTS: Mivacurium shifted the acetylcholine dose-response curve to the right. L-NAME and propranolol had no effect on the tension of tracheal smooth muscle after pretreating with mivacurium. CONCLUSIONS: We have found that mivacurium relaxes isolated rat tracheal smooth muscle and this effect has no relationship to beta-receptors or nitric oxide.

Vasodilatory Action of Propofol and the Effect of Propofol on the Contractile Response of Endotoxin Exposured Vessles in the Aortic Arteries of Rats / 대한마취과학회지

BACKGROUND: The relationship between the NO and its vasodilatory effect of propofol has been a somewhat controversial matter. And, the effects of propofol has not been evaluated in septic condition whether it is solely due to its increased iNOS activity. METHODS: First experiment is to study that the vasodilatory effect of propofol could be caused by NO. Isolated aortic rings with or without endothelium were contracted phenylephrine (10(-9)-10(-5)M) cumulatevely after porpofol (10(-5)M) administration. The effects of L-NAME (3 x 10(-4)M) and methylene blue (10(-5)M) on contractile responses for phenylephrine were evaluated. Second experiment is to study the effect of propofol on septic vesseles. the no LPS (lypopolysaccaride) and LPS treated rings with or without endothelium were contracted phenylephrine (10(-9)-10(-5)M) cumulatevely after porpofol (10(-5)M) administration. The development of sepsis was confirmed by iNOS expression using RT-PCR. RESULTS: All the aortic rings showed decreased response on phenylephrine contractile response with propofol administration. These responses were significantly less in denuded ones than in ones with intact endothelium. The endothelium dependent relaxation of propofol was inhibited by pretreatment with L-NAME and methylene blue in rat aortic rings having intact endothelium. All the aortic rings incubated with LPS showed decreased phenylephrine contractile response. The addition of propofol produced significantly more decrease in contractile response in LPS incubated rings in a greater than additive effect. The LPS induced hyporesponsiveness to phenylephrine was reversed by addition of cycloheximide. However, with the addition of propofol to LPS treated rings, complete reversal of this hyporesponsiveness to phenylephrine, failed to occur by addition of cycloheximide. CONCLUSIONS: 1) The vasodilatory effect of propofol seems to be mediatede by EDRF/NO, 2) The vasodilatory effect of propofol is increased in septic vesseles. Moreover, the inability of nitric oxide synthase inhibitior to reverse this response completely suggest that increased induction of iNOS may not be a sole responsible factor for this finding.

A Comparison of Recovery from Mivacurium during Enflurane or Propofol Anesthesia in Children / 대한마취과학회지

BACKGROUND: Mivacurium is a new, short acting, nondepolarizing muscle relaxant of the benzylisoquinolinium type. Enflurane produces relaxation and augments the neuromuscular blockade from muscle relaxation, but propofol does not produce muscle relaxation. We compared maintenance infusion rates, recovery index and correlations of recovery index to maintenance infusion rates and infusion duration after mivacurium during enflurane or propofol anesthesia in children. METHODS: Maintenance infusion rates, and the recovery index after mivacurium were studied in 30 pediatric patients in enflurane anesthesia (n = 15) and propofol anesthesia (n = 15). The ulnar nerve was stimulated at the wrist by repeated single twitch (1Hz) stimulus using the peripheral nerve stimulator (Model ST5 MaxiStimTM, Life-Tech , Inc, Texas, USA). We recorded the contraction of adductor pollicis longus via mechanomyography (MYOTRACE, Life-Tech, Inc, Texas, USA). RESULTS: The infusion rates of mivacurium for the maintenance of muscle relaxation (below 10% of control) were 9.6 0.80 microgram/kg/min in the enflurane anesthesia, and 11.04 1.22 microgram/kg/min in the propofol anesthesia. There was a significant difference between the groups. The recovery index was shorter in the propofol anesthesia, but regarding this index, there was no significant difference between both groups. The correlation between the recovery index and the infusion duration was significantly different in the enflurane anesthesia. CONCLUSIONS: We conclude that maintenance infusion rates are significantly lower in the enflurane anesthesia, the recovery index is insignificantly shorter in the propofol anesthesia, that there is a significant correlation between the maintenance infusion rates and recovery index in the enflurane anesthesia.

Influence of Various Muscle Relaxants on the Plasma Cholinesterase Activity / 대한마취과학회지

BACKGROUND: The reduction in the plasma cholinesterase (PChE) level results in slow to hydrolysis of succinylcholine (SCC) and mivacurium (MIV). The factors altering the level of the normal enzyme in human could be considered under the several conditions. We investigated in the present study whether the drugs induced decreases in normal PChE activity after administration of various muscle relaxants during anesthesia are evident and how these results should be influenced to the time course of neuromuscular blockade produced by SCC and MIV. METHODS: Young adult patients of ASA class I or II scheduled for elective surgery requiring muscle relaxation were premedicated and anesthesia was maintained with nitrous oxide in oxygen with increment of thiopentone or fentanyl as required. In the neuromuscular monitoring, surface electrodes were applied on the ulnar nerve at wrist. Supramaximal transcutaneous single twitch stimulation (1 Hz) during onset and 0.1 Hz during recovery of neuromuscular blockade induced by various muscle relaxants delivered by a peripheral nerve stimulator was applied. Twitch response of thumb adductor was measured mechanomyographically using 2 kg Load Cell Strain Gauge with thumb piece modification. Recordings were made on a Gould recorder. PChE levels were measured by the modified Garry method after induction of anesthesia and, at 3, 10, 20 and 30 min following administration of 2 x ED95 of pancuronium (PAN), vecuronium (VEC) and atracurium (ATR). Neuromuscular recordings were measured with onset time defined as lag time and manifest time, and recovery time defined as clinical duration, recovery index and total duration. RESULTS: The levels of PChE were significantly reduced after administration of PAN and VEC (p<0.05). Onset times were significantly shorten but recovery time in the group given MIV pretreated by small dose of PAN was significantly prolonged (p<0.05). And there were a evidence to prolong recovery time in the group pretreated by small dose of VEC but not significant. CONCLUSIONS: It is concluded that aminosteroidal derivative neuromuscular blocking agents have presumably evidence induced decreases in PChE activity rather than benzylisoquinolinium derivative neuromuscular blocking agents.

The Effects of Lipopolysaccharide on the Reactivity of Isolated Rat Trachea with or without Epithelium / 대한구급학회지

BACKGOUND: Gram negative bacterial lipopolysaccharide (LPS) induces increase in the production of nitric oxide (NO), or a related substance derived from L-arginine in the animal tissue. Recent evidence indicates that airway epithelium may secrete NO or a related compound. It has multiple regulatory roles in the airways. In vitro, the effects of lipopolysaccharide (LPS) on the reactivity of rat' tracheal wall with or without epithelium were examined. METHODS: Tracheas were removed from Sprague Dawley rats. Preparations were mounted for isometric recording in 20ml organ baths at 37degrees C containing Tis-buffered Tyrode solution continuously gassed with 100% O2. Tensions were measured with force displacement transducers and responses were recorded on a polygraph. Cummulative concentration-response curves were constructed for acetylcholine (Ach) in the tracheal strips with or without preincubation of Escherichia coli LPS (100 mcg/ml, 5hrs). And then effects of NO synthase inhibitors and removal of epithelium were examined. RESULTS: In isolated perfused tracheas preincubated by LPS, both removed epithelium and intact epithelium of rat tracheal rings showed decreased Ach-induced contraction. In intact epithelium group, 10 (-5)M L-NAME (N-nitro-L-arginine methyl ester), 10 (-5)M L-arginine or dexamethasone pretreatment was restored in Ach-induced contraction response. But in the removed epithelium group, Ach-induced contraction was potentiated by L-arginine pretreatment and was not restored by the pretreatment of L-NAME and dexamethasone. CONCLUSIONS: The results suggest that nitric oxide synthase is induced by endotoxin in the tracheal epithelium, resulting in inhibition of the contractile response.

The Vasodilation of Protamine and the Influence of Heparin on its Actions in the Isolated Aortic Arteries of Rats / 대한마취과학회지

BACKGROUND: When used to reverse the anticoagulant effect of heparin, protamine administration after cardiovascular bypass often can lead to systemic hypotension. During the reversal of heparin-induced anticoagulation, the effects of protamine on both a heparin-protamine complex and free protamine on the cardiovascular system should be considered. METHOD: To determine whether the hypotensive effect of heparin-protamine and/or protamine could be caused by endothelium-dependent and-independent component, we studied rings of the arotic arteries in rats suspended in organ chambers containing Tris Tyrode solution at 37oC and 100% O2. Arterial rings with or without endothelium were contracted with 40 mM KCl or 3 +/- 10-6M phenylephrine and then exposed to increasing concentrations of protamine (final organ bath concentration, 40~400 g/ml) both in the absence and presence of heparin (200 U/ml). RESULTS: Protamine induced concentration-dependent relaxation in arterial rings with endothelium, which were significantly greater than in rings without endothelium. The endothelium-dependent relaxation induced by protamine was inhibited by NG-monomethyl-L-arginine (L-NMMA) (10-5M) pretreatment, but was not inhibited by indomethacin (3x10-6M) pretreatment on rings with endothelium. Furthermore, the contractile inhibition was enhanced by superoxide dismutase (100 U/ml). Also, such vasodilating actions were not influenced in the presence of heparin (200 U/ml). In endothelium-denuded strips, protamine (400ug/ml) inhibited Ca++ induced contraction, which was evoked in Ca++-free solution containing 40 mM K+, and also inhibited the norepinephrine (NE)-induced contraction. Protamine inhibited on the NE-induced contraction, but not the caffein-induced contration in Ca++ free, 2 mM EGTA solution. Also, such inhibition of contracions were not inluenced in the presence of heparin (40 U/ml). CONCLUSION: This study demonstrates that protamine (in the presence or absence of heparin) acts on endothelial cell receptors to stimulate the production of nitric oxide and inhibits both Ca++-influx and the NE-induced Ca++ release from intracellular stores.

Effects of Lidocaine and Airway Epithelium on Tension in the Rat Tracheal Smooth Muscle / 대한마취과학회지

BACKGROUND: Lidocaine is often administered intravenously to suppress airway reflexes associated with tracheal intubation or tracheal suction. In addition, lidocaine is known to have airway relaxant effects through a direct relaxant mechanism on the smooth muscle. The presence of airway epithelium has been reported to reduce the sensitivity and maximum contractile response to histamine or acetylcholine(ACh). The purpose of this study was to determine whether the cumulative application of lidocaine may cause a concentration-dependent relaxation of the rat tracheal smooth muscle strips with intact or rubbed epithelium. METHODS: Using the rat tracheal smooth muscle strips, the effects of 10 6~3 10 3M of lidocaine pretreatment on isometric tension induced by 40 mM of K+ or 10 5M of ACh in presence or absence of adherent epithelium, and the influences of 10 6M of propranolol, 10 4M of L-NAME and 10 6M of atropine on relaxing response of lidocaine were studied. RESULTS: The tracheal smooth muscle concentration induced by K+ and ACh was similar magnitude both in presence or absence of adherent epithelium. The removal of epithelium did not affect the relaxant effect of lidocaine on the K+ and ACh-induced tracheal smooth muscle contraction. Lidocaine pretreatment reduced Ca2+-dependent contraction of the rat tracheal smooth muscle. Following pretreatment of the tracheal smooth muscle preparations respectively with propranolol, L-NAME and atropine the relaxing responses to lidocaine of tracheal smooth muscle were not depressed. CONCLUSIONS: These results suggest that the effect of the epithelium on lidocaine-induced relaxation of the tracheal smooth muscle is not significant and lidocaine may directly relax tracheal smooth muscle by the influences on the Ca2+ mobilization.

The Effect of Acetaminophen Rectally Administered before Operation on Postoperative Pain and Behavior after Tonsillectomy in Small Children / 대한마취과학회지

BACKGROUND: Prostaglandin inhibitors have been successfully used to inhibit some types of postoperative pain and reduce opioids requirements in others. Antiprostaglandin activity may be ineffective unless the preparations are given at the appropriate time before surgery. This study aimed to determine if the intrarectal administration of acetaminophen immediately before surgery would markedly reduce pain in the postoperative period. METHODS: The children were divided to two groups. Each group was consisted of 15 children. The children in control group were administered intramuscularly glycopyrrolate(0.004 mg/kg) 20 minute. The children in experimental group were administered glycopyrrolate(0.004 mg/kg) intramuscularly and were administered acetaminophen(250 mg) rectally 20 minute before the children were taken to the operating theatre. RESULTS: In the recovery room, the children who had recived acetaminophen were signifcantlly quieter (p<0.01), agitated less(p<0.01) and cried less(p<0.01) painless(p<0.01) than those nonadministered group. There were no obvious differnces between the groups in intra-operative bleeding (as estimated by the surgeon), or in measured blood loss. No postopertive complications become evident. CONCLUSIONS: The preoperative rectal administration of acetaminophen for pain relief after tonsillectomy is safe and effective.

Vasodilative Effects of Propofol on Isolated Pulmonary Artery in Rats / 대한마취과학회지

BACKGROUND: Propofol, 2,6-diisopropyl phenol, is a short-acting, potent intravenous anesthetics agent. In both general anesthetic care and the anesthetic care of patients undergoing cardiovascular surgery, the unique characteristics of propofol might make it a logical part of the anesthetic plan for patients such as pulmonary hypertension. But there are limited experimental and clinical data on the effects of propofol on pulmonary vascular resistance, and they are somewhat contradictory. the purpose of this study was to investigated.the effect and mechanism of vasodilation induced by propofol using isolated rat pulmonary artery rings. METHODS: Cumulative dose-response curves for propofol(10(-6)~10(-3)M) were obtained from tension measurements of rings that contracted with phenylephrine(10(-6)M) and KCI(40 mM) in the presence and absence of endothelium, and in the pretreatment of L-NAME(3x10(-4)M) and substance P(3x10(-4)M). Thereafter the effect of propofol(10(-4)M) on vascular smooth muscle contration in response to Ca++ mobilization in vscular rings were investigated. RESULTS: Propofol(10(-6)~10(-3)M) produced dose-dependent relaxation and had no signficant effect from endothelium. Pretreatment of L-NAME and substance P failed to have influence on cumulative dose-respose curves. Therefore vasodilator effect of propofol was not endothelium-dependent. And 10(-4)M propofol attenuated a contraction in response to CaCl2 in vascular rings depolarized by KCI, and vasoconstraction in response to calcium entry in the presence of phenylephine was attenuated by 10(-4)M propofol. Ryanodine preteament had not influence on contractile response. CONCLUSIONS: These results suggest that vasodilation produced by propofol is not endothelium-dependent but is probably due to nonspecific intracellular Ca++ influx blockade through voltage-operated calcium channels and receptor-operated channels.

The Gene Expression of Dynorphin, Enkephalin, c-Fos in the Neuropathic Rat / 대한마취과학회지

BACKGROUND: We studied the time course of gene expression of dynorphin, enkephalin, c-fos, and the changes of allodynia, and the effect of chemical sympathectomy on the gene expression and allodynia in neuropathic rat. METHODS: In two groups of rat (Sprague-Dawley), the left L5 and L6 spinal nerves were tight ligated. In gene expression group (N=25), behavioral tests for mechanical allodynia and cold allodynia were perfomed for the next two weeks. After the test of allodynia, the expression of dynorphin, enkephalin, c-fos were assessed by Northern blot hybridization. In chemical sympathectomy group (N=16), after chemical sympathectomy (guanethidine 70 mg/kg intraperitoneally, from postoperative 7 days to 9 days), the changes of allodynia and the gene expression of enkephalin, c-fos were tested. RESULTS: Mechanical allodynia and cold allodynia was developed on the postoperative 3, 5, 7, 14 days. Preprodynorphin mRNA expression was reached peak level at the postoperative 8 hrs, sustained increase by the postoperative 3 days, but preproenkephalin mRNA expression increased slightly after operation. c-Fos mRNA expression was increased immediately at the postoperative 30 min, 1 hr, returned to normal level thereafter, and increased again on the postoperative 3, 5, 7 days that neuropathic pain was developed. Mechanical allodynia and cold allodynia were decreased by chemical sympathectomy. The increased c-fos mRNA expression and pain at postoperative 7 days was reduced by chemical sympathectomy. CONCLUSION: These results suggest that the transient gene expression of dynorphin and c-fos after tight ligation of L5 and L6 spinal nerves induces the development neuropathic pain, and late c-fos expression is related to neuropathic pain.

Effects of Orally Administered Baclofen in the Animal Model for Neuropathic Pain / 대한마취과학회지

The aim of this study was to compare with the effects of baclofen using an animal model of neuropathic pain. The sciatic nerve of rats was ligated unilaterally about dorsal half-portion in the tight according to the method of Seltzer and his colleague. After surgical operation, the rats showed painful symptoms of the ipsilateral hind paw, suggesting the possibility of spontaneous pain. And then, the paw withdrawal latency to the local heating on the paw through the glass plate and the frequency of paw withdrawal response to innocuous mechanical stimulation with modified von Frey filaments were determined to compare with the effects of pre-and post-medication of baclofen, respectively, at postoperative 3, 7, and 10 days. The results obtained were as follows: 1) The thermal hyperalgesia and mechanical allodynia produced by partially tight ligation of sciatic nerve appeared continously postoperative 3 days later. 2) In the hyperesthetic rats, the thermal hyperalgesia was inhibited from the 3rd posroperative day with orally administered baclofen 0.2mg and 1.0mg. 3) In the hyperesthetic rats, the mechanical allodynia was inhibited with baclofen 0.2mg, but not with baclofen 1.0mg, These results suggest that baclofen have more specific effects on thermal hyperalgesia than mechanical allodynia.

The Cardiovascular and Intracranial Effects of Isoflurane, Sodium Nitroprusside, and Labetalol-Induced Hypotension in Cats / 대한마취과학회지

Controlled hypotension has been used to facilitate the surgical procedure and to reduce blood loss. This study was performed to compare the change of the cardiovascular systerm and intracranial pressure following the controlled hypotension induced by isoflurane, sodium nitroprusside, and labetalol in 28 cats. The results were as follows. 1) Heart rate was decreased with the isoflurane-induced hypotension, increased with the sodium nitroprusside-mduced hypotension. Both were not significant, but labetalol-induced hypotension increased heart rate significantly(P< 0.05). 2) Intracranial pressure was increased with isoflurane, sodium nitroprusside, and labetalol-induced hypotension significantly(P< 0.05), but there was significantly small per cent ehange in labetalol-induced hypotension than sodium nitroprusside-induced hypotension(P< 0.05). 3) Cerebral perfusion pressure was decreased with isoflurane, sodium nitroprusside, and labetalol-induced hypotension significantly(P< 0.01), but there was significantly small per cent change in labetalol-induced hypotension than isoflurane or sodium nitroprusside-induced hypotension(P < 0.01, P< 0.001).

The Cardiovascular and Intracranial Effects of Isoflurane, Sodium Nitroprusside, and Labetalol-Induced Hypotension in Cats / 대한마취과학회지

Controlled hypotension has been used to facilitate the surgical procedure and to reduce blood loss. This study was performed to compare the change of the cardiovascular systerm and intracranial pressure following the controlled hypotension induced by isoflurane, sodium nitroprusside, and labetalol in 28 cats. The results were as follows. 1) Heart rate was decreased with the isoflurane-induced hypotension, increased with the sodium nitroprusside-mduced hypotension. Both were not significant, but labetalol-induced hypotension increased heart rate significantly(P< 0.05). 2) Intracranial pressure was increased with isoflurane, sodium nitroprusside, and labetalol-induced hypotension significantly(P< 0.05), but there was significantly small per cent ehange in labetalol-induced hypotension than sodium nitroprusside-induced hypotension(P< 0.05). 3) Cerebral perfusion pressure was decreased with isoflurane, sodium nitroprusside, and labetalol-induced hypotension significantly(P< 0.01), but there was significantly small per cent change in labetalol-induced hypotension than isoflurane or sodium nitroprusside-induced hypotension(P < 0.01, P< 0.001).