The Analgesic Effect of Intrathecal Gabapentin in a Rat Model of Incisional Pain / 대한마취과학회지

BACKGROUND: Gabapentin, an anticonvulsant structurally related to gamma-aminobutyric acid (GABA), was recently reported to be effective in pain associated with reflex sympathetic dystrophy and neuropathy. However, the effects of intrathecal (IT) gabapentin in postoperative pain are unclear. This study was designed to evaluate the analgesic action of IT gabapentin in a rat model of postoperative pain which was similar to human postoperative pain states. METHODS: Rats were prepared with chronic intrathecal catheter. Under halothane anesthesia, a 1 cm incision was made in the plantar aspect of the hind paw and closed. Rats were divided into 7 groups, a control group (saline 20 microliter intrathecally n = 6); a GP 30 group (gabapentin 30 microgram intrathecally, n = 6); a GP 100 group (gabapentin 100 microgram intrathecally, n = 6); a GP 300 group (gabapentin 300 microgram intrathecally, n = 6); a GP 1000 group (gabapentin 1,000 microgram intrathecally, n = 6); a NS-GP group (saline 10 microliter and gabapentin 300 microgram intrathecally, n = 6) and DS-GP group (D-serine 100 microgram and gabapentin 300 microgram intrathecally, n = 6). The rats were placed on an elevated plastic mesh floor, and withdrawal threshold was determined using calibrated von Frey filaments applied from beneath the test cage to an area adjacent to the wound. A cumulative pain score based on the weight bearing behavior of the rats, and motor deficit score, were also assessed. RESULTS: In all group, the median withdrawal threshold for punctate hyperalgesia decreased from 148.4 mN before surgery to 1.5 mN-14.5 mN 2 hours after surgery-inducing hyperalgesia and remained unchanged during the 2hr testing period. The IT administration of gabapentin (30 300 microgram) increased the median withdrawal threshold toward preincision values dose-dependently and the nonevoked pain scores were also decreased. But the effects of intrathecal gabapentin were reversed by IT D-serine. The Analgegic effects of gabapentin were observed at doses that had no significant effect on motor function or spontaneous activity. CONCLUSIONS: These observations suggest that intrathecal gabapentin can modulate the facilitation of spinal nociceptive processing by tissue injury and may offer a therapeutic agent for the treatment of postoperative pain.

Hemodynamic Responses to Dobutamine, Hydralazine and Sodium Nitroprusside Following Pentastarch Infusion during Cardiac Tamponade in Dogs / 대한마취과학회지

Background: Cardiac tamponade results in a hemodynamic disorder associated with decreased cardiac output and blood pressure. To improve cardiac output in a subject with cardiac tamponade, cardiotonic drugs and vasodilators with blood volume expander can be used. The purpose of this study was to observe the hemodynamic effects of cardiotonic drugs and vasodilators following administration of plasma expander in the dogs with cardiac tamponade. Method: Three groups of dogs were studied during the induced cardiac tamponade. Following infusion of pentastarch, group I received dobutamine by dripping of 10 microg/kg/min, followed by injection of 20 microg/kg/min, group II received hydralazine (20 mg, 40 mg) and group III received sodium nitroprusside (5 microg/kg/min, 10 microg/kg/min). The heart rate, blood pressure, cardiac output and pulmonary arterial occluded pressure were measured. The atrial transmural pressure was calculated by subtracting intrapericardial pressure from mean atrial pressure. Results: Cardiac output was increased in the groups I and II, but mean arterial pressure was increased in only the group I. Atrial transmural pressure was not changed in all three groups. Conclusion: The most pronounced hemodynamic improvements during the cardiac tamponade is observed in group I with pentastarch-dobutamine combination.

Effects of both Clonidine Premedication and Esmolol Administration on the Hemodynamic Changes by Tracheal Intubation / 대한마취과학회지

BACKGROUND: Tracheal intubation by direct laryngoscopy induces frequently transient hypertension, tachycardia and arrhythmia. The purpose of this study was to examine the effect of esmolol and clonidine in attenuating the changes of blood pressure and heart rate by tracheal intubation. METHODS: Eighty patients were randomly divided into four groups: Group 1 (control , n=20), Group 2 (esmolol 0.5 mg/kg IV, n=20), Group 3 (clonidine 4 mcg/kg PO, n=20) and Group 4 (clonidine 4 mcg/kg PO and esmolol 0.5 mg/kg IV, n=20). The clonidine premedication were given orally with a sip of water 90 minutes before induction of anesthesia. Anesthesia was induced with thiopental 5 mg/kg, vecuronium 0.1 mg/kg, 50% nitrous oxide in oxygen and 2 vol % enflurane. After 5 minutes, tracheal intubation was performed. Patients in the group 2 and group 4 were given esmolol 0.5 mg/kg 90 seconds prior to tracheal intubation. Blood pressure and heart rate were measured at ward, preinduction, preintubation, immediately after intubation, 1, 3 and 5 minutes after intubation. RESULTS: After tracheal intubation, the increase in systolic blood pressure was supressed significantly in the clonidine-treated patients (Group 3, Group 4) compared with control group (p<0.05). The attenuating effect on increase of mean arterial pressure(MAP) was sustained longer in group 4 than group 3. Heart rate increased after tracheal intubation in all groups, but were markedly increased in the control group (p<0.05). The differences of MAP which measured at preinduction and immediately postintubation were smaller in group 4 than control group (p<0.05). The differences of heart rate which measured at preinduction and immediately postintubation were smaller in group 4 than group 1 or group 3 (p<0.05). CONCLUSIONS: Esmolol 0.5 mg/kg given as bolus, is effective for controlling the increase of heart rate but not in attenuating increase of blood pressure. Oral clonidine is effective for controlling the increase of blood pressure but not in attenuating increase of heart rate. Therefore esmolol combined with oral clonidine results in effective control of both heart rate and blood pressure.

Inhibitory Effect of Nicardipine on Cardiovascular Stimulation by Tracheal Intubation / 대한마취과학회지

BACKGROUND: Direct laryngoscopy and tracheal intubation frequently induce transient hypertension, tachycardia and arrhythmia. This study was to evaluate the effect of nicardipine on the changes of the blood pressure and heart rate induced by direct laryngoscopy and tracheal intubation. METHODS: Sixty patients were randomly divided into three groups: Group 1 (nicardipine 0.02 mg/kg, n=20), Group 2 (diltiazem 0.2 mg/kg, n=20), Group 3 (normal saline 3 cc, n=20). Two minutes after intravenous injection of 2 mcg/kg of fentanyl, thiopental 5 mg/kg and nicardipine or diltiazem or normal slaine was administered intravenously. Then succinylcholine 1.5 mg/kg was administered. One minute after succinylcholine injection, direct laryngoscopy and tracheal intubation was done and vecuronium 0.1 mg/kg was injected. Anesthesia was maintained with 50% nitrous oxide in oxygen and 2 vol % of enflurane. Blood pressure and heart rate were measured at the period of preintubation, immediately after intubation, 1, 3 and 5 minutes following intubation by noninvasive method. RESULTS: After tracheal intubation, the increase of systolic blood pressure was supressed significantly in nicardipine and diltiazem group compared with control group (nicardipine group 11%, diltiazem group 13%, control group 24%). The increase of heart rate was greatest in nicardipine group (nicardipine group 38% diltiazem group 29%, control group 20%). CONCLUSIONS: Nicardipine was effective in attenuating pressor responses to laryngoscopy and intubation, but in nicardipine group, increase of heart rate was greater than control group.

Relationship between expression of retinal intercellular adhesion molecule-1 and blood-retinal barrier rupture and therapeutic effect of triamcinolone acetonide in diabetic rats / 中华眼底病杂志

0.05) while was higher in the rest of TA treatment groups than that in the control group (P

The Divided Doses of Neostigmine for the Rapid Recovery at Profound Muscle Relaxation of Pancuronium in Rabbits / 대한마취과학회지

BACKGROUND: The reversal of neuromuscular blocker might be accelerated if the anticholinesterase was administered in divided doses. This study has been conducted to evaluate the correct ratio of divided doses of neostigmine for the rapid recovery in the rabbits after pancuronium when the profound relaxation(PTC=0) was confirmed. METHODS: Rabbits(n=60) were randomly allocated to 6 groups. After pancuronium 0.2 mg/kg intravenously, spontaneous recovery was evaluated in group 1. When the profound relaxation(PTC=O) was confirmed at 5 min. after pancuronium, neostigmine 50 ug/kg was injected as a bolus in group 2. At that time, neostigmine was given at 10 ug/kg followed by 40 ug/kg 3 min. later in group 3. At that time, neostigmine was given at 20 ug/kg followed by 30 ug/kg 3 min. later in group 4. At that time, neostigmine was given at 30 ug/kg followed by 20 ug/kg 3 min. later in group 5. At that time, neostigmine was given at 40 ug/kg followed by 10 ug/kg 3 min. later in group 6. RESULTS: The mean time from injection of pancuronium to 95% recovery was 99.3 min. in group 1, 59.8 min. in group 2, 53.2 min. in group 3, 51.5 min. in group 4, 50.8 min. in group 5 and 41.1 min. in group 6. The recovery index was significantly reduced in group 6(p<0.05). CONCLUSIONS: We conclude that the recovery time is reduced when neostigmine is administered in divided doses: a larger priming dose followed by a smaller bolus at profound relaxation.

Cardiovascular Response of Esmolol and Diltiazem to Endotracheal Extubation / 대한마취과학회지

BACKGROUND: Tracheal extubation causes hypertension and tachycardia. In susceptable patients, even this short period of hypertension and tachycardia can result in myocardial ischemia. The purpose of this study was to evaluate the effect of esmolol and diltiazem in attenuating cardiovascular responses to tracheal extubation. METHODS: Changes in heart rate, systolic and diastolic blood pressure were measured during extubation and emergence from anesthesia in 60 ASA physical status I patients to assess the effect of esmolol and diltiazem. The patients were randomly assigned to one of three groups (n=20 for each group) : saline 5 ml (as a control), 0.2 mg/kg diltiazem and 1.5 mg/kg esmolol. These medications were given 2 min before tracheal extubation. RESULTS: Both groups of diltiazem and esmolol were greater attenuating effect on changes of heart rate, systolic and diastolic blood pressure than control group. The inhibitory effect on changes of heart rate was greater with esmolol than diltiazem, but the attenuating effect on changes of systolic blood pressure was greater with diltiazem than esmolol. CONCLUSIONS: We concluded that a bolus dose of intravenous diltiazem 0.2 mg/kg or esmolol 1.5 mg/kg given at 2 min before extubation was of value in attenuating the cardiovascular changes occuring in association with tracheal extubation and emergence from anesthesia. Esmolol is more effective than diltiazem in attenuating the heart rate changes. Diltiazem is more effective than esmolol in attenuating the systolic blood pressures changes.