Meralgia paresthetica following hemorrhoidectomy in the jack-knife position: A case report

Meralgia paresthetica (MP) is a neuropathic pain caused by the entrapment of the lateral femoral cutaneous nerve (LFCN). There have been reports of MP following various surgeries; however, it has not yet been reported after hemorrhoid surgery. We report a case of bilateral MP after hemorrhoid surgery in a jack-knife position. The patient presented with pain, tightness, and a tingling sensation in the anterolateral aspect of both thighs. Ultrasonography-guided LFCN block was used for diagnosis and treatment, along with conservative management for 20 days with oral medication. One month later, the patient's symptoms had resolved completely. MP due to the jack-knife position may occur postoperatively in patients with predisposing risk factors such as obesity and diabetes mellitus, despite adequate padding and a shorter operating time.

Effects of warmed carrier fluid on nefopam injection-induced pain

BACKGROUND: Nefopam is a non-opioid, non-steroidal analgesic drug with fewer adverse effects than narcotic analgesics and nonsteroidal anti-inflammatory drugs, and is widely used for postoperative pain control. Because nefopam sometimes causes side effects such as nausea, vomiting, somnolence, hyperhidrosis and injection-related pain, manufacturers are advised to infuse it slowly, over a duration of 15 minutes. Nevertheless, pain at the injection site is very common. Therefore, we investigated the effect of warmed carrier fluid on nefopam injection-induced pain. METHODS: A total of 48 patients were randomly selected and allocated to either a control or a warming group. Warming was performed by diluting 40 mg of nefopam in 100 ml of normal saline heated to 31–32℃ using two fluid warmers. The control group was administered 40 mg of nefopam dissolved in 100 ml of normal saline stored at room temperature (21–22℃) through the fluid warmers, but the fluid warmers were not activated. RESULTS: The pain intensity was lower in the warming group than in the control group (P < 0.001). The pain severity and tolerance measurements also showed statistically significant differences between groups (P < 0.001). In the analysis of vital signs before and after the injection, the mean blood pressure after the injection differed significantly between the groups (P = 0.005), but the heart rate did not. The incidence of hypertension also showed a significant difference between groups (P = 0.017). CONCLUSIONS: Use of warmed carrier fluid for nefopam injection decreased injection-induced pain compared to mildly cool carrier fluid.

Effects of nefopam on catheter-related bladder discomfort in patients undergoing ureteroscopic litholapaxy / 대한마취과학회지

BACKGROUND: Patients who undergo urinary catheterization may experience postoperative catheter-related bladder discomfort (CRBD). Previous studies have indicated that drugs with antimuscarinic effects could reduce the incidence and severity of CRBD. Accordingly, this study was carried out to investigate whether nefopam, a centrally acting analgesic with concomitant antimuscarinic effect, reduces the incidence and severity of CRBD. METHODS: Sixty patients with American Society of Anesthesiologists physical status I and II and aged 18–70 years who were scheduled to undergo elective ureteroscopic litholapaxy participated in this double-blinded study. Patients were divided into control and nefopam groups, comprising 30 patients each. In the nefopam group, 40 mg nefopam in 100 ml of 0.9% saline was administered intravenously. In the control group, only 100 ml of 0.9% saline was administered. All patients had a urethral catheter and ureter stent inserted during surgery. The incidence and severity of CRBD, numerical rating scale (NRS) score of postoperative pain, rescue pethidine dose, and side effects were recorded in the post-anesthesia care unit after surgery. RESULTS: The incidence (P = 0.020) and severity (P < 0.001) of CRBD were significantly different between the control group and the nefopam group. The NRS score of postoperative pain (P = 0.006) and rescue dose of pethidine (P < 0.001) were significantly higher in the control group than in the nefopam group. CONCLUSIONS: Intravenous administration of nefopam in patients scheduled to undergo ureteroscopic litholapaxy reduced the incidence and severity of CRBD, NRS score of postoperative pain and analgesic requirements.

Greater auricular nerve neuropraxia with beach chair positioning during open reduction and internal fixation with plate for clavicular fracture: A case report

Greater auricular nerve neuropathy is a reported as complication in some cases of shoulder arthroscopy in the beach chair position using a horse-shoe headrest. Due to this risk, intubation pad-type headrest is recommended for the beach chair position, to effectively prevent greater auricular nerve palsy. In this case report, we described a patient who experienced greater auricular nerve neuropraxia after open reduction and internal fixation with plate of clavicular fracture in beach chair position using an intubation pad-type headrest. A 49-year-old man was diagnosed with left clavicular fracture without accompanying injury or complication. He underwent an operation for open reduction and internal fixation with a plate. After surgery, the patient reported numbness, and a tingling sensation without pain or skin lesion in the auricular area and the lower margin of the left mandible. Based on the clinical symptoms, greater auricular nerve neuropraxia was diagnosed. The symptoms disappeared completely after four weeks of outpatient follow-up.

Effects of glycopyrrolate premedication on preventing postoperative catheter-related bladder discomfort in patients receiving ureteroscopic removal of ureter stone / 대한마취과학회지

BACKGROUND: Glycopyrrolate given as reversing agents of muscle relaxants has been reported to be effective in reducing postoperative catheter-related bladder discomfort (CRBD). However, it remains unclear whether glycopyrrolate as premedication is also effective. This study aims to investigate the effectiveness of glycopyrrolate as premedication on preventing CRBD in the post-anesthesia care unit (PACU). METHODS: Eighty-three patients who received elective ureteroscopic removal of ureteral stone were randomly assigned to the control (n = 43) or the glycopyrrolate group (n = 40). The glycopyrrolate group was treated with glycopyrrolate 0.3 mg as premedication while the control group received 0.9% saline 1.5 ml. The incidence and severity of CRBD and pain score using numerical rating scale (NRS) were measured in the PACU. RESULTS: The incidence of CRBD (26 of 40 patients vs. 41 of 43 patients, relative risk [RR] = 0.68, 95% Confidence interval [CI] = 0.53–0.86, P = 0.001) and the moderate to severe CRBD incidence (6 of 40 patients vs. 20 of 43 patients, RR = 0.32, 95% CI = 0.14–0.72, P = 0.002) were lower in the glycopyrrolate group than in the control group. Also, postoperative pain NRS score was found to be lower in the glycopyrrolate group (median = 1 [Q1 = 0, Q3 = 2]) compared to the control group (3 [1, 5], median difference = 1.00, 95% CI = 0.00–2.00, P = 0.002). CONCLUSIONS: The use of glycopyrrolate 0.3 mg as premedication in patients receiving ureteroscopic removal of ureteral stone reduced the incidence and severity of CRBD, and decreased postoperative pain in the PACU.

The correlation between the Trendelenburg position and the stroke volume variation / 대한마취과학회지

BACKGROUND: The stroke volume variation (SVV), based on lung-heart interaction during mechanical ventilation, is a useful dynamic parameter for fluid responsiveness. However, it is affected by many factors. The aim of this study was to evaluate the effects of SVV on Trendelenburg (T) and reverse Trendelenburg (RT) position and to further elaborate on the patterns of the SVV with position. METHODS: Forty-two patients undergoing elective surgery were enrolled in this study. Fifteen minutes after standardized induction of anesthesia with propofol, fentanyl, and rocuronium with volume controlled ventilation (tidal volume of 8 ml/kg of ideal body weight, inspiration : expiration ratio of 1 : 2, and respiratory rate of 10-13 breaths/min), the patients underwent posture changes as follows: supine, T position at slopes of operating table of -5degrees, -10degrees, and -15degrees, and RT position at slopes of operating table of 5degrees, 10degrees, and 15degrees. At each point, SVV, cardiac output (CO), peak airway pressure (PAP), mean blood pressure, and heart rate (HR) were recorded. RESULTS: The SVV was significant decreased with decreased slopes of operating table in T position, and increased with increased slopes of operating table in RT position (P = 0.000). Schematically, it was increased by 1% when the slope of operating table was increased by 5degrees. But, the CO and PAP were significant increased with decreased slopes of operating table in T position, and decreased with increased slopes of operating table in RT position (P = 0.045, 0.027). CONCLUSIONS: SVV is subjected to the posture, and we should take these findings into account on reading SVV for fluid therapy.

A comparative study of emergence agitation between sevoflurane and propofol anesthesia in adults after closed reduction of nasal bone fracture / 대한마취과학회지

BACKGROUND: Emergence agitation is associated with increased morbidity and hospital costs. However, there have been few reports in the medical literature on the occurrence of emergence agitation in adults. The aim of this study was to compare emergence agitation between sevoflurane and propofol anesthesia in adults after closed reduction of nasal bone fracture. METHODS: Forty adults (ASA I-II, 20-60 yr) undergoing closed reduction of nasal bone fracture were randomly assigned to either sevoflurane or propofol group and anesthesia was maintained with sevoflurane or propofol. The bispectral index (BIS) was monitored and maintained within 40-60. At the end of surgery, patients were transported to the post anesthetic care unit (PACU) and agitation state scale was checked by Aono's four-point scale (AFPS). Emergence agitation was defined as and AFPS score of 3 or 4. Pain score were measured by numeric rating scale (NRS) on arrival and peak value at PACU. RESULTS: Nine (45.0%) patients in the sevoflurane group and 2 (10.0%) patients in the propofol group developed emergence agitation in the PACU (P = 0.031). There was no correlation between peak NRS and Aono's four-point scale. CONCLUSIONS: Propofol may decrease incidence of emergence agitation compared to sevoflurane in adults undergoing closed reduction of nasal bone fracture.

The Effects of Postoperative Brachial Plexus Block Using MgSO4 on the Postoperative Pain after Upper Extremity Surgery

BACKGROUND: Although a brachial plexus block can be used to provide anesthesia and analgesia for upper extremity surgery, its effects using MgSO4 on postoperative pain management have not been reported. The aim of this study was to evaluate brachial plexus block using MgSO4 on postoperative analgesia. METHODS: Thirty-eight patients who were scheduled to undergo upper extremity surgery were randomly allocated into two groups: patients receiving axillary brachial plexus block with 0.2% ropivacaine 20 ml and normal saline 2 ml (group S) or 0.2% ropivacaine 20 ml and MgSO4 200 mg (group M). Before extubation, the blocks were done and patient controlled analgesia was started, and then, the patients were transported to a postanesthetic care unit. The postoperative visual analogue scale (VAS), opioid consumption, and side effects were recorded. RESULTS: The two groups were similar regarding the demographic variables and the duration of the surgery. No differences in VAS scores were observed between the two groups. There was no statistically significant difference in opioid consumption between the two groups. Nausea was observed in three patients for each group. CONCLUSIONS: Axillary brachial plexus block using MgSO4 did not reduce the level of postoperative pain and opioid consumption.

Remifentanil-induced pronociceptive effect and its prevention with pregabalin / 대한마취과학회지

BACKGROUND: Experimental and clinical studies have suggested that remifentanil probably causes acute tolerance or postinfusion hyperalgesia. This study was designed to confirm whether remifentanil given during propofol anesthesia induced postoperative pain sensitization, and we wanted to investigate whether pregabalin could prevent this pronociceptive effect. METHODS: Sixty patients who were scheduled for total abdominal hysterectomy were randomly allocated to receive (1) a placebo as premedication and an intraoperative saline infusion (control group), (2) a placebo as premedication and an intraoperative infusion of remifentanil at a rate of 3-4 ng/ml (remifentanil group), or (3) pregabalin 150 mg as premedication and an intraoperative infusion of remifentanil at a rate of 3-4 ng/ml (pregabalin-remifentanil group). Postoperative pain was controlled by titration of fentanyl in the postanesthetic care unit (PACU), followed by patient-controlled analgesia (PCA) with fentanyl. The patients were evaluated using the visual analogue scale (VAS) for pain scores at rest and after cough, consumption of fentanyl, sedation score and any side effects that were noted over the 48 h postoperative period. RESULTS: The fentanyl titration dose given in the PACU was significantly larger in the remifentanil group as compared with those of the other two groups. At rest, the VAS pain score in the remifentanil group at 2 h after arrival in the PACU was significantly higher than those in the other two groups. CONCLUSIONS: The results of this study show that remifentanil added to propofol anesthesia causes pain sensitization in the immediate postoperative period. Pretreatment with pregabalin prevents this pronociceptive effect and so this may be useful for the management of acute postoperative pain when remifentanil and propofol are used as anesthetics.

Pneumothorax occurring during laparoscopic anterior resection of sigmoid colon cancer: A case report

Pneumothorax during laparoscopic surgery is a potentially fatal complication.We present a case of left-sided pneumothorax complicating laparoscopic anterior resection of the sigmoid colon cancer.After signs suggestive of pneumothorax were recognized during carbon dioxide pneumoperitoneum, chest X-ray confirmed the diagnosis.Oxygen saturation and vital signs were maintained by increasing the inspired oxygen fraction and deflating the pneumoperitoneum.The pneumothorax resolved spontaneously after surgery and there were no complications.This case shows the importance of vigilance on the part of the anesthesiologist during laparoscopic surgery.

The effect of milrinone infusion on right ventricular function during coronary anastomosis and early outcomes in patients undergoing off-pump coronary artery bypass surgery / 대한마취과학회지

BACKGROUND: During coronary anastomosis in off-pump coronary artery bypass surgery (OPCAB), hemodynamic alternations can be induced by impaired diastolic function of the right ventricle. This study was designed to examine the effect of milrinone on right ventricular function and early outcomes in patients undergoing OPCAB. METHODS: Forty patients undergoing OPCAB were randomly assigned in a double-blind manner to receive either milrinone (milrinone group, n = 20) or normal saline (control group, n = 20). Hemodynamic variables were measured after pericardiotomy (T1), 5 min after stabilizer application for anastomosis of the left anterior descending coronary artery (LAD, T2), the obtuse marginalis branch (OM, T3), the right coronary artery (RCA, T4), 5 min after sternal closure (T5), and after ICU arrival. The right ventricular ejection fraction (RVEF) and right ventricular volumetric parameters were also measured using the thermodilution technique. For evaluation of early outcomes, the 30-day operative mortality and morbidity risk models were used. RESULTS: There was no significant difference in hemodynamic variables, including mean arterial pressure, between the 2 groups, except for the cardiac index and RVEF. The cardiac index and RVEF were significantly greater at T3 in the milrinone group than in the control group. CONCLUSIONS: Continuous infusion of milrinone demonstrated a beneficial effect on cardiac output and right ventricular function in patients undergoing OPCAB, especially during anastomosis of the graft to the OM artery, and it had no adverse effect on early outcomes.

The effects of lidocaine and fentanyl on airway irritability during inhalation induction with desflurane / 대한마취과학회지

BACKGROUND: Inhalation induction with desflurane can cause airway irritability and sympathetic stimulation. The aim of this study was to investigate whether lidocaine and fentanyl could reduce these unwanted reactions. METHODS: Seventy-five patients who had premedication with midazolam were randomly allocated to one of three groups to receive intravenous saline (S group), lidocaine 1.5 mg/kg (L group), fentanyl 1 microgram/kg (F group), respectively, before tidal volume induction with desflurane in oxygen and nitrous oxide. We recorded airway irritability such as cough, apnea, laryngospasm and excitatory movement and hemodynamic changes. RESULTS: Airway irritability was not significantly different between the groups. In F group, mean blood pressure at LOC ver and LOC BIS and heart rate at LOC ver, LOC BIS and just before intubation were lower than those of S group (P < 0.05). Other results were not significantly different. CONCLUSIONS: The results of the study showed that intravenous fentanyl and lidocaine had no beneficial effects to reduce airway irritability, but intravenous fentanyl could significantly reduce hemodynamic stimulation during inhalation induction with desflurane in the patients who were premedicated with midazolam.

Spontaneous Intracranial Hypotension Treated with CT-guided Cervical Epidural Blood Patch : A case report / 대한마취과학회지

Spontaneous intracranial hypotension due to spinal cerebrospinal fluid leakage is uncommon, relatively benign and usually self-limiting. However it is being increasingly recognized as a cause of postural headaches. The treatment options range from conservative supportive measures to an pidural blood patch. We report a 40-year-old woman who developed intracranial hypotention without any preceding events such as lumbar puncture, back trauma, surgical procedures or medical illnesses. The site of the cerebrospinal fluid leakage was identified at between the C1 to C2 level using computerized tomographic myelography. Consequently, the patient underwent a CT-guided autologous epidural blood patch at the C3-C4 level. Her symptoms were relieved immediately without recurrence.

Tracheal Intubation using Remifentanil and No Muscle Relaxants: the Effect of Thiopental, Propofol, or Etomidate on Tracheal Intubating Conditions and Hemodynamic Changes / 대한마취과학회지

BACKGROUND: Many studies have suggested that propofol in combination with remifentanil may provide adequate conditions for tracheal intubation without the use of muscle relaxants. Other hypnotic drugs have not been thoroughly investigated in this regard. The goal of our study was to evaluate the effect of thiopental, propofol or etomidate on tracheal intubating conditions and hemodynamic changes using remifentanil in the absence of muscle relaxants. METHODS: A total of 45 healthy adults were divided randomly into three groups. After iv lidocaine 1.5 mg/kg, thiopental 5 mg/kg (thiopental group) or propofol 2.5 mg/kg (propofol group), or etomidate 0.4 mg/kg (etomidate group) were injected. After the injection of study drugs, remifentanil 2 mcg/kg was administered. Ninety seconds after the administration of remifentanil, laryngoscopy and intubation were attempted. Intubating conditions were assessed and the mean arterial pressure and the heart rate was measured. RESULTS: There were no significant differences in intubating conditions between patients in the three groups. The heart rate was significantly lower in the propofol and etomidate group patients when compared to the thiopental group patients after anesthetic induction. The mean arterial pressure was significantly lower in the propofol group patients when compared to the thiopental and etomidate group patients. Both heart rate and mean arterial pressure after tracheal intubation were significantly elevated in etomidate group patinets when compared to their preintubation value. CONCLUSIONS: The use of thiopental 5 mg/kg, propofol 2.5 mg/kg, and etomidate 0.4 mg/kg did not differ in effect under intubating conditions for tracheal intubation using remifentanil in the absence of muscle relaxants. Thiopental provided the best hemodynamic conditions.

Spinal Anesthesia of a Patient with Brugada Syndrome: A case report / 대한마취과학회지

Brugada syndrome is an arrhythmic syndrome characterized by right bundle branch block, ST segment elevation in the precordial lead (V1-3), and sudden death caused by ventricular fibrillation, but with no evidence of an underlying structural heart disease. We report one case of spinal anesthesia for an appendectomy in a 44-year-old male patient diagnosed as having Brugada syndrome by characteristic ECG findings without untoward cardiovascular events.

The Effects of Perioperative Ketorolac Infusion on Platelet Function and Blood Loss: Comparison of Anesthesia Methods / 대한마취과학회지

BACKGROUND: The purposes of this study were to investigate the effects of perioperative continuous infusion of ketorolac on platelet function and blood loss under either general or spinal anesthesia. METHODS: The patients under general anesthesia received saline 1 ml (C group) or ketorolac 30 mg (GK group) intravenously 10 min before skin incision, followed, respectively, by a continuous infusion of saline (4 ml/h) or ketorolac (2.5 mg/h) for 24 h. The patients under spinal anesthesia (SK group) received the same amount of ketorolac as that of the GK group. Blood loss was collected and measured at 3 h, 6 h, 12 h and 24 h postincision. Platelet count, hemoglobin, platelet aggregometry (PA) with adenosine diphosphate (ADP) and collagen, and bleeding time (BT) were measured at 30 min before skin incision and at 3 h and 24 h postincision. Blood coagulation status was analysed using thromboelastography (TEG) at 30 min before skin incision and at 3 h postincision. RESULTS: BT in the SK group at postincision increased significantly compared to preoperative value and were significantly higher than those of the GK and C group. PA with collagen at 3 h after skin incision was lower in the SK group than in the C group. There were no significant differences in any of the TEG variables among the three groups. No significant differences were observed in blood loss among the three groups. CONCLUSIONS: Blood loss was not increased by ketorolac under either general or spinal anesthesia, although platelet function was impaired under spinal anesthesia.

Neuromuscular Blockade of Mivacurium Following the Duration of Isepamicin Intramuscular Injection in Rabbits / 대한마취과학회지

BACKGROUND: Isepamicin, a new aminoglycoside antibiotic, was usually administered to patients for prophylactic use. Mivacurium has a short duration of action. The current study was undertaken to evaluate the neuromuscular blockade of mivacurium following the duration of an intramuscular injection of isepamicin 20 mg/kg/d in rabbits. METHODS: In the first study, the dose-response relations of mivacurium were studied in forty rabbits during thiopental anesthesia. Rabbits were randomly assigned to four groups; group 1: normal saline 2 ml/d IM for 7 days; group 2: isepamicin 20 mg/kg/d IM for 1 day; group 3: isepamicin 20 mg/kg/d IM for 3 days; group 4: isepamicin 20 mg/kg/d IM for 7 days. They received mivacurium 10, 20 and 30ng/kg in groups 1, 2 and 3; mivacurium 20, 30 and 40ng/kg in group 4, respectively. In the second study, time courses of action of mivacurium 0.18 mg/kg in forty rabbits were evaluated in each group. RESULTS: The calculated ED50 for mivacurium in groups 1, 2, 3 and 4 were 19.2 +/- 3.1ng/kg, 15.4 +/- 3.7ng/kg, 20.1 +/- 3.5ng/kg and 31.2 +/- 4.4ng/kg, respectively and corresponding ED95 was 29.9 +/- 3.7ng/kg, 22.1 +/- 4.5ng/kg, 30.1 +/- 5.9ng/kg and 43.4 +/- 5.1ng/kg, respectively. There were significant differences between group 4 and the others (P < 0.05). In the second study, the times after mivacurium 0.18 mg/kg until 95% twitch recovery in groups 1, 2, 3 and 4 were 35.1 +/- 5.1 min, 42.2 +/- 6.2 min, 32.8 +/- 4.9 min and 24.9 +/- 3.6 min, respectively. There were significant differences between group 2 and others, and between group 4 and group 1 or 3, respectively (P < 0.05). CONCLUSIONS: Mivacurium when used as a bolus isepamicin therapy, has both an increased potency and a longer duration of action, but when used during concurrent isepamicin therapy, has both a decreased potency and a shorter duration of action.

Fos Expression in the Brain of Neuropathic Pain Rats / 대한마취과학회지

BACKGROUND: There have been some investigations regarding expression of c-fos, as a marker of altered neuronal expression in the spinal cord of neuropathic rats. However, the expression of c-fos in the brain of a neuropathic pain model has not yet been investigated. The purpose of this study was to evaluate the time course of c-fos expression in the brain of neuropathic pain rats. METHODS: The experimental rats were divided into two group; neuropathic pain (n = 16) and control (n = 16) groups. The left L5 L6 spinal nerves of the neuropathic pain group were ligated but those of the control group not ligated (sham operation). Two hours, 1st day, 3rd day and 7th day after the operation, we examined the expression of Fos in the cerebral cortex, the amygdala, the thalamus and the hypothalamus of the coronary sectioned brains of the rats. RESULTS: C-fos expressions in the cerebral cortex and the amygdala of the neuropathic pain group were greater at 2 hours, the 3rd and the 7th day than the control group, but those of the thalamus and hypothalamus of the neuropathic pain group were greater on the 3rd and 7th day than the control group (P< 0.05). In the neuropathic pain group, c-fos expressions of four brain regions were greater on the 3rd and 7th day than those at 2 hours and day 1, but there was no difference between the 3rd and 7th day's (P< 0.05). CONCLUSIONS: There were significant expressions of Fos protein in the brain of the neuropathic pain group at 2 hours, the 3rd day and 7th day of the operation, but the meaning of each expression was different. The expression of Fos at postoperative 2 hours resulted from acute pain but that at the 3rd and 7th day of the operation resulted from neuropathic pain.

Anesthetic Management of Pediatric Patient with Pheochromocytoma: A case report / 대한마취과학회지

Pheochromocytoma is an unusual tumor in pediatric age group and there are several different aspects from adult counterparts. Children have fewer malignant, more extra-adrenal, and greater bilaterality and multiplicity of tumor. We present a case of 14-year old boy with pheochromocytoma who has symptoms such as episodic headaches, vomiting, seizure and paroxysmal hypertension which is less common in children. Although the duration of preoperative preparation was not long enough, we decided to remove the tumor because symptoms were disappeared rather rapidly after alpha and beta adrenergic blocker treatment. The patient was managed with continuous epidural block and light general anesthesia but extra use of adrenergic receptor blocker and vasodilator were demanded during tumor manipulation. The patient has remained well postoperatively but long-term follow up is essential because of the possibilities of recurrence.

Effects of Preemptive Intrathecal Bupivacaine on Postoperative Pain in Rats / 대한마취과학회지

BACKGROUND: Preemptive analgesia is an antinociceptive treatment that prevents the development of central sensitization which contributes to the post-injury pain hypersensitivity. But controversies exist over the effectiveness and clinical value of preemptive analgesia. The aim of this study is to evaluate the preemptive effect of intrathecal bupivacaine on incisional pain in rats. METHODS: Thirty male rats were divided into 3 groups, saline-treated control group (n=10), post-treatment group (n=10), and pre-treatment group (n=10) according to the time which intrathecal administration of bupivacaine was done. To evaluate postoperative mechanical hyperalgesia in injured feet, withdrawal frequency and withdrawal thresholds were measured by von Frey filaments at 30 min, 1 hr, 2 hrs, 3 hrs, 1 day, 3 days and 7 days after incision. RESULTS: In control group, the withdrawal frequency increased from 0+/-0% before incision to 98.0+/-1.3% after the foot incision and the responses gradually declined during the postoperative 7 days to 52.0+/-4.7%. The median withdrawal threshold decreased from 148.43 mN before incision to 0.05 mN after foot incision and gradually increased during the postoperative 7 days to 6.79 mN. The post-treatment group showed no significant differences in the withdrawal frequency and withdrawal thresholds when compared with control group at post-operative 1 hour and thereafter (P<0.05). The pre-treatment group showed significantly lower withdrawal frequency and significantly higher withdrawal threshold compared with control group at postoperative 30 min and thereafter (P<0.05), and significantly lower withdrawal frequency and higher withdrawal threshold compared with post-treatment group at postoperative 2 hours and thereafter (P<0.05). CONCLUSION: We conclude that intrathecal bupivacaine administered before incision reduces postoperative delayed hyperalgesia in incisional pain model, and it may result from preventing the development of injury- induced central sensitization.