Use of vasopressors to manage spinal anesthesia-induced hypotension during cesarean delivery

Cesarean sections are commonly performed under spinal anesthesia, which can lead to hypotension, adversely affecting maternal and fetal outcomes. Hypotension following spinal anesthesia is generally defined as a blood pressure of 80–90% below the baseline value. Various strategies have been implemented to reduce the incidence of spinal anesthesia-induced hypotension. The administration of vasopressors is a crucial method for preventing and treating hypotension. In the past decade, phenylephrine, a primarily alpha-adrenergic agonist, has been the preferred vasopressor for cesarean sections. Recently, norepinephrine, a potent alpha-agonist with modest beta-agonist activity, has gained popularity owing to its advantages over phenylephrine. Vasopressors can be administered via a bolus or continuous infusion. Although administering boluses alone is simpler in a clinical setting, continuous prophylactic infusion initiated immediately after spinal anesthesia is more effective in reducing the incidence of hypotension. Tailoring the infusion dose based on the patient’s body weight and adjusting the rate in response to blood pressure changes, in addition to using a prophylactic or rescue bolus, helps reduce blood pressure variability during cesarean sections under spinal anesthesia until neonatal delivery.

Utilizing ChatGPT in clinical research related to anesthesiology: a comprehensive review of opportunities and limitations

Chat generative pre-trained transformer (ChatGPT) is a chatbot developed by OpenAI that answers questions in a human-like manner. ChatGPT is a GPT language model that understands and responds to natural language created using a transformer, which is a new artificial neural network algorithm first introduced by Google in 2017. ChatGPT can be used to identify research topics and proofread English writing and R scripts to improve work efficiency and optimize time. Attempts to actively utilize generative artificial intelligence (AI) are expected to continue in clinical settings. However, ChatGPT still has many limitations for widespread use in clinical research, owing to AI hallucination symptoms and its training data constraints. Researchers recommend avoiding scientific writing using ChatGPT in many traditional journals because of the current lack of originality guidelines and plagiarism of content generated by ChatGPT. Further regulations and discussions on these topics are expected in the future.

Perinatal outcome of fetuses with congenital high airway obstruction syndrome: a single-center experience

Objective@#To report our experience with management of fetuses with congenital high airway obstruction syndrome (CHAOS). @*Methods@#We retrospectively reviewed the cases of fetuses who were prenatally diagnosed and postnatally confirmed with CHAOS between 2010 and 2019 at Asan Medical Center, Seoul, Korea. @*Results@#Of 13 fetuses prenatally diagnosed with CHAOS, 7 were lost to follow-up and 6 were postnatally confirmed as having CHAOS. All fetuses, except one were delivered via cesarean section with an ex utero intrapartum treatment (EXIT) procedure. Two patients had coexisting congenital heart diseases requiring several cardiac surgeries following birth. Both of these patients demonstrated developmental delay; however, the remaining 4 had a normal development except for expressive language. Two infants died of respiratory complications, and the remaining 4 were alive at the end of the follow-up period. All 4 live patients underwent tracheostomy with planned reconstruction surgery. Three children are now able to phonate, and 1 can maintain a conservation. @*Conclusion@#The proper management of CHAOS using the EXIT procedure results in high survival and low hypoxemia-induced complication rates. Therefore, an accurate prenatal diagnosis is necessary for an appropriate perinatal management.

Ex utero intrapartum treatment procedure in two fetuses with airway obstruction

The ex utero intrapartum treatment (EXIT) procedure was introduced to reduce fetal hypoxic damage while establishing an airway in fetuses with upper and lower airway obstruction. Delivery of the fetal head and shoulders while maintaining the uteroplacental circulation offers time to secure the fetal airway. Here, we report two cases of EXIT procedure for fetal airway obstruction, which were successfully managed with extensive preoperative planning by a professional multidisciplinary team.

Vagolytic atropine attenuates cerebral vasodilation response during acute orthostatic hypotension / 대한마취과학회지

BACKGROUND: Atropine is an anticholinergic drug which is commonly used in clinical practice. The effect of parasympathetic block with atropine on dynamic cerebrovascular regulation remains unclear. This study was aimed to identify effects of vagolytic atropine on cerebrovascular response during acute orthostatic hypotension in humans. METHODS: Continuous middle cerebral blood flow velocity (CBFV, transcranial Doppler) and arterial blood pressure (ABP, Finometer) were measured during a sit-to-stand procedure in 10 healthy subjects with placebo and vagolytic (10 microg/kg) doses of atropine. Cerebral vascular tone was assessed by cerebrovascular resistance (CVR = ABP / CBFV). Dynamic cerebral autoregulation was also assessed by transfer function analysis of ABP and CBFV. RESULTS: During the standing session, ABP fell to a similar extent in both groups by an average of 23 to 25 mmHg (26% to 29%). CBFV also fell in all subjects but significantly more in vagolytic atropine (-15.0 +/- 7.0 cm/s) compared with placebo (-12.0 +/- 5.8 cm/s, P < 0.05). CVR was decreased significantly in the placebo group during posture change (1.56 +/- 0.44 vs. 1.38 +/- 0.38, P < 0.05), in contrast, lesser decreased in the atropine group (1.60 +/- 0.50 vs. 1.53 +/- 0.42, P = 0.193). Transfer function coherence in the very-low-frequency range was significantly increased in the atropine group during the standing session (0.55 +/- 0.14), compared with the sitting session (0.45 +/- 0.14, P = 0.006). CONCLUSIONS: These data present that vagolytic atropine attenuates cerebral vasodilation response to acute orthostatic hypotension, suggesting the use of atropine may need care in patients with cerebrovascular disease with vagal impairment.

Delayed peripartum cardiomyopathy after emergency cesarean section / 대한마취과학회지

No abstract available.

Perimortem cesarean section in a pregnant woman with flecainide-induced ventricular tachycardia: A case report

Flecainide is a drug used to manage supraventricular and ventricular arrhythmias. It is also effective in the treatment of fetal tachyarrhythmia through administration to the mother. However, flecainide toxicity may cause serious complications, including cardiac conduction disturbance, ventricular arrhythmia, resulting in syncope and sudden death. We describe here a 27-year-old woman at 31 weeks of gestation who experienced ventricular tachycardia, leading a perimortem cesarean section. On her past medication history, she has taken overdose of oral flecainide for the treatment of fetal atrial flutter. Just after neonatal delivery, her ventricular tachycardia was successfully reverted to a sinus rhythm through administration of intravenous lidocaine and hemodynamics were stabilized. According to her clinical signs and symptoms, we presume the ventricular tachycardia was likely induced by flecainide toxicity, although serum flecainide concentration could not be measured in our institution.

Clinical Experiences of Transforaminal Balloon Decompression for Patients with Spinal Stenosis

Lumbar spinal stenosis is a commonly treated with epidural injections of local anesthetics and corticosteroids, however, these therapies may relieve leg pain for weeks to months but do not influence functional status. Furthermore, the majority of patients report no substantial symptom change over the repeated treatment. Utilizing balloon catheters, we successfully treated with three patients who complained persistent symptoms despite repeated conventional steroid injections. Our results suggest that transforaminal decompression using a balloon catheter may have potential in the nonsurgical treatment of spinal stenosis by modifying the underlying pathophysiology.

Value of Bone Scintigraphy and Single Photon Emission Computed Tomography (SPECT) in Lumbar Facet Disease and Prediction of Short-term Outcome of Ultrasound Guided Medial Branch Block with Bone SPECT

BACKGROUND: Facet joint disease plays a major role in axial low-back pain. Few diagnostic tests and imaging methods for identifying this condition exist. Single photon emission computed tomography (SPECT) is reported that it has a high sensitivity and specificity in diagnosing facet disease. We prospectively evaluated the use of bone scintigraphy with SPECT for the identification of patients with low back pain who would benefit from medial branch block. METHODS: SPECT was performed on 33 patients clinically suspected of facet joint disease. After SPECT, an ultrasound guided medial branch block was performed on all patients. On 28 SPECT-positive patients, medial branch block was performed based on the SPECT findings. On 5 negative patients, medial branch block was performed based on clinical findings. For one month, we evaluated the patients using the visual analogue scale (VAS) and Oswestry disability index. SigmaStat and paired t-tests were used to analyze patient data and compare results. RESULTS: Of the 33 patients, the ones who showed more than 50% reduction in VAS score were assigned 'responders'. SPECT positive patients showed a better response to medial branch blocks than negative patients, but no changes in the Oswestry disability index were seen. CONCLUSIONS: SPECT is a sensitive tool for the identification of facet joint disease and predicting the response to medial branch block.

Survey of malignant hyperthermia in Korea: Report for the necessity of establishing the center for caffeine and halothane contracture test in Korea: a questionnaire

BACKGROUND: Malignant hyperthermia (MH) has a high mortality rate and a family history. Then, caffeine and halothane contracture test (CHCT), generally used to detect MH susceptibility, is needed for early detection. The aim of this survey is to collect the opinion about establishment of the center for CHCT in Korea. METHODS: A people who were anesthesiologists working in the training hospital of Korea participated the survey between January and March 2011. Usual anesthetic drug during general anesthesia including volatile agents, opioids, muscle relaxants, incidence, diagnoses and treatments of MH, and opinion about establishment of the center for CHCT, were investigated. RESULTS: A total of 105 people who were anesthesiologists working in Korea were registered, they answered that 33 anesthesiologists (32%) met MH patient, and MH occurred once in a decade. If there is a diagnostic method such as CHCT in Korea, 89 anesthesiologists (89%) will recommend the test for the patients and their family. CONCLUSIONS: Many anesthesiologists want to recommend the CHCT for patients and their family. But, in Korea, it is impossible because there is no laboratory available for CHCT. Now, we considered carefully to establish the laboratory available for CHCT.

Comparison of intermittent versus continuous interscalene brachial plexus block for postoperative analgesia

BACKGROUND: Interscalene brachial plexus block (IBPB) is an effective method of postoperative analgesia after shoulder surgery. This study evaluates the effects and complications of IBPB with two different infusion methods (using intermittent bolus infusion versus automated continuous infusion). METHODS: Thirty six patients who were scheduled for shoulder surgery were randomly assigned into two groups (the continuous vs. intermittent groups). All the patients received preoperative IBPB using 15 ml of 0.25% ropivacaine followed by insertion of a 20 gauge catheter. This catheter was connected to a patient controlled analgesia (PCA) pump after the operation. The intermittent group (n = 18) received IBPB with 0.2% ropivacaine 100 ml (bolus 15 ml, lock time 4 h) without basal infusion. The continuous group (n = 18) received IBPB with 0.2% ropivacaine 100 ml (basal rate 4 ml/h) without bolus injection. All the patients were given meperidine 25 mg when the postoperative visual analogue score (VAS) >40 mm. The VAS, heart rate, noninvasive blood pressure, respiratory rate, consumption of meperidine and complications were measured during the 64 h following surgery at intervals of 8 h. RESULTS: The VAS was higher in the intermittent group than that in the continuous group at 24 h after surgery (P < 0.01).However, there was no significant difference for the VAS between the groups for the other assessment periods.There was no significant difference for the amount of meperidine consumed and the incidence of complications between the groups. CONCLUSIONS: Intermittent IBPB's analgesic effects and complications for treating pain after shoulder surgery are similar to those of continuous IBPB. Therefore, intermittent IBPB could be used for the management of pain after shoulder surgery.

Intermittent Interscalene Brachial Plexus Block vs. Continuous Intraarticular Infusion for the Management of Postoperative Pain after Shoulder Surgery

BACKGROUND: Severe postoperative pain is a well-known problem following shoulder surgery. This study evaluates the clinical efficacy of intermittent interscalene brachial plexus block (ISBPB) compared with that of continuous intraarticular infusion (IAPCA) for the management of postoperative pain after shoulder surgery. METHODS: Fifty seven patients, scheduled for shoulder surgery during general anesthesia, were randomly allocated to one of two groups. Group ISBPB (n = 19) received a preoperative interscalene brachial plexus block using 20 ml of 0.5% bupivacaine followed by insertion of a 20-gauge polyamide catheter. This catheter was connected to a patient-controlled analgesia pump set immediately after surgery to administer a bolus of 0.75% ropivacaine 15 ml at lockout time intervals 8 hours. Group IAPCA (n = 38) received patient- controlled analgesia with 0.2% ropivacaine 100 ml (basal rate 2 ml/hr, bolus 0.5 ml, lockout time 15 min). Both groups received intravascular patient-controlled analgesia with fentanyl 10? 15 microg/ml (basal rate 1 ml/hr, bolus 2 ml, lockout time 15 min). All patients were given pethidine 25 or 50 mg when visual analogue score (VAS) >40 mm. VAS, circulatory and respiratory stress parameter (heart rate, noninvasive blood pressure and respiratory rate) and consumption of pethidine were measured during 72 hours following surgery at intervals of 8 hours. RESULTS: The mean VAS scores in the ISBPB group were significantly lower than in the IAPCA group for 72 hr after surgery (P < 0.01). Pethidine consumption in the ISBPB group was significantly lower than in the IAPCA group (P < 0.01). CONCLUSIONS: We concluded that intermittent interscalene brachial plexus block is an effective method of postoperative analgesia after major shoulder surgery.

The Mechanism of R-PIA Induced Mechanical Antiallodynia in a Peripheral Neuropathic Rat / 대한마취과학회지

BACKGROUND: The injury by a nerve ligation produces a mechanical allodynia. The antiallodynic effect resulted from intrathecal administration of the adenosine analogues has been well known. ATP-sensitive potassium channel blockers have been known to reverse the effect of some antinociceptive drugs in animal and human studies. Therefore, the present study is to assess the relationship between antiallodynic effect of N6-(R)-phenylisopropyl adenosine (R-PIA) and mitochondrial ATP-sensitive potassium (mKATP) channel in a neuropathic pain model. METHODS: Allodynia was induced in male Sprague Dawley rats by the tight ligation of the left lumbar 5th and 6th spinal nerves. We tested the mechanical allodynia by pricking von Frey filaments to the left hind paw and assessed withdrawal thresholds of paw with up-down method. For the estimation of the antiallodynic effect of R-PIA, R-PIA (0.5, 1 and 2microgram) or saline were administered intrathecally.To investigate the reversal effect on antiallodynic effect of R-PIA, variable amounts of 5-hydroxydecanoate (5-HD, 20, 30 and 40 mg), mKATP channel blocker were administered intraperitoneally at 5 min prior to the intrathecal injection of 2microgram of R-PIA, and the degree of allodynia was assessed. RESULTS: The paw withdrawal threshold was gradually increased with increased dose of R-PIA and reached the maximum level with 2microgram R-PIA (P < 0.05). The increase of paw withdrawal threshold with 2microgram R-PIA was significantly reversed dose-dependently by intraperitoneal pretreatment of 20, 30 and 40 mg/kg 5-HD (P < 0.05). CONCLUSIONS: In our results, intraperitoneal injection of 5-HD before intrathecal injection of R-PIA had reversed the antiallodynic effect of R-PIA. This results suggest that the mechanism of mechanical antiallodynia induced by intrathecal injection of R-PIA may relate with the mK(ATP) channel in a rat model of nerve ligation injury.

Bilateral Pneumothorax Induced by Tracheal Injury during Total Thyroidectomy with Modified Radical Neck Dissection: A case report / 대한마취과학회지

We experienced one case of bilateral pneumothorax developed after total thyroidectomy with modified radical neck dissection in a 44-year-old male patient with thyroid carcinoma. After the conclusion of the operation, the patient was extubated after confirming recovery of consciousness and spontaneous respiration. Soon after the extubation, sudden-onset dyspnea with desaturation was developed. Rapid re-intubation was performed. Bilateral pneumothorax with severe subcutaneous emphysema was recognized on chest radiograph and successfully treated by chest tube insertion. Secondary operation was performed and tracheal injury was proved to be the source of the pneumothorax. The patient was discharged uneventfully 14 days later.

Effects of Phenytoin and Carbamazepine on Rocuronium-Induced Partial Neuromuscular Blockade

BACKGROUND: Phenytoin and carbamazepine may augment a neuromuscular block from nondepolarizing muscle relaxants. The potency of rocuronium is increased after the administration of an acute high dose of phenytoin. We investigated the effects of phenytoin and carbamazepine on rocuronium-induced neuromuscular blockade. METHODS: Male Sprague Dawley rats (n = 80) were randomly allocated into a control group, phenytoin group, carbamazepine group, and phenytoin with carbamazepine group. The phrenic nerve was stimulated with supramaximal intensity and twitch responses were measured. After a stabilization period, 300microg rocuronium was added. After 10 minutes, in the pheytoin group of rats, phenytoin in Krebs solution was administered at a concentration of 1microg/ml (P1), 10microg/ml (P10) and 100microg/ml (P100). In the carbamazepine group of rats, carbamazepine in Krebs solution was administered at a concentration of 0.5microg/ml (C0.5), 5microg/ml (C5) and 50microg/ml (C50). In the phenytoin with carbamazepine group of rats, phenytoin simultaneously with carbamazepine was administered in Krebs solution at a phenytoin concentration of 10microg/ml (P10) and a carbamazepine concentration of 5microg/ml (C5). We measured twitch responses at 10 minutes after rocuronium administration and 10 minutes after the administration of the anticonvulsants. RESULTS: There were significant depressions in the twitch response of rocuronium in the 100microg/ml phenytoin group of rats, 5microg/ml and 50microg/ml carbamazepine group of rats, and the 10microg/ml phenytoin with 5microg/ml carbamazepine group of rats. CONCLUSIONS: The potency of rocuronium increased with phenytoin and carbamazepine administration. Phenytoin and carbamazepine can cause recurarization perioperatively.

Effects of 5-hydroxytryptamine on Rocuronium-induced Neuromuscular Blockade in a Rat Phrenic Nerve-hemidiaphragm Preparation / 대한마취과학회지

BACKGROUND: The 5-hydroxytryptamine 3 receptor (5-HT3R) is a member of a superfamily of ligand-gated ion channels which has structural similarities and common evolutionary origin to those of the nicotinic acetylcholine receptor (nAChR). 5-hydroxytryptamine (5-HT) and muscle relaxants may have cross reaction. Rocuronium is a non-depolarizing neuromuscular blocking agent which has a rapid onset. The aim of this study was to examined the effects of 5-HT on rocuronium-induced neuromuscular blockade in a rat phrenic nerve-hemidiaphragm preparation. METHODS: Institutional approval was obtained for the experimental procedure. Fifty male Sprague-Dawley rats (150-200 g) were divided into 5 groups; the control, and 0.1, 1, 10, and 20microgram/ml of 5-HT. The animals were injected with phentobarbital at 40 mg/kg into the peritoneal cavity. The hemidiaphragm with the phrenic nerve was dissected and then mounted in a bath containing 100 ml Krebs solution at room temperature. The phrenic nerve was stimulated at the supramaximal intensity using a Grass(R) S88 stimulator via an SIU5 isolation unit. The twitch height was measured and recorded using a precalibrated Grass(R) FT88 force displacement transducer and recorded with a Grass(R) 79 polygraph, respectively. In the cumulative dose-response study, the rocuronium 100microgram/dl and each dose of 5-HT were administered simultaneously administered, with additional 50microgram/dl incremental doses of rocuronium were added to obtain grteater than 95% neuromuscular twitch inhibition. The ED5, ED50, ED90, and ED95 of rocuronium in each group were calculated using a probit model. RESULTS: The ED50, ED90, and ED95 of rocuronium were significantly reduced in 5-HT 20microgram/ml group (P < 0.05), but no differences were observed with the other 5-HT groups compared to the control groups. CONCLUSIONS: 5-HT at 20microgram/ml enhanced the neuromuscular blockade of rocuronium.

Action Duration of Rocuronium in the Elderly Patients / 대한마취과학회지

BACKGROUND: The effect of a muscle relaxant may differ in the elderly for pharmacokinetic and pharmacodynamic reasons. Rocuronium, a derivative of vecuronium is a non depolarizing neuromuscular blocker with a rapid onset and intermediate duration. The purpose of this study was to compare differences in the onset and duration of rocuronium in young adults and the elderly. METHODS: The study was approved by our instituitional review board, and informed consent was obtained from all patients. Twenty two young adults (15 59 yr) and 21 elderly (65 80 yr) patients, ASA physical status 1 2 underwent elective orthopedic surgery under general anesthesia. All were anesthetized with pentothal sodium, nitrous oxide, and isoflurane. Rocuronium (0.6 mg/kg) was given and then intubation was performed after TOF response had totally disappeared. Neuromuscular relaxation was measured by TOF response at the adductor pollicis muscle after a supramaximal stimulation of Train-of-four (TOF, 2 Hz every 12 sec) at the ulnar nerve. Onset (disappearance of T1) and the recovery times of T1, T2, T3 and T4 were recorded. RESULTS: The onset of neuromuscular block was slower in the elderly than the young adults (P < 0.05), and recovery times of T1, T2, T3, and T4 were prolonged in the elderly (P < 0.05). CONCLUSIONS: Rocuronium has a slower onset time and a delayed recovery in the elderly.

The Effect of Lidocaine on Withdrawal Movement Due to Rocuronium Injection in Pediatric Patients / 대한마취과학회지

BACKGROUND:Rocuronium is a non depolarizing muscle relaxant of rapid onset and of intermediate duration. It is useful for short operations and for rapid control of the airway in pediatric patients. However the intravenous injection of rocuronium cause pain and a withdrawal movement. The purpose of this study was to evaluate the effect of lidocaine pretreatment in pediatric patients receiving rocuronium (10 mg/ml) and diluted rocuronium (1 mg/ml) on withdrawal movement METHODS: The study was approved by our institutional review board, and informed consent was obtained from all parents. One hundred and twenty five patients, aged from 4 months to 10 years, ASA physical status 1-2 undergoing general anesthesia for elective surgery were randomly enrolled in the study. Allergy history to a trial drug, pediatric patients on analgesics, difficult vein access and severely crying pediatric patients on arrival were excluded. All patients were non-premedicated and had a 22 G i.v. catheter inserted into the dorsum of hand before operation. On arrival in the operation room, routine non invasive monitors were placed and a free flow of i.v. fluid without edema, redness, hardness or pain was confirmed. After the administration of glycopyrrolate 0.004 mg/kg, inhalational induction was performed with 4-8 vol% sevoflurane by face mask fitting. One group received rocuronium 0.3 mg/kg (RS group) or vecuronium 0.05 mg/kg (VS group) was administered after 0.5 ml of 0.9% NaCl. A second group received rocuronium 0.3 mg/kg (RL group) or vecuronium 0.5 mg/kg (VL group) after lidocaine 1 mg/kg. A third group received rocuronium 1 mg/ml diluted with 0.9% NaCl (1:9) (RD group). Muscle relaxant-induced withdrawal movements were assessed by using a 4-grade scales (0-3). We also observed pulse rate alterations. Vein redness was evaluated just after administration and vein hardness five minutes after intubation by using a 4-grade scale (0-3). RESULTS: Withdrawal movements were more intense in the rocuronium group (R group, 3.8 times, P < 0.01) than in the vecuronium group (V group). Lidocaine pretreatment (L group, 1.8 times, P < 0.01) or diluted rocuronium (RD group, 1.9 times, P < 0.01) decreased withdrawal movement incidence. Withdrawal movement incidence was positive correlated with a change in pulse rate (Spearman's rho = 0.36, P < 0.01). CONCLUSIONS: Lidocaine pretreatment in patients receiving rocuronium (10 mg/ml) or diluted rocuronium (1 mg/ml) effectively reduces withdrawal movement during the administration of rocuronium.

The Effects of Lidocaine on Pain Due to Rocuronium / 대한마취과학회지

BACKGROUND:Rocuronium is a non depolarizing muscle relaxant of rapid onset and of intermediate action duration. It is particularly suitable for short operation and rapid control airway. But, intravenous rocuronium cause pain and a withdrawal movement. The purpose of this study was to evaluate the effect of intravenous lidocaine on pain and withdrawal movement in patients receiving rocuronium. METHODS: The study was approved by our institutional review board, and informed consent was obtained from all patients. One hundred and twenty patients, ASA physical status 1-2 undergoing general anesthesia for elective surgery were randomly enrolled. Allergy history to trial drug, chronic pain, pregnancy, patient on analgesics, difficult vein access and deeply sedated patients were excluded. Patients were not premedicated, and had a 20-18 G intravenous catheter inserted into a hand dorsum before operation. On arrival in the operation room, routine non-invasive monitors were placed and the free flow of intravenous fluid without edema, redness or hardness was confirmed. A subparalyzing dose of rocuronium 0.06 mg/kg (RS group) or vecuronium 0.01 mg/kg (VS group) was administered after 2 ml of 0.9% NaCl in one group, and a subparalyzing dose of rocuronium 0.06 mg/kg (RL group) or vecuronium 0.01 mg/kg (VL group) was administered after 2 ml of 2% lidocaine injection in a second group. All patients then received 5 mg/kg of 2.5% thiopental sodium and 0.6 mg/kg rocuronium (RS and RL group) or 0.1 mg/kg of vecuronium (VS and VL group). Muscle relaxant-induced pain and withdrawal movements were assessed using 4-grade scales (0-3). Vein redness was measured just after administration and vein hardness five minutes after intubation using 4-grade scales (0-3). RESULTS: Incidence of pain (8.2 times) and withdrawal movement (6.2 times) was more frequent in the rocuronium group than in the vecuronium group (P< 0.01). Lidocaine pretreatment decreased the incidence of pain significantly (5.7 times, P < 0.01). CONCLUSIONS: Rocuronium causes more pain and withdrawal movements than vecuronium. Lidocaine pretreatment significantly reduced the incidence and severity of pain, and withdrawal movements in both groups.