Isoflurane cracks the polycarbonate connector of extra-corporeal circuit: A case report / 대한마취과학회지

Cardiopulmonary bypass (CPB) is widely used for cardiac surgery by virtue of its proven safety over the course of its use during the past half century. Even though perfusion is safer, incidents still occur. During the repair of a ventricular-septal defect in an 11-month-old infant, we experienced a critical incident related to the potential hazardous effect of volatile anesthetics on the polycarbonate connector of extra-corporeal circuit. The damage to the polycarbonate connector had occurred after spillage of isoflurane during the filling of the vaporizer, causing it to crack and leak. The incident was managed by replacement of the cracked connector during a temporary circulatory arrest. The patient was hypothermic and the time off bypass was less than 1.5 min. There were no neurologic sequelae, the patient made an uneventful recovery. In conclusion, the spillage of volatile anesthetics can cause cracks in the polycarbonate connector of the extra-corporeal circuit, leading to potentially interruption of CPB.

A comparison of the consumption of inhaled anesthetics according to fresh gas flow and anesthetic circuits / 대한마취과학회지

BACKGROUND: In the Korean National Health Insurance Corporation (KNHIC), payment for inhaled anesthetics are made according to the simulated dose and not the consumed dose. We compare the consumption of inhaled anesthetics according to fresh gas flow (FGF) and anesthetic circuits to compare the consumption of anesthetics and the guidelines for KNHIC payments. METHODS: 161 patients were randomized into six groups who received isoflurane using a closed circuit (group I-C), a semi-closed circuit with FGF 3 L/min (group I-3), or 4 L/min (group I-4), as for the sevoflurane group (group S-C, S-3, and S-4). Mean arterial pressure (MAP) and heart rate (HR) were maintained within +/- 20% of baseline. Minimum alveolar concentration (MAC) and consumption of inhaled anesthetics were recorded by a new anesthetic machine. RESULTS: There were no significant differences among the groups for MAP, HR, and MAC. During anesthesia maintenance, the mean consumption per 15 minutes of inhaled anesthetics was significantly lower in group I-C (1.0 +/- 0.3 ml) than in group I-3 (3.5 +/- 0.7 ml) and than group I-4 (4.9 +/- 0.9 ml) and similar to the sevoflurane groups (group S-C [1.3 +/- 0.4 ml] vs group S-3 [5.3 +/- 1.0 ml] vs group S-4 [6.9 +/- 1.3 ml], respectively; P < 0.05). CONCLUSIONS: In sevoflurane groups, inhaled anesthetics were consumed more than in isoflurane groups. The KNHIC payment guidelines were close to the actual consumption of inhaled anesthetics under using a semi-closed circuit with FGF 3 L/min in sevoflurane and FGF 4 L/min in isoflurane.

The Effects of Female Hormones on Postoperative Nausea and Vomiting / 대한마취과학회지

BACKGROUND: Postoperative nausea and vomiting (PONV) is one of the most common complaints following laparoscopic surgery, and being female is a risk factor for PONV. Therefore, we conducted this study to determine if the incidence of PONV is associated with variations in the blood concentration of female hormones that occur during different stages of the menstrual cycle. METHODS: We recruited 103 women who were undergoing gynecological laparoscopic surgery under general anesthesia and met all of the inclusion criteria for this study. A menstrual history was taken from each patient during the preoperative anesthetic visit and blood samples were collected from all patients to determine the concentration of female hormones (estradiol, progesterone). We then assessed the nausea rating scale (NRS) and the occurrence of retching and vomiting at 0-2 hours, 2-6 hours, and 6-24 hours postoperatively. RESULTS: The overall incidence of PONV was 60.2% within the first 24 hours following surgery. However, no significant differences in the incidence of PONV were observed in women in different menstrual phases (follicular phase, 63.5% vs. luteal phase, 56.9%). In addition, there was no significant difference observed in the female hormonal concentration of the blood of patients who experienced PONV and those that did not, and there was no correlation between the NRS and the blood concentration of female hormones. CONCLUSIONS: The results of this study suggest that female hormones (estradiol, progesterone) are not associated with the occurrence of PONV following gynecological laparoscopic surgery.

Optimal dosages of propofol and remifentanil for minimizing hemodynamic changes during laryngeal microscopic surgery / 대한마취과학회지

BACKGROUND: Laryngeal microscopic surgery (LMS) is stressful to the patient due to intubation and suspension laryngoscopy. The aim of this study was to determine the optimal dosages of propofol and remifentanil for minimizing hemodynamic changes during LMS. METHODS: Eighty outpatients undergoing LMS were randomly divided into four groups. In all patients, endotracheal intubation was done with an effect-site concentration of propofol at 3 or 4microgram/ml. Group I (propofol 3microgram/ml) and II (propofol 4microgram/ml) patients received remifentanil 0.5microgram/kg and an infusion at 0.1microgram/kg/min. Group III (propofol 3microgram/ml) and IV (propofol 4microgram/ml) patients received remifentanil 1.0microgram/kg and an infusion at 0.2microgram/kg/min. Hemodynamic changes and bispectral index (BIS) values during intubation and suspension laryngoscopy were compared among the groups. In addition, extubation time, emergence time, and state of recovery (Steward score) were compared. RESULTS: After intubation and suspension laryngoscopy, the mean arterial pressure (MAP) was significantly lower than baseline values in groups II and IV (P < 0.05). After suspension laryngoscopy, the heart rate (HR) was significantly lower than baseline value in group II (P < 0.05). Extubation time was significantly shorter in groups I, II, and III compared to group IV, and the time for responding to verbal commands was significantly shorter in groups I and II compared to group IV (P < 0.05). The incidence of hypotension was higher in group IV than in the other groups (P < 0.05). CONCLUSIONS: The results suggest that an effect-site concentration of propofol at 4microgram/ml with remifentanil 0.5microgram/kg and infusion of 0.1microgram/kg/min provide proper anesthesia with minimal hemodynamic changes during LMS.

What is the Optimal Effect-site Concentration of Remifentanil for Minimizing the Cardiovascular Changes to Endotracheal Intubation during Induction with Propofol? / 대한마취과학회지

BACKGROUND: In this study, the optimal effect-site concentration of remifentanil for blunting hemodynamic responses to endotracheal intubation during total intravenous anesthesia using propofol were evaluated. METHODS: 137 ASA class I and II patients, aged 18-60 years, were randomly allocated to one of six groups according to the effect-site concentration of remifentanil. Remifentanil was then infused at a target effect-site concentration of 0, 1, 2, 3, 4 or 6 ng/ml in groups R0, R1, R2, R3, R4 and R6, respectively. Anesthesia was induced with propofol infusion at a target effect-site concentration of 4microgram/ml endotracheal intubation was performed 5 minutes after remifentanil administration. Blood pressure (BP), heart rate (HR) and cardiac index (CI) were recorded at the baseline and then every 30 seconds until 3 minutes after intubation. RESULTS: BP and HR in groups R0, R1 and R2 increased significantly after intubation when compared with the baseline values. The CI in group R0 also increased significantly after intubation when compared with the baseline values. Incidences of hypertension and hypotension were 50% and 5% in R0, 32% and 14% in R1, 18% and 32% in R2, 10% and 48% in R3, 8% and 54% in R4, and 0% and 81% in R6. There were also 2 cases in which the mean blood pressure was less than 50 mmHg in group R6. CONCLUSIONS: We suggest that the optimal target effect-site concentrations of remifentanil for blunting hemodynamic responses to endotracheal intubation are 3 or 4 ng/ml during total intravenous anesthesia using propofol at an effect-site concentration of 4microgram/ml.

The Effect of Ondansetron on the Corrected QT Interval of Electrocardiography during General Anesthesia / 대한마취과학회지

BACKGOUND: Prolongation of the corrected QT interval (QTc) has a potential risk of inducing life-threatening cardiac dysrhythmia. Although 5-HT3 antagonists are useful antiemetics, several cases of cardiac dysrhythmia after administration of 5-HT3 antagonists have been reported. Therefore, this study was conducted to evaluate the changes in QTc interval that occur after administration of a clinical dose of ondansetron during general anesthesia. METHODS: Seventy-five patients, who underwent elective surgery under standardized general anesthesia were evaluated. After anesthetic induction, the patients were given either normal saline, 2 mg or 4 mg of iv ondansetron. The QTc on the electrocardiogram was measured immediately prior to administration of the treatment drug and then every minute after injection of the study drug for 10 minutes, 12 and 15 minutes. RESULTS: There were no differences observed in the baseline QTc of the different treatment groups. In addition, there were no significant changes in the QTc interval of the control group, however, the QTc interval was prolonged significantly in both the ondansetron 2 mg and 4 mg groups. Further, DeltaQTc (the difference in QTc interval from the baseline value) was significantly prolonged in the ondansetron 2 mg and 4 mg groups when compared with the control group. There were no differences in the number of patients who showed abnormal QTc and there were no incidences of dysrhythmia in any of the three groups. CONCLUSIONS: Ondansetron administration for emesis prophylaxis during general anesthesia was associated with statistically significant prolongation of the QTc interval. The authors recommend that caution be used when ondansetron is administered to prevent and/or treat postoperative nausea and vomiting, particularly in patients who have a prolonged QTc interval.

Effects of Female Hormones and the Menstrual Cycle on Postoperative Pain / 대한마취과학회지

BACKGOUND: This study was designed to examine the effects of female hormones and the menstrual cycle on postoperative pain. METHODS: Ninety women who underwent gynecologic surgery involving a lower abdominal incision were asked for information regarding their menstrual cycles, and blood samples were obtained to determine the progesterone and estrogen levels of the patients at the time of surgery. Patient controlled analgesia was applied to control postoperative pain and an estimate of the consumption of analgesic drugs by the patients was made. Analgesic consumption and pain scores were recorded at 2, 24, and 48 hours after operation. RESULTS: There was no relationship observed between the concentration of progesterone and estrogen and the consumption of analgesic drugs. However, patients that were in the luteal phase at the time of surgery consumed a significantly lower amount of analgesic drugs during the 2-24 hours following surgery than patients that were in the follicular phase (19.4 +/- 6.5 ml vs 24.6 +/- 11.0 ml, P < 0.05), Theree was, no significant difference in pain scores between two menstrual phases. CONCLUSIONS: This study demonstrates that there is less postoperative pain experienced by patients that are in the luteal phase of their menstrual cycle at the time of surgery than in patients that were in the follicular phase of their menstrual cycle, however, the results of this study did not reveal a relationship between the blood concentration of female hormones and postoperative pain.

The Effect of Age on the Cardiovascular Responses Induced by Inhaled High Concentration of Desflurane / 대한마취과학회지

BACKGROUND: The inhalation of high concentrations of desflurane transiently increases the cardiovascular responses. This study examined the effects of age on the cardiovascular response to desflurane. METHODS: Eighty two patients were divided into one of three groups: under 3 years (Group 1), 2050 years (Group 2), and over 65 years (Group 3). In each group, the inspired concentration of desflurane was increased abruptly to 12.0 vol% 2 minutes after a thiopental injection. The heart rate, blood pressure (BP), cardiac index (CI), End-tidal concentration of desflurane (ETdesf), and end-tidal concentration of CO2 were measured at the baseline and every 30 seconds. RESULTS: The heart rate, BP, and CI increased transiently in the three groups compared with the baseline. The ETdesf increased more rapidly in Groups 1 and 3 than in Group 2. The ETdesf to reach the maximal mean arterial pressure (MAP) was highest in Group 3 among three groups. The relative maximal HR to the baseline value was similar in the three groups, but the relative maximal MAP to baseline value was significantly highest in the elderly patient group. The times to reach the maximal HR and BP were shortest in Group 1 among three groups. There were no significant differences in the CI between three groups. CONCLUSIONS: The inhalation of a high concentration of desflurane increases the HR, BP and CI transiently in all age groups. In pediatric patients, HR and BP increases more rapidly than in young adults and elderly patients. The relative maximal MAP to the baseline value is higher in elderly patients.

Desflurane-induced Hemodynamic Changes in Patients with Hypertension / 대한마취과학회지

BACKGROUND: A rapid increase in the desflurane concentration induces tachycardia and hypertension and increases the plasma catecholamine concentration. This study compared the desflurane-induced hemodynamic responses in hypertensive patients with those of normotensive patients. METHODS: Sixty patients, 30 normotensive patient (group 1) and 30 hypertensive patients (group 2), were scheduled to undergo elective surgery under general anesthesia. The hypertensive patients have been taking regular antihypertensive drugs and their blood pressure and heart rate was well controlled. Thirty normotensive patients were not premedicated. The inspired concentration of desflurane through the mask was increased abruptly to 12.0 vol%. The target was to produce an end-tidal concentration of desflurane (ETdesf) of 10.0 vol% which was maintained until the end of the study by adjusting the vaporizer dial setting. The heart rate (HR), blood pressure (BP), cardiac index (CI), systemic vascular resistance (SVR), ETdesf, end-tidal concentration of carbon dioxide, and peripheral oxygen saturation were measured at the baseline and every 30 seconds for 5 minutes after inhaling of desflurane and for 2 minutes after intubation. RESULTS: The HR, BP, and CI increased significantly in the two groups compared with the baseline. However, the HR, blood pressure, CI, SVR, and ETdesf were similar in both groups. In addition, there were no significant differences of hemodynamic changes between the beta-blocker and the calcium channel blocker in the hypertensive patients. CONCLUSIONS: In patients with well-controlled hypertension, the hemodynamic responses to desflurane are similar to those in normotensive patients.

Intraventricular Hemorrhage during Cesarean Section under General Anesthesia: A case report / 대한마취과학회지

An intracranial hemorrhage is a fatal complication associated with general anesthesia. It can occur in patients with an intracranial aneurysm, hypertension, cerebral vascular malformation, and blood dyscrasia, etc. A sudden hemodynamic change during intubation and extubation in general anesthesia is dangerous, particularly in these patients. We encountered an intraventricular hemorrhage in a 42 year old pregnant woman after a cesarean section. The patient was induced with 300 mg of thiopental and 45 mg of rocuronium. The anesthesia was maintained with N2O/O2 and sevoflurane after endotracheal intubation. Five hours after surgery, the patient had a seizure at the ward. A MRI and CT scan of the brain showed a right intraventricular and basal ganglia hematoma. The CT 3-D brain angiography showed an unruptured small aneurysm on the right posterior communicating artery.

Acute Obstruction of an Endotracheal Tube Due to Large Mucous Plug: Removed Using Flexible Fiberoptic Bronchoscopy: A case report / 대한마취과학회지

An endotracheal tube obstruction causes serious complications, including cardiovascular instability, pneumothorax, pulmonary edema and brain death. A 74 year old woman was scheduled to undergo a laminectomy and instrument fixation due to tuberculosis spondylitis. The patient was intubated with a 7.0 mm reinforced endotracheal tube, and moved into the prone position. At 100 min after the initiation of anesthesia, signs of partial endotracheal obstruction were observed, including high airway pressure and low tidal volume. The signs of an airway obstruction were aggravated as the operation proceeded. Thirty minutes after the sign of a partial obstruction, those of a total endotracheal obstruction were observed. A mucoid impaction in the endotracheal tube was detected using flexible fiberoptic bronchoscopy. After removing this plug, the ventilation of the patient was maintained within normal limits.

Comparison of Desflurane-induced Circulatory Responses by the Rate of Increase in Inhaled Desflurane Concentration / 대한마취과학회지

BACKGROUND: A rapid increase in desflurane concentration induces tachycardia and hypertension and increases plasma catecholamine concentration. No clinical study is available as to whether the desflurane-induced circulatory responses is blunted by the rate of increase in inhaled desflurane concentration although there were many studies about methods to blunt the circulatory responses. The current study examined to compare desflurane-induced circulatory responses by the rate of increase in inhaled desflurane concentration. METHODS: Unpremedicated sixty ASA physical status 1 patients, aged 20-60 years, scheduled for elective surgery under general anesthesia were randomly allocated into one of two groups. The inspired concentration of desflurane via mask was increased to 12.0 vol% abruptly (group 1), or during 120 seconds (group 2). The target was to produce an end-tidal concentration of desflurane (ETdesf) of 10.0 vol% which was maintained until the end of the study by adjusting the vaporizer setting, when necessary. Heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), systemic vascular resistance (SVR), ETdesf, end-tidal concentration of carbon dioxide, and peripheral oxygen saturation were measured at baseline and every 30 seconds for 5 minutes after inhalation of desflurane and for 2 minutes after intubation. RESULTS: HR, blood pressure, and CI were significantly increased in two groups compared with baseline, but significant differences in maximum values were not observed between two groups. There were no significant differences between groups of the ETdesf at the maximal HR and MAP. Incidences of hypertension and tachycardia were lesser in slowly increased inhaled desflurane concentration (group 2) than abruptly increased group (group 1). CONCLUSIONS: The present study demonstrates that increasing inhaled desflurane concentration slowly for mask ventilation is partially effective in attenuating desflurane-induced circulatory responses.

Hydrothorax Detected at Postanesthetic Care Unit after Percutaneous Nephrolithotomy: A case report / 대한마취과학회지

Percutaneous nephrolithotomy (PCNL) is a well-established procedure for treating nearly all types of stones in the kidneys and middle-to-upper ureters. In addition, PCNL is less invasive, and provides safe results comparable to open surgery. However, there is risk of an increased risk of thoracic complications when performing a puncture above the 12 th rib to optimize kidney access. We experienced a 30-years-old female who had oxygen desaturation and complained dyspnea and chest pain at the postanesthetic care unit after percutaneous nephrolithotomy. Therefore, patients undergoing percutaneous renal manipulation need to be monitored for pulmonary complications during and after the procedure.

Application of One Lung Ventilation in the Detection of Pulmonary Embolism during Operation / 대한마취과학회지

Intraoperative pulmonary thromboembolism (PTE) is rare, but is nevertheless one of the important causes of morbidity and mortality in patient undergoing surgery. However, The detection of PTE is difficult because it's clinical symptoms and signs are nonspecific during surgery, and specialized diagnostic tools are not readily available in the operating room. We report a case of PTE due to cancer emboli with thrombi encountered during a nephrectomy in patient with renal cell cancer, and demonstrate that one-lung ventilation can aid in the diagnosis of massive PTE when the evaluation is suspected.

The Effects of Measurement Time and Blood Temperature on Thromboelastographic Parameters / 대한마취과학회지

BACKGROUND: Thromboelastography (TEG) measures the viscoelastic properties of clotting blood, displaying a visual trace of all phases of coagulation and fibrinolysis. When performing a TEG, it is commonly recommended to store whole blood at 37oC with only a 3-6 min delay after sampling. However, it is difficult to actually keep this recommend time and temperature. The purpose of this study is to investigate the effects on TEG by inadvertent technical errors due to inappropriate measurement time and temperature. METHODS: Twenty healthy male volunteers were studied. TEG measurements were performed at: stat, 4 min, and 8 min at room temperature, and 4 min and 8 min at 37 degrees C. Parameters used were: reaction time (R), clot formation time (K), maximal amplitude (MA), clot formation velocity (alpha-angle), clot lysis 60 min (LY60) and TEG index. RESULTS: When compared with the routine recommendation, 4 min lag time at 37 degrees C, R and K were shortened and alpha angle and LY60 were increased at 8 min after the sample. However, temperature differences did not significantly affect TEG parameters. CONCLUSIONS: Inappropriate measurement temperature does not result in significant changes of TEG parameters, but, delayed storage resulted in a false hypercoagulation state and increased fibrinolysis.

The Effects of Ketorolac Used for Postoperative Analgesia on Hemostatic Function: A Thromboelastographic Evaluation / 대한마취과학회지

BACKGROUND: Thromboelastography (TEG) has recently become popular for assessment of whole blood coagulation in the operating room. Ketorolac, a potent injectable nonsteroidal anti-inflammatory drug (NSAID), is commonly used for postoperative analgesia. NSAID inhibit platelet aggregation in coagulation process. This study was designed to determine whether ketorolac used for postoperative analgesia can affect hemostatic function using a TEG. METHODS: Seventy-four female patients, ASA physical status 1 or 2, scheduled for an elective gynecologic surgery were randomly allocated into one of four groups (Group 1: n = 10, control without patient-controlled analgesia (PCA); Group 2: n = 21, PCA with morphine 60 mg; Group 3: n = 20, PCA with morphine 30 mg + ketorolac 90 mg; Group 4: n = 23, PCA with ketorolac 180 mg). Blood samples were obtained for TEG analysis preoperatively and 24, 48 and 72 h after surgery. Cumulative drug dosage, visual analog pain scale, satisfaction degree and side effects were measured at 24, 48 and 72 h after surgery. RESULTS: There were no significant differences in TEG parameters among the four groups at each time. There were no significant differences in visual analog pain scales and satisfaction degrees among the three groups using PCA for postoperative analgesia. Among the three groups using PCA for postoperative analgesia, Group 2 experienced more side effects. CONCLUSIONS: Ketorolac does not affect hemostatic function for 3 days after surgery when administrated as a PCA drug.

Traumatic Aortic Regurgitation Caused by Blunt Chest Injury / 대한마취과학회지

Blunt chest trauma can result in significant cardiothoracic injury, which can include a cardiac contusion, aortic injury, and myocardial valvular injury. Traumatic aortic regurgitation is an uncommon consequence of closed chest injury. Isolated aortic valvular injury following blunt chest trauma is difficult to diagnose in a patient with multiple injuries. We report a case of traumatic aortic regurgitation which was detected just before anesthesia induction in the operating room. This report is presented to emphasize the possibility of aortic regurgitation and the need for careful evaluation of the cardiac status in patients with blunt chest trauma.

A Comparison of Carbon Dioxide Tensions between Arterial Blood and Oxygenator Exhaust Gas during Cardiopulmonary Bypass / 대한마취과학회지

BACKGROUND: Maintenance of adequate concentration of carbon dioxide during hypothermic cardiopulmonary bypass is important in order to improve tissue perfusion by maintaining vasodilatation. This study evaluated the usefulness of the analysis of gas sampled from the exhaust port of a membrane oxygenator in the estimation of carbon dioxide tension in arterial blood (PaCO2). METHODS: One hundred sixty four arterial blood gases were drawn from 45 adult and 30 pediatric cardiac surgical patients undergoing hypothermic cardiopulmonary bypass. Carbon dioxide tensions were measured in the membrane oxygenator exhaust gas (swept gas; PswCO2) using a capnography and in arterial blood using intermittent gas analysis. We compared the PswCO2 with temperature-uncorrected (alpha-stat) and -corrected (pH-stat) PaCO2 during cardiopulmoary bypass. RESULTS: The mean PaCO2 measured with alpha-stat and pH-stat, and PswCO2 obtained in adult patients during hypothermic cardiopulmonary bypass were 29.8 +/- 4.9, 19.5 +/- 4.1 and 22.3 +/- 4.2 mmHg, respectively. In pediatric patients, alpha-stat PaCO2, pH-stat PaCO2 and PswCO2 were 39.7 +/- 7.7, 24.7 +/- 6.2 and 20.3 +/- 6.0 mmHg, respectively. There was a significant positive correlation between PswCO2 and alpha-stat PaCO2 (adult patients: slope = 0.49, r = 0.64, P < 0.001; pediatric patients: slope = 0.53, r = 0.68, P < 0.001) and pH-stat PaCO2 (adult patients: slope = 0.85, r = 0.81, P < 0.001; pediatric patients: slope = 0.73, r = 0.73, P < 0.001). On comparison of subsequent measurements, 3.8% (adult patients) and 11.4% (pediatric patients) of changes in PaCO2 and PswCO2 were in opposite direction. CONCLUSIONS: Our results indicate that in adult and pediatric patients undergoing hypothermic cardiopulmonary bypass PswCO2 can be an indicator of changes in trend of PaCO2.

Massive Thrombosis after Central Venous Catheterization in a Patient with Previously Undiagnosed Behcet's Disease

Thrombosis is an important complication of central venous catheterization. Among the many intrinsic and extrinsic factors, the patient's medical disease can play a role in thrombogenesis. Behcet's disease (BD), classified as a vasculitis, is a multisystem disease involving the small blood vessels. It is often difficult to recognize and diagnose the disease. A 24-yr-old female patient showed massive central venous thrombosis which caused superior vena cava syndrome after subclavian vein catheterization. Twenty days after catheterization, the patient exhibited swelling of the face, neck, and both upper extremities. Despite thrombectomy and continuous anticoagulation therapy, her facial and upper extremity swelling reappeared and follow-up chest computed tomography (CT) showed the recurrent thrombosis in the same central veins previously affected. A diagnosis of BD was then made. Following steroid therapy, neither clinical symptoms nor CT findings suggestive of central venous thrombosis were observed during the subsequent 6-months of follow-up period. This case emphasizes that central venous catheterization in a patient with BD should be performed with great caution.

How Long Should a Patient Stay in Lateral Position for Unilateral Spinal Anesthesia with Hyperbaric Bupivacaine? / 대한마취과학회지

BACKGROUND: In searching for a differential spinal block between dependent and nondependent sides, we evaluated the influence of the duration of lateral decubitus on the spread of hyperbaric bupivacaine during spinal anesthesia. METHODS: Spinal anesthesia with 1.2 ml of hyperbaric 0.5% bupivacaine (6 mg) was administered with a 25-gauge Whitacre unidirectional needle to 50 ASA 1 patients undergoing unilateral knee arthroscopy. The patients were allocated randomly to three groups according to the duration of lateral decubitus after spinal injection in the lateral position operation side dependent: Group 1, 10 min in lateral decubitus then supine; Group 2, 20 min in lateral decubitus then supine; Group 3, 30 min in lateral decubitus then supine. Sensory and motor block (pinprick/modified Bromage scale) as well as skin temperature were compared between the dependent and nondependent sides. Circulatory variables were recorded for 10 min after being turned supine. RESULTS: The sensory block between dependent and nondependent sides were significantly different in Group 3. In Group 1, the level of maximum sensory block was higher than Group 3 on nondependent side. There was no difference in the number of patients having achieved Grade 3 and 0 motor block among three groups on dependent and nondependent sides. The skin temperature in lateral decubitus was significantly higher on the dependent side than nondependent side in three groups. In Groups 1 and 2, the skin temperatures of nondependent side were increased after turned supine, but that was maintained during supine position in Group 3. The circulatory variables were stable in all 50 patients. CONCLUSIONS: We conclude that when a small dose of 0.5% hyperbaric bupivacaine is injected into patients in the lateral position, complete unilateral spinal anesthesia is achieved when the patients arekeep in a lateral position for more than 30 min after spinal injection.