Comparison of the Effects of Nitroglycerin and Nitroprusside on Hypoxic Pulmonary Vasoconstriction in the Isolated Rabbit Lung / 대한마취과학회지

BACKGROUND: It has been reported that two common vasodilators, nitroglycerin (NTG) and sodium nitroprusside (SNP), inhibit regional HPV and decrease arterial oxygenation as a result. The purpose of the present study was, therefore, to determine the comparative effect of NTG and SNP on HPV in a rabbit model of isolated lung perfusion with exclusion of the influential factors on HPV. METHODS: In adult white rabbits (n=20), lungs were isolated and perfused with the constant pulmonary blood flow. The acid-base status and temperature of perfusate was also constantly maintained. Thirty minutes later, baseline hypoxic pressor response (HPR) was measured as the difference of pulmonary artery pressure (PAP) between a period of 95% hyperoxic gas inhalation and that of 3% hypoxic gas inhalation. ED50 of NTG and SNP was calculated from the hypoxic pressor response measured in the same way, according to changes of doses (0.5, 1.0, 2.0, and 5.0 microgram/kg). RESULTS: Both NTG and SNP significantly decreased the baseline PAP in the doses of 1.0 microgram/kg and above, and also decreased the HPR in a dose-related manner. ED50 of SNP was significantly lower than that of NTG. CONCLUSIONS: NTG and SNP dilated directly the pulmonary vasculature and inhibited HPV in a dose- related manner. SNP had a greater inhibiting effect on HPV than NTG.

A Comparison of the Effects of Ondansetron and Granisetron on the Prevention of Postoperative Nausea and Vomiting after Gynecologic Surgery / 대한마취과학회지

BACKGROUND: The purpose of this study was to compare the effects of ondansetron and granisetron on the prevention of postoperative nausea and vomiting (PONV) in gynecologic patients. METHODS: In a randomized placebo-controlled study, 200 gynecologic patients were divided into 5 groups. Each patient received one of 5 medications: placebo (saline 3 ml), ondansetron 4 mg (O4), ondansetron 8 mg (O8), granisetron 1.5 mg (G1.5) and granisetron 3 mg (G3). They were administered intravenously immediately before the induction of anesthesia. A standardized inhalation anesthesia and a postoperative intravenous patient-controlled analgesia were applied. Twenty four hours after anesthesia, the incidence and severity of PONV and other adverse effects were assessed. RESULTS: The incidence of PONV was 88%, 83%, 75%, 70% and 60% in the placebo, O4, O8, G1.5 and G3 groups, respectively, which showed significantly lower value in the G3 group than in the placebo and O4 groups (P< 0.05). The severity of PONV was also significantly lower in the G3 group than in the placebo group (P < 0.05). CONCLUSIONS: In this study, granisetron 3 mg showed a better prophylactic effect in the mitigation of PONV in gynecologic patients then a placebo or ondansetron 4 mg.

Total Intravenous Anesthesia with Sufentanil and Midazolam for Open Heart Surgery / 대한마취과학회지

BACKGROUND: This study was conducted to evaluate the hemodynamic effects, the time to arousal and the postoperative recall with the continuous infusion technique of sufentanil and midazolam used for induction and maintenance of anesthesia in patients undergoing open heart surgery. METHODS: Forty patients with good ventricular function undergoing elective open heart surgery were evaluated. They received midazolam 0.1 mg/kg, pancuronium 0.15 mg/kg and sufentanil 2.5 mcg/kg, followed by infusions of midazolam 0.1 mg/kg/hr, pancuronium 0.02 mg/kg/hr and sufentanil 1.5 mcg/kg/hr until the end of operation. We observed the mean arterial pressure, heart rate and central venous pressure before the initiation of cardiopulmonary bypass(CPB) and recorded the time to arousal after the end of operation and asked about awareness of any intraoperative events on the third postoperative day. RESULTS: The mean arterial pressures during prebypass period were lower than preinduction value but there were no severe hypotension with mean arterial pressures less than 60 mmHg. The mean arousal time of eye opening was 119 minutes and there was no postoperative recall case. CONCLUSIONS: The results show that the infusion of sufentanil with midazolam to patients with good ventricular function provides a stable and safe anesthesia hemodynamically and neurologically and a rapid recovery from anesthesia without postoperative recall.

The Effect of Injection Direction during Hyperbaric Tetracaine Spinal Anesthesia with Pencil-Point Needle / 대한마취과학회지

BACKGROUND: Pencil-point needle currently are used for spinal anesthesia because of an alleged lowered incidence of postdural puncture headache. Although the direction of the side hole is one of the important factors that might affect the level and the duration of anesthesia, those data are not readily available. The aim of this study was to assess if the side hole direction of pencil-point needle during hyperbaric tetracaine injection affects the level and the duration of anesthesia. METHODS: We induced spinal anesthesia in 80 young men presenting for elective orthopedic surgery. Patients were allocated randomly with the side hole direction of the 25 gauge pencil-point needle in one of the four directions; cephalad, caudad, left lateral, right lateral. Hyperbaric 0.5% tetracaine 15~17 mg (3 to 3.4 ml) was injected with the speed of 0.75 ml/sec. Maximum sensory block level, time to maximum sensory block level, duration of sensory block (2 segments regression time) were assessed by a blinded observer with the pin-prick test and degree of motor block were measured by Bromage motor scale. Data were analysed using the Kruskal-Wallis test followed by the Mann-Whitney U test and chi-square test as appropriate (SAS v. 6.04). RESULTS: Time to maximum sensory block level was significantly fast in group 'cephalad'. Other values have no statistical differences. Post-spinal headache was observed in one case in group 'caudad'. CONCLUSIONS: Using the pencil-point needle, the time to maximum sensory block level was fast in group cephalad but there were no differences in the maximum sensory block level and the duration of sensory block among the four groups.

Anesthetic Management of Patient with Renal Cell Carcinoma Extending into the Right Atrium Using Adjunctive Deep Hypothermic Circulatory Arrest: A case report / 대한마취과학회지

Renal cell carcinoma is associated with inferior vena cava tumor spread in 4~10% of cases and with extension of the tumor thrombus into the right atrium in less than 1% of cases. Because inferior vena caval involvement does not affect the ultimate survival in patients with nonmetastatic renal cell carcinoma, aggressive surgical resection is indicated. We experienced a case of complete tumor excision with radical nephrectomy and inferior vena caval and right atrial thrombectomy using adjunctive cardiopulmonary bypass(CPB) and deep hypothermic circulatory arrest(DHCA). During total circulatory arrest(TCA), we protected brain from ischemic insult using deep hypothermia, retrograde cerebral perfusion, thiopental, and high dose steroid. The patient recovered uneventfully except minor neuropsychiatric symptom for 3 weeks after operation.

Usefulness of PAR Score and Modified PADSS as Patient Discharge Criteria in Ambulatory Surgery / 대한마취과학회지

Background: Although an ambulatory surgical practice continues to increase, there is a few data exist about patient discharge criteria. This study was undertaken to evaluate the usefulness and safety of Aldrete PAR (postanesthetic recovery) score and modified PADSS (modified postaneathesia discharge scoring system) on ambulatory surgery patients for recovery in Korea. Methods: Demographic, anesthetic data, Aldrete PAR score and modified PADSS on 279 patients were recorded. The time to dicharge, from recovery room and postoperative complications were evaluated, also. Results: PAR score and modified PADSS are correlated to length of stay in ambulatory surgery center. 24hr after discharge, 16% patients complained postoperative complications. Pain was most frequent postoperative complication. The PAR score was correlated with the occurrence of the complication. Conclusion: PAR score and modified PADSS are useful scoring systems to evaluate patients and make a decision to discharge the patients from ambulatory surgery center in safe.

Acute Normovolemic Hemodilution Decreases Transfusion Requirement in Spinal Surgery / 대한마취과학회지

BACKGROUND: Acute normovolemic hemodilution (ANH) is known as the easieat and most economical and the quality of autologous blood saved by it is the best of all methods of autotransfusion. To investigate the efficacy of ANH, we studied whether it could reduce the transfusion requirement in spinal surgery. METHODS: Forty patients were randomly divided into 2 groups. In the hemodilution group (n=20), 2 or 3 units of autologous blood were procured immediately before or after anesthetic induction while Ringer's lactate and pentastarch were infused to maintain normovolemia. All patients received deliberate hypotension induced by labetalol. Perioperative changes of hemoglobin, hematocrit and platelets, the transfusion requirement and the amount of postoperative drainage were compared between each group. RESULTS: Perioperative changes of hemoglobin, hematocrit and platelet showed no significant differences between each group. Less packed RBC were used in the hemodilution group (1.9 2.0 units) than in control group (5.9 6.8 units) (p<0.05). In the control group, 4 patients were transfused with fresh frozen plasma (mean 4.8 units), 3 patients with platelets (mean 13 units) and 1 patient with cryoprecipitate (10 units) while only one patient was transfused with 3 units of fresh frozen plasma in the hemodilution group. Postoperative drainage was significantly less in the hemodilution group (1,494 488 ml) than in the control group (2,476 1,730 ml). CONCLUSION: ANH seems to decrease the transfusion requirement in spinal surgery. Reduction of postoperative wound drainage appears to play an important role in that.

Influence of Lateral Decubitus on the Spread of Spinal Anesthetics during Spinal Anesthesia / 대한마취과학회지

BACKGROUND: The purpose of our study was to evaluate whether, by varing the duration of lateral decubitus, subarachnoid administration of hyperbaric bupivacaine in a lateral decubitus position could produce a differential spread between the dependent and nondependent sides, and also to determine the clinical advantage of this procedure. METHODS: In a lateral position with the operating side dependent, all patients received 15mg of hyperbaric 0.5% bupivacaine and were randomized into four groups according to the duration of lateral decubitus after subarachnoid injection: Group I: patients immediately turned supine after the injection, Group II: 5 min in lateral decubitus position after the injection, then supine, Group III: 10 min in lateral decubitus position after the injection, then supine, Group IV: 15 min in lateral decubitus position after the injection, then supine. The maximum sensory block level using pinprick test, the time to maximum sensory block, the duration of sensory block, the time to complete motor block and the duration of complete motor block in the dependent and nondependent sides were measured. RESULTS: There were no statistical difference in maximum sensory block level, duration of sensery block, and duration of complete motor block between both sides in the same group nor among four groups. CONCLUSIONS: In conclusion, there was no significant influence of lateral decubitus on the spread of hyperbaric bupivacaine and the present study does not demonstrate any clinical advantage of a prolonged lateral position for 15 min after subarachnoid injection.

Duration and Frequency of Apnea and Frequency of Unconsciousness with Propofol according to Single Injection Dosage / 대한마취과학회지

BACKGROUND: It is well known that induction with large dose of propofol causes high incidence of apnea and marked decrease in mean arterial blood pressure. So, it is wise to titrate adequate dose to induce sleep for induction of anesthesia. In this study, we evaluated the incidence and duration of apnea and the frequency of unconciousness according to variable single dosage of propofol. METHOD: We evaluated 99 adult patients (ASA class 1 or 2) who was undertaken general anesthesia. We allocated patients randomly into three groups according to dosage of propofol. Without premedication, we administered propofol 1 mg/kg(group 1) or 1.5 mg/kg(group 2) or 2 mg/kg(group 3) over 10 seconds as an indution agent. To assess apnea, we observed chestwall movement and ETCO2 waveform. Unconsciousness was assessed by asking the patient to open his/her eyes. RESULTS: As the dose of propofol increased, the frequency and duration of apnea significantly increased. The frequencies of apnea were 44% in group 1, 63% in group 2 and 83% in group 3. The durations of apnea were 27 12sec, 60 33sec, 74 34sec respectively. And the frequencies of unconsciousness were 66% in group 1, 75% in group 2 and 97% in group 3. CONCLUSION: Incidence and duration of apnea and frequency of unconciousness increase as injection dose of propofol increase. To get unconciousness in adult patients, adequate single-dosage of propofol is more than 2 mg/kg of propofol.

Clinical Evaluation of Univent Tube for One Lung Ventilation / 대한마취과학회지

BACKGROUND: Univent tube(endotracheal tube with a movable blocker), introduced by Inoue et al in 1982, has properties to overcome the disadvantages of double lumen endotracheal tube for one lung anesthesia. This study was performed to evaluate the effectiveness of Univent tube for one lung ventilation. METHODS: Univent tube was inserted to the patients for open thoracic surgery and positioned to the side of bronchus under the guidance of fiberoptic bronchoscope that was scheduled to lung collapse. One lung anesthesia was performed with the inflation of cuff of blocker. Each case was anaylzed with respect to ease or difficulty of positioning of blocker, tube displacement, efficacy of lung collapse and adequacy of single lung ventilation. RESULTS: In the 69 patients out of 80 patients, adequate positioning was performed by first trial. In the two patients, insertion of bronchial blocker was failed that resulted in replacement with a double lumen tube. Observed disadvantages were delayed deflation(10 patients) of affected lung and displacement of bronchial cuff into the main tracheal lumen during position change or surgical manipulation(7 patients). CONCLUSIONS: Univent tube is useful for one lung anesthesia but there are several distinct limitaitons in the safe use.

A Comparison for Tourniquet Pain in Spinal Anesthesia / 대한마취과학회지

BACKGROUND: It has been suggested that the incidence of tourniquet pain is less frequent in patients in whom bupivacaine has been employed for spinal anesthesia than in patients to whom tetracaine has been administrated. The current study was accomplished to compare the incidence of tourniquet pain in patients in whom 0.5% plain bupivacaine spinal anesthesia and 0.5% hyperbaric tetracaine spinal anesthesia were employed. METHODS: The incidence of tourniquet pain was evaluated in 40 patients having orthopaedic surgery of the lower extremities during spinal anesthesia using 15 mg of hyperbaric 0.5% tetracaine(group I) or 15 mg of a plain solution of 0.5% bupivacaine(group II). The drugs were administrated in a randomized fashion. We measured the maximal sensory spread of analgesia to pinprick test, the incidence of tourniquet pain, the sensory anesthesia to pinprick test at time of onset of tourniquet pain and the number of patient treated with IV injection of fentanyl to relieving tourniquet pain. RESULTS: The maximal sensory spread of analgesia mean was higher in patients given hyperbaric tetracaine (T8) than in patients given plain bupivacaine (T9). The incidence of tourniquet pain was significantly greater in patients given hyperbaric tetracaine (65%) than in patients given plain bupivacaine (15%). The incidence of analgesics injection for tourniquet pain was greater in patients given hyperbaric tetracaine (10%) than in patients given plain bupivacaine (none). CONCLUSIONS: In conclusion, the tourniquet pain in surgery of the lower extremities occurs less frequently when plain bupivacaine is employed for spinal anesthesia as compared to hyperbaric tetracaine.

Hyperbaric and Plain Bupivacaine Spinal Anesthesia for Lower Extremity Operation / 대한마취과학회지

BACKGROUND: The present study was undertaken to determine the clinical effect of hyperbaric 0.5% bupivacaine spinal anesthesia compared with the 0.5% plain bupivacaine anesthesia for lower extremity operation. METHODS: We evaluated the clinical effects in 40 patients having orthopedic surgery of the lower extremities during spinal anesthesia using 15 mg of bupivacaine 0.5% in 8% dextrose (group I) or 15 mg of bupivacaine 0.5% plain (group II). The drugs were administrated in a randomized fashion. We measured the maximal sensory block level according to pinprick test, the time to maximal sensory block, the regression time, the duration of sensory block, the time to complete motor block and the duration of complete motor block. RESULTS: The mean maximal sensory block level was higher in group II (T6) than in group I (T7). The regression time, the duration of sensory block and the duration of complete motor block was significantly longer in group II than in group I. CONCLUSIONS: In conclusion, both the hyperbaric and the plain 0.5% bupivacaine spinal anesthesia are equally suitable for lower extremity operation.

The Effects of Isoflurane - induced Hypotension on Cerebral Blood Flow and Cerebral Metabolic Rate for Oxygen in Dogs / 대한마취과학회지

We investigated the effects of isoflurane-induced hypotension on global cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO,), and the balance between cerebral oxygen supply and demand in 8 mongrel dogs. After endotracheal intubation, anesthesia was maintained with nitrous oxide (50%)-oxygen (50%)-fentanyl (2u/kg/hour). Ventilation was controlled to normocapnia. Mean arterial pressure (MAP) was lowered to 60 mmHg with inhalation of isoflurane. CBF was measured directly using sagittal sinus outflow method before (prehypotension), during (hypotension), and after (posthypotension) isoflurane-induced hypotension. Concomitantly, arterio-sagittal sinus venous oxygen content differen- ce was measured to calculate CMRO2. During hypotension, CBF and CMRO, were measured at 20 minutes after MAP was lowered to 60 mmHg and maintained stably. The time to induce hypotension was 8.6+/-6.1 (mean+/-SD) min. Mean inspired isoflurane concentra tion to induce desired hypotension was 3.1+/-0.9 vol%. The time to recover from hypotension was 28.6+/-7.7 min. MAP and heart rate were reduced significantly during hypotension (p<0.05, respectively) and returned to prehypotensive values during posthypotension. CBF was not changed between three peroiods. CMRO2 was reduced significantly during hypotension (6.5+/-1.2 vs 4.3+/-0.8ml/100/g/min, mean+/-SD, p<0.05) and returned to prehypotensive values during posthypotension. The percentage of CMRO2 reduction from prehypotension to hypotension (% CMRO2 reduction) was 32.5+/-12.9%. CBF/CMRO2 ratio was increased significantly during hypotension (12.8+/-3.3 vs 18.2+/-6.1, mean+/-SD, p<0.05) and lowered to prehypotensive values during posthypotension. Isoflurane-induced hypotension maintained CBF and reduced CMRO2 and therefore favorably influenced the balance between the global cerebral oxygen supply and demand. In conclusion, isoflurane induced-hypotension may be a safe and effective technique in view of the balance of the global cerebral oxygen supply and demand.