Anesthetic complications due to extremely low ankle blood pressure caused by peripheral arterial disease / 대한마취과학회지

No abstract available.

Cardiac arrest in the elderly with silent myocardial ischemia during general anesthesia / 대한마취과학회지

No abstract available.

Postoperative pain relief effect of a suprascapular nerve block before arthroscopic shoulder surgery

BACKGROUND: Arthroscopic shoulder surgery results in severe postoperative pain in 45% of patients which requires a large amount of opioids for relief. We hypothesized that a suprascapular nerve block before arthroscopic shoulder surgery would improve the quality of postoperative pain relief thereby allowing patients to require significantly reduced amounts of opioids. METHODS: Sixty patients were randomized from a elective arthroscopic shoulder surgery list either into a control group (group 1, n = 30) with only intravenous, patient-controlled analgesia (IV PCA) or an experimental group (group 2, n = 30) involving a suprascapular nerve block before arthroscopic shoulder surgery. The patients had an induction of general endotracheal anesthesia with or without suprascapular nerve block before operation. The IV PCA was connected to the patients 10 minutes after induction. Both groups were analyzed by chi square test and t-test. RESULTS: The postoperative VAS scores for group 2 decreased more than those for group 1. In particular, the VAS scores for group 2 within 12 hours after the operation were significantly higher than those 12 hours postoperative, as compared to group 1. CONCLUSIONS: Increased pain relief and less reliance on opioid can be expected through the use of a suprascapular nerve block prior to arthroscopic shoulder surgery.

Ankle-brachial blood pressure differences in the beach-chair position of the shoulder surgery / 대한마취과학회지

BACKGROUND: During shoulder surgery, blood pressure is frequently measured at the ankle. Anesthetic complications may result when ankle blood pressure is higher than brachial blood pressure and anesthesiologists misinterpret ankle blood pressure as brachial blood pressure. Therefore, we investigated whether ankle blood pressure is significantly higher than brachial blood pressure before anesthesia induction, during induction, after tracheal intubation, before beach chair position, and in the beach chair position. METHODS: Thirty patients requiring general anesthesia for shoulder surgery were included in this study. Ankle and brachial blood pressure were simultaneously measured before induction, during induction, after intubation, before beach chair position, and in the beach chair position. RESULTS: Ankle blood pressure was higher than brachial blood pressure before induction, during induction, after intubation, before beach chair position, and in the beach chair position. Ankle-brachial blood pressure differences in the beach chair condition were much higher than in four other conditions. The correlation coefficient between mean ankle-brachial blood pressure differences before the beach chair position and mean ankle-brachial blood pressure differences in the beach chair position was 0.616. Brachial systolic blood pressure could be predicted by regression equations (R2 = 0.306-0.771). CONCLUSIONS: These results suggest that anesthesiologists should consider these ankle-brachial blood pressure differences when monitoring anesthesia in the beach chair position.

Aging impairs vasodilatory responses in rats / 대한마취과학회지

BACKGROUND: Aging causes profound changes of stiffness and compliance in the cardiovascular system, which contributes to decreased cardiovascular reserve. Mechanisms of the underlying endothelial vasodilator dysfunction in vasodilator signaling pathways may occur at multiple sites within any of these pathways. METHODS: Age-related changes in the vasculature were investigated in adult young (3-6 months, Y) and old (26-29 month, O) Wistar rats (n = 6). The aortas were carefully dissected from the rat and cut into rings 1.5-2.0 mm in length to measure in vitro isometric tension. Vasorelaxant responses of aortic rings to acetylcholine (ACh), sodium nitroprusside (SNP) and P1075 were examined using Dose Response software (AD Instruments, Mountain View, CA). RESULTS: Endothelium-dependent vasodilator function was impaired. The endothelium of aging rats impaired endothelial NO dependent vasodilation, but the machinery for vasodilation was not impaired. CONCLUSIONS: Age-related NO-mediated vasorelaxation in the aging endothelium was inhibited and appears to be major mechanism of vascular change and impaired vascular regulation.

The vasorelaxatory effect of the milrinone on the preconstricted rat aorta / 대한마취과학회지

BACKGROUND: Milrinone, phosphodiesterase III inhibitor, has been used effectively in patients with right heart failure, especially resulted from pulmonary hypertension. However, milrinone is often used with alpha- and beta-adrenergic receptor agonist to prevent severe systemic vasodilation and unfavorable hypotension. Furthermore, structural and functional vasacular changes are associated with aging and are greatest in the aorta. We evaluated the vasodilatory effects of milrinone and sodium nitroprusside (SNP) on young and old rat aortic rings preconstricted with various catecholamines. METHODS: Aortic rings of young and old rat were placed in 25 ml organ chamber and preconstricted with epinephrine (EPI, 10(-6) M), norepinephrine (NE, 10(-7) M) , phenylephrine 10(-7) M) , and U46619 (10(-8) M). Cummulative dose-responses to milrinone (10(-9)-10(-5) M) and SNP (10(-9)-10(-5) M) were obtained to characterize vasodilatory effects. RESULTS: Relaxation response to milrinone was markedly enhanced in both young and old aortic rings preconstricted with U46619 compared with other vasoconstrictors. The maximal response of the young rat aortic rings preconstricted with NE is significantly reduced, compared with that of EPI. The maximal vasorelaxant response of SNP in young and old aortic rings are nearly identical. CONCLUSIONS: We conclude that combined use of milrinone and epinephrine may be more useful in prevention and treatment of systemic hypotension.

Impaired but reversible vascular reactivity in a rat model of microgravity / 대한마취과학회지

BACKGROUND: The hindlimb unweighting (HLU) rat model mimics cardiovascular deconditioning following microgravity or human bed rest, particularly for the development of orthostatic intolerance. We have examined vascular responses to alpha1 adrenergic and non-alpha1 adrenergic agonists in vitro. We have also explored the reversibility of the contractile abnormalities observed. METHODS: Dose-response curves were generated to phenylephrine (PE) and norepinephrine (NE) (10(-9) to 10(-4) M), U46619 (U4) (10(-10) to 10(-6) M) at one-half log order intervals in controls (n = 6), HLU (n = 6), or recovered rats (n = 6). EC(50)s and maximal responses (E(max)) were calculated by nonlinear logistic regression analysis with PRIZM software (Graphpad, Mountain View, CA). RESULTS: Simulated microgravity results in attenuated contractile responses to both alpha1 adrenergic and non-alpha1 adrenergic agonists, but the impaired contractile phenomenon reverses with time. CONCLUSIONS: The decreased vascular reactivity after microgravity and prolonged bed rest could cause attenuated baroreflex function and produce orthostatic intolerance, but that problem resolved with time.

Impaired but reversible vascular reactivity in a rat model of microgravity / 대한마취과학회지

BACKGROUND: The hindlimb unweighting (HLU) rat model mimics cardiovascular deconditioning following microgravity or human bed rest, particularly for the development of orthostatic intolerance. We have examined vascular responses to alpha1 adrenergic and non-alpha1 adrenergic agonists in vitro. We have also explored the reversibility of the contractile abnormalities observed. METHODS: Dose-response curves were generated to phenylephrine (PE) and norepinephrine (NE) (10(-9) to 10(-4) M), U46619 (U4) (10(-10) to 10(-6) M) at one-half log order intervals in controls (n = 6), HLU (n = 6), or recovered rats (n = 6). EC(50)s and maximal responses (E(max)) were calculated by nonlinear logistic regression analysis with PRIZM software (Graphpad, Mountain View, CA). RESULTS: Simulated microgravity results in attenuated contractile responses to both alpha1 adrenergic and non-alpha1 adrenergic agonists, but the impaired contractile phenomenon reverses with time. CONCLUSIONS: The decreased vascular reactivity after microgravity and prolonged bed rest could cause attenuated baroreflex function and produce orthostatic intolerance, but that problem resolved with time.

The Effect of Doxapram Hydrochloride on Bispectral (BIS) Index and Recovery from Desflurane Inhalational Anesthesia / 대한마취과학회지

BACKGROUND: Doxapram hydrochloride is a respiratory stimulant that produces arousal effects in patients under anesthesia. We investigated the effects of doxapram on the recovery time and BIS index of patients administered desflurane inhalational anesthesia. METHODS: 40 patients who underwent general anesthesia using desflurane that had an ASA physical status of I or II received either 1 mg/kg of doxapram hydrochloride (doxapram group, n = 20) or normal saline (control group, n = 20) IV at end of surgery. Anesthetic recovery after the injection of doxapram was then determined based on the time to eye opening in response to verbal command, hand squeezing on command, time to extubation, and Aldrete recovery score. BIS index, systolic blood pressure, tidal volume and heart rate were recorded every minute for up to thirteen minutes. RESULTS: The doxapram group showed significantly shorter times to emergence based on eye opening in response verbal command (sec) (409 +/- 114 vs 320 +/- 116), hand squeezing on command (sec) (458 +/- 119 vs 351 +/- 114) and extubation (sec) (491 +/- 103 vs 418 +/- 79) compared to control group. The BIS score was not significantly different between the two groups. CONCLUSIONS: The Bis index was not significant higher in the doxapram group, with the exception of the measurement recorded at 2 minutes, however the recovery time from desflurane inhalational anesthesia was faster in the doxapram group than the control group.

Cardiovascular Effects of Hind-limb Unweighing in Mice / 대한마취과학회지

BACKGROUND: Orthostatic intolerance is a debilitating problem that can occur after prolonged bed-rest, exposure to microgravity, and in the elderly. This study examined the integrated cardiovascular response to baroreceptor activation in a hind-limb unweighing (HLU) mouse model of microgravity to test the hypothesis that both the pressor and contractility response are attenuated in HLU mice. METHODS: C57BL/6 mice (25-30 g body wt, 8-10 wk old) were exposed to HLU for 2 weeks. A bilateral carotid artery occlusion and open-loop baroreceptor stimulus was performed to measure the myocardial contractile responses using a left ventricular micromanometer-conductance catheter in the mice. In isolated myocytes simultaneous sarcomere shortening and calcium transient were measured in response to increasing concentrations of the beta-agonist isoproterenol. RESULTS: In the controls, bilateral carotid artery occlusion increased the heart rate and mean arterial pressure. These responses were markedly attenuated in the HLU mice. A bilateral carotid artery occlusion also increased the slope of the end-systolic pressure volume relationship (Ees) by 70 +/- 11% and the slope was markedly attenuated to 10 +/- 8% in the HLU mice. Isoproterenol increased the sarcomere shortening in both control and HLU mice in a dose-dependent manner. However the contractile response to isoproterenol was significantly attenuated in the HLU mice than the controls. CONCLUSIONS: Both the pressor and myocardial contractile responses appear to be impaired in a mouse model of microgravity.

Oral Alprazolam Attenuates Preoperative Stress Responses to Regional Anesthesia / 대한마취과학회지

BACKGROUND: Preoperative anxiety activates the hypothalamo-pituitary-adrenal axis and the sympathetic nervous system, and also affects immune responses. Therefore, there is a need to reduce the anxiety. METHODS: Forty-eight healthy patients scheduled for elective knee arthroscopic and reconstructive surgery under spinal anesthesia (SA) were randomly allocated into the control (CG, n = 24) and the alprazolam group (AG, n = 24). Oral 0.25 mg alprazolam in the evening before SA and 0.5 mg alprazolam 90 min before SA were administered to patients of the AG. Visual analogue scale (VAS) scores of anxiety were measured in the operating room before SA (ORSA) and operating room during operation and discharge day (DD). Serum ACTH and cortisol in the ORSA and DD, systolic and diastolic blood pressure and heart rate in the ward and ORSA, sleep time and number of night awakenings in the night before SA were measured. RESULTS: Age (31.9 +/- 10.8 yr), sex, height, weight, and sleep time were not significantly different between the two groups. The number of night awakenings in the AG were significantly lower than in the CG. VAS scores of anxiety in the ORSA were significantly higher in the CG than in the AG. ACTH and cortisol levels in the CG were significantly higher in the ORSA than in the DD. ACTH and cortisol levels in the AG were not significantly different between the ORSA and the DD. Cortisol level in the ORSA were significantly lower in the AG than in the CG. Diastolic blood pressure and heart rate in the ORSA were significantly lower in the AG than in the CG. CONCLUSIONS: These indicate that oral alprazolam attenuates preoperative stress responses to regional anesthesia.

The Aortic Reactivity to Nitric Oxide after Cardiopulmonary Bypass in Rats / 대한마취과학회지

BACKGROUND: We evaluated whether vessel reactivity to nitric oxide changed after cardiopulmonary bypass, which would play an inportant role in temporary vital organ perfusion. METHODS: We used the distal aortas of five rats weighing 400-500 g after cardiopulmonary bypass in experimental group. We also used the distal aortas of five rats before cardiopulmonary bypass under sham operation in control group. All cumulative concentration-effect curves were performed in the aortic rings and EC50 and maximal response (Emax) were calculated by using nonlineal logistic regression analysis with the software PRISM (Graphpad, Mountain View, CA). RESULTS: CPB inhibited acetylcholine induced relaxation in aortic rings and also inhibited sodium nitroprusside (SNP) induced relaxation in ones. It was similar to depression of acetylcholine induced relaxation. CONCLUSIONS: The depression of aortic rings relaxation after CPB may be associated with attenuated sensitivity of them to NO in rats.

The Pulmonary Arterial Reactivity to Nitric Oxide after Cardiopulmonary Bypass and Reperfusion in Pigs / 대한마취과학회지

BACKGROUND: We hypothesized that the decreased nitric oxide after cardiopulmonary bypass and reperfusion would play an important role in temporary pulmonary hypertension. METHODS: We used the pulmonary arteries of three pigs weighing 40-50 kg after cardiopulmonary bypass and reperfusion in experimental group. We also used the pulmonary arteries of five pigs before cardiopulmonary bypass under sham operation in control group. All cumulative concentration-effect curves were performed on vessel rings beginning at their optimum resting zone. EC50 and maximal response (Emax) were calculated by using nonlineal logistic regression analysis with the software PRISM (Graphpad, Mountain View, CA). RESULTS: CPB inhibited endothelium-dependent relaxation to acetylcholine in pulmonary arterial rings, but did not affect SNP induced relaxation in ones. CONCLUSIONS: The Ability of pulmonary arterial relaxation after CPB and reperfusion in pigs was decreased without attenuated pulmonary arterial sensitivity to NO.

The Effect of Pretreatment with Thiopental on Reducing Pain Induced by Rocuronium Injection

We examined whether pretreatment with a small dose of thiopental was effective in reducing pain induced by the intravenous injection of rocuronium. Withdrawal movement was used to assess pain reduction. Ninety patients were randomly assigned to one of two groups: patients in the control group were pretreated with 2 mL saline, and those in the thiopental group were pretreated with 2 mL (50 mg) thiopental. Thiopental 5 mg/kg was injected intravenously. After a loss of consciousness, the upper arm was compressed with a rubber tourniquet, and the pretreatment drugs were administered. Thirty seconds later the tourniquet was removed and 0.6 mg/kg rocuronium was administered. Withdrawal movement was assessed using a four-grade scale: no movement, movement limited to the wrist, to the elbow or to the shoulder. The frequency of withdrawal movement in the group pretreated with thiopental was lower than in the control group (34 vs. 13, p 0.05). We concluded that pretreatment with 2 mL (50 mg) thiopental is effective in reducing pain caused by the intravenous injection of rocuronium.

Prejunctional Phenomenon during Succinylcholine Onset in Cats / 대한마취과학회지

BACKGROUND: Succinylcholine (Sch) has been generally reported not to produce tetanic stimulation fade on train of four in phase I block, except phase II block. But, the prejunctional phenomenon of Sch during onset is rarely reported these days, and so we investigated whether the prejunctional phenomenon of Sch during onset exists in cats. METHODS: We checked train of four ratios (TOF-R) and tetanic fade ratios (TF-R) by using a nerve stimulator before and after 50microgram/kg of Sch less than ED95 was administered, and during recovery in anesthetized cats. We analyzed TOF-R and TF-R before drug administration as a control and during onset and recovery time in order to estimate the statistic significance of fade. RESULTS: TOF fade and tetanic stimulation during the onset of Sch appeared like those in the partial block of nondepolarizing neuromuscular blockades TOF-R and TF-R during Sch onset compared with those in control and recovery time of Sch had statistical significance (P <0.05). CONCLUSIONS: The prejunctional phenomenon appeared only during Sch onset in cats and then disappeared during recovery to the control level.

The Potentiation of the Analgesic Effect of Intrathecally Coadministered Magnesium Sulphate and Bupivacaine in Duration of Sensory Blockade in Rats / 대한마취과학회지

BACKGROUND: Based on previously reported articles, magnesium sulphate seemed to cause a motor paralysis, but not complete analgesia when administered intrathecally alone, but is likely to have a partial analgesic effect. Accordingly, we tested a hypothesis that magnesium sulphate might potentiate the analgesic effect when coadministered intrathecally with bupivacaine. METHODS: Eighteen male Sprague-Dawley rats were allocated into three groups of six animals each. The duration of sensory blockade was determined by observing the period when the animal did not vocalize and/or withdraw (struggle) while forceps-pinch tests were applied to a hindlimb paw. The six animals in each of the following three groups were injected intrathecally with 0.03 ml of the different test substances: (group 1) 16.7% magnesium sulphate {50% magnesium sulphate (0.01 ml) + 0.9% sodium chloride (0.02 ml)}; (group 2) 50% magnesium sulphate (0.01 ml) + 0.5% bupivacaine (0.02 ml); (group 3) 0.33% bupivacaine {0.5% bupivacaine (0.02 ml) + 0.9% sodium chloride (0.01 ml)}. RESULTS: Sensory blockade in the hindlimbs was observed only in group 2 and lasted for 12 to 14 minutes, while there were no sensory blockades in group 1 and group 3. CONCLUSIONS: Magnesium sulphate potentiated the analgesic effect of bupivacaine when coadministered intrathecally with bupivacaine in rats. These results suggest that intrathecal administration of magnesium sulphate may be a useful adjunct to spinal bupivacaine anesthesia.

Non-invasive Positive Pressure Ventilation for Pulmonary Edema in Kidney Transplanted Patient / 대한마취과학회지

Non-invasive positive pressure ventilation (NIPPV) was mainly applied to acute respiratory failure in chronic obstructive pulmonary disease (COPD) and to intrinsic lung disease such as neuromuscular disorders. It has been reported that this maneuver reduces morbidity, mortality and hospital stay in patients in the intensive care unit. We observed a 32-year-old female renal transplantation patient who developed pulmonary edema during the perioperative state. The mainteance of an endotracheal tube in intubated patients who were on immunosuppresive therapy might increase nosocomial pneumonia significantly. In this case, the mortality increase was expected, therefore we considered that early extubation and mask continuous positive airway pressure (mask CPAP) could help. By using mask CPAP, the patient showed a good response and the pulmonary edema was improved. We report a case about the benefits of NIPPV in the treatment of pulmonary edema in an immunosuppressed patient of which the result was very satisfactory.

Hemodynamic Effect of Pulmonary Artery Ligation during Pneumonectomy / 대한구급학회지

BACKGROUND: Pulmonary artery ligation during pneumonectomy increase the pulmonary blood flow of dependent lung and may increase the pulmonary arterial pressure and pulmonary vascular resistance. The purpose of this study is to evaluate the hemodynamic effect of pulmonary artery ligation during pneumonectomy. METHODS: Nine patients who were supposed to receive pneumonectomy were studied. Hemodynamic measurements were performed following two lung ventilation (TLV), one lung ventilation (OLV), after pulmonary artery ligation and after pneumonectomy. RESULTS: There is no significant differences in heart rate, systemic arterial pressure, pulmonary arterial pressure, pulmonary capillary wedge pressure, cardiac index and pulmonary vascular resistance index. Arterial oxygen tension significantly reduced during OLV and increased after pulmonary artery ligation and after pneumonectomy. CONCLUSIONS: These results suggest that pulmonary artery ligation during pneumonectomy may not affect the cardiopulmonary hemodynamics.

On the Accuracy of Cervicothoracic Vertebral Level Determination by Palpation of Spinous Processes / 대한마취과학회지

BACKGROUND: The C7-T1 interspinous space is commonly chosen for cervical epidural blockade, usually regarding the vertebral prominence as C7. But determining the vertebral prominence itself is confusing and unreliable because of individual variances. For this reason, we decided to look into the accuracy of estimating segmental level from palpating the surface anatomy. METHODS: 1. When the neck was flexed in the sitting position, cervical spinous processes were palpated and the first and most prominent spinous processes were marked. 2. In the same position, the estimated location of the C7 vertebral spinous process was marked, counting cephalads from the lower end of scapular (known to be at the T7 level, customarily). 3. By using the radiologic imaging method, actual cervical vertebral levels were confirmed and the results were compared with the vertebral spinous processes palpated and marked by the above methods. RESULTS: The first prominent spinous process was most commonly the C6 spinous process in both male and female subjects. The most prominent spinous processes palpated were C7 in males and C6 in females in the largest number of subjects. Estimates from the lower end of the scapular were correct in only 47.2% of cases. CONCLUSIONS: Because of considerable individual variances, estimates from the surface references can be incorrect in many circumstances, and radiologic imaging methods are suggested for the correct determination of the cervical vertebral levels.

On the Accuracy of Cervicothoracic Vertebral Level Determination by Palpation of Spinous Processes / 대한마취과학회지

BACKGROUND: The C7-T1 interspinous space is commonly chosen for cervical epidural blockade, usually regarding the vertebral prominence as C7. But determining the vertebral prominence itself is confusing and unreliable because of individual variances. For this reason, we decided to look into the accuracy of estimating segmental level from palpating the surface anatomy. METHODS: 1. When the neck was flexed in the sitting position, cervical spinous processes were palpated and the first and most prominent spinous processes were marked. 2. In the same position, the estimated location of the C7 vertebral spinous process was marked, counting cephalads from the lower end of scapular (known to be at the T7 level, customarily). 3. By using the radiologic imaging method, actual cervical vertebral levels were confirmed and the results were compared with the vertebral spinous processes palpated and marked by the above methods. RESULTS: The first prominent spinous process was most commonly the C6 spinous process in both male and female subjects. The most prominent spinous processes palpated were C7 in males and C6 in females in the largest number of subjects. Estimates from the lower end of the scapular were correct in only 47.2% of cases. CONCLUSIONS: Because of considerable individual variances, estimates from the surface references can be incorrect in many circumstances, and radiologic imaging methods are suggested for the correct determination of the cervical vertebral levels.