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Halothane, isoflurane and desflurane are metabolized to hepatotoxic trifluoroacetyl proteins. But sevoflurane is metabolized to hexafluoroisopropanol. Hexafluoroisopropanol has a low binding affinity for liver protein and is therefore rapidly converted to glucuronidate that are excreted in the urine. Thus sevoflurane has been considered to have a very low potential for hepatotoxicity. We report a case of a 67 years old woman who developed acute hepatic dysfunction after sevoflurane anesthesia.

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. (Korean J Anesthesiol 2008; 54: 12∼7)

A 28-year old woman in DM (Ed note: Define DM) and chronic renal failure underwent an uneventful open reduction and internal fixation for an ankle fracture under spinal anesthesia. PCA with fentanyl and tramadol was started in the operating room with a background infusion of 2 ml/hr (10 μg/h of fentanyl and 6 mg/h of tramadol), a bolus dose of 2 ml and a lockout interval of fifteen minutes. Approximately eight hours after initiating PCA the patient was found unresponsive in the ward with respiratory failure. Resuscitation was started with endotracheal intubation and cardiac massage with an injection of epinephrine and atropine. The patient made a full and immediate recovery two hours later.

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 α1 adrenergic and non-α1 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). EC50s and maximal responses (Emax) were calculated by nonlinear logistic regression analysis with PRIZM software (Graphpad, Mountain View, CA). Results: Simulated microgravity results in attenuated contractile responses to both α1 adrenergic and non-α1 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. (Korean J Anesthesiol 2008; 55: 602～6)

Pneumothroax may occur during and after general anesthesia unexpectedly, and the diagnosis may be difficult when the manifestations are non-specific. An early diagnosis and treatment is important to prevent tension pneumothorax. Pneumothorax can be occurred from injury to the chest wall, airway, lung, and diaphragm. We report a case of a 50-year-old female patient who underwent segmentectomy of liver under general anesthesia and developed pneumothorax after restoration of spontaneous respiration from unexpected diaphragm injury. (Korean J Anesthesiol 2008; 55: 765～8)

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 β-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. (Korean J Anesthesiol 2007; 53: 222～8)

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. (Korean J Anesthesiol 2007; 52: 132～7)

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 and maximal response () 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.

Background: Video-assisted thoracic surgery (VATS) is widely used as a less invasive procedure for thoracic surgery. However, there is still significant postoperative pain, although less severe than with conventional thoracic surgery. The aim of this study was to assess the efficacy of an interpleural block and a paravertebral block for postoperative pain control and the recovery of the pulmonary function. Methods: Fifty-one patients with similar demographic and preoperative physiologic parameters were divided randomly into interpleural or thoracic paravertebral block groups. The visual analogue pain score (VAS) was assessed at 30 min, and 2, 6, 12, and 24 hours after surgery and the forced vital capacity was tested preoperatively, the pulmonary function was evaluated at 30 min, and 2, 6, 12, and 24 hours. Results: The pain scores were significantly lower in the paravertebral block group at 30 min, 2, 6 and 12 hours after surgery during rest (6.4 1.8, 5.1 1.1, 4.2 1.5, 2.8 0.8 vs 2.9 1.8, 2.5 1.6, 2.1 1.6, 1.9 1.7, P ＜ 0.05), and only within 2 hours after operation for coughing (7.8 1.0, 6.4 0.8 vs 4.7 2.2, 4.2 2.1, P ＜ 0.05) than in the interpleural block group. There was significant recovery of the pulmonary function 30 min, 2, and 6 hours after surgery (32%, 43%, 56%, 67%, 75% vs 59%, 59%, 71%, 75%, 84%, P ＜ 0.05) in the paravertebral block group. Conclusions: A thoracic paravertebral block is more effective in decreasing the level of post-VATS pain, and allows earlier recovery of the forced vital capacity compared with an interpleural block.

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. and maximal response () 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.