Fatal isoflurane hepatotoxicity without re-exposure.

Isoflurane is less hepatotoxic than its predecessors, halothane and enflurane. We present a 68-year-old man who developed fulminant and fatal hepatic necrosis two days after open cholecystectomy done under isoflurane anesthesia. Laboratory findings included grossly elevated transaminases and bilirubin and prolonged prothrombin time. Serological studies were negative for viral hepatitis. Postmortem examination demonstrated centrilobular necrosis of liver.     

Effect of isoflurane on skin-pressure-induced vasodilation

Since general anesthesia has been shown to attenuate endothelium-dependent vasodilation, it was of interest to verify whether general anesthesia would modify skin vasodilation in response to local pressure application, which is endothelium dependent. To study the effect of general anesthesia on pressure-induced vasodilation development, we examined the effects of low- and high-dose isoflurane. Skin blood flow was measured by laser Doppler flowmetry during 11.1 Pa s(-1) increases in locally applied pressure in anesthetized rats treated with low or high doses of isoflurane. Following the administration of low doses of isoflurane, skin blood flow increased from baseline, with increasing local pressure application (+37 +/- 10% at 2.0 kPa). The increase in skin blood flow was absent in rats treated with high doses (-20 +/- 5% at 2.0 kPa), even when the anesthesia-induced hypotension was corrected by gelofusine infusion (-20 +/- 10% at 2.0 kPa). Whereas sodium-nitroprusside-induced vasodilation developed following low and high doses of isoflurane, acetylcholine-induced vasodilation was impaired with high doses compared to low doses. These data show that pressure-induced vasodilation is abolished with high doses of anesthetics. It is not the anesthesia-induced hypotension, but the depth of anesthesia, which can lead to the disappearance of pressure-induced vasodilation by an alteration in endothelial function.     

Even low-grade inflammation impacts on small intestinal function

Independent of the cause and location,inflammation-even when minimal-has clear effects on gastrointestinal morphology and function.These result in altered digestion,absorption and barrier function.There is evidence of reduced villus height and crypt depth,increased permeability,as well as altered sugar and peptide absorption in the small intestine after induction of inflammation in experimental models,which is supported by some clinical data.Identification of inflammatory factors which may promote the process of gastrointestinal dysfunction as well as clinical research to verify experimental observations of inflammatory modulation of gastrointestinal function are required.Moreover,nutritional strategies to support functional restitution are needed.     

Even with other options, patients overuse ERs

A California study shows that clinicians need to educate HIV-infected patients about when to contact their physicians instead of automatically going to the emergency room when faced with a health crisis. Patients often use the emergency department instead of visiting their regular doctor, even for common symptoms such as tension headaches, concludes the study published in the December 2000 issue of the Journal of General Internal Medicine.     

Even in culture, oligodendrocytes myelinate solely axons.

Cerebral hemispheres from mouse embryos at 15 days of gestation were dissociated and maintained in culture for several weeks in a medium which permitted homochronic and homotypic oligodendrocytes and neurons to interact in the presence of other central nervous system cells. After 13-14 days in culture a few oligodendrocytes changed from highly branched, "sun-like," nonmyelinating cells to sparcely branched myelinating cells. The number of fibers myelinated per oligodendrocyte ranged from 1 to 10, similar to that described previously in vivo in the corpus callosum. When an oligodendrocyte began to myelinate, it immediately myelinated a maximum number of fibers, suggesting that the number of axons to be myelinated by the oligodendrocyte was predetermined. When only one fiber was in the vicinity of a myelinating oligodendrocyte, whorls of myelin-like figures were seen at the tip of oligodendrocyte processes that had not reached an axon. Myelinated fibers were unambiguously identified as axons both by immunostaining and by electron microscopy. Myelin was not observed around astrocyte processes or around dendrites. The exclusive myelination of axons suggests the existence of a specific axonal recognition signal which attracts oligodendrocyte processes.     

Comparison of sevoflurane and isoflurane in OPCAB surgery

Maintenance of anaesthesia with volatile anaesthetic agents affects the perioperative course of patients undergoing off-pump coronary artery bypass (OPCAB) surgery. This facilitates adequate depth of anaesthesia, reduction in need of analgesic dosage, early extubation and transfer from Intensive Care Unit. We compared two volatile anaesthetic agents sevoflurane and isoflurane in terms of haemodynamic effects, amount of analgesic needed during surgery, quantity of agent needed for maintenance of anaesthesia and postoperative recovery in 40 patients undergoing OPCAB surgery. Anaesthesia was induced with fentanyl, midazolam and thiopentone, and vecuronium was used for muscle relaxation. An Octopus stabiliser was used and coronary anastomosis was performed using internal mammary artery and saphenous vein grafts. Routine monitoring was performed. The depth of anaesthesia was monitored using Bispectral index monitor. The inspired/expired concentration of anaesthetic agents to maintain the desired BIS and the amount of volatile anaesthetic agent needed was also noted. The amount of analgesic used intraoperatively was noted in both the groups. The 'time of awakening' defined as eye opening on verbal commands, and time of extubation were noted. There were no differences in haemodynamic parameters, depth of anaesthesia, and quantity of agent needed, but patients in isoflurane group required more intraoperative analgesics than sevoflurane group. Time of awakening (48+/-13 vs 114 +/- 21 mins; P < 0.001) and subsequent extubation (124 +/- 25 vs 177 +/- 36 mins, P<0.001) was earlier in sevoflurane group than isoflurane group. There was no evidence of perioperative myocardial infarction in both the groups. We conclude that sevoflurane and isoflurane can both be safely used in OPCAB surgery, but the awakening and extubation times are significantly less with sevoflurane.     

Thyroid function during isoflurane anesthesia and valvular heart surgery

Proper thyroid function is essential for maintaining cardiovascular integrity during normal and stressful situations. In this study, the effects of isoflurane-O₂ anesthesia and surgical stress on serum TSH, T₄, free T₄, T₃, rT₃ and cortisol were investigated in nine patients before, during, and after valve surgery. Compared with preoperative control values, serum TSH decreased in the postoperative period. Both T₄ and free T₄ had similar decreases after cardiopulmonary bypass (CPB) and remained depressed postoperatively. Both T₃ and rT3 decreased at the start of cardiopulmonary bypass; T₃ remained low in the postoperative period, while rT₃ increased. Cortisol decreased during anesthesia and surgery in the prebypass period, but increased during cardiopulmonary bypass and in the postoperative period. The results suggest that isoflurane-O₂ anesthesia during valve surgery produces a rapid decrease in T₃, resulting in the low T₃ syndrome postoperatively. Isoflurane, in the dose studied, similar to fentanyl, can suppress the cortisol response to anesthesia and surgery in the prebypass period, but not during and after CPB.     

异氟醚预处理对心肌缺血再灌注损伤的保护作用

目的:观察异氟醚预处理对体外循环心内直视手术心肌的保护作用。方法:20例瓣膜置换术患者(ASA 2～3 级),随机分为预处理组(Ⅰ组)和对照组(C组)。分别于麻醉后(T_1),主动脉开放后15分钟(T_2)、2小时(T_3)、24小时(T_4)时间点取血样,检测血清CGRP、ET、cTnI;另于术前、术后第1、3天记录同步12导联心电图.测定其QTd和 QTcd。结果:主动脉开放后,CGRP含量在两组患者24小时之内都有显著增加(P<0.01),T_2时,预处理组的CGRP水平明显高于对照组的(P<0.05);ET在T_2时两组都有显著上升(P<0.01),但预处理组的上升幅度明显低于对照组(P<0.05);T3、T4时,对照组cTnI水平显著高于预处理组;术后两组QTd和 QTcd显著增加(P<0.01),其中对照组的增加较多,且第1天明显多于预处理组(P<0.05);结论:异氟醚预处理能减少心肌的缺血再灌注损伤,降低术后心律失常发生率,有利体外循环后心功能恢复。     

Effect of emulsified isoflurane on apoptosis of anoxia-reoxygenation neonatal rat cardiomyocytes

ObjectiveTo explore the effect of emulsified isoflurane (EI) on apoptosis of anoxia-reoxygenation neonatal rat cardiomyocytes and relevant protein expression.MethodsCardiac muscle anoxia-reoxygenation damage model was established with culture in vitro neonatal rat cardiomyocytes. The cardiomyocytes were divided into control group, model group, fat emulsion group and EI group. The cardiomyocytes apoptosis rates and lactic dehydrogenase (LDH), superoxide dismutase (SOD) and malondialdehyde (MDA) index standardization were detected after relevant treatment. The expression of apoptosis-related proteins Bel-2, Bax and Caspase-3 were detected with Western blot approach.ResultsAfter hypoxia/reoxygenation (H/R) model was treated by EI, the cells apoptosis rate decreased and was dramatically below the fat emulsion group (P<0.05). Cardiomyocytes biochemical index detection presented that, compared with the control group that the LDH activity and MDA content dramatically increased (P<0.05), while the SOD activity notably decreased (P<0.05); compared with the H/R group, the SOD activity of the fat emulsion group and EI group increased (P<0.05); while the LDH activity and MDA content decreased (P<0.05). And the change of the EI group was more remarkable than the fat emulsion group (P<0.05). The Western blot analysis presented that, compared with the control group, the Bcl-2 protein expression of the other groups significantly decreased (P<0.05), the expressions of Bax protein and Caspase-3 protein increased significantly (P<0.05); compared with H/R group, cardiomyocytes Bcl-2 protein expression of EI group increased significantly (P<0.05), the expressions of Bax protein and Caspase-3 protein decreased significantly (P<0.05), and the change of EI group was more remarkable than the fat emulsion group (P<0.05).ConclusionsEI can inhabit the apoptosis of anoxia-reoxygenation damage model cardiomyocytes, and may be related to the up-regulation of expression of Bcl-2 and down-regulation of expression of Caspase-3 protein.     

Enflurane and isoflurane inhibit the oxidative activity of pulmonary alveolar macrophages

Enflurane and isoflurane, widely used general anesthetic agents, were shown to significantly inhibit the microbicidal oxidative activity of pulmonary alveolar macrophages (PAM) at clinically relevant concentrations. This inhibition was reversible, as exposing the anesthetic-treated PAM to air for 30 min completely removed any depression of oxidative activity. Using chemoluminigenic probes to analyze the generation of oxidative metabolites, a significant reduction in superoxide anion (O-2) production was found in PAM exposed to enflurane or isoflurane.     

Questioning,and Maybe Even Shaking Up,The Interventional Approach to STEMI

• A drug‐coated balloon (DCB) in the setting of a STEMI may have long‐term advantages that overshadow the risk of not stenting the vessel.
• Conversely, a temporary or permanent scaffold may be critical in the setting of a STEMI.
• The rationale for the trial is bold, sound, and the human subjects are well‐protected.