Liver Function and Inhaled Anesthetics

The liver is the major site of endogenous and exogenous drug metabolism. The primary result of drug metabolism is the production of more water-soluble and therefore more easily excreted drug metabolites. Drugs are sometimes biotransformed into more reactive metabolites, which may lead to toxicity. Volatile anesthetics, like most drugs, undergo metabolism in the body and are sometimes associated with toxic reactions. Here, author will discuss the metabolism and hepatic toxicity of inhaled anesthetics. Toxicity and liver injury have been reported after repeated exposure on subsequent occasions to different fluorinated anesthetics. This phenomenon of cross-sensitization has also been reported with the chlorofluorocarbon(CFC) replacement agents, the hydrochlorofluorocarbons(HCFCs). Halothane, enflurane, sevoflurane, isoflurane, desflurane are all metabolized to trifluoroacetic acid, which have been reported to induce liver injury in susceptible patients. The propensity to produce liver injury appears to parrel metabolism of the parent drug: halothane(20%) >>>> enflurane(2.5%) >> sevoflurane(1%) > isoflurane(0.2%) > desflurane(0.02%). The use of any anesthetic must be based on its benefits and risks, how it may produce toxicity, and in which patients it may be most safely administered. Nonhalogenated inhaled anesthetics (nitrous oxide, xenon) chemically inert and not metabolized in human tissue. The perfect anesthetic agents dose not exist. But ongoing research attempts to uncover emerging toxicities. Xenon is not currently approved for clinical use. Other than the expense associated with its use, it may be the most ideal anesthetic agent. In general, surgical manipulation or disturbance of the surgical site appears to be more important in decreasing hepatic blood flow than current anesthetic agents such as isoflurane, sevoflurane, and desflurane or technique. However, the clinician is challenged to balance new information with current clinical practices and choice the safest, most effective agents for each patient.ope

A Questionnaire Survey of Domestic Anesthesiologists on the Ethics of Publishing.

BACKGROUND: The importance of publication ethics has recently been emphasized.Therefore, inquiries regarding dual publications were analyzed to obtain basic data on whether domestic anesthetists recognized its importance and understood its practicalities. METHODS: The data for the questionnaire was collected from doctors who participated in a review workshop with full consent. A total of 15 questions were classified into 3 categories:a general interest regarding the ethics of publication, personal objective opinions and reactivity toward an illegal act in this regard. RESULTS: Thirty-eight participants responded spontaneously to the questionnaire.Thirty-six participants were aware of the principle of dual publications and 35 participants were aware of the contents in the home page.Twenty participants had contact with lectures or other media related to redundant publishing.Fourteen participants answered 'yes' regarding their colleague in an illegal action.However, 25 participants said that they were prepared to report an illegal act to the department or society.Only 5 participants tried to take into consideration ethical issues of dual publication while 15 participants were tempted regarding dual publication while writing a paper.Twenty-seven participants agreed with the principle of duplicate or illegal publication.Thirty participants were prepared to have a consistent attitude toward any individual that committed a violation against publication ethics.Nineteen participants worried about the possibility of exposure of an illegal publication. CONCLUSIONS: According to the development of a watch system, dual publication can easily be detected. Regular education regarding publication ethics and notification to members to prevent an illegal act is necessary.ope

Cannulation of the dorsal radial artery: an underused, yet useful, technique.

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Effects of Epidural Naloxone on Pruritus Induced by Epidural Sufentanil

Background Postoperative pruritus following the administration of epidural narcotics is a very common and undesirable side effect. Therefore, we evaluated the use of a combination of naloxone and sufentanil via patient controlled epidural analgesia to determine if the incidence of pruritus was decreased when compared to the use of sufentanil alone. Methods Patients scheduled for subtotal gastrectomy under general anesthesia were enrolled in a prospective, double-blinded and randomized trial. All patients received a 20 µg epidural bolus of sufentanil in 5 ml of 0.2% ropivacaine. Following administration of the epidural, patients in the sufentanyl group (S) received a continuous epidural comprised of sufentanil (0.75 µg/ml) in 0.2% ropivacaine, whereas patients in the naloxone group (N) received an epidural infusion comprised of naloxone (4 µg/ml) and sufentanil (0.75 µg/ml) in 0.2% ropivacaine. The infusion rate, demand dose and lockout interval were 5 ml/hr, 0.5 ml and 15 minutes respectively. Next, the occurrence of postoperative analgesia and side effects were evaluated by blinded observers. Results The incidence of pruritus (47.4% versus 20.0%, P = 0.013) and nausea (42.1% versus 20.0%, P = 0.043) were lower in group N than in group S. In addition, there were no significant differences observed in the visual analogue scale, the incidence of vomiting or the incidence of sedation. Furthermore, epidural infusion of naloxone at 0.25-0.4 µg/kg/hr did not affect the requirement for postoperative sufentanil. Conclusions Epidural naloxone reduces epidural sufentanil induced pruritus and nausea without reversing its analgesic effects.ope

Anesthesia for Living Related Liver Transplantation in Argininosuccinic Acidemia: A case report

We describe our initial experience of the perioperative anesthetic care provided to 8 years old female child with argininosuccinic acidemia undergoing living-related liver transplantation because it is the only available therapy for end-stage liver disease. Induction and maintenance of anesthesia has been conventional method. Arterial catheterized at radial and femoral arteries for continuous blood pressure monitoring and sampling. 18 G central vein catheterization was placed in left subclavian vein for fluid, drug infusion and CVP monitoring. EKG, pulse oxymetry, end-tidal CO2, urine output and body temperature were monitored. CBC, PT, aPTT, serum electrolyte were checked at preanhepatic, anhepatic phase and just after hepatic artery anastomosis. ABGA was checked every 1 hour. The level of serum ammmonia returned to normal range without protein restriction. We describe this case and a brief review of the literature.ope

Central Venous Pressure and Its Effect on Blood Loss During Hepatic Lobectomy

Background Some studies reported that lowering central venous pressure (LCVP) during liver resection could significantly reduce the intra-operative blood loss, however it is still controversial concerning LCVP induced renal dysfunction, hypovolemia, hemodynamic instability. This study evaluated the association of low central venous pressure with blood loss during liver resection comparing the control group. Methods A total 62 patients aged 20 to 70 underwent hepatectomy by the same group of surgeon were randomized into group L (CVP 10 mmHg, n = 32) during dissection and lobectomy period. Data such as age, sex, concurrent disease, liver resection site (right or left), pre-, intra- and postoperative day 3 hemoglobin, blood urea nitrogen, creatinine, bleeding time, prothrombin time, activated partitial thromboplastin time, intraoperative blood loss, urine output, transfusion volume, length of hospital stay were collected and compared between the two groups and t-test was used for comparison of results. Results The difference of total blood loss between two groups was 193.6 ± 432.2 ml (group L; 589.1 ± 380.8 ml, group C; 782.7 ± 316.7 ml), however statistically insignificant (P value = 0.1243). Additionally, there were no significant differences in other data including the length of hospital stay. Conclusions Our results suggest maintaining CVP under 10 mmHg is not effective in reducing blood loss during liver resection.ope

Ventricular arrhythmia in patients with prolonged QT interval during liver transplantation: two cases report.

QT interval prolongation is associated with an increased risk of ventricular arrhythmia in various conditions. Cardiac electrophysiologic abnormalities including QT interval prolongation are well documented in patients with advanced liver cirrhosis. We report two cases of patients with QT interval prolongation on preoperative electrocardiography who exhibited repetitive ventricular arrhythmias with significant hemodynamic deterioration during liver transplantation. For the treatment and prevention of ventricular arrhythmias during the intraoperative period, we performed intravenous administration of lidocaine and isoproterenol, corrected imbalances of electrolytes including potassium and magnesium, and prepared a defibrillator. These cases emphasize that preoperative recognition of QT interval prolongation and adequate management to prevent fatal arrhythmias are important in patients undergoing liver transplantation.ope

Effects of Reactive Oxygen Species on ATP-Induced Intracellular Ca2+ Activity in Osteoblasts

Background: The physiological activity of osteoblsts is known to be closely related to increased intracellular Ca2+ activity ([Ca2+]i) in osteoblasts. The cellular regulation of ([Ca2+]i) in osteoblasts is mediated by Ca2+ movements associated with Ca2+ release from intracellular Ca2+ stores, and transmembrane Ca2+ influx via Na+-Ca2+ exchanger, and Ca2+ ATPase. Reactive oxygen species, such as H2O2, play an important role in the regulation of cellular functions, and act as signaling molecules or as toxins in cells. Methods: Osteoblasts were isolated from the femurs and tibias of neonatal Sprague-Dawley rats, and cultured for 7 days. The cultured osteoblasts were loaded with a Ca2+-sensitive fluorescent dye, Fura-2 AM ester, and fluorescence images were monitored using a cooled CCD camera. Ca-spike changes upon ATP application were checked for (1) osteoblasts in Ca2+-free and 2.5 mM CaCl2 normal Tyrode solution, (2) osteoblasts in which the Ca2+ of the endoplastic reticulumin had been depleted with ryanodine, thapsigargin ord caffein, and (3) osteoblasts pretreated with H2O2, in which the expression of IP3 receptor was checked by Western blotting. Results: ATP increased intracellular free Ca2+ regardless of extracellular Ca2+ concentration. When the intracellular Ca2+ store was depleted, the level of increased Ca2+ activity by ATP was suppressed. H2O2 sustained the Ca2+ increase induced by ATP. The expression of IP3 receptor was enhanced by H2O2. Conclusions: H2O2 modulates intracellular Ca2+ activity in osteoblasts by increasing Ca2+ release from the intracellular Ca2+ stores.ope

Anesthetic management in a patient with severe primary pulmonary hypertension with right ventricular dysfunction

Primary pulmonary hypertension is characterized by progressive increase in pulmonary vascular resistance leading to right ventricular (RV) failure and death. The desirable goal of primary pulmonary hypertension is preserving coronary perfusion of RV while decreasing pulmonary arterial pressure with selective pulmonary vasodilators. We report a case in which anesthetic management was successfully performed in a 67 years old man, who had experienced ventricular tachycardia at the previous anesthesia induction, with severe pulmonary hypertension and right ventricular dysfunctionope

Airway Management for General Anesthesia in a Patient with Severe Trismus due to Temporomandibular Joint Ankylosis

An ankylosis of temporomandibular joint (TMJ) can cause severe trismus, thus it may bring on many difficulties in airway management such as orotracheal intubation or laryngeal mask airway insertion. Such difficulties may cause serious complications related to airway management because the trismus due to ankylosis of TMJ can not be improved by administration of muscle relaxants or deep anesthesia in most cases.We report a case of nasotracheal intubation guided by a fiberoptic bronchoscope in a male patient with severe trismus due to TMJ ankylosis, who was scheduled for undergoing ophthalmic surgeryope