DNA damage assessment in peripheral blood of Swiss albino mice after combined exposure to volatile anesthetics and 1 or 2 Gy radiotherapy in vivo.

PURPOSE: Patient immobilization by general volatile anesthesia (VA) may be necessary during medical radiology treatment, and its use has increased in recent years. Although ionizing radiation (IR) is a well-known genotoxic and cytotoxic agent, and VA exposure has caused a range of side effects among patients and occupationally exposed personnel, there are no studies to date comparing DNA damage effects from combined VA and single fractional IR dose exposure. MATERIAL AND METHODS: We investigate whether there is a difference in white blood cells DNA damage response (by the alkaline comet assay) in vivo in 185 healthy Swiss albino mice divided into 37 groups, anesthetized with isoflurane/sevoflurane/halothane and exposed to 1 or 2 Gy of IR. Blood samples were taken after 0, 2, 6 and 24 h after exposure, and comet parameters were measured: tail length, tail intensity and tail moment. The cellular DNA repair index was calculated to quantify the efficiency of cells in repairing and re-joining DNA strand breaks following different treatments. RESULTS: In combined exposures, halothane caused higher DNA damage levels that were dose-dependent; sevoflurane damage increase did not differ significantly from the initial 1 Gy dose, and isoflurane even demonstrated a protective effect, particularly in the 2 Gy dose combined exposure. Nevertheless, none of the exposures reached control levels even after 24 h. CONCLUSION: Halothane appears to increase the level of radiation-induced DNA damage, while sevoflurane and isoflurane exhibited a protective effect. DNA damage may have been even greater in target organs such as liver, kidney or even the brain, and this is proposed for future study.

The impact of sevoflurane anesthesia on postoperative renal function: a systematic review and meta-analysis of randomized-controlled trials.

PURPOSE: Renal damage secondary to fluoride ions and compound A (CpdA) after sevoflurane anesthesia remains unclear. For safety reasons, some countries still recommend minimum fresh-gas flows (FGFs) with sevoflurane. We review the evidence regarding the intraoperative use of sevoflurane for anesthesia maintenance and postoperative renal function compared with other anesthetic agents used for anesthetic maintenance. Secondarily, we examine the effects of peak plasma fluoride and CpdA levels and the effect of FGF and duration of anesthesia on these parameters. SOURCE: The databases of MEDLINE (OVID and Pubmed), EMBASE, the Cochrane Library, Health Technology Assessment Database, CINAHL, and Web of Science were searched from inception until 23 April 2020 to identify randomized-controlled trials (RCTs) in humans utilizing sevoflurane or an alternative anesthetic for anesthesia maintenance with subsequent measurements of renal function. Two different paired reviewers independently selected the studies and extracted data. The quality of the evidence was appraised using GRADE recommendations. PRINCIPAL FINDINGS: Of 3,766 publications screened, 41 RCTs in human patients were identified. There was no difference between creatinine at 24 hr (21 studies; n = 1,529), or creatinine clearance (CCR) at 24 hr (12 studies; n = 728) in the sevoflurane vs alternative anesthetic groups. Peak fluoride and fluoride measured at 24 hr were higher with sevoflurane compared with other inhaled anesthetics. Subgroup analyses for sevoflurane usage in various contexts showed no significant difference between sevoflurane and alternative anesthetics for creatinine or CCR at 24 hr at varying FGF, duration of exposure, baseline renal function, or absorbent use. CONCLUSIONS: We did not find any association between the use of sevoflurane and postoperative renal impairment compared with other agents used for anesthesia maintenance. The scientific basis for recommending higher FGF with the use of sevoflurane needs to be revisited.

RéSUMé: OBJECTIF: Les lésions rénales secondaires aux ions fluorure et au composé A (CpdA) après une anesthésie au sévoflurane demeurent incertaines. Pour des raisons de sécurité, certains pays recommandent encore des débits de gaz frais (DGF) minimaux lors de l'utilisation du sévoflurane. Nous avons passé en revue les données probantes concernant l'utilisation peropératoire de sévoflurane pour le maintien de l'anesthésie sur la fonction rénale postopératoire comparativement à d'autres agents anesthésiques utilisés pour le maintien de l'anesthésie. En analyse secondaire, nous avons examiné les effets des taux plasmatiques maximaux de fluorure et de CpdA et l'effet du DGF et de la durée de l'anesthésie sur ces paramètres. SOURCE: Des recherches ont été menées dans les bases de données de MEDLINE (OVID et Pubmed), EMBASE, the Cochrane Library, Health Technology Assessment Database, CINAHL et Web of Science, de leur création jusqu'au 23 avril 2020. Nous y avons identifié les études randomisées contrôlées (ERC) réalisées sur des sujets humains utilisant du sévoflurane ou un agent anesthésique alternatif pour le maintien de l'anesthésie et présentant des mesures subséquentes de la fonction rénale. Deux différents réviseurs appariés ont sélectionné de manière indépendante les études et extrait les données. La qualité des données probantes a été évaluée à l'aide des recommandations GRADE. CONSTATATIONS PRINCIPALES: Parmi les 3766 publications passées en revue, 41 ERC réalisées chez des patients humains ont été identifiées. Aucune différence n'a été observée en ce qui touchait à la valeur de créatinine à 24 h (21 études; n = 1529) ou de la clairance de la créatinine (CCR) à 24 h (12 études; n = 728) dans les groupes sévoflurane vs autres anesthésiques. Les taux maximaux de fluorure et le fluorure mesuré à 24 h étaient plus élevés lors de l'utilisation de sévoflurane que d'autres agents anesthésiques halogénés. Les analyses de sous-groupe portant sur l'utilisation du sévoflurane dans divers contextes n'ont démontré aucune différence significative entre le sévoflurane et les autres anesthésiques en matière de valeur de créatinine ou de CCR à 24 h selon différents DGF, durées d'exposition, fonctions rénales de base ou absorbants. CONCLUSION: Nous n'avons pas trouvé d'association entre l'utilisation du sévoflurane et des détériorations de la fonction rénale postopératoires par rapport aux autres agents utilisés pour le maintien de l'anesthésie. Les raisons scientifiques sur lesquelles repose la recommandation d'un DGF plus élevé lors de l'utilisation de sévoflurane doivent être réexaminées.

Feasibility, safety, and economic consequences of using low flow anesthesia according to body weight.

BACKGROUND: Low flow anesthesia (LFA) provides a saving up to 75% and improves the dynamics of inhaled anesthesia gas, increases mucociliary clearance, maintains body temperature, and reduces water loss. LFA has been recommended for anesthesiologists in recent years to avoid high fresh gas flow (FGF). However, LFA use is limited due to associated risks. The main purpose of this study was to investigate whether LFA according to body weight, which is the main determinant of oxygen requirement, is feasible and safe in the normoxia range. The second aim was to show that this method can provide economic benefit. METHODS: Eighty donor hepatectomy cases were included to study in two groups as prospective, observational. A surgery room and a team were allocated only for this study. Considering the oxygen requirement (approximately 3-3.5 mL/kg/min), for the first 40 cases, 10 mL/kg (group 10) FGF was applied; for the second 40 cases, 20 mL/kg (group 20) was applied. Desflurane (Suprane©) was used as an inhalation agent, and analgesia was achieved with remifentanil infusion. Patients' demographic, respiratory, hemodynamic, and tissue perfusion parameters (SpO2 and NIRS), and comsumption data (anesthetic agent and CO2 absorbent) were collected and compared. RESULTS: No significant differences were detected between the groups in terms of demographic data, duration of surgery, and hemodynamic, respiratory, and tissue perfusion parameters. These parameters were within normal limits in all patients at all times. The maximum O2 concentration in the FGF that maintained FiO2:0.4 and provided adequate oxygenation during the LFA was 61% (min 56%; max 67%) in group 10, and 47% (min 43%; max 51%) in group 20. The hourly anesthetic agent consumption was significantly different in group 10 than in group 20 (12.4 ± 4 mL vs. 21.5 ± 8 mL/h, respectively (p < 0.001). CONCLUSIONS: We performed 10 mL/kg FGF speed without deviating from the safety limits to be FiO2:0.4 in donor hepatectomies, reducing the total costs 38% compared with 20 mL/kg FGF.

Sevoflurane Consumption During Inhalational Induction in Children: A Randomized Comparison of Minute Ventilation-Based Techniques With Standard Fixed Fresh Gas Flow Technique.

This study was done to ascertain the optimum fresh gas flow (FGF) offering the best balance between rapid induction and minimal waste in pediatric patients. Forty-five children (weighing 10-20 kg) undergoing elective procedures under general anesthesia were randomly assigned into 3 groups: 0.5 minute ventilation (MV), MV, and S (FGF = 6 L/min). After priming the pediatric closed circuit, anesthesia was induced using a face mask with 8% sevoflurane in 100% oxygen (Draeger Primus Vista 120 anesthesia machine) at FGF-determined MV per group allocation. After loss of eyelash reflex (time 1 [T1]), intravenous cannulation (T2) and laryngeal mask airway (LMA) placement (T3) were done. Total sevoflurane consumed during induction (measured using logbook function) was the primary outcome. The cost of sevoflurane, any reflex movement, tachycardia (heart rate change > 20%), or additional propofol boluses required were also recorded. Sevoflurane consumption (3.8 vs 5.8 vs 9.2 mL) and cost of sevoflurane (104.2 vs 199.4 vs 312.8 rupees) were lowest in group 0.5 MV (P < .001). There was no difference in hemodynamic parameters, movement on cannulation/LMA insertion, and rescue propofol boluses required. For pediatric sevoflurane induction, half the MV-based FGF provided similar anesthetic conditions for LMA insertion with minimum sevoflurane consumption.

European Society of Anaesthesiology Task Force on Nitrous Oxide: a narrative review of its role in clinical practice.

Nitrous oxide (N2O) is one of the oldest drugs still in use in medicine. Despite its superior pharmacokinetic properties, controversy remains over its continued use in clinical practice, reflecting in part significant improvements in the pharmacology of other anaesthetic agents and developing awareness of its shortcomings. This narrative review describes current knowledge regarding the clinical use of N2O based on a systematic and critical analysis of the available scientific literature. The pharmacological properties of N2O are reviewed in detail along with current evidence for the indications and contraindications of this drug in specific settings, both in perioperative care and in procedural sedation. Novel potential applications for N2O for the prevention or treatment of chronic pain and depression are also discussed. In view of the available evidence, we recommend that the supply of N2O in hospitals be maintained while encouraging its economic delivery using modern low flow delivery systems. Future research into its potential novel applications in prevention or treatment of chronic conditions should be pursued to better identify its role place in the developing era of precision medicine.

Efficacy of Malignant Hyperthermia Association of the United States-Recommended Methods of Preparation for Malignant Hyperthermia-Susceptible Patients Using Dräger Zeus Anesthesia Workstations and Associated Costs.

BACKGROUND: The objective of this study was to assess the efficacy and cost of Malignant Hyperthermia Association of the United States-recommended methods for preparing Dräger Zeus anesthesia workstations (AWSs) for the malignant hyperthermia-susceptible patient. METHODS: We studied washout profiles of sevoflurane, isoflurane, and desflurane in 3 Zeus AWS following 3 preparation methods. AWS was primed with 1.2 minimum alveolar concentration anesthetic for 2 hours using 2 L/min fresh gas flow, 500 mL tidal volume, and 12/min respiratory rate. Two phases of washout were performed: high flow (10 L/min) until anesthetic concentration was <5 parts per million (ppm) for 20 minutes and then low flow (3 L/min) for 20 minutes to identify the rebound effect. Preparation methods are as follows: method 1 (M1), changing disposables (breathing circuit, soda lime, CO2 line, and water traps); method 2 (M2), M1 plus replacing the breathing system with an autoclaved one; and method 3 (M3), M1 plus mounting 2 activated charcoal filters on respiratory limbs. Primary outcomes are as follows: time to obtain anesthetic concentration <5 ppm in the high-flow phase, peak anesthetic concentrations in the low-flow phase, and for M3 only, peak anesthetic concentration after 70 minutes of low-flow phase, when activated charcoal filters are removed. Secondary outcomes are as follows: cost analysis of time and resources to obtain anesthetic concentration <5 ppm in each method and a vapor-free Zeus AWS. Sensitivity analyses were performed using alternative assumptions regarding the costs and the malignant hyperthermia-susceptible caseload per year. RESULTS: Primary outcomes were as follows: M3 instantaneously decreased anesthetic concentration to <1 ppm with minimal impact of low-flow phase. M1 (median, 88 minutes; 95% confidence interval [CI], 69-112 minutes) was greater than M2 (median, 11 minutes; 95% CI, 9-15 minutes). Means of peak rebound anesthetic concentrations in M1, M2, and M3 were 15, 6, and 1 ppm, respectively (P < .001). Anesthetic concentration increased 33-fold (95% CI, 21-50) after removing charcoal filters (from 0.7 to 20 ppm). The choice of anesthetic agents did not impact the results. Secondary outcomes were as follows: M3 was the lowest cost when the cost of lost operating room (OR) time due to washout was included, and M1 was the lowest cost when it was not included. When the cost of lost OR time due to washout was considered the estimated cost/case of M3 was US $360 (M1, US $2670; M2, US $969; and a "vapor-free" Zeus AWS was US $930). The OR time and equipment costs represent the largest differentiators among the methods. CONCLUSIONS: Institutions in which demand for OR time has exceeded capacity should consider M3, and institutions with surplus OR capacity should consider M1.

Exposure Assessment, Biological Monitoring, and Liver Function Tests of Operating Room Personnel Exposed to Halothane in Hamedan Hospitals, West of Iran.

BACKGROUND: Occupational exposure to halogenated hydrocarbons has been associated with halothane hepatitis, an increase of liver enzymes, and congenital malformations. The objectives of this study were to investigate whether bromide, a urinary metabolite of halothane, could be used as a biological marker of exposure to this anesthetic gas and assessment of associated exposure to halothane with any significant changes in conventional parameters of liver function (serum aminotransferase activities). STUDY DESIGN: A cross-sectional study. METHODS: Seventy-five anesthesiologists, anesthesia nurses, operating room nurses, and surgeons (exposed group) and 75 matched unexposed individuals (reference group) were selected randomly from two public hospitals in Hamadan City, western Iran.  Atmospheric concentrations of halothane in the breathing zone of the exposed subjects and urinary bromide levels were measured by headspace gas chromatography. Similarly, serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured by the enzymatic method using an automatic Prestige instrument. RESULTS: Mean atmospheric concentrations of halothane and urinary bromide levels for exposed subjects were 1.49 ±1.36 ppm and 0.83 ±0.29 mM, respectively. A relatively good correlation was found between exposure to halothane and urinary bromide levels (r=0.38). The chi-squared test results showed that the proportions of the subjects with abnormal ALT and AST among the women exposed were significantly higher than those of reference individuals (P<0.05). CONCLUSIONS: Urinary bromide can be used as a potential biomarker of exposure to halothane, although additional studies are necessary to further validate these initial findings.

Prevalence of malignant hyperthermia diagnosis in hospital discharge records in California, Florida, New York, and Wisconsin.

STUDY OBJECTIVE: Malignant hyperthermia (MH) is a rare yet potentially fatal pharmacogenetic disorder triggered by exposure to inhalational anesthetics and the depolarizing neuromuscular blocking agent succinylcholine. Epidemiologic data on the geographic variation in MH prevalence is scant. The objective of this study is to examine the prevalence of recorded MH diagnosis in patients discharged from hospitals in four states in the United States. DESIGN: Observational study. SETTING: Healthcare Cost and Utilization Project (HCUP) State Inpatient Database (SID) for California (2011), Florida (2011), New York (2012) and Wisconsin (2012). PATIENTS: A total of 164 hospital discharges that had a recorded diagnosis of MH using the International Classification of Disease, 9th Revision, Clinical Modification code 995.86. METHODS: MH prevalence was assessed by patient demographic and clinical characteristics. MAIN RESULTS: The prevalence of MH per 100,000 hospital discharges ranged from 1.23 (95% Confidence Interval [CI], 0.80-1.66) in New York to 1.91 (95% CI, 1.48-2.34) in California, and the prevalence of MH per 100,000 surgical discharges ranged from 1.47 (95% CI, 0.93-2.02) in New York to 2.86 (95% CI, 2.00-3.71) in Florida. The prevalence of MH in male patients was more than twice the prevalence in female patients. Of the 164 patients with MH diagnosis, 11% were dead on discharge. CONCLUSIONS: There exists a modest variation in the prevalence of recorded MH diagnosis in hospital discharges in California, Florida, New York and Wisconsin. Epidemiologic patterns of MH diagnosis in hospital discharges appear to be similar across the four states. Further research is needed to better understand the geographic variation and contributing factors of MH in different populations.

Adverse Events and Resource Utilization After Spinal and General Anesthesia in Infants Undergoing Pyloromyotomy.

BACKGROUND AND OBJECTIVES: Interest in spinal anesthesia (SA) is increasing because of concern about the long-term effects of intravenous (IV) and inhaled anesthetics in young children. This study compared SA versus general anesthesia (GA) in infants undergoing pyloromyotomy. METHODS: Between 2000 to 2013, the University of Vermont Medical Center almost exclusively used SA for infant pyloromyotomy surgery, whereas Columbia University Medical Center relied on GA. Outcomes included adverse events (AEs) within 48 hours of surgery, operating room (OR) time, and postoperative length of stay (LOS). Regression was used to evaluate the association between anesthesia technique and outcomes, accounting for demographic and clinical covariates. RESULTS: We studied 218 infants with SA at the University of Vermont Medical Center and 206 infants with GA at Columbia University Medical Center. In the SA group, 96.3% of infants had adequate initial analgesic levels, but 35.8% required supplemental IV or inhaled anesthetic agents. Compared with GA, the risk of AEs in SA (adjusted odds ratio, 0.60; 95% confidence interval [CI], 0.27-1.36) did not significantly differ, but SA was associated with shorter OR times (17.5 minutes faster; 95% CI, 13.5-21.4 minutes) and shorter postoperative LOS (GA is 1.19 times longer; 95% CI, 1.01-1.40). CONCLUSIONS: Infants undergoing pyloromyotomy with SA had shorter OR times and postoperative LOS, no significant differences in AE rates, and decreased exposure to IV and inhaled anesthetics, although SA infants often still required supplemental anesthetics. Whether these differences result in any long-term benefit is unclear; further studies are needed to determine the risk of rare AEs, such as aspiration.

Economic and Environmental Considerations During Low Fresh Gas Flow Volatile Agent Administration After Change to a Nonreactive Carbon Dioxide Absorbent.

BACKGROUND: Reducing fresh gas flow (FGF) during general anesthesia reduces costs by decreasing the consumption of volatile anesthetics and attenuates their contribution to greenhouse gas pollution of the environment. The sevoflurane FGF recommendations in the Food and Drug Administration package insert relate to concern over potential toxicity from accumulation in the breathing circuit of compound A, a by-product of the reaction of the volatile agent with legacy carbon dioxide absorbents containing strong alkali such as sodium or potassium hydroxide. Newer, nonreactive absorbents do not produce compound A, making such restrictions moot. We evaluated 4 hypotheses for sevoflurane comparing intervals before and after converting from a legacy absorbent (soda lime) to a nonreactive absorbent (Litholyme): (1) intraoperative FGF would be reduced; (2) sevoflurane consumption per minute of volatile agent administration would be reduced; (3) cost savings due to reduced sevoflurane consumption would (modestly) exceed the incremental cost of the premium absorbent; and (4) residual wastage in discarded sevoflurane bottles would be <1%. METHODS: Inspired carbon dioxide (PICO2), expired carbon dioxide, oxygen, air, and nitrous oxide FGF, inspired volatile agent concentrations (FiAgent), and liquid volatile agent consumption were extracted from our anesthesia information management system for 8 4 week intervals before and after the absorbent conversion. Anesthesia providers were notified by e-mail and announcements at Grand Rounds about the impending change and were encouraged to reduce their average intraoperative sevoflurane FGF to 1.25 L/min. Personalized e-mail reports were sent every 4 weeks throughout the study period regarding the average intraoperative FGF (i.e., from surgery begin to surgery end) for each agent. Batch means methods were used to compare FGF, volatile agent consumption, net cost savings, and residual sevoflurane left in bottles to be discarded in the trash after filling vaporizers. The time from reaching a PICO2 = 3 mm Hg for 3 minutes until agent exhaustion (PICO2 = 5 mm Hg for 5 minutes) was evaluated. RESULTS: A total of N = 20,235 cases were analyzed (80.2% sevoflurane, 15.1% desflurane, and 4.7% isoflurane). Intraoperative FGF was reduced for cases in which sevoflurane was administered by 435 mL/min (95% confidence interval [CI], 391 to 479 mL/min; P < 10). Hypothesis 1 was accepted. Sevoflurane consumption per minute of administration decreased by 0.039 mL/min (95% CI, 0.029 to 0.049 mL/min; P < 10) after the change to the nonreactive absorbent. Hypothesis 2 was accepted. The difference in mean cost for the sum of the sevoflurane and absorbent purchases for each of the 10 4-week intervals before and after the absorbent switch was -$293 per 4-week interval (95% CI, -$2853 to $2266; P = 0.81). Hypothesis 3 was rejected. The average amount of residual sevoflurane per bottle was 0.67 ± 0.06 mL (95% CI, 0.54 to 0.81 mL per bottle; P < 10 vs 2.5 mL). Hypothesis 4 was accepted. Once the PICO2 reached 3 mm Hg for at least 3 consecutive minutes, the absorbent became exhausted within 95 minutes in most (i.e., >50%) canisters. CONCLUSIONS: We showed that an anesthesia department can transition to a premium, nonreactive carbon dioxide absorbent in a manner that is at least cost neutral by reducing FGF below the lower flow limits recommended in the sevoflurane package insert. This was achieved, in part, by electronically monitoring PICO2, automatically notifying the anesthesia technicians when to change the absorbent, and by providing personalized feedback via e-mail to the anesthesia providers.

Assessment of nasal mucociliary clearance in anesthetists.

BACKGROUND/AIM: To assess mucociliary clearance in anesthetists who were exposed to waste anesthetic gases occupationally. MATERIALS AND METHODS: The first group consisted of 30 anesthetists who had been working at least 2 years. The control group of 30 subjects was selected from hospital staff with no history of occupational exposure to waste anesthetic gases. Mucociliary clearance time was assessed by measuring the saccharine nasal transit time (SNTT). RESULTS: Thirty-six women and 24 men aged between 25 and 60 years were enrolled in the study. There were no differences between the anesthetist and control groups in terms of age, sex, height, or weight. The median SNTT for the anesthetists (10 min) was longer than that for the control group (8.3 min). The difference was significant (P = 0.025). In addition, there was a significant correlation between the SNTT and the working time (P = 0.02). Furthermore, anesthetists who had worked for 4 years or more had prolonged SNTT compared to those who had worked less than 4 years (P < 0.001). CONCLUSION: The present study demonstrated the impairment of mucociliary clearance in anesthetists. Increasing impairment with increasing working time was also detected.

Evaluation of Genomic Damage in Peripheral Lymphocytes from Occupationally Exposed Anesthetists: Assessment of the Effects of Age, Sex, and GSTT1 Gene Polymorphism.

Occupational exposure to anaesthetic gases is one of the major hazards to healthcare personnel. We evaluated the cytogenetic effects of chronic exposure to low concentrations of anaesthetic gases in operating theatres. The study included 21 anesthetists and 21 control subjects who matched in age and gender. Chromosome aberrations (CAs) and sister chromatid exchanges (SCEs) assays were performed. All subjects were also genotyped for glutathione S-transferase T1 (GSTT1) gene polymorphisms. Significant differences were found between exposed and controls in terms of SCEs frequency (P = 0.001) and replication index value (P = 0.005), but not in terms of CAs (P = 0.201) and aberrant cells (P = 0.227) frequencies. Regression analyses indicated that age and the years of employment did not influence the level of chromosomal damage in both groups. Finally, among anesthetists, GSTT1 null individuals showed a significant higher frequency of SCE with respect to GSTT1-positive subjects.

Delayed onset of suspected malignant hyperthermia during sevoflurane anesthesia in an Afghan trauma patient: a case report.

Malignant hyperthermia (MH) is a rare pathologic hypermetabolic pharmacogenetic disorder of skeletal muscle calcium regulation following exposure to depolarizing muscle relaxants and/or volatile anesthetics. Although its pathogenesis is relatively well understood, there is wide variability in both the time of onset and the presentation of clinical signs and symptoms. In some circumstances the delayed onset of the hypermetabolic state may hinder timely recognition and treatment. Differential diagnosis of an MH crisis can be particularly challenging in a trauma patient, especially in an austere environment. This case report describes the presentation and management of a suspected case of MH in an Afghan national who underwent surgery following lower extremity trauma resulting from an improvised explosive device.

Efficiency and safety of inhalative sedation with sevoflurane in comparison to an intravenous sedation concept with propofol in intensive care patients: study protocol for a randomized controlled trial.

BACKGROUND: State of the art sedation concepts on intensive care units (ICU) favor propofol for a time period of up to 72 h and midazolam for long-term sedation. However, intravenous sedation is associated with complications such as development of tolerance, insufficient sedation quality, gastrointestinal paralysis, and withdrawal symptoms including cognitive deficits. Therefore, we aimed to investigate whether sevoflurane as a volatile anesthetic technically implemented by the anesthetic-conserving device (ACD) may provide advantages regarding 'weaning time', efficiency, and patient's safety when compared to standard intravenous sedation employing propofol. METHOD/DESIGN: This currently ongoing trial is designed as a two-armed, monocentric, randomized prospective phase II study including intubated intensive care patients with an expected necessity for sedation exceeding 48 h. Patients are randomly assigned to either receive intravenous sedation with propofol or sevoflurane employing the ACD. Primary endpoint is the comparison of the 'weaning time' defined as the time required from discontinuation of the sedating agent until sufficient spontaneous breathing occurs. Moreover, sedation depth evaluated by Richmond Agitation Sedation Scale and parameters of patient's safety (that is, vital signs, laboratory monitoring of organ function) as well as the duration of mechanical ventilation and overall stay on the ICU are analyzed and compared. An intention-to-treat analysis will be carried out with all patients for whom it will be possible to define a wake-up time. In addition, a per-protocol analysis is envisaged. Completion of patient recruitment is expected by the end of 2012. DISCUSSION: This clinical study is designed to evaluate the impact of sevoflurane during long-term sedation of critically ill patients on 'weaning time', efficiency, and patient's safety compared to the standard intravenous sedation concept employing propofol. TRIAL REGISTRATION: EudraCT2007-006087-30; ISRCTN90609144.

[Perioperative medication management]. / Perioperatives Medikamentenmanagement.

The management of chronic medication in the perioperative phase represents as a serious challenge for the involved physicians. Especially patients with elevated ASA-scores frequently suffer from multiple co-morbidities which often need numerous medications. The probability of pharmacological interactions rises with the number of these medications. Moreover it must be taken into consideration that chronic medication potentially interferes with both intravenous and inhaled anesthetics and moreover, bleeding complications are more likely to occur in patients undergoing chronic pharmacotherapy. The aim of this article is to provide a summary of the existing evidence concerning perioperative medication in patients undergoing non-cardiac surgery. Several guidelines and advisories dealing with cardiovascular medication have been published during the last decade. The main scope of these publications was on beta-blockers and other cardiovascular medication. There is less evidence on not-cardiovascular medication as in most cases only case reports and expert opinions are published. Existing epidemiologic studies on this topic are rather heterogeneous.

Halothane: how should it be used in a developing country?

The anaesthetic agent halothane is still widely used in developing countries including the Islamic Republic of Iran because of its low price. Because of halothane-induced hepatitis, a rare complication, it has been replaced by other inhalation anaesthetics in Western countries; it has been suggested by some Iranian professionals that the Islamic Republic of Iran should do the same. We evaluated various dimensions of this replacement through a literature review to assess the incidence of halothane-induced hepatitis and costs of anaesthetics in the country. We also conducted a questionnaire survey of 30 anaesthesiology/gastroenterology experts about their views on the subject. The results indicate that the incidence of halothane hepatitis in the Islamic Republic of Iran is very low and could mostly be avoided by strict adherence to guidelines. Complete withdrawal of halothane in the Islamic Republic of Iran might not be appropriate at present. Comprehensive cost-effectiveness studies are needed before a decision is made on complete replacement of halothane with other anaesthetics.

Avaliação da indução, recuperação, agitação ao despertar e consumo com uso de duas marcas de sevoflurano para anestesia ambulatorial / Assessment of induction, recovery, agitation upon awakening, and consumption with the use of two brands of sevoflurane for ambulatory anesthesia / Evaluación de la inducción, recuperación, agitación al despertar y consumo con el uso de dos marcas de sevoflurano para la anestesia ambulatorial

JUSTIFICATIVA E OBJETIVOS: O sevoflurano por suas características farmacológicas é o anestésico ideal para procedimentos de curta duração. Existem duas marcas de sevoflurano no mercado brasileiro, o Sevocris® e Sevorane®, com diferentes formulações e envasamento. O objetivo deste estudo foi analisar se existem diferenças entre os dois anestésicos na indução, manutenção, recuperação e consumo. MÉTODO: Foram incluídas 130 crianças dividas em dois grupos segundo a marca do agente utilizado: Grupo 1 sevoflurano da Cristália® e Grupo 2 da Abbott®. Foram analisados os seguintes parâmetros: frequência cardíaca, pressão arterial sistólica e diastólica, fração inspirada e expirada de sevoflurano, valores de BIS, temperatura timpânica, tempos de indução e recuperação, agitação ao despertar pela escala PAED e consumo do anestésico por pesagem dos vaporizadores. A indução foi realizada com 1 CAM e incrementadas a cada três movimentos respiratórios em 0,5 CAM, até no máximo 3 CAM. RESULTADO: Não houve diferença entre os grupos quanto ao tempo de procedimento e de anestesia e nos parâmetros avaliados na indução. No Grupo 1, o número de crianças que necessitaram bolus adicionais de sevoflurano na manutenção da anestesia foi maior que no 2 (p < 0,05). A fração inspirada e expirada de sevoflurano no final do procedimento foi menor no Grupo 1 (p < 0,001). No momento do despertar o valor do BIS foi menor no Grupo 1 (p = 0,045). Outros parâmetros avaliados na recuperação não mostraram diferença entre os grupos. O consumo de anestésico foi semelhante entre os grupos.

BACKGROUND AND OBJECTIVES: Due to its pharmacological characteristics, sevoflurane is the ideal anesthetic for short-duration procedures. There are two brands of sevoflurane in the Brazilian market, Sevocris® and Sevorane®, with different formulations and packaging. The objective of this study was to assess whether there are differences between the two anesthetics regarding induction, maintenance, recovery, and consumption. METHODS: One hundred and thirty children were included, divided into two groups according to the brand used: Group 1 was assigned to sevoflurane Cristália® and Group 2 to sevoflurane Abbott®. The following parameters were assessed: heart rate, systolic and diastolic blood pressure, fraction of inspired and expired sevoflurane, BIS values, tympanic temperature, induction and recovery time, agitation upon awakening measured by the PAED scale, and anesthetic consumption by weighing the vaporizers. Anesthesia was induced with 1 MAC and increased every three breaths at 0.5 MAC, up to 3 MAC. RESULTS: There was no difference between groups regarding the duration of the procedure, the anesthesia, and the parameters evaluated at induction. In Group 1, the number of children who required additional bolus of sevoflurane for anesthesia maintenance was higher than in Group 2 (p < 0.05). The fraction of inspired and expired sevoflurane at the end of the procedure was lower in Group 1 (p < 0.001). Upon awakening, BIS value was lower in Group 1 (p = 0.045). Other parameters evaluated in recovery showed no difference between groups. The use of anesthesia was similar between groups.

JUSTIFICATIVA Y OBJETIVOS: El sevoflurano, por sus características farmacológicas, es el anestésico ideal para procedimientos de corta duración. Existen dos marcas de sevoflurano en el mercado brasileño, el Sevocris® y el Sevorane®, con diferentes formulaciones y envases. El objetivo de este estudio, fue analizar si existen diferencias entre los dos anestésicos en la inducción, mantenimiento, recuperación y consumo. MÉTODO: Se incluyeron 130 niños divididos en dos grupos según la marca del agente utilizado: Grupo 1 sevoflurano de Cristália® y Grupo 2 de Abbott®. Se analizaron los siguientes parámetros: frecuencia cardíaca, presión arterial sistólica y diastólica, fracción inspirada y espirada de sevoflurano, valores de BIS, temperatura timpánica, tiempos de inducción y recuperación, agitación al despertar por la escala PAED, y consumo del anestésico por pesaje de los vaporizadores. La inducción fue realizada con 1 CAM e incrementada a cada tres movimientos respiratorios en 0,5 CAM, hasta el máximo de 3 CAM. RESULTADO: No hubo diferencia entre los grupos en cuanto al tiempo de procedimiento y de anestesia y en los parámetros evaluados en la inducción. En el Grupo 1, el número de niños que necesitaron bolos adicionales de sevoflurano en el mantenimiento de la anestesia, fue mayor que en el 2 (p < 0,05). La fracción inspirada y espirada de sevoflurano al final del procedimiento fue menor en el Grupo 1 (p < 0,001). Al momento del despertar, el valor del BIS fue menor en el Grupo 1 (p = 0,045). Otros parámetros evaluados en la recuperación no arrojaron diferencia entre los grupos. El consumo de anestésico fue similar entre los grupos.