The long-term survival outcomes of gastric cancer patients with total intravenous anesthesia or inhalation anesthesia: a single-center retrospective cohort study.

BACKGROUND: The relationship between the type of anesthesia and the survival outcomes of gastric cancer patients is uncertain. This study compared the overall outcome of gastric cancer patients after surgery with total intravenous anesthesia (TIVA) or inhalation anesthesia (IHA). METHODS: Clinicopathological variables of gastric cancer patients were retrieved from the database of the Surgical Gastric Cancer Patient Registry in West China Hospital, Sichuan University. Patients were grouped according to whether they received TIVA or IHA during the operation. Propensity score (PS) matching was used to balance the baseline variables, and survival outcomes were compared between these two groups. In addition, studies comparing survival outcomes between TIVA and IHA used for gastric cancer surgery and published before April 20th, 2020, were identified, and their data were pooled. RESULTS: A total of 2827 patients who underwent surgical treatment from Jan 2009 to Dec 2016 were included. There were 323 patients in the TIVA group and 645 patients in the IHA group, with 1:2 PS matching. There was no significant difference in overall survival outcomes between the TIVA and IHA groups before matching the cohort (p = 0.566) or after matching the cohort (p = 0.679) by log-rank tests. In the Cox hazard regression model, there was no significant difference between the TIVA and IHA groups before (HR: 1.054, 95% CI: 0.881-1.262, p = 0.566) or after (HR: 0.957, 95% CI: 0.779-1.177, p = 0.679) PS matching. The meta-analysis of survival outcomes between the TIVA and IHA groups found critical statistical value in the before PS matching cohort (HR 0.74, 95% CI: 0.57-0.96 p < 0.01) and after PS matching cohort (HR: 0.65, 95% CI: 0.46-0.94, p < 0.01). CONCLUSIONS: Combined with the results of previous studies, total intravenous anesthesia has been shown to be superior to inhalation anesthesia in terms of overall survival for gastric cancer patients undergoing surgical treatment. The selection of intravenous or inhalation anesthesia for gastric cancer surgery should take into account the long-term prognosis of the patient.

mu-Opioid Receptor Polymorphisms and Breast Cancer Recurrence in Adult Korean Women Undergoing Breast Cancer Surgery: A Retrospective Study.

Background: Genetic variations of mu-opioid receptors are well known to contribute to growth and progression of tumors. The most common single-nucleotide polymorphism (SNP) in the mu-opioid receptor 1 gene (OPRM1) is the A118G mutation. We examined the association between the recurrent breast cancer and genotypes of OPRM1 A118G SNP (AA vs. AG vs. GG) in Korean women population. Methods: We analysed medical records and genetic data of 200 patients aged more than 20 who underwent primary breast cancer surgery from June 2012 to June 2014 and diagnosed recurrent breast cancer from June 2012 to September 2019. Results: The incidence of recurrent breast cancer was 6.1%, 8.2%, and 4.8% in genotype AA, AG and GG, respectively (p=0.780). The incidence of recurrent breast cancer in volatile anaesthesia group was 7.0% and 7.1% in total intravenous anaesthesia (TIVA) group (RR = 0.984, 95% CI = 0.328 - 2.951; p = 0.978). Conclusion: OPRM1 A118G SNP had no influence on breast cancer recurrence in Korean women. Anaesthesia technique did not show significant effect on the incidence of recurrent breast cancer.

Anaesthetic technique and outcomes after colorectal cancer surgery.

INTRODUCTION: Previous studies have suggested that choice of anaesthesia can affect long-term outcome. In this study, the association between type of anaesthesia and outcomes in terms of survival, recurrence, post-operative complications and recovery after surgery for colorectal cancer was investigated in an Enhanced Recovery after Surgery (ERAS) setting. METHODS: This was a retrospective study including patients undergoing elective curative-intended surgery for colorectal cancer between April 2013 and May 2015 at Zealand University Hospital, Denmark. Patients were stratified by anaesthetic technique. The primary outcome was cancer recurrence. Cox regression analyses were used for time-to-event variables; recurrence, disease-free survival, mortality, length of hospitalisation and time to bowel movement. Odds ratios for post-operative complications and time to discharge were estimated using logistic regression. RESULTS: A total of 534 patients were included, 51 were exposed to inhalational anaesthesia and 483 had total intravenous anaesthesia. We found no statistically significant difference in recurrence (hazard ratio (HR) = 0.70; 95% confidence interval (CI): 0.21-1.68; p = 0.421). Patients in the inhalational aneasthesia group had a significantly lower chance of discharge per post-operative day (HR = 0.66; 95% CI: 0.48-0.91; p = 0.012). The same was seen for time to bowel movement (HR = 0.65; 95% CI: 0.46-0.90; p = 0.011). No statistically significant differences were seen for the other outcomes. CONCLUSION: Anaesthetic technique might influence time to discharge and bowel function in an ERAS setting. FUNDING: none TRIAL REGISTRATION: The study was approved by the Danish Data Protection Agency (record number 2008-58-0020). Under Danish law, consent from participants is not required in observational studies.

Total intravenous versus inhalational anesthesia in endoscopic sinus surgery: A meta-analysis.

OBJECTIVE: Achieving optimal intraoperative surgical field visibility and minimizing blood loss are two important parameters in endoscopic sinus surgery (ESS). The aim of this meta-analysis was to compare two total intravenous anesthesia (TIVA) and inhalational anesthesia (IA) to determine if either conferred superior outcomes of these and other parameters based on randomized control trials (RCTs) only. METHODS: The recommended Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines were followed, and searches of electronic databases from inception to September 2018 identified 157 articles for screening. Data were extracted and analyzed using meta-analysis of proportions. RESULTS: In total, we identified 15 RCTs that satisfied our selection criteria. There were 828 ESS cases described, with 391 (47%) and 437 (53%) being managed by TIVA and IA, respectively. Pooled analysis demonstrated significantly superior visibility scores for TIVA compared to IA based on 10-point grading scores (P = 0.049, visual analog scale; P = 0.009, Wormald scale) and 5-point grading scores (P = 0.002, Boezaart scale). Blood loss was significantly less following TIVA (P = 0.003), with no significant difference in intraoperative heart rate (P = 0.70) or mean arterial pressure (P = 0.96). Additionally, duration of surgery (P = 0.16) and anesthesia (P = 0.39) were comparable between the two approaches. CONCLUSION: This meta-analysis indicates that TIVA has the potential to confer superior surgical field visibility and reduce intraoperative blood loss compared to IA in ESS. Currently, there are significant heterogeneity concerns in this meta-analysis, which temper any expectations that either approach is absolutely superior to the other. Caution should be exercised when interpreting these results until further validation can be achieved. LEVEL OF EVIDENCE: 1A Laryngoscope, 130:575-583, 2020.

The effect of fresh gas flow during induction of anaesthesia on sevoflurane usage: a quality improvement study.

Reducing fresh gas flow during inhalational anaesthesia results in cost savings and decreases environmental impact. We are interested in the influence of fresh gas flow on the early (induction) phase of overall fresh gas flow and vapour consumption. This stage is often excluded in studies of fresh gas flow. Data were collected from 3199 sevoflurane anaesthetics over an 11-month period in four operating theatres. We determined fresh gas flow at different stages of anaesthesia, and developed an explanatory model for the influence of the 'induction' period. Following a three-month collection of baseline data we emphasised the importance of the early phase to our department repeatedly over a two-week period. We explored the relationship between fresh gas flow and total vapour usage, and used a simple mathematical model to explore the effect of changes in the fresh gas flow and duration of the 'induction' phase. Mean fresh gas flow was 1.15 l.min-1 in the baseline period and 0.91 l.min-1 in the two months following our educational effort (p = 0.0005). In the following six months, mean fresh gas flow was 1.17 l.min-1 (p = 0.7726 compared with baseline). These results were driven by changes in both fresh gas flow and duration of the initial high-flow period. We found some correlation (R2  = 0.85) between overall fresh gas flow and vapour consumption; a 1 l.min-1 increase in fresh gas flow consumes an additional 18 ml.hr-1 of liquid sevoflurane. This preliminary study demonstrates that an episode of high fresh gas flow at the start of anaesthesia has a large and modifiable effect on overall fresh gas flow and vapour consumption. We also confirmed the linear relationship between fresh gas flow and vapour usage.

Total Intravenous Anesthesia versus Inhalation Anesthesia for Breast Cancer Surgery: A Retrospective Cohort Study.

BACKGROUND: The association between type of anesthesia used and recurrence of cancer remains controversial. This retrospective cohort study compared the influence of total IV anesthesia and inhalation anesthesia on the primary outcome of recurrence-free survival after breast cancer surgery. METHODS: The authors reviewed the electronic medical records of patients who had breast cancer surgery at a tertiary care teaching hospital between January 2005 and December 2013. The patients were grouped according to whether IV or inhalation anesthesia was used for surgery. Propensity score matching was used to account for differences in baseline characteristics. Kaplan-Meier survival curves were constructed to evaluate the influence of type of anesthesia on recurrence-free survival and overall survival. The risks of cancer recurrence and all-cause mortality were compared between each type of anesthesia. RESULTS: Of 7,678 patients who had breast cancer surgery during the study period, data for 5,331 patients were available for analysis (IV group, n = 3,085; inhalation group, n = 2,246). After propensity score matching, 1,766 patients remained in each group. Kaplan-Meier survival curves showed that there was no significant difference in recurrence-free survival or overall survival between the two groups, with 5-yr recurrence-free survival rates of 93.2% (95% CI, 91.9 to 94.5) in the IV group and 93.8% (95% CI, 92.6 to 95.1) in the inhalation group. Inhalation anesthesia had no significant impact on recurrence-free survival (hazard ratio, 0.96; 95% CI, 0.69 to 1.32; P = 0.782) or overall survival (hazard ratio, 0.96; 95% CI, 0.69 to 1.33, P = 0.805) when compared with total IV anesthesia. CONCLUSIONS: The authors found no association between type of anesthesia used and the long-term prognosis of breast cancer. The results of this retrospective cohort study do not suggest specific selection of IV or inhalation anesthesia for breast cancer surgery.

Volumetric and reflective device dead space of anaesthetic reflectors under different conditions.

Inhalation sedation is increasingly performed in intensive care units. For this purpose, two anaesthetic reflectors, AnaConDa™ and Mirus™ are commercially available. However, their internal volume (100 ml) and possible carbon dioxide reflection raised concerns. Therefore, we compared carbon dioxide elimination of both with a heat moisture exchanger (HME, 35 ml) in a test lung model. A constant flow of carbon dioxide was insufflated into the test lung, ventilated with 500 ml, 10 breaths per minute. HME, MIRUS and AnaConDa were connected successively. Inspired (insp-CO2) and end-tidal carbon dioxide concentrations (et-CO2) were measured under four conditions: ambient temperature pressure (ATP), body temperature pressure saturated (BTPS), BTPS with 0.4 Vol% (ISO-0.4), and 1.2 Vol% isoflurane (ISO-1.2). Tidal volume increase to maintain normocapnia was also determined. Insp-CO2 was higher with AnaConDa compared to MIRUS and higher under ATP compared to BTPS. Isoflurane further decreased insp-CO2 and abolished the difference between AnaConDa and MIRUS. Et-CO2 showed similar effects. In addition to volumetric dead space, reflective dead space was determined as 198 ± 6/58 ± 6/35 ± 0/25 ± 0 ml under ATP/BTPS/ISO-0.4/ISO-1.2 conditions for AnaConDa, and 92 ± 6/25 ± 0/25 ± 0/25 ± 0 ml under the same conditions for MIRUS, respectively. Under BTPS conditions and with the use of moderate inhaled agent concentrations, reflective dead space is small and similar between the two devices.

Desflurane usage during anesthesia with and without N2O using FLOW-i Automatic Gas Control with three different wash-in speeds.

AGC® (Automatic Gas Control) is the FLOW-i's automated low flow tool (Maquet, Solna, Sweden) that target controls the inspired O2 (FIO2) and end-expired desflurane concentration (FAdes) while (by design) exponentially decreasing fresh gas flow (FGF) during wash-in to a maintenance default FGF of 300 mL min-1. It also offers a choice of wash-in speeds for the inhaled agents. We examined AGC performance and hypothesized that the use of lower wash-in speeds and N2O both reduce desflurane usage (Vdes). After obtaining IRB approval and patient consent, 78 ASA I-II patients undergoing abdominal surgery were randomly assigned to 1 of 6 groups (n = 13 each), depending on carrier gas (O2/air or O2/N2O) and wash-in speed (AGC speed 2, 4, or 6) of desflurane, resulting in groups air/2, air/4, air/6, N2O/2, N2O/4, and N2O/6. The target for FIO2 was set at 35%, while the FAdes target was selected so that the AGC displayed 1.3 MAC (corrected for the additive affect of N2O if used). AGC was activated upon starting mechanical ventilation. Varvel's criteria were used to describe performance of achieving the targets. Patient demographics, end-expired N2O concentration, MAC, FGF, and Vdes were compared using ANOVA. Data are presented as mean ± standard deviation, except for Varvel's criteria (median ± quartiles). Patient demographics did not differ among the groups. Median performance error was -2-0% for FIO2 and -3-1% for FAdes; median absolute performance error was 1-2% for FIO2 and 0-3% for FAdes. MAC increased faster in N2O groups, but total MAC decreased 0.1-0.25 MAC below that in the O2/air groups after 60 min. The effect of wash-in speed on Vdes faded over time. N2O decreased Vdes by 62%. AGC performance for O2 and desflurane targeting is excellent. After 1 h, the wash-in speeds tested are unlikely to affect desflurane usage. N2O usage decreases Vdes proportionally with its reduction in FAtdes.

The State of UK Dental Anaesthesia: Results From The NAP5 Activity Survey. A national survey by the 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland.

The National Health Service anaesthesia annual activity (2013) was recently reported by the Fifth National Audit Program of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland. Within a large dataset were 620 dental cases. Here, we describe this data subset. The estimated annual dental caseload was 111,600:60% were children (< 16 y), 38.5% adults (16 - 65y) and 1.5% the elderly (> 65y). Almost all were elective day procedures (97%) and ASA 1 or 2 patients (95%).The most senior anaesthetist present was a Consultant in 82% and a non-career grade doctor in 14%.Virtually all (98%) cases were conducted during GA. Propofol was used to induce anaesthesia in almost all adults compared with 60% of children. Propofol maintenance was used in 5% of both children and adults. Almost all adults received an opioid (including remifentanil) compared with only 40% of children. Thirty one per cent of children had a GA for a dental procedure without either opioid or LA supplementation. Approximately 50% of adults and 16% of children received a tracheal tube: 20% of children needed only anaesthesia by face mask. These data show that anaesthetists almost always use general anaesthesia for dental procedures and this exposes difficulties in training of anaesthetists in sedation techniques. Dentists, however, are well known to use sedation when operating alone and our report provides encouragement for a comprehensive survey of dental sedation and anaesthesia practice in both NHS and non-NHS hospitals and clinics in the UK.

Effects of Volatile Anesthetics on Mortality and Postoperative Pulmonary and Other Complications in Patients Undergoing Surgery: A Systematic Review and Meta-analysis.

BACKGROUND: It is not known whether modern volatile anesthetics are associated with less mortality and postoperative pulmonary or other complications in patients undergoing general anesthesia for surgery. METHODS: A systematic literature review was conducted for randomized controlled trials fulfilling following criteria: (1) population: adult patients undergoing general anesthesia for surgery; (2) intervention: patients receiving sevoflurane, desflurane, or isoflurane; (3) comparison: volatile anesthetics versus total IV anesthesia or volatile anesthetics; (4) reporting on: (a) mortality (primary outcome) and (b) postoperative pulmonary or other complications; (5) study design: randomized controlled trials. The authors pooled treatment effects following Peto odds ratio (OR) meta-analysis and network meta-analysis methods. RESULTS: Sixty-eight randomized controlled trials with 7,104 patients were retained for analysis. In cardiac surgery, volatile anesthetics were associated with reduced mortality (OR = 0.55; 95% CI, 0.35 to 0.85; P = 0.007), less pulmonary (OR = 0.71; 95% CI, 0.52 to 0.98; P = 0.038), and other complications (OR = 0.74; 95% CI, 0.58 to 0.95; P = 0.020). In noncardiac surgery, volatile anesthetics were not associated with reduced mortality (OR = 1.31; 95% CI, 0.83 to 2.05, P = 0.242) or lower incidences of pulmonary (OR = 0.67; 95% CI, 0.42 to 1.05; P = 0.081) and other complications (OR = 0.70; 95% CI, 0.46 to 1.05; P = 0.092). CONCLUSIONS: In cardiac, but not in noncardiac, surgery, when compared to total IV anesthesia, general anesthesia with volatile anesthetics was associated with major benefits in outcome, including reduced mortality, as well as lower incidence of pulmonary and other complications. Further studies are warranted to address the impact of volatile anesthetics on outcome in noncardiac surgery.

Long-term Survival for Patients Undergoing Volatile versus IV Anesthesia for Cancer Surgery: A Retrospective Analysis.

BACKGROUND: Surgical resection remains the best option for long-term survival in many solid tumors. Surgery can, however, lead to tumor cell release into the circulation. Data have suggested differential effects of anesthetic agents on cancer cell growth. This retrospective analysis investigated the association of anesthetic technique with long-term survival in patients presenting for elective surgery in a comprehensive cancer center over 3 yr. METHODS: All patients undergoing elective surgery between June 2010 and May 2013 were included. Patients were grouped according to whether they had received volatile inhalational (INHA) or total IV anesthesia (TIVA). After excluding those who received both forms of anesthesia during the study period, Kaplan-Meier survival curves were constructed from the date of surgery to death. After propensity matching, univariate and multivariable regression models were used to compare hazard ratios for death. RESULTS: A total of 11,395 anesthetics using INHA or TIVA were delivered in the study period. After exclusions, 3,316 patients (796 deaths, 24%) remained in the INHA group and 3,714 (504 deaths, 13.5%) in the TIVA group. After propensity matching, 2,607 patients remained in each group (597 deaths, 22.8%, in INHA group vs. 407, 15.6%, in TIVA group). Volatile inhalational anesthesia was associated with a hazard ratio of 1.59 (1.30 to 1.95) for death on univariate analysis and 1.46 (1.29 to 1.66) after multivariable analysis of known confounders in the matched group. CONCLUSIONS: This retrospective analysis demonstrates an association between type of anesthetic delivered and survival. This analysis alongside biological plausibility should lead to urgent prospective work exploring the effect of anesthetic technique on survival.

Use of volatile anaesthetic agents in anaesthesia: A survey of practice in France in 2012.

Volatile anaesthetic agents are used in the vast majority of general anaesthesias performed in France. We assessed the degree of understanding of French anaesthetists with regard to the general pharmacology of these products and their understanding of the factors that govern selection of the different agents available for use in adults. A validated 13-item questionnaire was sent electronically in 2012 using files from the Société française d'anesthésie et de réanimation (Sfar). It covered four categories: general characteristics of the respondent; practical aspects of anaesthesia with volatile agents; pharmacological properties and criteria for choosing a volatile agent; risk of intra-operative awareness. Among the 981 respondents, the anaesthetic technique used by 50% was that of an intravenous induction followed by maintenance with sevoflurane. The concepts relating to the practical use of these products are well known. A fresh gas flow of less than 2 L/min is used by 96% of the respondents. However, knowledge levels are often inadequate (rate of correct answers often<50%). This lack of knowledge pertains to current themes (climate pollution), those of debatable clinical significance, e.g. pre-conditioning, hypoxic vasoconstriction and those that concern scientific theory (medullary action). However, a lack of knowledge is also observed with regard to basic pharmacology (respiratory, vascular, neurological or pharmacokinetic effects). There is no significant difference in the mode of practice. The experience of the anaesthetist (measured by number of years post diploma) resulted in a number of differences in response to many aspects of the questionnaire but these were minor. These results suggest the need for an improvement both in the initial and continued training of anaesthetists with respect to volatile anaesthetic agents.

Integridad renal y hepática tras la sedación prolongada con sevoflurano administrado a través del dispositivo AnaConDa(R): comparación con la sedación intravenosa con propofol en modelo animal / Renal and hepatic integrity in long-term sevoflurane sedation using the anesthetic conserving device: a comparison with intravenous propofol sedation in an animal model

Introducción: En la actualidad la sedación de los pacientes críticos se realiza mediante agentes intravenosos. La utilización de agentes inhalatorios, como alternativa a la sedación intravenosa, se encuentra limitada por su potencial riesgo de toxicidad. El incremento de los niveles de fluoruros inorgánicos, tras su metabolización, ha sido considerado potencialmente nefrotóxico. Por otro lado, la afectación hepática después de la administración prolongada de sevoflurano no ha sido estudiada. Se evaluó la potencial toxicidad renal y hepática causada por la administración prolongada (72 h) de sevoflurano. Métodos: Estudio experimental, prospectivo, aleatorizado y controlado. Veintidós animales cerdas de la raza Landrace x Large-White fueron asignadas aleatoriamente a 2 grupos en función del régimen de sedación administrado (P: propofol por vía intravenosa; o S: sevoflurano inhalado a través del sistema AnaConDa(R), endtidal 2,5%). El grupo P se mantuvo sedado durante 108 h con propofol. Al grupo S se le administró sevoflurano durante 72 h, cambiando a propofol durante las 36 h restantes, con el objetivo de observar la cinética de los fluoruros plasmáticos tras la interrupción del sevoflurano. Se midieron la creatinina plasmática como variable principal, las concentraciones de fluoruros inorgánicos y otras variables de función renal, hepática y cardiorrespiratoria. Resultados: Ambos grupos de animales fueron comparables en el momento basal. No hubo diferencias significativas entre ambos grupos en cuanto a los valores de creatinina plasmática, urea y aclaramiento de creatinina. Los niveles de fluoruros fueron significativamente mayores en el grupo de sevoflurano. No encontramos una correlación entre las cifras de fluoruros inorgánicos y los valores de creatinina plasmática. Tampoco se observaron diferencias significativas en los parámetros de función hepática. Las variables hemodinámicas, respiratorias y gasométricas fueron comparables entre los grupos. Conclusiones: La sedación de larga duración no afecta a la función renal ni hepática, independientemente del agente utilizado (AU)

Introduction: Critically ill patients are sedated with intravenous agents because the use of inhaled agents is limited by their potential risk of toxicity. Increasing levels of inorganic fluorides after the metabolism of these agents have been considered potentially nephrotoxic. However, hepatic involvement after prolonged administration of sevoflurane has not yet been studied. The present study evaluated the potential renal and hepatic toxicity caused by prolonged administration (72 h) of sevoflurane. Methods: For this experimental, prospective, randomized, controlled trial, 22 Landrace x Large-White female pigs were randomly assigned to two groups: intravenous propofol (P) or inhaled sevoflurane via the AnaConDa(TM) device (S, end-tidal 2.5 vol%). The P group remained sedated for 108 h with propofol. In the S group, sevoflurane was administered for 72 h and then changed to propofol for the remaining 36 h in order to observe the kinetics of fluoride after discontinuation of sevoflurane. Serum creatinine was the primary outcome variable, but inorganic fluoride concentrations and other renal, hepatic, and cardiorespiratory variables were also measured. Results: Both groups of animals were comparable at baseline. No differences were found between the two groups for plasma creatinine and urea or creatinine clearance throughout the study. Fluoride levels were significantly higher in the sevoflurane group. No correlation was found between inorganic fluoride and serum creatinine values. No significant differences were observed for hepatic function. Hemodynamic, respiratory, and blood gas variables were comparable between the groups. Conclusions: Long-term sedation with sevoflurane using AnaConDa(TM) or propofol does not negatively affect renal or hepatic function (AU)

[Impact of the decrease of nitrous oxide use on the consumption of halogenated agents]. / Impact de la diminution d'utilisation du protoxyde d'azote sur la consommation d'agents halogénés.

OBJECTIVE: Nitrous oxide (N2O) toxicity and its impact on pollution lead to restrict its use. A decrease of N2O consumption should increase the hypnotic inhaled consumption. This monocentric study estimated consumptions and costs of halogenated agents (HA) and N2O over 5 years when the N2O consumption was reduced. STUDY DESIGN: Retrospective from a computerized database. PATIENTS: Between 2006 and 2010, 34,097 procedures were studied after two meetings exposing the risks of the N2O. METHODS: At the end of anesthesia, consumptions of hypnotic agents (millilitres transmitted by the injectors and the blender) were archived in the database. The annual consumption of agents was obtained by adding the individual consumptions, then divided by the annual number of cases. The costs were given by the hospital pharmacy from invoices. RESULTS: N2O consumption per anesthesia constantly decreased during the study, from 75.1L by act to 22.7L. The sum of the annual consumptions of N2O and air did not change suggesting that total fresh gas flow remained stable. Between 2006 and 2010, the sevoflurane consumption by act increased by 25%, from 16.5 to 20.6mL, and desflurane consumption by 37%, from 46.1 to 63.1mL by patient. The costs of the administration of hypnotic agents remained stable. CONCLUSION: N2O consumption decrease had an impact on the consumption of HA. The cost reduction of the N2O was counterbalanced by the increase of halogenated vapor cost. The profit of the ecological impact of the reduction in N2O use could be quantified.

Current use of nitrous oxide in public hospitals in Scandinavian countries.

BACKGROUND: The use of nitrous oxide in modern anaesthesia has been questioned. We surveyed changes in use of nitrous oxide in Scandinavia and its justifications during the last two decades. METHODS: All 191 departments of anaesthesia in the Scandinavian countries were requested by email to answer an electronic survey in SurveyMonkey. RESULTS: One hundred and twenty-five (64%) of the departments responded; four were excluded. The 121 departments provided 807.520 general anaesthetics annually. The usage of nitrous oxide was reported in 11.9% of cases, ranging from 0.6% in Denmark to 38.6% in Iceland while volatile anaesthetics were employed in 48.9%, lowest in Denmark (22.6%) and highest in Iceland (91.9%). Nitrous oxide was co-administered with volatile anaesthetics in 21.5% of general anaesthetics [2.4% (Denmark) -34.5% (Iceland)]. Use of nitrous oxide was unchanged in five departments (4%), decreasing in 75 (62%) and stopped in 41 (34%). Reasons for decreasing or stopping use of nitrous oxide were fairly uniform in the five countries, the most important being that other agents were 'better', whereas few put weight on its potential risk for increasing morbidity. Decision to stop using nitrous oxide was made by the departments except in four cases. Of 87 maternity wards, nitrous oxide was used in 72, whereas this was the case in 42 of 111 day-surgery units. CONCLUSION: The use of nitrous oxide has decreased in the Scandinavian countries, apparently because many now prefer other agents. Difference in practices between the five countries were unexpected and apparently not justified on anticipated evidence only.

Volatile anesthetic rescue therapy in children with acute asthma: innovative but costly or just costly?.

OBJECTIVES: To describe volatile anesthesia (VA) use for pediatric asthma, including complications and outcomes. DESIGN: Retrospective cohort study. SETTING: Children's hospitals contributing to the Pediatric Health Information System between 2004-2008. PATIENTS: Children 2-18 years old with a primary diagnosis code for asthma supported with mechanical ventilation. INTERVENTION: Those treated with VA were compared to those not treated with VA or extracorporeal membrane oxygenation. Hospital VA use was grouped as none, <5%, 5-10% and >10% among intubated children. MEASUREMENTS AND MAIN RESULTS: One thousand five hundred and fifty-eight patients received mechanical ventilation at 40 hospitals for asthma: 47 (3%) received VA treatment at 11 (28%) hospitals. Those receiving a VA were significantly less likely to receive inhaled b-agonists, ipratropium bromide, and heliox, but more likely to receive neuromuscular blocking agents than patients treated without VA. Length of mechanical ventilation, hospital stay (length of stay [LOS]) and charges were significantly greater for those treated with VA. Aspiration was more common but death and air leak did not differ. Patients at hospitals with VA use >10% were significantly less likely to receive inhaled b agonist, ipratropium bromide, methylxanthines, and heliox, but more likely to receive systemic b agonist, neuromuscular blocking agents compared to those treated at hospitals not using VA. LOS, duration of ventilation, and hospital charges were significantly greater for patients treated at centers with high VA use. CONCLUSIONS: Mortality does not differ between centers that use VA or not. Patients treated at centers with high VA use had significantly increased hospital charges and increased LOS.

Evidence-based analysis of risk factors for postoperative nausea and vomiting.

BACKGROUND: /st> In assessing a patient's risk for postoperative nausea and vomiting (PONV), it is important to know which risk factors are independent predictors, and which factors are not relevant for predicting PONV. METHODS: /st> We conducted a systematic review of prospective studies (n>500 patients) that applied multivariate logistic regression analyses to identify independent predictors of PONV. Odds ratios (ORs) of individual studies were pooled to calculate a more accurate overall point estimate for each predictor. RESULTS: /st> We identified 22 studies (n=95 154). Female gender was the strongest patient-specific predictor (OR 2.57, 95% confidence interval 2.32-2.84), followed by the history of PONV/motion sickness (2.09, 1.90-2.29), non-smoking status (1.82, 1.68-1.98), history of motion sickness (1.77, 1.55-2.04), and age (0.88 per decade, 0.84-0.92). The use of volatile anaesthetics was the strongest anaesthesia-related predictor (1.82, 1.56-2.13), followed by the duration of anaesthesia (1.46 h(-1), 1.30-1.63), postoperative opioid use (1.39, 1.20-1.60), and nitrous oxide (1.45, 1.06-1.98). Evidence for the effect of type of surgery is conflicting as reference groups differed widely and funnel plots suggested significant publication bias. Evidence for other potential risk factors was insufficient (e.g. preoperative fasting) or negative (e.g. menstrual cycle). CONCLUSIONS: /st> The most reliable independent predictors of PONV were female gender, history of PONV or motion sickness, non-smoker, younger age, duration of anaesthesia with volatile anaesthetics, and postoperative opioids. There is no or insufficient evidence for a number of commonly held factors, such as preoperative fasting, menstrual cycle, and surgery type, and using these factors may be counterproductive in assessing a patient's risk for PONV.