Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

An Examination of the Food Allergy Quality of Life Questionnaire Performance in a Countrywide American Sample of Children:Cross-Cultural Differences in Age and Impact in the United States and Europe

BACKGROUND: It is important to ensure that tools are valid and reliable in the context in which they are used. The development of age and country norms is part of this process. OBJECTIVES: The primary aim of the present study was to examine the performance of the Food Allergy Quality of Life Questionnaire - Parent Form (FAQLQ-PF) in a countrywide American sample of children with food allergy. The secondary aim was to compare age differences in impact across 9 European countries. METHODS: In a cross-sectional quantitative design, questionnaires were completed by the parents of 1029 food-allergic children (0-12 years). Participants were recruited via support groups and allergists. Data were analyzed by using multivariate analysis of variance and tests for internal consistency and validity. The average score was calculated for each age group in 15 studies in Ireland, Switzerland, the Netherlands, Spain, Portugal, Germany, Italy, Denmark, Israel, and the United Kingdom. RESULTS: The FAQLQ-PF has high convergent validity (child: r = 0.49, n = 695, P = .01; parent: r = 0.36, n = 696, P = .01) and discriminant validity, parent: t (719) = 4.67, P = .001 (anaphylaxis yes vs no); t (513), P = .009 (single vs multiple allergens). Internal consistency was excellent (r = 0.96). US health-related quality of life was worse than European health-related quality of life, as indicated by higher FAQLQ-PF scores in US samples. Burden increased with age in all populations. CONCLUSIONS: The FAQLQ-PF is appropriate for use in an American population. Findings will form the basis for further work in the development of an online manual with food allergy-normed age scores to allow for precise measurement, interpretation of scores, and comparison across countries and cultures, in clinical and research settings. (C) 2016 American Academy of Allergy, Asthma & Immunolog

Outcomes for Infants Born in Perinatal Centers Performing Fewer Surgical Ligations for Patent Ductus Arteriosus: A Swiss Population-Based Study

Objective To assess patent ductus arteriosus treatment variation between Swiss perinatal centers and to determine its effect on outcome in a population-based setting. Study design This was a retrospective cohort study of infants born less than 28 weeks of gestation between 2012 and 2017. Outcomes between surgically ligated and pharmacologically treated infants as well as infants born in centers performing ≤10% ligation (“low” group) and >10% (“high” group) were compared using logistic regression and 1:1 propensity score matching. Matching was based on case-mix and preligation confounders: intraventricular hemorrhages grades 3-4, necrotizing enterocolitis, sepsis, and ≥28 days’ oxygen supply. Results Of 1389 infants, 722 (52%) had pharmacologic treatment and 156 (11.2%) received surgical ligation. Compared with infants who received pharmacologic treatment, ligated infants had greater odds for major morbidities (OR 2.09, 95% CI 1.44-3.04) and 2-year neurodevelopmental impairment (OR 1.81, 95% CI 1.15-2.84). Mortality was comparable after restricting the cohort to infants surviving at least until day 10 to avoid survival bias. In the “low” group, 34 (4.9%) of 696 infants were ligated compared with 122 (17.6%) of 693 infants in the “high” group. Infants in the “high” group had greater odds for major morbidities (OR 1.49, 95% CI 1.11-2.0). Conclusions Our analysis identified a burden on infants receiving surgical ligation vs pharmacologic treatment in a population-based setting where there was no agreed-on common procedure. These results may guide a revision of patent ductus arteriosus treatment practice in Switzerland

Assessment of farm soil, biochar, compost and weathered pine mulch to mitigate methane emissions

Previous studies have demonstrated the effective utility of volcanic pumice soil to mitigate both high and low levels of methane (CH4) emissions through the activity of both γ-proteobacterial (type I) and α-proteobacterial (type II) aerobic methanotrophs. However, the limited availability of volcanic pumice soil necessitates the assessment of other farm soils and potentially suitable, economical and widely available biofilter materials. The potential biofilter materials, viz. farm soil (isolated from a dairy farm effluent pond bank area), pine biochar, garden waste compost and weathered pine bark mulch, were inoculated with a small amount of volcanic pumice soil. Simultaneously, a similar set-up of potential biofilter materials without inoculum was studied to understand the effect of the inoculum on the ability of these materials to oxidise CH4 and their effect on methanotroph growth and activity. These materials were incubated at 25 °C with periodic feeding of CH4, and flasks were aerated with air (O2) to support methanotroph growth and activity by maintaining aerobic conditions. The efficiency of CH4 removal was monitored over 6 months. All materials supported the growth and activity of methanotrophs. However, the efficiency of CH4 removal by all the materials tested fluctuated between no or low removal (0–40 %) and high removal phases (>90 %), indicating biological disturbances rather than physico-chemical changes. Among all the treatments, CH4 removal was consistently high (>80 %) in the inoculated farm soil and inoculated biochar, and these were more resilient to changes in the methanotroph community. The CH4 removal from inoculated farm soil and inoculated biochar was further enhanced (up to 99 %) by the addition of a nutrient solution. Our results showed that (i) farm soil and biochar can be used as a biofilter material by inoculating with an active methanotroph community, (ii) an abundant population of α-proteobacterial methanotrophs is essential for effective and stable CH4 removal and (iii) addition of nutrients enhances the growth and activity of methanotrophs in the biofilter materials. Further studies are underway to assess the feasibility of these materials at small plot and field scales.No Full Tex

Associations of intraoperative end–tidal CO2 levels with postoperative outcome–secondary analysis of a worldwide observational study

Background: Patients receiving intraoperative ventilation during general anesthesia often have low end-tidal CO2 (etCO2). We examined the association of intraoperative etCO2 levels with the occurrence of postoperative pulmonary complications (PPCs) in a conveniently-sized international, prospective study named 'Local ASsessment of Ventilatory management during General Anesthesia for Surgery' (LAS VEGAS). Methods: Patients at high risk of PPCs were categorized as 'low etCO2' or 'normal to high etCO2' patients, using a cut-off of 35 mmHg. The primary endpoint was a composite of previously defined PPCs; the individual PPCs served as secondary endpoints. The need for unplanned oxygen was defined as mild PPCs and severe PPCs included pneumonia, respiratory failure, acute respiratory distress syndrome, barotrauma, and new invasive ventilation. We performed propensity score matching and LOESS regression to evaluate the relationship between the lowest etCO2 and PPCs. Results: The analysis included 1843 (74 %) 'low etCO2' patients and 648 (26 %) 'normal to high etCO2' patients. There was no difference in the occurrence of PPCs between 'low etCO2' and 'normal to high etCO2' patients (20 % vs. 19 %; RR 1.00 [95 %-confidence interval 0.94 to 1.06]; P = 0.84). The proportion of severe PPCs among total occurring PPCs, were higher in 'low etCO2' patients compared to 'normal to high etCO2' patients (35 % vs. 18 %; RR 1.16 [1.08 to 1.25]; P < 0.001). Propensity score matching did not change these findings. LOESS plot showed an inverse relationship of intraoperative etCO2 levels with the occurrence of PPCs. Conclusions: In this cohort of patients at high risk of PPCs, the overall occurrence of PPCs was not different between 'low etCO2' patients and 'normal to high etCO2' patients, but severe PPCs occurred more often in 'low etCO2', with an inverse dose-dependent relationship between intraoperative etCO2 levels and PPCs. Funding: This analysis was performed without additional funding. LAS VEGAS was partially funded and endorsed by the European Society of Anesthesiology and Intensive Care (ESAIC) and the Amsterdam University Medical Centers, location 'AMC'. Registration: LAS VEGAS was registered at Clinicaltrials.gov (NCT01601223), first posted on May 17, 2012

Intraoperative ventilator settings and their association with postoperative pulmonary complications in neurosurgical patients: Post-hoc analysis of LAS VEGAS study

Background: Limited information is available regarding intraoperative ventilator settings and the incidence of postoperative pulmonary complications (PPCs) in patients undergoing neurosurgical procedures. The aim of this post-hoc analysis of the 'Multicentre Local ASsessment of VEntilatory management during General Anaesthesia for Surgery' (LAS VEGAS) study was to examine the ventilator settings of patients undergoing neurosurgical procedures, and to explore the association between perioperative variables and the development of PPCs in neurosurgical patients. Methods: Post-hoc analysis of LAS VEGAS study, restricted to patients undergoing neurosurgery. Patients were stratified into groups based on the type of surgery (brain and spine), the occurrence of PPCs and the assess respiratory risk in surgical patients in Catalonia (ARISCAT) score risk for PPCs. Results: Seven hundred eighty-four patients were included in the analysis; 408 patients (52%) underwent spine surgery and 376 patients (48%) brain surgery. Median tidal volume (VT) was 8 ml [Interquartile Range, IQR = 7.3-9] per predicted body weight; median positive end-expiratory pressure (PEEP) was 5 [3 to 5] cmH20. Planned recruitment manoeuvres were used in the 6.9% of patients. No differences in ventilator settings were found among the sub-groups. PPCs occurred in 81 patients (10.3%). Duration of anaesthesia (odds ratio, 1.295 [95% confidence interval 1.067 to 1.572]; p = 0.009) and higher age for the brain group (odds ratio, 0.000 [0.000 to 0.189]; p = 0.031), but not intraoperative ventilator settings were independently associated with development of PPCs. Conclusions: Neurosurgical patients are ventilated with low VT and low PEEP, while recruitment manoeuvres are seldom applied. Intraoperative ventilator settings are not associated with PPCs

Association between night-time surgery and occurrence of intraoperative adverse events and postoperative pulmonary complications

Background: The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs)

Intraoperative ventilator settings and their association with postoperative pulmonary complications in neurosurgical patients: post-hoc analysis of LAS VEGAS study

Background: Limited information is available regarding intraoperative ventilator settings and the incidence of postoperative pulmonary complications (PPCs) in patients undergoing neurosurgical procedures. The aim of this post-hoc analysis of the 'Multicentre Local ASsessment of VEntilatory management during General Anaesthesia for Surgery' (LAS VEGAS) study was to examine the ventilator settings of patients undergoing neurosurgical procedures, and to explore the association between perioperative variables and the development of PPCs in neurosurgical patients. Methods: Post-hoc analysis of LAS VEGAS study, restricted to patients undergoing neurosurgery. Patients were stratified into groups based on the type of surgery (brain and spine), the occurrence of PPCs and the assess respiratory risk in surgical patients in Catalonia (ARISCAT) score risk for PPCs. Results: Seven hundred eighty-four patients were included in the analysis; 408 patients (52%) underwent spine surgery and 376 patients (48%) brain surgery. Median tidal volume (VT) was 8 ml [Interquartile Range, IQR = 7.3-9] per predicted body weight; median positive end-expiratory pressure (PEEP) was 5 [3 to 5] cmH20. Planned recruitment manoeuvres were used in the 6.9% of patients. No differences in ventilator settings were found among the sub-groups. PPCs occurred in 81 patients (10.3%). Duration of anaesthesia (odds ratio, 1.295 [95% confidence interval 1.067 to 1.572]; p = 0.009) and higher age for the brain group (odds ratio, 0.000 [0.000 to 0.189]; p = 0.031), but not intraoperative ventilator settings were independently associated with development of PPCs. Conclusions: Neurosurgical patients are ventilated with low VT and low PEEP, while recruitment manoeuvres are seldom applied. Intraoperative ventilator settings are not associated with PPCs