The number of comorbidities as an important cofactor to ASA class in predicting postoperative outcome: An international multicentre cohort study.

BACKGROUND: Multimorbidity is a growing burden in our ageing society and is associated with perioperative morbidity and mortality. Despite several modifications to the ASA physical status classification, multimorbidity as such is still not considered. Thus, the aim of this study was to quantify the burden of comorbidities in perioperative patients and to assess, independent of ASA class, its potential influence on perioperative outcome. METHODS: In a subpopulation of the prospective ClassIntra® validation study from eight international centres, type and severity of anaesthesia-relevant comorbidities were additionally extracted from electronic medical records for the current study. Patients from the validation study were of all ages, undergoing any type of in-hospital surgery and were followed up until 30 days postoperatively to assess perioperative outcomes. Primary endpoint was the number of comorbidities across ASA classes. The associated postoperative length of hospital stay (pLOS) and Comprehensive Complication Index (CCI®) were secondary endpoints. On a scale from 0 (no complication) to 100 (death) the CCI® measures the severity of postoperative morbidity as a weighted sum of all postoperative complications. RESULTS: Of 1421 enrolled patients, the mean number of comorbidities significantly increased from 1.5 in ASA I (95% CI, 1.1-1.9) to 10.5 in ASA IV (95% CI, 8.3-12.7) patients. Furthermore, independent of ASA class, postoperative complications measured by the CCI® increased per each comorbidity by 0.81 (95% CI, 0.40-1.23) and so did pLOS (geometric mean ratio, 1.03; 95% CI, 1.01-1.06). CONCLUSIONS: These data quantify the high prevalence of multimorbidity in the surgical population and show that the number of comorbidities is predictive of negative postoperative outcomes, independent of ASA class.

Randomized comparison of sevoflurane versus propofol to reduce perioperative myocardial ischemia in patients undergoing noncardiac surgery.

BACKGROUND: Volatile anesthetics provide myocardial preconditioning in coronary surgery patients. We hypothesized that sevoflurane compared with propofol reduces the incidence of myocardial ischemia in patients undergoing major noncardiac surgery. METHODS AND RESULTS: We enrolled 385 patients at cardiovascular risk in 3 centers. Patients were randomized to maintenance of anesthesia with sevoflurane or propofol. We recorded continuous ECG for 48 hours perioperatively, measured troponin T and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) on postoperative days 1 and 2, and evaluated postoperative delirium by the Confusion Assessment Method. At 6 and 12 months, we contacted patients by telephone to assess major adverse cardiac events. The primary end point was a composite of myocardial ischemia detected by continuous ECG and/or troponin elevation. Additional end points were postoperative NT-proBNP concentrations, major adverse cardiac events, and delirium. Patients and outcome assessors were blinded. We tested dichotomous end points by χ(2) test and NT-proBNP by Mann-Whitney test on an intention-to-treat basis. Myocardial ischemia occurred in 75 patients (40.8%) in the sevoflurane and 81 (40.3%) in the propofol group (relative risk, 1.01; 95% confidence interval, 0.78-1.30). NT-proBNP release did not differ across allocation on postoperative day 1 or 2. Within 12 months, 14 patients (7.6%) suffered a major adverse cardiac event after sevoflurane and 17 (8.5%) after propofol (relative risk, 0.90; 95% confidence interval, 0.44-1.83). The incidence of delirium did not differ (11.4% versus 14.4%; P=0.379). CONCLUSIONS: Compared with propofol, sevoflurane did not reduce the incidence of myocardial ischemia in high-risk patients undergoing major noncardiac surgery. The sevoflurane and propofol groups did not differ in postoperative NT-proBNP release, major adverse cardiac events at 1 year, or delirium.

Efficacy of individual nucleic acid amplification testing in reducing the risk of transfusion-transmitted hepatitis B virus infection in Switzerland, a low-endemic region.

BACKGROUND: The risk of transfusion-transmitted hepatitis B virus (HBV) in Switzerland by testing blood donors for hepatitis B surface antigen (HBsAg) alone has been historically estimated at 1:160,000 transfusions. The Swiss health authorities decided not to introduce mandatory antibody to hepatitis B core antigen (anti-HBc) testing but to evaluate the investigation of HBV nucleic acid testing (NAT). STUDY DESIGN AND METHODS: Between June 2007 and February 2009, a total of 306,000 donations were screened routinely for HBsAg and HBV DNA by triplex individual-donation (ID)-NAT (Ultrio assay on Tigris system, Gen-Probe/Novartis Diagnostics). ID-NAT repeatedly reactive donors were further characterized for HBV serologic markers and viral load by quantitative polymerase chain reaction. The relative sensitivity of screening for HBsAg, anti-HBc, and HBV DNA was assessed. The residual HBV transmission risk of NAT with or without anti-HBc and HBsAg was retrospectively estimated in a mathematical model. RESULTS: From the 306,000 blood donations, 31 were repeatedly Ultrio test reactive and confirmed HBV infected, of which 24 (77%) and 27 (87%) were HBsAg and anti-HBc positive, respectively. Seven HBV-NAT yields were identified (1:44,000), two pre-HBsAg window period (WP) donations (1:153,000) and five occult HBV infections (1:61,000). Introduction of ID-NAT reduced the risk of HBV WP transmission in repeat donors from 1:95,000 to 1:296,000. CONCLUSIONS: Triplex NAT screening reduced the HBV WP transmission risk approximately threefold. NAT alone was more efficacious than the combined use of HBsAg and anti-HBc. The data from this study led to the decision to introduce sensitive HBV-NAT screening in Switzerland. Our findings may be useful in designing more efficient and cost-effective HBV screening strategies in low-prevalence countries.

Prospective validation of classification of intraoperative adverse events (ClassIntra): international, multicentre cohort study.

OBJECTIVE: To prospectively assess the construct and criterion validity of ClassIntra version 1.0, a newly developed classification for assessing intraoperative adverse events. DESIGN: International, multicentre cohort study. SETTING: 18 secondary and tertiary centres from 12 countries in Europe, Oceania, and North America. PARTICIPANTS: The cohort study included a representative sample of 2520 patients in hospital having any type of surgery, followed up until discharge. A follow-up to assess mortality at 30 days was performed in 2372 patients (94%). A survey was sent to a representative sample of 163 surgeons and anaesthetists from participating centres. MAIN OUTCOME MEASURES: Intraoperative complications were assessed according to ClassIntra. Postoperative complications were assessed daily until discharge from hospital with the Clavien-Dindo classification. The primary endpoint was construct validity by investigating the risk adjusted association between the most severe intraoperative and postoperative complications, measured in a multivariable hierarchical proportional odds model. For criterion validity, inter-rater reliability was evaluated in a survey of 10 fictitious case scenarios describing intraoperative complications. RESULTS: Of 2520 patients enrolled, 610 (24%) experienced at least one intraoperative adverse event and 838 (33%) at least one postoperative complication. Multivariable analysis showed a gradual increase in risk for a more severe postoperative complication with increasing grade of ClassIntra: ClassIntra grade I versus grade 0, odds ratio 0.99 (95% confidence interval 0.69 to 1.42); grade II versus grade 0, 1.39 (0.97 to 2.00); grade III versus grade 0, 2.62 (1.31 to 5.26); and grade IV versus grade 0, 3.81 (1.19 to 12.2). ClassIntra showed high criterion validity with an intraclass correlation coefficient of 0.76 (95% confidence interval 0.59 to 0.91) in the survey (response rate 83%). CONCLUSIONS: ClassIntra is the first prospectively validated classification for assessing intraoperative adverse events in a standardised way, linking them to postoperative complications with the well established Clavien-Dindo classification. ClassIntra can be incorporated into routine practice in perioperative surgical safety checklists, or used as a monitoring and outcome reporting tool for different surgical disciplines. Future studies should investigate whether the tool is useful to stratify patients to the appropriate postoperative care, to enhance the quality of surgical interventions, and to improve long term outcomes of surgical patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT03009929.