Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine.

SummaryWe conducted a meta-analysis of the utility of pre-operative B-type natriuretic peptide (BNP) and N-terminal-pro B-type natriuretic peptide in predicting early (< 30 days) and intermediate (< 180 days) term mortality and major adverse cardiac events (cardiac death and nonfatal myocardial infarction) in patients following vascular surgery. A Pubmed Central and EMBASE search was conducted up to January 2008. Of 81 studies identified, seven prospective observational studies were included in the meta-analysis representing five patient cohorts: early outcomes (504 patients) and intermediate-term outcomes (623 patients). A B-type natriuretic peptide or N-terminal-pro B-type natriuretic peptide above the optimal discriminatory threshold determined by receiver operating characteristic curve analysis was associated with 30-day cardiac death (OR 7.6, 95% CI 1.33-43.4, p = 0.02), nonfatal myocardial infarction (OR 6.24, 95% CI 1.82-21.4, p = 0.004) and major adverse cardiac events (OR 17.37, 95% CI 3.31-91.15, p = 0.0007), and intermediate-term, all-cause mortality (OR 3.1, 95% CI 1.85-5.2, p < 0.0001), nonfatal myocardial infarction (OR 2.95, 95% CI 1.17-7.46, p = 0.02) and major adverse cardiac events (OR 3.31, 95% CI 2.1-5.24, p < 0.00001). B-type natriuretic peptide and N-terminal-pro B-type natriuretic peptide are potentially useful pre-operative prognostic tests in vascular surgical patients. Vascular surgery is associated with major adverse perioperative cardiac events. Unfortunately, the currently used pre-operative diagnostic tests for these patients are not statistically robust enough to accurately predict these events [1]. This was recently confirmed in a meta-analysis of six pre-operative tests for vascular surgical patients, which included: ambulatory ECG, exercise ECG, radionuclide ventriculography, myocardial perfusion scintigraphy, dipyridamole stress echocardiography and dobutamine stress echocardiography [2]. Dobutamine stress echocardiography had a trend to the best performance of the six tests for the prediction of major adverse cardiac events (defined as peri-operative cardiac death and nonfatal myocardial infarction (MI)) within 30 days of surgery [2], with a positive likelihood ratio (LR) and negative LR of 2.8 and 0.21 respectively. As statistically good discrimination requires a LR of < 0.2 and > 10, there are clearly clinical limitations to the utility of these pre-operative tests for vascular surgical patients [1].There has been recent interest in brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) as prognostic biomarkers of death and major cardiovascular events, even after control for other cardiovascular risk factors [3]. BNP is an

SummaryWe conducted a meta-analysis of the utility of pre-operative C reactive protein (CRP) in predicting early (< 30 days), intermediate (30-180 days) and long term (> 180 days) mortality and major adverse cardiac events (MACE; cardiac mortality and nonfatal myocardial infarction (MI) combined) following vascular surgery. Of 291 studies identified, ten prospective patient cohorts were identified. A pre-operative CRP > 3 mg. Vascular surgery is associated with major adverse perioperative cardiac events. Unfortunately, currently used pre-operative diagnostic tests for these patients are not statistically robust enough to accurately predict these events [1]. A meta-analysis of six pre-operative tests for vascular surgical patients which included; ambulatory ECG, exercise ECG, radionuclide ventriculography, myocardial perfusion scintigraphy, dipyridamole stress echocardiography and dobutamine stress echocardiography, showed that dobutamine stress echocardiography had a trend to the best performance of the six tests for the prediction of major adverse cardiac events (MACE; defined as peri-operative cardiac death and non-fatal myocardial infarction (MI) within 30 days of surgery [2]), with a positive likelihood ratio (LR) and negative LR of 2.8 and 0.21 respectively. As statistically, good discrimination requires a LR of > 10 and < 0.2, there are clearly clinical limitations to the utility of these pre-operative tests for vascular surgical patients [1].

Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high‐ (HICs) and low‐ and middle‐income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7‐day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally.