Method of Anesthesia and Perioperative Risk Factors, Maternal Anesthesia Complications, and Neonatal Mortality Following Cesarean Delivery in Africa: A Substudy of a 7-Day Prospective Observational Cohort Study.

BACKGROUND: The African Surgical Outcomes Study (ASOS) found that maternal mortality following cesarean delivery in Africa is 50 times higher than in high-income countries, and associated with obstetric hemorrhage and anesthesia complications. Mothers who died were more likely to receive general anesthesia (GA). The associations between GA versus spinal anesthesia (SA) and preoperative risk factors, maternal anesthesia complications, and neonatal outcomes following cesarean delivery in Africa are unknown. METHODS: This is a secondary explanatory analysis of 3792 patients undergoing cesarean delivery in ASOS, a prospective observational cohort study, across 22 African countries. The primary aim was to estimate the association between preoperative risk factors and the outcome of the method of anesthesia delivered. Secondary aims were to estimate the association between the method of anesthesia and the outcomes (1) maternal intraoperative hypotension, (2) severe maternal anesthesia complications, and (3) neonatal mortality. Generalized linear mixed models adjusting for obstetric gravidity and gestation, American Society of Anesthesiologists (ASA) category, urgency of surgery, maternal comorbidities, fetal distress, and level of anesthesia provider were used. RESULTS: Of 3709 patients, SA was performed in 2968 (80%) and GA in 741 (20%). Preoperative factors independently associated with GA for cesarean delivery were gestational age (adjusted odds ratio [aOR], 1.093; 95% confidence interval [CI], 1.052-1.135), ASA categories III (aOR, 11.84; 95% CI, 2.93-46.31) and IV (aOR, 11.48; 95% CI, 2.93-44.93), eclampsia (aOR, 3.92; 95% CI, 2.18-7.06), placental abruption (aOR, 6.23; 95% CI, 3.36-11.54), and ruptured uterus (aOR, 3.61; 95% CI, 1.36-9.63). SA was administered to 48 of 94 (51.1%) patients with eclampsia, 12 of 28 (42.9%) with cardiac disease, 14 of 19 (73.7%) with preoperative sepsis, 48 of 76 (63.2%) with antepartum hemorrhage, 30 of 55 (54.5%) with placenta previa, 33 of 78 (42.3%) with placental abruption, and 12 of 29 (41.4%) with a ruptured uterus. The composite maternal outcome "all anesthesia complications" was more frequent in GA than SA (9/741 [1.2%] vs 3/2968 [0.1%], P < .001). The unadjusted neonatal mortality was higher with GA than SA (65/662 [9.8%] vs 73/2669 [2.7%], P < .001). The adjusted analyses demonstrated no association between method of anesthesia and (1) intraoperative maternal hypotension and (2) neonatal mortality. CONCLUSIONS: Analysis of patients undergoing anesthesia for cesarean delivery in Africa indicated patients more likely to receive GA. Anesthesia complications and neonatal mortality were more frequent following GA. SA was often administered to high-risk patients, including those with eclampsia or obstetric hemorrhage. Training in the principles of selection of method of anesthesia, and the skills of safe GA and neonatal resuscitation, is recommended.

High-Sensitivity Cardiac Troponin I Thresholds to Identify Myocardial Injury After Noncardiac Surgery: A Cohort Study.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) is common and associated with short- and long-term major cardiovascular events. Diagnostic criteria for MINS using Abbott high-sensitivity cardiac troponin I (hs-cTnI) are unknown. METHODS: We performed a prospective cohort study of adults who had in-patient noncardiac surgery and measured hs-cTnI (Abbott Laboratories) on postoperative serum samples collected up to postoperative day 3. The objective was to determine prognostically important hs-cTnI thresholds associated with major cardiac events and death at 30 days after noncardiac surgery. Using Cox proportional iterative analyses, we determined peak postoperative hs-cTnI thresholds associated with the occurrence of the 30-day composite of major cardiac events (ie, nonfatal myocardial infarction after 3 postoperative days, cardiac arrest, and congestive heart failure) and death. RESULTS: Of 3953 included patients, 66 (1.7%) experienced the primary outcome at 30 days. Peak hs-cTnI values and associated incidence of major cardiac events and death were as follows: < 60 ng/L: 1.0% (95% CI 0.7-1.3); 60 to < 700 ng/L: 8.6% (5.6-13.0); and ≥ 700 ng/L: 27.3% (16.4-41.9). Compared with peak hs-cTnI < 60 ng/L, adjusted hazard ratios were 7.54 (95% CI% 4.27-13.32) for hs-cTnI values of 60 to < 700 ng/L and 26.87 (13.27-54.41) for values ≥ 700 ng/L. CONCLUSIONS: Hs-cTnI elevation within the first 3 days after noncardiac surgery independently predicts major cardiac events and death at 30 days. A postoperative hs-cTnI ≥ 60 ng/L was associated with a > 7-fold increase in the risk of subsequent major cardiac events and mortality at 30 days.

An Evaluation of Severe Anesthetic-Related Critical Incidents and Risks From the South African Paediatric Surgical Outcomes Study: A 14-Day Prospective, Observational Cohort Study of Pediatric Surgical Patients.

BACKGROUND: Severe anesthetic-related critical incident (SARCI) monitoring is an essential component of safe, quality anesthetic care. Predominantly retrospective data from low- and middle-income countries (LMICs) report higher incidence but similar types of SARCI compared to high-income countries (HIC). The aim of our study was to describe the baseline incidence of SARCI in a middle-income country (MIC) and to identify associated risk for SARCI. We hypothesized a higher incidence but similar types of SARCI and risks compared to HICs. METHODS: We performed a 14-day, prospective multicenter observational cohort study of pediatric patients (aged <16 years) undergoing surgery in government-funded hospitals in South Africa, a MIC, to determine perioperative outcomes. This analysis described the incidence and types of SARCI and associated perioperative cardiac arrests (POCAs). We used multivariable logistic regression analysis to identify risk factors independently associated with SARCI, including 7 a priori variables and additional candidate variables based on their univariable performance. RESULTS: Two thousand and twenty-four patients were recruited from May 22 to August 22, 2017, at 43 hospitals. The mean age was 5.9 years (±standard deviation 4.2). A majority of patients during this 14-day period were American Society of Anesthesiologists (ASA) physical status I (66.4%) or presenting for minor surgery (54.9%). A specialist anesthesiologist managed 59% of cases. These patients were found to be significantly younger (P < .001) and had higher ASA physical status (P < .001). A total of 426 SARCI was documented in 322 of 2024 patients, an overall incidence of 15.9% (95% confidence interval [CI], 14.4-17.6). The most common event was respiratory (214 of 426; 50.2%) with an incidence of 8.5% (95% CI, 7.4-9.8). Six children (0.3%; 95% CI, 0.1-0.6) had a POCA, of whom 4 died in hospital. Risks independently associated with a SARCI were age (adjusted odds ratio [aOR] = 0.95; CI, 0.92-0.98; P = .004), increasing ASA physical status (aOR = 1.85, 1,74, and 2.73 for ASA II, ASA III, and ASA IV-V physical status, respectively), urgent/emergent surgery (aOR = 1.35, 95% CI, 1.02-1.78; P = .036), preoperative respiratory infection (aOR = 2.47, 95% CI, 1.64-3.73; P < .001), chronic respiratory comorbidity (aOR = 1.75, 95% CI, 1.10-2.79; P = .018), severity of surgery (intermediate surgery aOR = 1.84, 95% CI, 1.39-2.45; P < .001), and level of hospital (first-level hospitals aOR = 2.81, 95% CI, 1.60-4.93; P < .001). CONCLUSIONS: The incidence of SARCI in South Africa was 3 times greater than in HICs, and an associated POCA was 10 times more common. The risk factors associated with SARCI may assist with targeted interventions to improve safety and to triage children to the optimal level of care.

Development of a Clinical Prediction Model for In-hospital Mortality from the South African Cohort of the African Surgical Outcomes Study.

BACKGROUND: Data on the factors that influence mortality after surgery in South Africa are scarce, and neither these data nor data on risk-adjusted in-hospital mortality after surgery are routinely collected. Predictors related to the context or setting of surgical care delivery may also provide insight into variation in practice. Variation must be addressed when planning for improvement of risk-adjusted outcomes. Our objective was to identify the factors predicting in-hospital mortality after surgery in South Africa from available data. METHODS: A multivariable logistic regression model was developed to identify predictors of 30-day in-hospital mortality in surgical patients in South Africa. Data from the South African contribution to the African Surgical Outcomes Study were used and included 3800 cases from 51 hospitals. A forward stepwise regression technique was then employed to select for possible predictors prior to model specification. Model performance was evaluated by assessing calibration and discrimination. The South African Surgical Outcomes Study cohort was used to validate the model. RESULTS: Variables found to predict 30-day in-hospital mortality were age, American Society of Anesthesiologists Physical Status category, urgent or emergent surgery, major surgery, and gastrointestinal-, head and neck-, thoracic- and neurosurgery. The area under the receiver operating curve or c-statistic was 0.859 (95% confidence interval: 0.827-0.892) for the full model. Calibration, as assessed using a calibration plot, was acceptable. Performance was similar in the validation cohort as compared to the derivation cohort. CONCLUSION: The prediction model did not include factors that can explain how the context of care influences post-operative mortality in South Africa. It does, however, provide a basis for reporting risk-adjusted perioperative mortality rate in the future, and identifies the types of surgery to be prioritised in quality improvement projects at a local or national level.

Natriuretic peptide-directed medical therapy: a systematic review.

Natriuretic peptides (NP) are strongly associated with perioperative cardiovascular events. However, in patients with raised NP, it remains unknown whether treatment to reduce NP levels prior to surgery results in better perioperative outcomes. In this systematic review and meta-analysis, we investigate NP-directed medical therapy in non-surgical patients to provide guidance for NP-directed medical therapy in surgical patients. The protocol was registered with PROSPERO (CRD42017051468). The database search included MEDLINE (PubMed), CINAHL (EBSCO host), EMBASE (EBSCO host), ProQuest, Web of Science, and Cochrane database. The primary outcome was to determine whether NP-directed medical therapy is effective in reducing NP levels within 6 months, compared to standard of care. The secondary outcome was to determine whether reducing NP levels is associated with decreased mortality. Full texts of 18 trials were reviewed. NP-directed medical therapy showed no significant difference compared to standard care in decreasing NP levels (standardized mean difference - 0.04 (- 0.16, 0.07)), but was associated with a 6-month (relative risk (RR) 0.82 (95% confidence interval (CI) 0.68-0.99)) reduction in mortality.

Preoperative N-Terminal Pro-B-Type Natriuretic Peptide and Cardiovascular Events After Noncardiac Surgery: A Cohort Study.

Background: Preliminary data suggest that preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) may improve risk prediction in patients undergoing noncardiac surgery. Objective: To determine whether preoperative NT-proBNP has additional predictive value beyond a clinical risk score for the composite of vascular death and myocardial injury after noncardiac surgery (MINS) within 30 days after surgery. Design: Prospective cohort study. Setting: 16 hospitals in 9 countries. Patients: 10 402 patients aged 45 years or older having inpatient noncardiac surgery. Measurements: All patients had NT-proBNP levels measured before surgery and troponin T levels measured daily for up to 3 days after surgery. Results: In multivariable analyses, compared with preoperative NT-proBNP values less than 100 pg/mL (the reference group), those of 100 to less than 200 pg/mL, 200 to less than 1500 pg/mL, and 1500 pg/mL or greater were associated with adjusted hazard ratios of 2.27 (95% CI, 1.90 to 2.70), 3.63 (CI, 3.13 to 4.21), and 5.82 (CI, 4.81 to 7.05) and corresponding incidences of the primary outcome of 12.3% (226 of 1843), 20.8% (542 of 2608), and 37.5% (223 of 595), respectively. Adding NT-proBNP thresholds to clinical stratification (that is, the Revised Cardiac Risk Index [RCRI]) resulted in a net absolute reclassification improvement of 258 per 1000 patients. Preoperative NT-proBNP values were also statistically significantly associated with 30-day all-cause mortality (less than 100 pg/mL [incidence, 0.3%], 100 to less than 200 pg/mL [incidence, 0.7%], 200 to less than 1500 pg/mL [incidence, 1.4%], and 1500 pg/mL or greater [incidence, 4.0%]). Limitation: External validation of the identified NT-proBNP thresholds in other cohorts would reinforce our findings. Conclusion: Preoperative NT-proBNP is strongly associated with vascular death and MINS within 30 days after noncardiac surgery and improves cardiac risk prediction in addition to the RCRI. Primary Funding Source: Canadian Institutes of Health Research.

An audit of paediatric pain prevalence, intensity, and treatment at a South African tertiary hospital.

INTRODUCTION: Pain in paediatric inpatients is common, underrecognised, and undertreated in resource-rich countries. Little is known about the status of paediatric pain prevention and treatment in low- and middle-income countries. OBJECTIVES: This audit aimed to describe the prevalence and severity of pain in paediatric patients at a tertiary hospital in South Africa. METHOD: A single-day prospective observational cross-sectional survey and medical chart review of paediatric inpatients at Grey's Hospital, Pietermaritzburg, South Africa. RESULTS: Sixty-three children were included, and mean patient age was 9.7 years (SD 6.17). Most patients (87%) had pain during admission, with 29% reporting preexisting (possibly chronic) pain. At the time of the study, 25% had pain (median pain score 6/10). The worst pain reported was from needle procedures, including blood draws, injections, and venous cannulation (34%), followed by surgery (22%), acute illness/infection (18%), and other procedures (14%). Pharmacological treatments included WHO step 1 (paracetamol and ibuprofen) and step 2 (tramadol, tilidine, and morphine) analgesics. The most effective integrative interventions were distraction, swaddling, and caregiver participation. Although a pain narrative was present in the majority of charts, only 16% had documented pain intensity scores. CONCLUSION: The prevalence of pain in hospitalised children in a large South African Hospital was high and pain assessment inadequately documented. There is an urgent need for pain education and development of guidelines and protocols, to achieve better pain outcomes for children. This audit will be repeated as part of a quality-improvement initiative.

Dabigatran in patients with myocardial injury after non-cardiac surgery (MANAGE): an international, randomised, placebo-controlled trial.

BACKGROUND: Myocardial injury after non-cardiac surgery (MINS) increases the risk of cardiovascular events and deaths, which anticoagulation therapy could prevent. Dabigatran prevents perioperative venous thromboembolism, but whether this drug can prevent a broader range of vascular complications in patients with MINS is unknown. The MANAGE trial assessed the potential of dabigatran to prevent major vascular complications among such patients. METHODS: In this international, randomised, placebo-controlled trial, we recruited patients from 84 hospitals in 19 countries. Eligible patients were aged at least 45 years, had undergone non-cardiac surgery, and were within 35 days of MINS. Patients were randomly assigned (1:1) to receive dabigatran 110 mg orally twice daily or matched placebo for a maximum of 2 years or until termination of the trial and, using a partial 2-by-2 factorial design, patients not taking a proton-pump inhibitor were also randomly assigned (1:1) to omeprazole 20 mg once daily, for which results will be reported elsewhere, or matched placebo to measure its effect on major upper gastrointestinal complications. Research personnel randomised patients through a central 24 h computerised randomisation system using block randomisation, stratified by centre. Patients, health-care providers, data collectors, and outcome adjudicators were masked to treatment allocation. The primary efficacy outcome was the occurrence of a major vascular complication, a composite of vascular mortality and non-fatal myocardial infarction, non-haemorrhagic stroke, peripheral arterial thrombosis, amputation, and symptomatic venous thromboembolism. The primary safety outcome was a composite of life-threatening, major, and critical organ bleeding. Analyses were done according to the intention-to-treat principle. This trial is registered with ClinicalTrials.gov, number NCT01661101. FINDINGS: Between Jan 10, 2013, and July 17, 2017, we randomly assigned 1754 patients to receive dabigatran (n=877) or placebo (n=877); 556 patients were also randomised in the omeprazole partial factorial component. Study drug was permanently discontinued in 401 (46%) of 877 patients allocated to dabigatran and 380 (43%) of 877 patients allocated to placebo. The composite primary efficacy outcome occurred in fewer patients randomised to dabigatran than placebo (97 [11%] of 877 patients assigned to dabigatran vs 133 [15%] of 877 patients assigned to placebo; hazard ratio [HR] 0·72, 95% CI 0·55-0·93; p=0·0115). The primary safety composite outcome occurred in 29 patients (3%) randomised to dabigatran and 31 patients (4%) randomised to placebo (HR 0·92, 95% CI 0·55-1·53; p=0·76). INTERPRETATION: Among patients who had MINS, dabigatran 110 mg twice daily lowered the risk of major vascular complications, with no significant increase in major bleeding. Patients with MINS have a poor prognosis; dabigatran 110 mg twice daily has the potential to help many of the 8 million adults globally who have MINS to reduce their risk of a major vascular complication [corrected]. FUNDING: Boehringer Ingelheim and Canadian Institutes of Health Research.

Humeral Stem Loosening Following Reverse Shoulder Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: Aseptic stem loosening following reverse shoulder arthroplasty (RSA) is an uncommon complication. The timing and the factors contributing to aseptic stem loosening remain poorly understood. METHODS: We performed a systematic review that identified 75 articles; 65 of the included articles were case series (Level-IV evidence), 8 were cohort studies (7 Level III, 1 Level II), and 2 were prospective randomized controlled trials (Level I). A meta-analysis of 1,660 cemented and 805 uncemented RSA stems was performed. We compared the rates of aseptic stem loosening, humeral radiolucent lines, and revision for stem loosening (1) between cemented and uncemented stems in cohorts with short and long mean follow-up periods (<5 and ≥5 years) as well as in all cohorts combined, and (2) among different etiological subgroups. RESULTS: Aseptic stem loosening occurred more commonly in the cohort with long compared with short follow-up time (2% versus 0.8%, p = 0.01). When comparing cemented with uncemented stems, there was no significant difference in the rates of aseptic stem loosening or revision for stem loosening in either the short or long-term follow-up groups. Humeral radiolucent lines were more common with cemented compared with uncemented stems (15.9% versus 9.5%, p = 0.002). Analyzed by etiology, the highest rate of aseptic stem loosening occurred in the tumor subgroup (10.8%), followed by RSA as a revision procedure after a failed arthroplasty (3.7%). No stems in the acute fracture or fracture sequelae subgroups developed aseptic stem loosening. CONCLUSIONS: Aseptic stem loosening occurred more commonly in cohorts with longer follow-up. There were no differences in the rates of aseptic stem loosening or revision for stem loosening between cemented and uncemented stems. Patients treated with RSA following excision of proximal humeral tumors and RSA as a revision procedure after a failed arthroplasty were at greater risk of aseptic stem loosening. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Design of a Randomized Placebo-Controlled Trial to Assess Dabigatran and Omeprazole in Patients with Myocardial Injury after Noncardiac Surgery (MANAGE).

BACKGROUND: Worldwide approximately 200 million adults undergo major surgery annually, of whom 8 million are estimated to suffer a myocardial injury after noncardiac surgery (MINS). There is currently no trial data informing the management of MINS. Antithrombotic agents such as direct oral anticoagulants might prevent major vascular complications in patients with MINS. METHODS: The Management of Myocardial Injury After Noncardiac Surgery (MANAGE) trial is a large international blinded randomized controlled trial of dabigatran vs placebo in patients who suffered MINS. We used a partial factorial design to also determine the effect of omeprazole vs placebo in reducing upper gastrointestinal bleeding and complications. Both study drugs were initiated in eligible patients within 35 days of suffering MINS and continued for a maximum of 2 years. The primary outcome is a composite of major vascular complications for the dabigatran trial and a composite of upper gastrointestinal complications for the omeprazole trial. We present the rationale and design of the trial and baseline characteristics of enrolled patients. RESULTS: The trial randomized 1754 patients between January 2013 and July 2017. Patients' mean age was 69.9 years, 51.1% were male, 14.3% had a history of peripheral artery disease, 6.6% had a history of stroke or transient ischemic attack, 12.9% had a previous myocardial infarction, and 26.0% had diabetes. The diagnosis of MINS was on the basis of an isolated ischemic troponin elevation in 80.4% of participants. CONCLUSION: MANAGE is the first randomized controlled trial to evaluate a potential treatment of patients who suffered MINS.

A Prospective International Multicentre Cohort Study of Intraoperative Heart Rate and Systolic Blood Pressure and Myocardial Injury After Noncardiac Surgery: Results of the VISION Study.

BACKGROUND: The association between intraoperative cardiovascular changes and perioperative myocardial injury has chiefly focused on hypotension during noncardiac surgery. However, the relative influence of blood pressure and heart rate (HR) remains unclear. We investigated both individual and codependent relationships among intraoperative HR, systolic blood pressure (SBP), and myocardial injury after noncardiac surgery (MINS). METHODS: Secondary analysis of the Vascular Events in Noncardiac Surgery Cohort Evaluation (VISION) study, a prospective international cohort study of noncardiac surgical patients. Multivariable logistic regression analysis tested for associations between intraoperative HR and/or SBP and MINS, defined by an elevated serum troponin T adjudicated as due to an ischemic etiology, within 30 days after surgery. Predefined thresholds for intraoperative HR and SBP were: maximum HR >100 beats or minimum HR <55 beats per minute (bpm); maximum SBP >160 mm Hg or minimum SBP <100 mm Hg. Secondary outcomes were myocardial infarction and mortality within 30 days after surgery. RESULTS: After excluding missing data, 1197 of 15,109 patients (7.9%) sustained MINS, 454 of 16,031 (2.8%) sustained myocardial infarction, and 315 of 16,061 patients (2.0%) died within 30 days after surgery. Maximum intraoperative HR >100 bpm was associated with MINS (odds ratio [OR], 1.27 [1.07-1.50]; P < .01), myocardial infarction (OR, 1.34 [1.05-1.70]; P = .02), and mortality (OR, 2.65 [2.06-3.41]; P < .01). Minimum SBP <100 mm Hg was associated with MINS (OR, 1.21 [1.05-1.39]; P = .01) and mortality (OR, 1.81 [1.39-2.37]; P < .01), but not myocardial infarction (OR, 1.21 [0.98-1.49]; P = .07). Maximum SBP >160 mm Hg was associated with MINS (OR, 1.16 [1.01-1.34]; P = .04) and myocardial infarction (OR, 1.34 [1.09-1.64]; P = .01) but, paradoxically, reduced mortality (OR, 0.76 [0.58-0.99]; P = .04). Minimum HR <55 bpm was associated with reduced MINS (OR, 0.70 [0.59-0.82]; P < .01), myocardial infarction (OR, 0.75 [0.58-0.97]; P = .03), and mortality (OR, 0.58 [0.41-0.81]; P < .01). Minimum SBP <100 mm Hg with maximum HR >100 bpm was more strongly associated with MINS (OR, 1.42 [1.15-1.76]; P < .01) compared with minimum SBP <100 mm Hg alone (OR, 1.20 [1.03-1.40]; P = .02). CONCLUSIONS: Intraoperative tachycardia and hypotension are associated with MINS. Further interventional research targeting HR/blood pressure is needed to define the optimum strategy to reduce MINS.

Period-dependent Associations between Hypotension during and for Four Days after Noncardiac Surgery and a Composite of Myocardial Infarction and Death: A Substudy of the POISE-2 Trial.

BACKGROUND: The relative contributions of intraoperative and postoperative hypotension to perioperative morbidity remain unclear. We determined the association between hypotension and a composite of 30-day myocardial infarction and death over three periods: (1) intraoperative, (2) remaining day of surgery, and (3) during the initial four postoperative days. METHODS: This was a substudy of POISE-2, a 10,010-patient factorial-randomized trial of aspirin and clonidine for prevention of myocardial infarction. Clinically important hypotension was defined as systolic blood pressure less than 90 mmHg requiring treatment. Minutes of hypotension was the exposure variable intraoperatively and for the remaining day of surgery, whereas hypotension status was treated as binary variable for postoperative days 1 to 4. We estimated the average relative effect of hypotension across components of the composite using a distinct effect generalized estimating model, adjusting for hypotension during earlier periods. RESULTS: Among 9,765 patients, 42% experienced hypotension, 590 (6.0%) had an infarction, and 116 (1.2%) died within 30 days of surgery. Intraoperatively, the estimated average relative effect across myocardial infarction and mortality was 1.08 (98.3% CI, 1.03, 1.12; P < 0.001) per 10-min increase in hypotension duration. For the remaining day of surgery, the odds ratio was 1.03 (98.3% CI, 1.01, 1.05; P < 0.001) per 10-min increase in hypotension duration. The average relative effect odds ratio was 2.83 (98.3% CI, 1.26, 6.35; P = 0.002) in patients with hypotension during the subsequent four days of hospitalization. CONCLUSIONS: Clinically important hypotension-a potentially modifiable exposure-was significantly associated with a composite of myocardial infarction and death during each of three perioperative periods, even after adjustment for previous hypotension.

Colchicine for Prevention of Perioperative Atrial Fibrillation in patients undergoing lung resection surgery: a pilot randomized controlled study.

OBJECTIVES: We carried out a pilot randomized controlled study to determine the feasibility of a large trial evaluating the impact of colchicine versus placebo on postoperative atrial fibrillation or atrial flutter (POAF) among patients undergoing lung resection surgery. METHODS: Patients ≥55 years of age undergoing lung resection surgery were randomly assigned to receive colchicine 0.6 mg or placebo starting a few hours before surgery. Postoperatively, patients received colchicine 0.6 mg or placebo twice daily for an additional 9 days. Our feasibility outcomes included the period of time required to recruit 100 patients, the completeness of follow-up and compliance with the study drug. The primary efficacy outcome was POAF within 30 days of randomization. RESULTS: One hundred patients were randomized (49 to colchicine and 51 to placebo) over a period of 12 months at 2 centres in Canada. All patients completed the 30-day follow-up. The mean staff time required to recruit and to follow-up each patient was 165 min. In all, 71% of patients completed the study drug course without interruption. Patient refusal to continuing taking the study drug was the main reason for permanent drug discontinuation. New POAF occurred in 5 (10.2%) patients in the colchicine group and 7 (13.7%) patients in the placebo group (adjusted hazard ratio 0.69, 95% confidence interval 0.20-2.34). CONCLUSIONS: These results show the feasibility of a trial evaluating Colchicine for the prevention of perioperative Atrial Fibrillation in patients undergoing lung resection surgery. This pilot study will serve as the foundation for the large multicentre COP-AF trial.

Predicting postoperative haemoglobin changes after burn surgery.

BACKGROUND: Burn surgery is associated with significant blood loss and fluid shifts that cause rapid haemoglobin (Hb) changes during and after surgery. Understanding the relationship between intraoperative and postoperative (day 1) Hb changes may assist in avoiding postoperative anaemia and unnecessary peri-operative blood transfusion. OBJECTIVE: To describe the Hb changes into the first day after burn surgery and to identify factors predictive of Hb changes that would guide blood transfusion decisions. METHODS: This was a single-institution, retrospective cohort study that included 158 patients who had undergone burn surgery. Hb was measured at the start and end of surgery, and on the first day (16 - 32 hours) after surgery, and the results were analysed. Peri-operative factors (Hb at the end of surgery, total body surface area operated on (TBSA-op), fluid administration and intraoperative blood administration) were evaluated to determine their association with Hb changes on the first day after surgery. RESULTS: The mean (standard deviation) preoperative Hb was 10.6 (2.29) g/dL, the mean postoperative Hb was 9.4 (2.01) g/dL, and the mean Hb on the first day after surgery was 9.2 (2.19) g/dL. Median total burn surface area was 7% (interquartile range 9%, min. 1%, max. 45%), with a mean body surface area operated on (debridement area plus donor area) of 9.7%. Of the 158 patients, 26 (16%) had an Hb <7 g/dL (transfusion trigger) on the first day after surgery. For patients with a high (≥9 g/dL), intermediate (≥7 - <9 g/dL), or low (<7 g/dL) Hb measurement at the end of burn surgery, those with an Hb below the transfusion trigger on the first day after burn surgery were 0%, 27%, and 75%, respectively. End-of-surgery Hb and TBSA-op strongly predicted the first day Hb level. In the intermediate group, 55% of patients with a TBSA-op ≥11% had an Hb below the transfusion trigger on the first day after surgery. CONCLUSION: Hb at the end of burn surgery was the best predictor of Hb on the first day after surgery. Patients with an Hb <7 g/dL remained as such on the first postoperative day. Half of the patients with an end-of-surgery Hb ≥7 - <9 g/dL and who had ≥11% TBSA-op had an Hb <7 g/dL on the first postoperative day.

Association of Postoperative High-Sensitivity Troponin Levels With Myocardial Injury and 30-Day Mortality Among Patients Undergoing Noncardiac Surgery.

IMPORTANCE: Little is known about the relationship between perioperative high-sensitivity troponin T (hsTnT) measurements and 30-day mortality and myocardial injury after noncardiac surgery (MINS). OBJECTIVE: To determine the association between perioperative hsTnT measurements and 30-day mortality and potential diagnostic criteria for MINS (ie, myocardial injury due to ischemia associated with 30-day mortality). DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of patients aged 45 years or older who underwent inpatient noncardiac surgery and had a postoperative hsTnT measurement. Starting in October 2008, participants were recruited at 23 centers in 13 countries; follow-up finished in December 2013. EXPOSURES: Patients had hsTnT measurements 6 to 12 hours after surgery and daily for 3 days; 40.4% had a preoperative hsTnT measurement. MAIN OUTCOMES AND MEASURES: A modified Mazumdar approach (an iterative process) was used to determine if there were hsTnT thresholds associated with risk of death and had an adjusted hazard ratio (HR) of 3.0 or higher and a risk of 30-day mortality of 3% or higher. To determine potential diagnostic criteria for MINS, regression analyses ascertained if postoperative hsTnT elevations required an ischemic feature (eg, ischemic symptom or electrocardiography finding) to be associated with 30-day mortality. RESULTS: Among 21 842 participants, the mean age was 63.1 (SD, 10.7) years and 49.1% were female. Death within 30 days after surgery occurred in 266 patients (1.2%; 95% CI, 1.1%-1.4%). Multivariable analysis demonstrated that compared with the reference group (peak hsTnT <5 ng/L), peak postoperative hsTnT levels of 20 to less than 65 ng/L, 65 to less than 1000 ng/L, and 1000 ng/L or higher had 30-day mortality rates of 3.0% (123/4049; 95% CI, 2.6%-3.6%), 9.1% (102/1118; 95% CI, 7.6%-11.0%), and 29.6% (16/54; 95% CI, 19.1%-42.8%), with corresponding adjusted HRs of 23.63 (95% CI, 10.32-54.09), 70.34 (95% CI, 30.60-161.71), and 227.01 (95% CI, 87.35-589.92), respectively. An absolute hsTnT change of 5 ng/L or higher was associated with an increased risk of 30-day mortality (adjusted HR, 4.69; 95% CI, 3.52-6.25). An elevated postoperative hsTnT (ie, 20 to <65 ng/L with an absolute change ≥5 ng/L or hsTnT ≥65 ng/L) without an ischemic feature was associated with 30-day mortality (adjusted HR, 3.20; 95% CI, 2.37-4.32). Among the 3904 patients (17.9%; 95% CI, 17.4%-18.4%) with MINS, 3633 (93.1%; 95% CI, 92.2%-93.8%) did not experience an ischemic symptom. CONCLUSIONS AND RELEVANCE: Among patients undergoing noncardiac surgery, peak postoperative hsTnT during the first 3 days after surgery was significantly associated with 30-day mortality. Elevated postoperative hsTnT without an ischemic feature was also associated with 30-day mortality.

Predicting the occurrence of major adverse cardiac events within 30 days of a vascular surgery: an empirical comparison of the minimum p value method and ROC curve approach using individual patient data meta-analysis.

We aimed to compare the minimum p value method and the area under the receiver operating characteristics (ROC) curve approach to categorize continuous biomarkers for the prediction of postoperative 30-day major adverse cardiac events in noncardiac vascular surgery patients. Individual-patient data from six cohorts reporting B-type natriuretic peptide (BNP) or N-terminal pro-B-type natriuretic peptide (NTproBNP) were obtained. These biomarkers were dichotomized using the minimum p value method and compared with previously reported ROC curve-derived thresholds using logistic regression analysis. A final prediction model was developed, internally validated, and assessed for its sensitivity to clustering effects. Finally, a preoperative risk score system was proposed. Thresholds identified by the minimum p value method and ROC curve approach were 115.57 pg/ml (p < 0.001) and 116 pg/ml for BNP, and 241.7 pg/ml (p = 0.001) and 277.5 pg/ml for NTproBNP, respectively. The minimum p value thresholds were slightly stronger predictors based on our logistic regression analysis. The final model included a composite predictor of the minimum p value method's BNP and NTproBNP thresholds [odds ratio (OR) = 8.5, p < 0.001], surgery type (OR = 2.5, p = 0.002), and diabetes (OR = 2.1, p = 0.015). Preoperative risks using the scoring system ranged from 2 to 49 %. The minimum p value method and ROC curve approach identify similar optimal thresholds. We propose to replace the revised cardiac risk index with our risk score system for individual-specific preoperative risk stratification after noncardiac nonvascular surgery.

Comparison of hydroxyethyl starch colloids with crystalloids for surgical patients: A systematic review and meta-analysis.

BACKGROUND: Fluid therapy is one of the most ubiquitous medical therapeutic interventions. There is a debate over whether colloids or crystalloids are better for fluid resuscitation. Recent large trials and meta-analyses suggest no mortality benefit and possible harm with hydroxyethyl starch (HES) use. However, these trials were conducted in critically ill and septic patients and their applicability to perioperative patients has been challenged. OBJECTIVE: We aimed to evaluate the impact of HES use in scheduled and elective surgical patients. DESIGN: Systematic review and meta-analysis of randomised controlled trials (RCTs). ELIGIBILITY CRITERIA: Only RCTs comparing the use of the synthetic colloid HES with any crystalloid in adults undergoing noncardiac surgery (up to 24 h postop) were considered eligible. For each eligible trial, we extracted the outcomes of all-cause mortality within 90 days, length of hospital stay, major infectious complications, acute kidney injury (AKI) and renal replacement therapy (RRT). RESULTS: We identified 1555 citations, selected 90 for full-text evaluation, and identified 13 eligible RCTs. Trials were small (n = 20 to 202) with low event rates. There was a trend to increased mortality with HES within 90 days [13/373 vs. 3/368; risk ratio 2.97; 95% confidence interval (95% CI) 0.96 to 9.19; I = 0%], no difference in AKI and RRT (risk ratio 1.11; 95% CI 0.26 to 4.69; I = 34%), and no difference in major infectious complications (risk ratio 1.19; 95% CI 0.59 to 2.39; I = 0%). Patients resuscitated with HES had a shorter length of hospital stay (mean difference -1.52 days; 95% CI -2.87 to -0.18), although heterogeneity was high (I = 90%). CONCLUSION: This meta-analysis, based on small studies with low event rates, suggests that there are currently insufficient data to identify a difference in outcomes associated with crystalloids and HES in scheduled or elective noncardiac surgery.

Preoperative Score to Predict Postoperative Mortality (POSPOM): Derivation and Validation.

BACKGROUND: An accurate risk score able to predict in-hospital mortality in patients undergoing surgery may improve both risk communication and clinical decision making. The aim of the study was to develop and validate a surgical risk score based solely on preoperative information, for predicting in-hospital mortality. METHODS: From January 1, 2010, to December 31, 2010, data related to all surgeries requiring anesthesia were collected from all centers (single hospital or hospitals group) in France performing more than 500 operations in the year on patients aged 18 yr or older (n = 5,507,834). International Statistical Classification of Diseases, 10th revision codes were used to summarize the medical history of patients. From these data, the authors developed a risk score by examining 29 preoperative factors (age, comorbidities, and surgery type) in 2,717,902 patients, and then validated the risk score in a separate cohort of 2,789,932 patients. RESULTS: In the derivation cohort, there were 12,786 in-hospital deaths (0.47%; 95% CI, 0.46 to 0.48%), whereas in the validation cohort there were 14,933 in-hospital deaths (0.54%; 95% CI, 0.53 to 0.55%). Seventeen predictors were identified and included in the PreOperative Score to predict PostOperative Mortality (POSPOM). POSPOM showed good calibration and excellent discrimination for in-hospital mortality, with a c-statistic of 0.944 (95% CI, 0.943 to 0.945) in the development cohort and 0.929 (95% CI, 0.928 to 0.931) in the validation cohort. CONCLUSION: The authors have developed and validated POSPOM, a simple risk score for the prediction of in-hospital mortality in surgical patients.

Pre-treatment serum lactate dehydrogenase and alkaline phosphatase as predictors of metastases in extremity osteosarcoma.

BACKGROUND: The prognosis of patients with metastatic osteosarcoma remains poor. However, the chance of survival can be improved by surgical resection of all metastases. In this study we investigate the value of serum alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in predicting the presence of metastatic disease at time of diagnosis. METHODS: Sixty-one patients with histologically confirmed conventional osteosarcoma of the extremity were included in the study. Only 19.7% of cases presented without evidence of systemic spread of the disease. Pre-treatment serum ALP and LDH were analysed in patients with and without skeletal or pulmonary metastases. RESULTS: Serum LDH and ALP levels were not significantly different in patients with or without pulmonary metastases (p=0.88 and p=0.47, respectively). The serum LDH and ALP levels did however differ significantly in patients with or without skeletal metastases (p<0.001 and p=0.02, respectively). The optimal breakpoint for serum LDH as a marker of skeletal metastases was 849 IU/L (AUC 0.839; Sensitivity=0.88; Specificity=0.73). LDH >454 IU/L equated to 100% sensitivity for detected bone metastases (positive diagnostic likelihood ratio (DLR)=1.32). With a cut-off of 76 IU/L a sensitivity of 100% was reached for serum ALP predicting the presence of skeletal metastases (positive DLR=1.1). In a multivariate analysis both LDH ≥850 IU/L (odds ratio [OR]=9; 95% confidence interval (CI) 1.8-44.3) and ALP ≥280 IU/L (OR=10.3; 95% CI 2.1-50.5) were predictive of skeletal metastases. LDH however lost its significance in a multivariate model which included pre-treatment tumour volume. CONCLUSION: In cases of osteosarcoma with LDH >850 IU/L and/or ALP >280 IU/L it may be prudent to consider more sensitive staging investigations for detection of skeletal metastases. Further research is required to determine the value and the most sensitive cut-off points of serum ALP and LDH in the prediction of skeletal metastases.

N-terminal pro-B-type Natriuretic Peptides' Prognostic Utility Is Overestimated in Meta-analyses Using Study-specific Optimal Diagnostic Thresholds.

BACKGROUND: N-terminal fragment B-type natriuretic peptide (NT-proBNP) prognostic utility is commonly determined post hoc by identifying a single optimal discrimination threshold tailored to the individual study population. The authors aimed to determine how using these study-specific post hoc thresholds impacts meta-analysis results. METHODS: The authors conducted a systematic review of studies reporting the ability of preoperative NT-proBNP measurements to predict the composite outcome of all-cause mortality and nonfatal myocardial infarction at 30 days after noncardiac surgery. Individual patient-level data NT-proBNP thresholds were determined using two different methodologies. First, a single combined NT-proBNP threshold was determined for the entire cohort of patients, and a meta-analysis conducted using this single threshold. Second, study-specific thresholds were determined for each individual study, with meta-analysis being conducted using these study-specific thresholds. RESULTS: The authors obtained individual patient data from 14 studies (n = 2,196). Using a single NT-proBNP cohort threshold, the odds ratio (OR) associated with an increased NT-proBNP measurement was 3.43 (95% CI, 2.08 to 5.64). Using individual study-specific thresholds, the OR associated with an increased NT-proBNP measurement was 6.45 (95% CI, 3.98 to 10.46). In smaller studies (<100 patients) a single cohort threshold was associated with an OR of 5.4 (95% CI, 2.27 to 12.84) as compared with an OR of 14.38 (95% CI, 6.08 to 34.01) for study-specific thresholds. CONCLUSIONS: Post hoc identification of study-specific prognostic biomarker thresholds artificially maximizes biomarker predictive power, resulting in an amplification or overestimation during meta-analysis of these results. This effect is accentuated in small studies.