Effects of an open lung extubation strategy compared with a conventional extubation strategy on postoperative pulmonary complications after general anesthesia: a single-centre pilot randomized controlled trial

PURPOSE

Postoperative pulmonary complications (PPCs) are a common cause of morbidity. Postoperative atelectasis is thought to be a significant risk factor in their development. Recent imaging studies suggest that patients' extubation may result in similar postoperative atelectasis regardless of the intraoperative mechanical ventilation strategy used. In this pilot trial, we hypothesized that a study investigating the effects of an open lung extubation strategy compared with a conventional one on PPCs would be feasible.

METHODS

We conducted a pilot, single-centre, double-blinded randomized controlled trial. Adult patients at moderate to high risk of PPCs and scheduled for elective surgery were eligible. Patients were randomized to an open lung extubation strategy (semirecumbent position, fraction of inspired oxygen [FIO2] 50%, pressure support ventilation, unchanged positive end-expiratory pressure) or to a conventional extubation strategy (dorsal decubitus position, FIO2 100%, manual bag ventilation). The primary feasibility outcome was global protocol adherence while the primary exploratory efficacy outcome was PPCs.

RESULTS

We randomized 35 patients to the conventional extubation group and 34 to the open lung extubation group. We observed a global protocol adherence of 96% (95% confidence interval, 88 to 99), which was not different between groups. Eight PPCs occurred (two in the conventional extubation group vs six in the open lung extubation group). Less postoperative supplemental oxygen and better lung aeration were observed in the open lung extubation group.

CONCLUSIONS

In this single-centre pilot trial, we observed excellent feasibility. A multicentre pilot trial comparing the effect of an open lung extubation strategy with that of a conventional extubation strategy on the occurrence of PPCs is feasible.

STUDY REGISTRATION DATE

ClinicalTrials.gov (NCT04993001); registered 6 August 2021.

Variation in Anesthesiology Provider-Volume for Complex Gastrointestinal Cancer Surgery: A Population-Based Study

OBJECTIVE

Examine between-hospital and between-anesthesiologist variation in anesthesiology provider-volume (PV) and delivery of high-volume anesthesiology care.

BACKGROUND

Better outcomes for anesthesiologists with higher PV of complex gastrointestinal cancer surgery have been reported. The factors linking anesthesiology practice and organization to volume are unknown.

METHODS

We identified patients undergoing elective esophagectomy, hepatectomy, and pancreatectomy using linked administrative health data sets (2007-2018). Anesthesiology PV was the annual number of procedures done by the primary anesthesiologist in the 2 years before the index surgery. High-volume anesthesiology was PV>6 procedures/year. Funnel plots to described variation in anesthesiology PV and delivery of high-volume care. Hierarchical regression models examined between-anesthesiologist and between-hospital variation in delivery of high-volume care use with variance partition coefficients (VPCs) and median odds ratios (MORs).

RESULTS

Among 7893 patients cared for at 17 hospitals, funnel plots showed variation in anesthesiology PV (median ranging from 1.5, interquartile range: 1-2 to 11.5, interquartile range: 8-16) and delivery of HV care (ranging from 0% to 87%) across hospitals. After adjustment, 32% (VPC 0.32) and 16% (VPC: 0.16) of the variation were attributable to between-anesthesiologist and between-hospital differences, respectively. This translated to an anesthesiologist MOR of 4.81 (95% CI, 3.27-10.3) and hospital MOR of 3.04 (95% CI, 2.14-7.77).

CONCLUSIONS

Substantial variation in anesthesiology PV and delivery of high-volume anesthesiology care existed across hospitals. The anesthesiologist and the hospital were key determinants of the variation in high-volume anesthesiology care delivery. This suggests that targeting anesthesiology structures of care could reduce variation and improve delivery of high-volume anesthesiology care.

The Association Between Hospital High-volume Anesthesiology Care and Patient Outcomes for Complex Gastrointestinal Cancer Surgery: A Population-based Study

OBJECTIVE

To examine the association of between hospital rates of high-volume anesthesiology care and of postoperative major morbidity.

BACKGROUND

Individual anesthesiology volume has been associated with individual patient outcomes for complex gastrointestinal cancer surgery. However, whether hospital-level anesthesiology care, where changes can be made, influences the outcomes of patients cared at this hospital is unknown.

METHODS

We conducted a population-based retrospective cohort study of adults undergoing esophagectomy, pancreatectomy, or hepatectomy for cancer from 2007 to 2018. The exposure was hospital-level adjusted rate of high-volume anesthesiology care. The outcome was hospital-level adjusted rate of 90-day major morbidity (Clavien-Dindo grade 3-5). Scatterplots visualized the relationship between each hospital's adjusted rates of high-volume anesthesiology and major morbidity. Analyses at the hospital-year level examined the association with multivariable Poisson regression.

RESULTS

For 7893 patients at 17 hospitals, the rates of high-volume anesthesiology varied from 0% to 87.6%, and of major morbidity from 38.2% to 45.4%. The scatter plot revealed a weak inverse relationship between hospital rates of high-volume anesthesiology and of major morbidity (Pearson: -0.23). The adjusted hospital rate of high-volume anesthesiology was independently associated with the adjusted hospital rate of major morbidity (rate ratio: 0.96; 95% CI, 0.95-0.98; P <0.001 for each 10% increase in the high-volume rate).

CONCLUSIONS

Hospitals that provided high-volume anesthesiology care to a higher proportion of patients were associated with lower rates of 90-day major morbidity. For each additional 10% patients receiving care by a high-volume anesthesiologist at a given hospital, there was an associated reduction of 4% in that hospital's rate of major morbidity.

Perioperative clinical practice in liver transplantation: a cross-sectional survey

PURPOSE

The objective of this study was to describe some components of the perioperative practice in liver transplantation as reported by clinicians.

METHODS

We conducted a cross-sectional clinical practice survey using an online instrument containing questions on selected themes related to the perioperative care of liver transplant recipients. We sent email invitations to Canadian anesthesiologists, Canadian surgeons, and French anesthesiologists specialized in liver transplantation. We used five-point Likert-type scales (from "never" to "always") and numerical or categorical answers. Results are presented as medians or proportions.

RESULTS

We obtained answers from 130 participants (estimated response rate of 71% in Canada and 26% in France). Respondents reported rarely using transesophageal echocardiography routinely but often using it for hemodynamic instability, often using an intraoperative goal-directed hemodynamic management strategy, and never using a phlebotomy (medians from ordinal scales). Fifty-nine percent of respondents reported using a restrictive fluid management strategy to manage hemodynamic instability during the dissection phase. Forty-two percent and 15% of respondents reported using viscoelastic tests to guide intraoperative and postoperative transfusions, respectively. Fifty-four percent of respondents reported not pre-emptively treating preoperative coagulations disturbances, and 91% reported treating them intraoperatively only when bleeding was significant. Most respondents (48-64%) did not have an opinion on the maximal graft ischemic times. Forty-seven percent of respondents reported that a piggyback technique was the preferred vena cava anastomosis approach.

CONCLUSION

Different interventions were reported to be used regarding most components of perioperative care in liver transplantation. Our results suggest that significant equipoise exists on the optimal perioperative management of this population.

Post-transplant outcomes among cystic fibrosis patients undergoing lung transplantation colonized by Burkholderia: A single center cohort study

BACKGROUND

Prior infection with Burkholderia cepacia complex (BCC) has been associated with poorer outcomes after lung transplantation, posing an important dilemma for cystic fibrosis (CF). Although current guidelines consider BCC infection to be a relative contraindication, some centers continue to offer lung transplantation to BCC-infected CF patients.

METHODS

We conducted a retrospective cohort study which included all consecutive CF-LTR between 2000 and 2019 to compare the postoperative survival of BCC-infected CF lung transplant recipients (CF-LTR) to BCC-uninfected patients. We used a Kaplan-Meier analysis to compare survival of BCC-infected to BCC-uninfected CF-LTR and fitted a multivariable Cox model, adjusted for age, sex, BMI and year of transplantation as potential confounders. As an exploratory analysis, Kaplan-Meier curves were also stratified by the presence of BCC and urgency of transplantation.

RESULTS

A total of 205 patients were included with a mean age of 30.5 years. Seventeen patients (8%) were infected with BCC prior to LT. Patients were infected with the following species: B. multivorans5, B. vietnamiensis3, combined B. multivorans and B. vietnamiensis3 and others4. None of the patients were infected with B. cenocepacia. Three patients were infected with B. gladioli. One-year survival was 91.7% (188/205) for the entire cohort, 82.4% (14/17) among BCC-infected CF-LTR, and 92.5% (173/188) among BCC uninfected CF-LTR (crude HR = 2.19; 95%CI 0.99-4.85; p = 0.05). In the multivariable model, presence of BCC was not significantly associated with worse survival (adjusted HR 1.89; 95%CI 0.85-4.24; p = 0.12). In the stratified analysis for both presence of BCC and urgency of transplantation, urgency of transplantation among BCC-infected CF-LTR appeared to be associated with poorer outcome (p = 0.003 across the 4 subgroups).

CONCLUSION

Our results suggest that non-cenocepacia BCC-infected CF-LTR have comparable survival rate to BCC-uninfected CF-LTR.

Association Between Familiarity of the Surgeon-Anesthesiologist Dyad and Postoperative Patient Outcomes for Complex Gastrointestinal Cancer Surgery

Importance

The surgeon-anesthesiologist teamwork and relationship is crucial to good patient outcomes. Familiarity among work team members is associated with enhanced success in multiple fields but rarely studied in the operating room.

Objective

To examine the association between surgeon-anesthesiologist dyad familiarity-as the number of times working together-with short-term postoperative outcomes for complex gastrointestinal cancer surgery.

Design, Setting, and Participants

This population-based retrospective cohort study based in Ontario, Canada, included adults undergoing esophagectomy, pancreatectomy, and hepatectomy for cancer from 2007 through 2018. The data were analyzed January 1, 2007, through December 21, 2018.

Exposures

Dyad familiarity captured as the annual volume of procedures of interest done by the surgeon-anesthesiologist dyad in the 4 years before the index surgery.

Main Outcomes and Measures

Ninety-day major morbidity (any Clavien-Dindo grade 3 to 5). The association between exposure and outcome was examined using multivariable logistic regression.

Results

Seven thousand eight hundred ninety-three patients with a median age of 65 years (66.3% men) were included. They were cared for by 737 anesthesiologists and 163 surgeons who were also included. The median surgeon-anesthesiologist dyad volume was 1 (range, 0-12.2) procedures per year. Ninety-day major morbidity occurred in 43.0% of patients. There was a linear association between dyad volume and 90-day major morbidity. After adjustment, the annual dyad volume was independently associated with lower odds of 90-day major morbidity, with an odds ratio of 0.95 (95% CI, 0.92-0.98; P = .01) for each incremental procedure per year, per dyad. The results did not change when examining 30-day major morbidity.

Conclusions and Relevance

Among adults undergoing complex gastrointestinal cancer surgery, increasing familiarity of the surgeon-anesthesiologist dyad was associated with improved short-term patient outcomes. For each additional time that a unique surgeon-anesthesiologist dyad worked together, the odds of 90-day major morbidity decreased by 5%. These findings support organizing perioperative care to increase the familiarity of surgeon-anesthesiologist dyads.

Cost-effectiveness of remdesivir plus usual care versus usual care alone for hospitalized patients with COVID-19: an economic evaluation as part of the Canadian Treatments for COVID-19 (CATCO) randomized clinical trial

BACKGROUND

The role of remdesivir in the treatment of hospitalized patients with COVID-19 remains ill-defined. We conducted a cost-effectiveness analysis alongside the Canadian Treatments for COVID-19 (CATCO) open-label, randomized clinical trial evaluating remdesivir.

METHODS

Patients with COVID-19 in Canadian hospitals from Aug. 14, 2020, to Apr. 1, 2021, were randomly assigned to receive remdesivir plus usual care versus usual care alone. Taking a public health care payer's perspective, we collected in-hospital outcomes and health care resource utilization alongside estimated unit costs in 2020 Canadian dollars over a time horizon from randomization to hospital discharge or death. Data from 1281 adults admitted to 52 hospitals in 6 Canadian provinces were analyzed.

RESULTS

The total mean cost per patient was $37 918 (standard deviation [SD] $42 413; 95% confidence interval [CI] $34 617 to $41 220) for patients randomly assigned to the remdesivir group and $38 026 (SD $46 021; 95% CI $34 480 to $41 573) for patients receiving usual care (incremental cost -$108 [95% CI -$4953 to $4737], p > 0.9). The difference in proportions of in-hospital deaths between remdesivir and usual care groups was -3.9% (18.7% v. 22.6%, 95% CI -8.3% to 1.0%, p = 0.09). The difference in proportions of incident invasive mechanical ventilation events between groups was -7.0% (8.0% v. 15.0%, 95% CI -10.6% to -3.4%, p = 0.006), whereas the difference in proportions of total mechanical ventilation events between groups was -5.7% (16.4% v. 22.1%, 95% CI -10.0% to -1.4%, p = 0.01). Remdesivir was the dominant intervention (but only marginally less costly, with mildly lower mortality) with an incalculable incremental cost effectiveness ratio; we report results of incremental costs and incremental effects separately. For willingness-to-pay thresholds of $0, $20 000, $50 000 and $100 000 per death averted, a strategy using remdesivir was cost-effective in 60%, 67%, 74% and 79% of simulations, respectively. The remdesivir costs were the fifth highest cost driver, offset by shorter lengths of stay and less mechanical ventilation.

INTERPRETATION

From a health care payer perspective, treating patients hospitalized with COVID-19 with remdesivir and usual care appears to be preferrable to treating with usual care alone, albeit with marginal incremental cost and small clinical effects. The added cost of remdesivir was offset by shorter lengths of stay in the intensive care unit and less need for ventilation.

STUDY REGISTRATION

ClinicalTrials. gov, no. NCT04330690.

Association of first trimester anaesthesia with risk of congenital heart defects in offspring

BACKGROUND

A substantial number of pregnant women require anaesthesia for non-obstetric surgery, but the risk to fetal heart development is unknown. We assessed the relationship between first trimester anaesthesia and risk of congenital heart defects in offspring.

METHODS

We conducted a longitudinal cohort study of 2 095 300 pregnancies resulting in live births in hospitals of Quebec, Canada, between 1990 and 2016. We identified women who received general or local/regional anaesthesia in the first trimester, including anaesthesia between 3 and 8 weeks post-conception, the critical weeks of fetal cardiogenesis. The main outcome measures were critical and non-critical heart defects in offspring. We estimated risk ratios (RR) and 95% confidence intervals (CI) for the association of first trimester anaesthesia with congenital heart defects, using log-binomial regression models adjusted for maternal characteristics.

RESULTS

There were 107.3 congenital heart defects per 10 000 infants exposed to anaesthesia, compared with 87.2 per 10 000 unexposed infants. Anaesthesia between 3 and 8 weeks post-conception was associated with 1.50 times the risk of congenital heart defects (95% CI 1.11-2.03), compared with no anaesthesia. Anaesthesia between 5 and 6 weeks post-conception was associated with 1.84 times the risk (95% CI 1.10-3.08). Associations were driven mostly by general anaesthesia, which was associated with 2.49 times the risk between weeks 5 and 6 post-conception (95% CI 1.40-4.44).

CONCLUSIONS

General anaesthesia during critical periods of fetal heart development may increase the risk of congenital heart defects. Further research is needed to confirm that anaesthetic agents are cardiac teratogens.

Restrictive versus liberal transfusion in patients with diabetes undergoing cardiac surgery: An open-label, randomized, blinded outcome evaluation trial

AIM

To characterize the association between diabetes and transfusion and clinical outcomes in cardiac surgery, and to evaluate whether restrictive transfusion thresholds are harmful in these patients.

MATERIALS AND METHODS

The multinational, open-label, randomized controlled TRICS-III trial assessed a restrictive transfusion strategy (haemoglobin [Hb] transfusion threshold <75 g/L) compared with a liberal strategy (Hb <95 g/L for operating room or intensive care unit; or <85 g/L for ward) in patients undergoing cardiac surgery on cardiopulmonary bypass with a moderate-to-high risk of death (EuroSCORE ≥6). Diabetes status was collected preoperatively. The primary composite outcome was all-cause death, stroke, myocardial infarction, and new-onset renal failure requiring dialysis at 6 months. Secondary outcomes included components of the composite outcome at 6 months, and transfusion and clinical outcomes at 28 days.

RESULTS

Of the 5092 patients analysed, 1396 (27.4%) had diabetes (restrictive, n = 679; liberal, n = 717). Patients with diabetes had more cardiovascular disease than patients without diabetes. Neither the presence of diabetes (OR [95% CI] 1.10 [0.93-1.31]) nor the restrictive strategy increased the risk for the primary composite outcome (diabetes OR [95% CI] 1.04 [0.68-1.59] vs. no diabetes OR 1.02 [0.85-1.22]; P_interaction  = .92). In patients with versus without diabetes, a restrictive transfusion strategy was more effective at reducing red blood cell transfusion (diabetes OR [95% CI] 0.28 [0.21-0.36]; no diabetes OR [95% CI] 0.40 [0.35-0.47]; P_interaction  = .04).

CONCLUSIONS

The presence of diabetes did not modify the effect of a restrictive transfusion strategy on the primary composite outcome, but improved its efficacy on red cell transfusion. Restrictive transfusion triggers are safe and effective in patients with diabetes undergoing cardiac surgery.

Remdesivir for the treatment of patients in hospital with COVID-19 in Canada: a randomized controlled trial

Background:

The role of remdesivir in the treatment of patients in hospital with COVID-19 remains ill defined in a global context. The World Health Organization Solidarity randomized controlled trial (RCT) evaluated remdesivir in patients across many countries, with Canada enrolling patients using an expanded data collection format in the Canadian Treatments for COVID-19 (CATCO) trial. We report on the Canadian findings, with additional demographics, characteristics and clinical outcomes, to explore the potential for differential effects across different health care systems.

Methods:

We performed an open-label, pragmatic RCT in Canadian hospitals, in conjunction with the Solidarity trial. We randomized patients to 10 days of remdesivir (200 mg intravenously [IV] on day 0, followed by 100 mg IV daily), plus standard care, or standard care alone. The primary outcome was in-hospital mortality. Secondary outcomes included changes in clinical severity, oxygen- and ventilator-free days (at 28 d), incidence of new oxygen or mechanical ventilation use, duration of hospital stay, and adverse event rates. We performed a priori subgroup analyses according to duration of symptoms before enrolment, age, sex and severity of symptoms on presentation.

Results:

Across 52 Canadian hospitals, we randomized 1282 patients between Aug. 14, 2020, and Apr. 1, 2021, to remdesivir (n = 634) or standard of care (n = 648). Of these, 15 withdrew consent or were still in hospital, for a total sample of 1267 patients. Among patients assigned to receive remdesivir, in-hospital mortality was 18.7%, compared with 22.6% in the standard-of-care arm (relative risk [RR] 0.83 (95% confidence interval [CI] 0.67 to 1.03), and 60-day mortality was 24.8% and 28.2%, respectively (95% CI 0.72 to 1.07). For patients not mechanically ventilated at baseline, the need for mechanical ventilation was 8.0% in those assigned remdesivir, and 15.0% in those receiving standard of care (RR 0.53, 95% CI 0.38 to 0.75). Mean oxygen-free and ventilator-free days at day 28 were 15.9 (± standard deviation [SD] 10.5) and 21.4 (± SD 11.3) in those receiving remdesivir and 14.2 (± SD 11) and 19.5 (± SD 12.3) in those receiving standard of care (p = 0.006 and 0.007, respectively). There was no difference in safety events of new dialysis, change in creatinine, or new hepatic dysfunction between the 2 groups.

Interpretation:

Remdesivir, when compared with standard of care, has a modest but significant effect on outcomes important to patients and health systems, such as the need for mechanical ventilation. Trial registration: ClinicalTrials.gov, no. NCT04330690.

Maternal prepregnancy surgery and risk of neonatal abstinence syndrome in future newborns: a longitudinal cohort study

BACKGROUND

Neonatal abstinence syndrome is increasingly prevalent, and may be related to opioid use disorders caused by postoperative prescriptions for pain control. We assessed the association of maternal prepregnancy surgery with risk of neonatal abstinence syndrome from opioid use disorders in future pregnancies.

METHODS

We conducted a longitudinal retrospective cohort study of 2 182 365 deliveries in Quebec, Canada, between 1989 and 2016. The main exposure was maternal prepregnancy surgery. The main outcome measure was neonatal abstinence syndrome in offspring. We adjusted associations for maternal comorbidity and pregnancy characteristics using log-binomial regression models.

RESULTS

The prevalence of neonatal abstinence syndrome in the cohort was 10.7 per 10 000 births. Compared with no surgery, prepregnancy surgery was associated with a risk ratio (RR) of neonatal abstinence syndrome of 1.63 (95% confidence interval [CI] 1.49-1.78). Risk was greater for 3 or more prepregnancy surgeries (RR 2.34, 95% CI 2.07-2.63) and age < 15 years at first surgery (1 surgery: RR 2.08, 95% CI 1.71-2.54; 2 or more surgeries: RR 2.79, 95% CI 2.32-3.37). Nearly all surgical specialties increased the risk of neonatal abstinence syndrome, but associations were strongest for cardiothoracic surgery (RR 4.45, 95% CI 2.87-6.91), neurosurgery (RR 3.00, 95% CI 1.56-5.77) and urologic surgery (RR 3.03, 95% CI 2.16-4.26).

INTERPRETATION

Prepregnancy surgery is associated with the risk of neonatal abstinence syndrome in future pregnancies. Prescription opioids for postsurgical pain may result in opioid use disorders during future pregnancies, inadvertently increasing the risk of neonatal abstinence syndrome in offspring.

Six-Month Outcomes after Restrictive or Liberal Transfusion for Cardiac Surgery

BACKGROUND

We reported previously that, in patients undergoing cardiac surgery who were at moderate-to-high risk for death, a restrictive transfusion strategy was noninferior to a liberal strategy with respect to the composite outcome of death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis by hospital discharge or 28 days after surgery, whichever came first. We now report the clinical outcomes at 6 months after surgery.

METHODS

We randomly assigned 5243 adults undergoing cardiac surgery to a restrictive red-cell transfusion strategy (transfusion if the hemoglobin concentration was <7.5 g per deciliter intraoperatively or postoperatively) or a liberal red-cell transfusion strategy (transfusion if the hemoglobin concentration was <9.5 g per deciliter intraoperatively or postoperatively when the patient was in the intensive care unit [ICU] or was <8.5 g per deciliter when the patient was in the non-ICU ward). The primary composite outcome was death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis occurring within 6 months after the initial surgery. An expanded secondary composite outcome included all the components of the primary outcome as well as emergency department visit, hospital readmission, or coronary revascularization occurring within 6 months after the index surgery. The secondary outcomes included the individual components of the two composite outcomes.

RESULTS

At 6 months after surgery, the primary composite outcome had occurred in 402 of 2317 patients (17.4%) in the restrictive-threshold group and in 402 of 2347 patients (17.1%) in the liberal-threshold group (absolute risk difference before rounding, 0.22 percentage points; 95% confidence interval [CI], -1.95 to 2.39; odds ratio, 1.02; 95% CI, 0.87 to 1.18; P=0.006 for noninferiority). Mortality was 6.2% in the restrictive-threshold group and 6.4% in the liberal-threshold group (odds ratio, 0.95; 95% CI, 0.75 to 1.21). There were no significant between-group differences in the secondary outcomes.

CONCLUSIONS

In patients undergoing cardiac surgery who were at moderate-to-high risk for death, a restrictive strategy for red-cell transfusion was noninferior to a liberal strategy with respect to the composite outcome of death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis at 6 months after surgery. (Funded by the Canadian Institutes of Health Research and others; TRICS III ClinicalTrials.gov number, NCT02042898 .).

Restrictive or Liberal Red-Cell Transfusion for Cardiac Surgery

BACKGROUND

The effect of a restrictive versus liberal red-cell transfusion strategy on clinical outcomes in patients undergoing cardiac surgery remains unclear.

METHODS

In this multicenter, open-label, noninferiority trial, we randomly assigned 5243 adults undergoing cardiac surgery who had a European System for Cardiac Operative Risk Evaluation (EuroSCORE) I of 6 or more (on a scale from 0 to 47, with higher scores indicating a higher risk of death after cardiac surgery) to a restrictive red-cell transfusion threshold (transfuse if hemoglobin level was <7.5 g per deciliter, starting from induction of anesthesia) or a liberal red-cell transfusion threshold (transfuse if hemoglobin level was <9.5 g per deciliter in the operating room or intensive care unit [ICU] or was <8.5 g per deciliter in the non-ICU ward). The primary composite outcome was death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis by hospital discharge or by day 28, whichever came first. Secondary outcomes included red-cell transfusion and other clinical outcomes.

RESULTS

The primary outcome occurred in 11.4% of the patients in the restrictive-threshold group, as compared with 12.5% of those in the liberal-threshold group (absolute risk difference, -1.11 percentage points; 95% confidence interval [CI], -2.93 to 0.72; odds ratio, 0.90; 95% CI, 0.76 to 1.07; P<0.001 for noninferiority). Mortality was 3.0% in the restrictive-threshold group and 3.6% in the liberal-threshold group (odds ratio, 0.85; 95% CI, 0.62 to 1.16). Red-cell transfusion occurred in 52.3% of the patients in the restrictive-threshold group, as compared with 72.6% of those in the liberal-threshold group (odds ratio, 0.41; 95% CI, 0.37 to 0.47). There were no significant between-group differences with regard to the other secondary outcomes.

CONCLUSIONS

In patients undergoing cardiac surgery who were at moderate-to-high risk for death, a restrictive strategy regarding red-cell transfusion was noninferior to a liberal strategy with respect to the composite outcome of death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis, with less blood transfused. (Funded by the Canadian Institutes of Health Research and others; TRICS III ClinicalTrials.gov number, NCT02042898 .).