A vanguard randomised feasibility trial comparing three regimens of peri-operative oxygen therapy on recovery after major surgery.

International recommendations encourage liberal administration of oxygen to patients having surgery under general anaesthesia, ostensibly to reduce surgical site infection. However, the optimal oxygen regimen to minimise postoperative complications and enhance recovery from surgery remains uncertain. The hospital operating theatre randomised oxygen (HOT-ROX) trial is a multicentre, patient- and assessor-blinded, parallel-group, randomised clinical trial designed to assess the effect of a restricted, standard care, or liberal peri-operative oxygen therapy regimen on days alive and at home after surgery in adults undergoing prolonged non-cardiac surgery under general anaesthesia. Here, we report the findings of the internal vanguard feasibility phase of the trial undertaken in four large metropolitan hospitals in Australia and New Zealand that included the first 210 patients of a planned overall 2640 trial sample, with eight pre-specified endpoints evaluating protocol implementation and safety. We screened a total of 956 participants between 1 September 2019 and 26 January 2021, with data from 210 participants included in the analysis. Median (IQR [range]) time-weighted average intra-operative Fi O2 was 0.30 (0.26-0.35 [0.20-0.59]) and 0.47 (0.44-0.51 [0.37-0.68]) for restricted and standard care, respectively (mean difference (95%CI) 0.17 (0.14-0.20), p < 0.001). Median time-weighted average intra-operative Fi O2 was 0.83 (0.80-0.85 [0.70-0.91]) for liberal oxygen therapy (mean difference (95%CI) compared with standard care 0.36 (0.33-0.39), p < 0.001). All feasibility endpoints were met. There were no significant patient adverse events. These data support the feasibility of proceeding with the HOT-ROX trial without major protocol modifications.

Postoperative systemic inflammation after major abdominal surgery: patient-centred outcomes.

Postoperative systemic inflammation is strongly associated with surgical outcomes, but its relationship with patient-centred outcomes is largely unknown. Detection of excessive inflammation and patient and surgical factors associated with adverse patient-centred outcomes should inform preventative treatment options to be evaluated in clinical trials and current clinical care. This retrospective cohort study analysed prospectively collected data from 3000 high-risk, elective, major abdominal surgery patients in the restrictive vs. liberal fluid therapy for major abdominal surgery (RELIEF) trial from 47 centres in seven countries from May 2013 to September 2016. The co-primary endpoints were persistent disability or death up to 90 days after surgery, and quality of recovery using a 15-item quality of recovery score at days 3 and 30. Secondary endpoints included: 90-day and 1-year all-cause mortality; septic complications; acute kidney injury; unplanned admission to intensive care/high dependency unit; and total intensive care unit and hospital stays. Patients were assigned into quartiles of maximum postoperative C-reactive protein concentration up to day 3, after multiple imputations of missing values. The lowest (reference) group, quartile 1, C-reactive protein ≤ 85 mg.l-1 , was compared with three inflammation groups: quartile 2 > 85 mg.l-1 to 140 mg.l-1 ; quartile 3 > 140 mg.l-1 to 200 mg.l-1 ; and quartile 4 > 200 mg.l-1 to 587 mg.l-1 . Greater postoperative systemic inflammation had a higher adjusted risk ratio (95%CI) of persistent disability or death up to 90 days after surgery, quartile 4 vs. quartile 1 being 1.76 (1.31-2.36), p < 0.001. Increased inflammation was associated with increasing decline in risk-adjusted estimated medians (95%CI) for quality of recovery, the quartile 4 to quartile 1 difference being -14.4 (-17.38 to -10.71), p < 0.001 on day 3, and -5.94 (-8.92 to -2.95), p < 0.001 on day 30. Marked postoperative systemic inflammation was associated with increased risk of complications, poor quality of recovery and persistent disability or death up to 90 days after surgery.

Machine learning to predict myocardial injury and death after non-cardiac surgery.

Myocardial injury due to ischaemia within 30 days of non-cardiac surgery is prognostically relevant. We aimed to determine the discrimination, calibration, accuracy, sensitivity and specificity of single-layer and multiple-layer neural networks for myocardial injury and death within 30 postoperative days. We analysed data from 24,589 participants in the Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation study. Validation was performed on a randomly selected subset of the study population. Discrimination for myocardial injury by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.70 (0.69-0.72) vs. 0.71 (0.70-0.73) with variables available before surgical referral, p < 0.001; 0.73 (0.72-0.75) vs. 0.75 (0.74-0.76) with additional variables available on admission, but before surgery, p < 0.001; and 0.76 (0.75-0.77) vs. 0.77 (0.76-0.78) with the addition of subsequent variables, p < 0.001. Discrimination for death by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.71 (0.66-0.76) vs. 0.74 (0.71-0.77) with variables available before surgical referral, p = 0.04; 0.78 (0.73-0.82) vs. 0.83 (0.79-0.86) with additional variables available on admission but before surgery, p = 0.01; and 0.87 (0.83-0.89) vs. 0.87 (0.85-0.90) with the addition of subsequent variables, p = 0.52. The accuracy of the multiple-layer model for myocardial injury and death with all variables was 70% and 89%, respectively.

Postoperative systemic inflammatory dysregulation and corticosteroids: a narrative review.

In some patients, the inflammatory-immune response to surgical injury progresses to a harmful, dysregulated state. We posit that postoperative systemic inflammatory dysregulation forms part of a pathophysiological response to surgical injury that places patients at increased risk of complications and subsequently prolongs hospital stay. In this narrative review, we have outlined the evolution, measurement and prediction of postoperative systemic inflammatory dysregulation, distinguishing it from a healthy and self-limiting host response. We reviewed the actions of glucocorticoids and the potential for heterogeneous responses to peri-operative corticosteroid supplementation. We have then appraised the evidence highlighting the safety of corticosteroid supplementation, and the potential benefits of high/repeated doses to reduce the risks of major complications and death. Finally, we addressed how clinical trials in the future should target patients at higher risk of peri-operative inflammatory complications, whereby corticosteroid regimes should be tailored to modify not only the a priori risk, but also further adjusted in response to markers of an evolving pathophysiological response.

Analgesia for major laparoscopic abdominal surgery: a randomised feasibility trial using intrathecal morphine.

Effective pain control enhances patient recovery after surgery. Laparoscopic techniques for major abdominal surgery are increasingly utilised to reduce surgical trauma. Intrathecal morphine is an attractive analgesic option that is gaining popularity. However, limited evidence guides its use in the setting of laparoscopic surgery. In addition, enhanced recovery after surgery pathways advocate opioid-sparing techniques. We conducted a feasibility trial to compare intrathecal morphine with non-neuraxial analgesia in laparoscopic or laparoscopic-assisted major abdominal surgery to inform the design of a future large clinical trial. This multicentre, double-blind, randomised controlled trial was conducted at two tertiary hospitals in Australia. Fifty-one patients were randomly allocated to receive either intrathecal morphine (intervention group) or a sham subcutaneous injection of normal saline in the lumbar area (control group) immediately before the induction of general anaesthesia. Co-primary outcomes were patient recruitment and successful adherence to treatment allocation as per the study protocol. The primary endpoints of feasibility and protocol adherence were met with a 46% recruitment rate (51 of 110 eligible patients) and 96% protocol adherence. There was only one patient with failed access to the intrathecal space. For secondary endpoints, fewer patients in the intrathecal morphine group required opioids in the post-anaesthesia care unit, their postoperative pain scores at rest were lower across the four time-points measured (p = 0.007), but not dynamic pain scores (p = 0.061), and pruritus was more common following intrathecal morphine (p = 0.007). Total oral morphine equivalents until postoperative day 3 were less in the intrathecal morphine group (median (95%CI) difference 82 (-13 to 168) mg), but this reduction was not statistically significant (p = 0.10). These findings support conducting a definitive clinical trial.

Minimal clinically important difference in days at home up to 30 days after surgery.

Patient-centred outcomes are increasingly recognised as crucial measures of healthcare quality. Days alive and at home up to 30 days after surgery (DAH30 ) is a validated and readily obtainable patient-centred outcome measure that integrates much of the peri-operative patient journey. However, the minimal difference in DAH30 that is clinically important to patients is unknown. We designed and administered a 28-item survey to evaluate the minimal clinically important difference in DAH30 among adult patients undergoing inpatient surgery. Patients were approached pre-operatively or within 2 days postoperatively. We did not study patients undergoing day surgery or nursing home residents. Patients ranked their opinions on the importance of discharge home using a Likert scale (from 1, not important at all to 6, extremely important) and the minimum number of extra days at home that would be meaningful using this scale. We recruited 104 patients; the survey was administered pre-operatively to 45 patients and postoperatively to 59 patients. The mean (SD) age was 53.5 (16.5) years, and 51 (49%) patients were male. Patients underwent a broad range of surgery of mainly intermediate (55%) to major (33%) severity. The median minimal clinically important difference for DAH30 was 3 days; this was consistent across a broad range of scenarios, including earlier discharge home, complications delaying hospital discharge and the requirement for admission to a rehabilitation unit. Discharge home earlier than anticipated and discharge home rather than to a rehabilitation facility were both rated as important (median score = 5). Empirical data on the minimal clinically important difference for DAH30 may be useful to determine sample size and to guide the non-inferiority margin for future clinical trials.

Predictors of death and new disability after critical illness: a multicentre prospective cohort study.

PURPOSE: This study aimed to determine the prevalence and predictors of death or new disability following critical illness. METHODS: Prospective, multicentre cohort study conducted in six metropolitan intensive care units (ICU). Participants were adults admitted to the ICU who received more than 24 h of mechanical ventilation. The primary outcome was death or new disability at 6 months, with new disability defined by a 10% increase in the WHODAS 2.0. RESULTS: Of 628 patients with the primary outcome available (median age of 62 [49-71] years, 379 [61.0%] had a medical admission and 370 (58.9%) died or developed new disability by 6 months. Independent predictors of death or new disability included age [OR 1.02 (1.01-1.03), P = 0.001], higher severity of illness (APACHE III) [OR 1.02 (1.01-1.03), P < 0.001] and admission diagnosis. Compared to patients with a surgical admission diagnosis, patients with a cardiac arrest [OR (95% CI) 4.06 (1.89-8.68), P < 0.001], sepsis [OR (95% CI) 2.43 (1.32-4.47), P = 0.004], or trauma [OR (95% CI) 6.24 (3.07-12.71), P < 0.001] diagnosis had higher odds of death or new disability, while patients with a lung transplant [OR (95% CI) 0.21 (0.07-0.58), P = 0.003] diagnosis had lower odds. A model including these three variables had good calibration (Brier score 0.20) and acceptable discriminative power with an area under the receiver operating characteristic curve of 0.76 (95% CI 0.72-0.80). CONCLUSION: Less than half of all patients mechanically ventilated for more than 24 h were alive and free of new disability at 6 months after admission to ICU. A model including age, illness severity and admission diagnosis has acceptable discriminative ability to predict death or new disability at 6 months.

Comparing the accuracy of lay diagnosis of childhood malaria and pneumonia with that of the revised IMCI guidelines in Nigeria.

BACKGROUND: Improving caregivers' recognition of childhood malaria and pneumonia is crucial to early treatment and improving outcomes. The objective of this study was to assess the accuracy and reliability of caregivers' recognition of malaria and pneumonia (lay diagnosis) as compared to the revised IMCI guidelines. METHODS: A cross-sectional study design was used to recruit 903 children aged 2-59 months who were assessed for malaria and pneumonia by health workers at five primary healthcare centres in Benin City, Nigeria. Accuracy of lay diagnosis as compared to the revised IMCI guidelines was assessed using sensitivity, specificity, positive and negative predictive values and area under the receiver operating characteristic curve (AUROC) values. RESULTS: The accuracy of caregivers' ability to recognise malaria (AUROC: 0.60; 95% CI: 0.57-0.64) and pneumonia (AUROC: 0.54; 95% CI: 0.50-0.58) was, respectively, moderate and poor as compared to the IMCI guidelines. Caregivers were better able to identify children without than those with malaria and pneumonia. Agreement between caregivers and the IMCI guidelines for malaria and pneumonia diagnosis was poor (k = 0.14, 95% CI: 0.09-0.19; P = 0.0001). CONCLUSION: Caregivers' ability to recognise these childhood diseases as compared to the IMCI guidelines was poor overall, which was partly due to the approach used to ascertain lay diagnosis.

Data on the modulatory effects of a single bolus dexamethasone on the surface marker expression of various leucocyte subsets.

Dexamethasone is frequently administered to surgical patients for anti-emetic prophylaxis. We have examined the immunomodulatory effects of a single bolus of dexamethasone on circulating peripheral blood mononuclear cells (PBMCs) in the same 10 healthy male volunteers, previously used in our investigation on early in vivo effects of a single anti-emetic dose of dexamethasone on innate immune cell gene expression and activation [1]. Blood samples were drawn at baseline, 2 h, 4 h and 24 h. Immune cell phenotypes were examined with flow cytometry. In this data article the expression strength of markers involved in immune activation and immunosuppression as well as maturation, migration, cell death and responsiveness to signalling on monocyte and cDC subsets, as well as NK cells, CD4+ and CD8+ T cells and regulatory T cells (Treg) are presented. These data improve our understanding of the immunomodulatory effects of the glucocorticoid dexamethasone in-vivo, which may be important for the optimisation of treatment regimens as well as the evaluation of new indications for glucocorticoid treatment.

Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study.

Healthcare workers involved in aerosol-generating procedures, such as tracheal intubation, may be at elevated risk of acquiring COVID-19. However, the magnitude of this risk is unknown. We conducted a prospective international multicentre cohort study recruiting healthcare workers participating in tracheal intubation of patients with suspected or confirmed COVID-19. Information on tracheal intubation episodes, personal protective equipment use and subsequent provider health status was collected via self-reporting. The primary endpoint was the incidence of laboratory-confirmed COVID-19 diagnosis or new symptoms requiring self-isolation or hospitalisation after a tracheal intubation episode. Cox regression analysis examined associations between the primary endpoint and healthcare worker characteristics, procedure-related factors and personal protective equipment use. Between 23 March and 2 June 2020, 1718 healthcare workers from 503 hospitals in 17 countries reported 5148 tracheal intubation episodes. The overall incidence of the primary endpoint was 10.7% over a median (IQR [range]) follow-up of 32 (18-48 [0-116]) days. The cumulative incidence within 7, 14 and 21 days of the first tracheal intubation episode was 3.6%, 6.1% and 8.5%, respectively. The risk of the primary endpoint varied by country and was higher in women, but was not associated with other factors. Around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID-19 subsequently reported a COVID-19 outcome. This has human resource implications for institutional capacity to deliver essential healthcare services, and wider societal implications for COVID-19 transmission.

More than just morbidity and mortality - quality of recovery and long-term functional recovery after surgery.

Traditional surgical outcome measures include minor and major complications, hospital length of stay and sometimes longer-term survival. Each of these is important but there needs to be greater emphasis on patient-reported outcome measures. Global measures of a patient's quality of recovery, avoidance of postoperative morbidities, early hospital discharge to home (without re-admission) and longer term disability-free survival can better define postoperative recovery. A patient's recovery pathway can be mapped through the immediate days or weeks after surgery with documentation of morbidity using the postoperative morbidity survey and/or a quality of recovery score, days alive and at home up to 30 days after surgery and then longer term disability-free survival using the WHO Disability Assessment Schedule 2.0 scale. These can be used to define quality of recovery after surgery.

Postoperative recovery: the importance of the team.

An ageing population and rising healthcare costs are challenging cost-efficient hospital systems wanting to adapt, employing novel organisational structures designed to merge diverse skill sets. This needs not only physician and nursing leadership but also new models of care. Anaesthetists have expanded their role into the broader multidisciplinary field of peri-operative medicine, emphasising collaboration and safety in health teams. A greater focus on patient-centred care and shared decision making, along with validated metrics to quantify quality improvement activities, have emphasised the importance of comfort, patient satisfaction and quality of life after surgery. Shared decision-making is more likely to be manifest in a flat hierarchy in which each member of the team brings their own experience and skills to optimise patient care. Successful surgery is best achieved by a coordinated, multidisciplinary team, embedded in a culture of collaboration and safety.

Integration of the Duke Activity Status Index into preoperative risk evaluation: a multicentre prospective cohort study.

BACKGROUND: The Duke Activity Status Index (DASI) questionnaire might help incorporate self-reported functional capacity into preoperative risk assessment. Nonetheless, prognostically important thresholds in DASI scores remain unclear. We conducted a nested cohort analysis of the Measurement of Exercise Tolerance before Surgery (METS) study to characterise the association of preoperative DASI scores with postoperative death or complications. METHODS: The analysis included 1546 participants (≥40 yr of age) at an elevated cardiac risk who had inpatient noncardiac surgery. The primary outcome was 30-day death or myocardial injury. The secondary outcomes were 30-day death or myocardial infarction, in-hospital moderate-to-severe complications, and 1 yr death or new disability. Multivariable logistic regression modelling was used to characterise the adjusted association of preoperative DASI scores with outcomes. RESULTS: The DASI score had non-linear associations with outcomes. Self-reported functional capacity better than a DASI score of 34 was associated with reduced odds of 30-day death or myocardial injury (odds ratio: 0.97 per 1 point increase above 34; 95% confidence interval [CI]: 0.96-0.99) and 1 yr death or new disability (odds ratio: 0.96 per 1 point increase above 34; 95% CI: 0.92-0.99). Self-reported functional capacity worse than a DASI score of 34 was associated with increased odds of 30-day death or myocardial infarction (odds ratio: 1.05 per 1 point decrease below 34; 95% CI: 1.00-1.09), and moderate-to-severe complications (odds ratio: 1.03 per 1 point decrease below 34; 95% CI: 1.01-1.05). CONCLUSIONS: A DASI score of 34 represents a threshold for identifying patients at risk for myocardial injury, myocardial infarction, moderate-to-severe complications, and new disability.

Systematic review and consensus definitions for the Standardised Endpoints in Perioperative Medicine initiative: patient-centred outcomes.

BACKGROUND: Patient-centred outcomes are increasingly used in perioperative clinical trials. The Standardised Endpoints in Perioperative Medicine (StEP) initiative aims to define which measures should be used in future research to facilitate comparison between studies and to enable robust evidence synthesis. METHODS: A systematic review was conducted to create a longlist of patient satisfaction, health-related quality of life, functional status, patient well-being, and life-impact measures for consideration. A three-stage Delphi consensus process involving 89 international experts was then conducted in order to refine this list into a set of recommendations. RESULTS: The literature review yielded six patient-satisfaction measures, seven generic health-related quality-of-life measures, eight patient well-being measures, five functional-status measures, and five life-impact measures for consideration. The Delphi response rates were 92%, 87%, and 100% for Rounds 1, 2, and 3, respectively. Three additional measures were added during the Delphi process as a result of contributions from the StEP group members. Firm recommendations have been made about one health-related quality-of-life measure (EuroQol 5 Dimension, five-level version with visual analogue scale), one functional-status measure (WHO Disability Assessment Schedule version 2.0, 12-question version), and one life-impact measure (days alive and out of hospital at 30 days after surgery). Recommendations with caveats have been made about the Bauer patient-satisfaction measure and two life-impact measures (days alive and out of hospital at 1 yr after surgery, and discharge destination). CONCLUSIONS: Several patient-centred outcome measures have been recommended for use in future perioperative studies. We suggest that every clinical study should consider using at least one patient-centred outcome within a suite of endpoints.

Evidence for compromised data integrity in studies of liberal peri-operative inspired oxygen.

In 2016 the World Health Organization recommended intra-operative ventilation with 80% inspired oxygen to reduce surgical site infection rates, based upon a meta-analysis of 15 randomised controlled trials, of which two were by Mario Schietroma's research group. Five trials by this group have been retracted for duplication, plagiarism, statistical error and lack of ethical approval. We analysed 40 papers by this group: 24 randomised controlled trials (5064 participants) and 16 observational studies (1847 patients). There was evidence that data integrity was compromised in 38 out of the 40 analysed papers. The distribution of baseline characteristics in randomised controlled trials was unlikely, p = 1.5 × 10-8 : continuous variables within trials were heterogeneous, p = 1.9 × 10-9 , and categorical variables were homogeneous, p = 8.5 × 10-20 . Effects of interventions varied less than expected between studies: for categorical variables, for instance postoperative wound infection, p < 1 × 10-7 , and for continuous variables, for instance HLA-DR concentration, p = 0.00001. Of 184 calculable p values, for baseline variables or results, 179 (98%) were incorrect, ranging from three orders of magnitude too small to 10 orders of magnitude too large. Twenty-one graphs occurred 81 times in 23 out of 40 papers. Liberal peri-operative oxygen did not reduce surgical site infection in a meta-analysis of 20 trials that excluded seven trials by Mario Schietroma and colleagues (odds ratio (95%CI) 0.89 (0.73-1.08); p = 0.23). An update by the World Health Organization has now excluded trials of liberal oxygen by Schietroma's group, four of which have not been retracted. We conclude that Mario Schietroma's work should not inform practice until investigated.

A qualitative study exploring factors influencing clinical decision-making for influenza-like illness in Solapur city, Maharashtra, India.

The co-existence of different types of medical systems (medical pluralism) is a typical feature of India's healthcare system. For conditions such as influenza-like illness (ILI), where non-specific disease signs/symptoms exist, clinical reasoning in the context of medical pluralism becomes crucial. Recognising this need, we undertook a qualitative study, which explored factors underpinning clinical decisions on diagnosis and management of ILI. The study involved semi-structured interviews including clinical vignettes with 20 healthcare practitioners (working within allopathy, homeopathy and Ayurveda) working in the private healthcare sector in Solapur city, India. An inquiry was conducted into criteria influencing the diagnosis, treatment, referral to specialist care and role of treatment guidelines for ILI. Thematic analysis was used to identify aspects relating to ILI diagnosis, treatment and referral. The diagnosis of influenza was based largely on clinical symptoms suggestive of influenza in the absence of other diagnoses. Referral for laboratory tests was only initiated if illness did not resolve, generally after 2-3 consultations. Antibiotics were often prescribed for persistent illness, with antivirals rarely considered. Some differences between practitioners from different medical systems were observed in relation to treatment and referral in case of persistent illness. A combination of analytical and intuitive clinical reasoning was used by the participants and clinical decisions were based on both social and clinical factors. Clinical decision-making was rarely a linear process and respondents felt that broad guidelines on influenza that allowed doctors to account for the sociocultural context within which they practised medicine would be helpful.

Using a mobile application to detect health needs among children and adolescents who are newly arrived migrants in Europe.

BACKGROUND: Unprecedented numbers of migrants have arrived in Europe, including children and adolescents. Little is known about their unique health needs. Prospective data collection has been sparse. Mobile applications may help to facilitate global health surveillance. METHODS: A pre-validated survey instrument was converted into a mobile application covering self-reported exposures and disruptions of healthcare before/during migration, communicable and non-communicable diseases. Participation was voluntary, anonymous and confidential. RESULTS: Data were obtained from 405 migrant children and adolescents in Berlin, Germany, between 7 October 2015 and 15 March 2016 (median age 19 years, range: 1-24; 80.7% males) with the majority from Syria (62.5%), Afghanistan (9.1%) and Iraq (8.2%). In total, 55% were without family, 64% registered asylum-seekers with access to healthcare; 54% had seen a doctor since arrival, with colds or respiratory complaints (37.5 and 13.6%), followed by pain (26.7%) gastrointestinal (12.4%) and skin problems (11.1%). Underlying conditions were reported in 15.6%, predominantly asthma. Overall, 73% reported being up-to date on immunizations, but only 22% held a vaccination record with 46.4% having lost it during migration. CONCLUSIONS: The lack of medical and immunization records among newly arrived migrants provides a challenge to healthcare systems. Mobile applications offer rapid screening tools in times of crisis, helping stakeholders with timely information.

Using the 6-minute walk test to predict disability-free survival after major surgery.

BACKGROUND: The 6-min walk test (6MWT) is a common means of functional assessment. Its relationship to disability-free survival (DFS) is uncertain. METHODS: This sub-study of the Measurement of Exercise Tolerance for Surgery study had co-primary outcome measures: correlation of the preoperative 6MWT distance with 30 day quality of recovery (15-item quality of recovery) and 12 month WHO Disability Assessment Schedule scores. The prognostic utility of the 6MWT and other risk assessment tools for 12 month DFS was assessed with logistic regression and receiver-operating-characteristic-curve analysis. RESULTS: Of 574 patients recruited, 567 (99%) completed the 6MWT. Twelve months after surgery, 16 (2.9%) patients had died and 444 (77%) had DFS. The 6MWT correlated weakly with 30 day 15-item quality of recovery (ρ=0.14; P=0.001) and 12 month WHO Disability Assessment Schedule (ρ=-0.23; P<0.0005) scores. When the cohort was split into 6MWT distance tertiles, the adjusted odds ratio of low vs high tertiles for DFS was 3.13 [95% confidence interval (CI): 1.54-6.35]. The only independent variable predictive of DFS was the Duke Activity Status Index (DASI) score (adjusted odds ratio: 1.06; P<0.0005). The area under the receiver-operating-characteristic curve for DFS was 0.63 (95% CI: 0.57-0.70) for the 6MWT, 0.60 (95% CI: 0.53-0.67) for cardiopulmonary-exercise-testing-derived peak oxygen consumption, and 0.70 (95% CI: 0.64-0.76) for the DASI score. CONCLUSIONS: Of the risk assessment tools analysed, the DASI was the most predictive of DFS. The 6MWT was safe and comparable with cardiopulmonary exercise testing for all predictive assessments. Future research should aim to determine the optimal 6MWT distance thresholds for risk prediction.

Systematic review and consensus definitions for the Standardised Endpoints in Perioperative Medicine (StEP) initiative: renal endpoints.

BACKGROUND: Renal injury is a common perioperative complication. The adoption of renal endpoints, standardised and valid for use in perioperative clinical trials, would enhance the quality of perioperative clinical research. The Standardised Endpoints in Perioperative Medicine (StEP) initiative was established to derive standardised endpoints for use in perioperative clinical trials. METHODS: A systematic review was conducted to identify renal endpoints currently reported in perioperative clinical trials. In parallel, an initial list of candidate endpoints was developed based on renal theme group expertise. A multi-round Delphi consensus process was used to refine this list and produce a suite of recommended perioperative renal outcome measures. RESULTS: Based on our systematic review, 63 studies were included for analysis. Marked heterogeneity and imprecision of endpoint definitions were observed. Our initial list of candidate endpoints included 10 endpoints for consideration. The response rates for Delphi rounds 1, 2, and 3 were 89% (n=16), 90% (n=75), and 100% (n=6), respectively. A final list of four renal endpoints was identified: acute kidney injury defined by the Kidney Disease: Improving Global Outcomes (KDIGO) consensus criteria, acute kidney disease defined by ≥30% decline in estimated glomerular filtration rate from baseline at 30 days after operation in patients meeting the acute-kidney-injury criteria within 7 days of surgery, the composite of death or renal replacement therapy, and the Major Adverse Kidney Events (MAKE) composite. CONCLUSIONS: We identified four key renal outcome measures that should be considered for use in perioperative clinical trials. Using standardised definitions to capture and report these endpoints will facilitate improved benchmarking and meta-analysis of future trials.