Postoperative complications in Australia and New Zealand (the REASON study)

Disparities in perioperative mortality outcomes between First Nations and non-First Nations peoples in Australia: protocol for a systematic review and planned meta-analysis

BACKGROUND

Health inequities persist among First Nations people living in developed countries. Surgical care is pivotal in addressing a significant portion of the global disease burden. Evidence regarding surgical outcomes among First Nations people in Australia is limited. The perioperative mortality rate (POMR) indicates timely access to safe surgery and predicts long-term survival after major surgery. This systematic review will examine POMR among First Nations and non-First Nations peoples in Australia.

METHODS

A systematic search strategy using MEDLINE, Embase, Emcare, Global Health, and Scopus will identify studies that include First Nations people and non-First Nations people who underwent a surgical intervention under anaesthesia in Australia. The primary focus will be on documenting perioperative mortality outcomes. Title and abstract screening and full-text review will be conducted by independent reviewers, followed by data extraction and bias assessment using the ROBINS-E tool. Meta-analysis will be considered if there is sufficient homogeneity between studies. The quality of cumulative evidence will be evaluated following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria.

DISCUSSION

This protocol describes the comprehensive methodology for the proposed systematic review. Evaluating disparities in perioperative mortality rates between First Nations and non-First Nations people remains essential in shaping the discourse surrounding health equity, particularly in addressing the surgical burden of disease.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021258970.

Development and validation of 'Patient Optimizer' (POP) algorithms for predicting surgical risk with machine learning

BACKGROUND

Pre-operative risk assessment can help clinicians prepare patients for surgery, reducing the risk of perioperative complications, length of hospital stay, readmission and mortality. Further, it can facilitate collaborative decision-making and operational planning.

OBJECTIVE

To develop effective pre-operative risk assessment algorithms (referred to as Patient Optimizer or POP) using Machine Learning (ML) that predict the development of post-operative complications and provide pilot data to inform the design of a larger prospective study.

METHODS

After institutional ethics approval, we developed a base model that encapsulates the standard manual approach of combining patient-risk and procedure-risk. In an automated process, additional variables were included and tested with 10-fold cross-validation, and the best performing features were selected. The models were evaluated and confidence intervals calculated using bootstrapping. Clinical expertise was used to restrict the cardinality of categorical variables (e.g. pathology results) by including the most clinically relevant values. The models were created with logistic regression (LR) and extreme gradient-boosted trees using XGBoost (Chen and Guestrin, 2016). We evaluated performance using the area under the receiver operating characteristic curve (AUROC) and the area under the precision-recall curve (AUPRC). Data was obtained from a metropolitan university teaching hospital from January 2015 to July 2020. Data collection was restricted to adult patients undergoing elective surgery.

RESULTS

A total of 11,475 adult admissions were included. The performance of XGBoost and LR was very similar across endpoints and metrics. For predicting the risk of any post-operative complication, kidney failure and length-of-stay (LOS), POP with XGBoost achieved an AUROC (95%CI) of 0.755 (0.744, 0.767), 0.869 (0.846, 0.891) and 0.841 (0.833, 0.847) respectively and AUPRC of 0.651 (0.632, 0.669), 0.336 (0.282, 0.390) and 0.741 (0.729, 0.753) respectively. For 30-day readmission and in-patient mortality, POP with XGBoost achieved an AUROC (95%CI) of 0.610 (0.587, 0.635) and 0.866 (0.777, 0.943) respectively and AUPRC of 0.116 (0.104, 0.132) and 0.031 (0.015, 0.072) respectively.

CONCLUSION

The POP algorithms effectively predicted any post-operative complication, kidney failure and LOS in the sample population. A larger study is justified to improve the algorithm to better predict complications and length of hospital stay. A larger dataset may also improve the prediction of additional specific complications, readmission and mortality.

Failure to Rescue in Major Abdominal Surgery: A Regional Australian Experience

BACKGROUND

Failure to rescue (FTR) is increasingly recognised as a measure of the quality care provided by a health service in recognising and responding to patient deterioration. We report the association between a patient's pre-operative status and FTR following major abdominal surgery.

METHODS

A retrospective chart review was conducted on patients who underwent major abdominal surgery and who suffered Clavien-Dindo (CDC) III-V complications at the University Hospital Geelong between 2012 and 2019. For each patient suffering a major complication, pre-operative risk factors including demographics, comorbidities (Charlson Comorbidity Index (CCI)), American Society of Anaesthesiology (ASA) Score and biochemistry were compared for patients who survived and patients who died. Statistical analysis utilised logistic regression with results reported as odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

There were 2579 patients who underwent major abdominal surgery, of whom 374 (14.5%) suffered CDC III-V complications. Eighty-eight patients subsequently died from their complication representing a 23.5% FTR and an overall operative mortality of 3.4%. Pre-operative risk factors for FTR included ASA score ≥ 3, CCI ≥ 3 and pre-operative serum albumin of < 35 g/L. Operative risk factors included emergency surgery, cancer surgery, greater than 500 ml intraoperative blood loss and need for ICU admission. Patients who suffered end-organ failure were more likely to die from their complication.

CONCLUSION

Identification of patients at high risk of FTR should they develop a complication would inform shared decision-making, highlight the need for optimisation prior to surgery, or in some cases, result in surgery not being undertaken.

Protocol paper for SMART OPS: Shared decision-making Multidisciplinary Approach - a Randomised controlled Trial in the Older adult Population considering Surgery

INTRODUCTION

The Australian population presenting with surgical pathology is becoming older, frailer and more comorbid. Shared decision-making is rapidly becoming the gold standard of care for patients considering high-risk surgery to ensure that appropriate, value-based healthcare decisions are made. Positive benefits around patient perception of decision-making in the immediacy of the decision are described in the literature. However, short-term and long-term holistic patient-centred outcomes and cost implications for the health service require further examination to better understand the full impact of shared decision-making in this population.

METHODS

We propose a novel multidisciplinary shared decision-making model of care in the perioperative period for patients considering high-risk surgery in the fields of general, vascular and head and neck surgery. We assess it in a two arm prospective randomised controlled trial. Patients are randomised to either 'standard' perioperative care, or to a multidisciplinary (surgeon, anaesthetist and end-of-life care nurse practitioner or social worker) shared decision-making consultation. The primary outcome is decisional conflict prior to any surgical procedure occurring. Secondary outcomes include the patient's treatment choice, how decisional conflict changes longitudinally over the subsequent year, patient-centred outcomes including life impact and quality of life metrics, as well as morbidity and mortality. Additionally, we will report on healthcare resource use including subsequent admissions or representations to a healthcare facility up to 1 year.

ETHICS AND DISSEMINATION

This study has been approved by the Hunter New England Human Research Ethics Committee (2019/ETH13349). Study findings will be presented at local and national conferences and within scientific research journals.

TRIAL REGISTRATION NUMBER

ACTRN12619001543178.

Exploring Risk, Antecedents and Human Costs of Living with a Retained Surgical Item: A Narrative Synthesis of Australian Case Law 1981-2018

Objectives

This study aimed to critically examine the circumstances contributing to, and the human costs arising from, the retention of surgical items through the lens of Australian case law.

Design Setting and Participants

We reviewed Australian cases from 1981 to 2018 to establish a pattern of antecedents and identify long-term patient impacts (human costs) of retained surgical items. We used a modified four-step process to conduct a systematic review of legal doctrine, combined with a narrative synthesis approach to bring the information together for understanding. We searched LexisNexis, AustLII, Coroner Court websites, Australian Health Practitioner Regulation Agency Tribunal Decisions and Panel Hearings, Civil and Administrative Tribunal summaries, and other online sources for publicly available civil cases, medical disciplinary cases, coronial cases, and criminal cases across all Australian jurisdictions.

Results

Ten cases met the inclusion criteria, including one coronial case, three civil appeal cases, and six civil first instance cases. Time from item retention to discovery ranged from 12 days to 20 years, with surgical sponges the most frequently retained item. Five case reports indicated possible deviations from standard protocols regarding counting procedures and record-keeping. In the four cases that reported on count status, the count was deemed correct at the end of surgery. Case reports also showed the human costs of retained surgical items, that is, the long-term impacts on patients associated with a retained surgical item. In eight of the nine civil cases, ongoing pain was the most frequently reported physical symptom; in three cases, patients suffered psychosocial symptoms requiring treatment.

Conclusion

While there was little uniformity in the items retained or how items came to be retained, we identified significant time delays between item retention and item discovery, coupled with long-lasting physical and psychosocial harms suffered by patients living with a retained surgical item. Current prevention strategies, including national standards-based professional practices, are not always effective in preventing retained surgical items. An internationally standardised taxonomy and reporting criteria, more consistent reporting, and open access to event and risk data could inform a more accurate global estimate of risk and incidence of this hospital-acquired complication.

Relative importance of clinical and sociodemographic factors in association with post-operative in-hospital deaths in colorectal cancer patients in New South Wales: An artificial neural network approach

RATIONALE, AIMS AND OBJECTIVES

Co-morbidities in colorectal cancer patients complicate hospital care, and their relative importance to post-operative deaths is largely unknown. This study was conducted to examine a range of clinical and sociodemographic factors in relation to post-operative in-hospital deaths in colorectal cancer patients and identify whether these contributions would vary by severity of co-morbidities.

METHODS

In this multicentre retrospective cohort study, we used the complete census of New South Wales inpatient data to select colorectal cancer patients admitted to public hospitals for acute surgical care, who underwent procedures on the digestive system during the period of July 2001 to June 2014. The primary outcome was in-hospital death at the end of acute care. Multilayer perceptron and back-propagation artificial neural networks (ANNs) were used to quantify the relative importance of a wide range of clinical and sociodemographic factors in relation to post-operative deaths, stratified by severity of co-morbidities based on Charlson co-morbidity index.

RESULTS

Of 6288 colorectal cancer patients, approximately 58.3% (n = 3669) had moderate to severe co-morbidities. A total of 464 (7.4%) died in hospitals. The performance for ANN models was superior to logistic models. Co-morbid musculoskeletal and mental disorders, adverse events in health care, and socio-economic factors including rural residence and private insurance status contributed to post-operative deaths in hospitals.

CONCLUSION

Identification of relative importance of factors contributing to in-hospital deaths in colorectal cancer patients using ANN may help to enhance patient-centred strategies to meet complex needs during acute surgical care and prevent post-operative in-hospital deaths.

Systematic Review and Meta-analysis of Objective Assessment of Physical Fitness in Patients Undergoing Colorectal Cancer Surgery

BACKGROUND

Gas exchange-derived variables obtained from cardiopulmonary exercise testing allow objective assessment of functional capacity and hence physiological reserve to withstand the stressors of major surgery. Field walk tests provide an alternate means for objective assessment of functional capacity that may be cheaper and have greater acceptability, in particular, in elderly patients.

OBJECTIVE

This systematic review evaluated the predictive value of cardiopulmonary exercise testing and field walk tests in surgical outcomes after colorectal surgery.

DATA SOURCE

A systematic search was undertaken using Medline, PubMed, Embase, CINAHL, and PEDro.

STUDY SELECTION

Adult patients who had cardiopulmonary exercise testing and/or field walk test before colorectal surgery were included.

MAIN OUTCOME MEASURE

The primary outcomes measured were hospital length of stay and postoperative morbidity and mortality.

RESULTS

A total of 7 studies with a cohort of 1418 patients who underwent colorectal surgery were identified for inclusion in a qualitative analysis. Both pooled oxygen consumption at anaerobic threshold (range, 10.1-11.1 mL·kg·min) and peak oxygen consumption (range, 16.7-18.6 mL·kg·min) were predictive of complications (OR for anaerobic threshold, 0.76; 95% CI, 0.66-0.85, p<0.0001; OR for peak oxygen consumption, 0.76; 95% CI, 0.67-0.85, p<0.0001). Patients had significant increased risk of developing postoperative complications if their anaerobic threshold was below this cut point (p<0.001). However, it was not predictive of anastomotic leak (p = 0.644). Shorter distance (<250 m) walked in incremental shuttle walk test, lower anaerobic threshold, and lower peak oxygen consumption were associated with prolonged hospital length of stay, which was closely related to the development of complications.

CONCLUSIONS

Variables derived from cardiopulmonary exercise testing are predictive of postoperative complications and hospital length of stay. Currently, there are insufficient data to support the predictive role of the field walk test in colorectal surgery.