Achieving equity: patient demographics and outcomes after surgical and non-surgical procedures in South Australia, 2022.

BACKGROUND: Although modern Australian healthcare systems provide patient-centred care, the ability to predict and prevent suboptimal post-procedural outcomes based on patient demographics at admission may improve health equity. This study aimed to identify patient demographic characteristics that might predict disparities in mortality, readmission, and discharge outcomes after either an operative or non-operative procedural hospital admission. METHODS: This retrospective cohort study included all surgical and non-surgical procedural admissions at three of the four major metropolitan public hospitals in South Australia in 2022. Multivariable logistic regression, with backwards selection, evaluated association between patient demographic characteristics and outcomes up to 90 days post-procedurally. RESULTS: 40 882 admissions were included. Increased likelihood of all-cause, post-procedure mortality in-hospital, at 30 days, and 90 days, were significantly associated with increased age (P < 0.001), increased comorbidity burden (P < 0.001), an emergency admission (P < 0.001), and male sex (P = 0.046, P = 0.03, P < 0.001, respectively). Identification as ATSI (P < 0.001) and being born in Australia (P = 0.03, P = 0.001, respectively) were associated with an increased likelihood of 30-day hospital readmission and decreased likelihood of discharge directly home, as was increased comorbidity burden (P < 0.001) and emergency admission (P < 0.001). Being married (P < 0.001) and male sex (P = 0.003) were predictive of an increased likelihood of discharging directly home; in contrast to increased age (P < 0.001) which was predictive of decreased likelihood of this occurring. CONCLUSIONS: This study characterized several associations between patient demographic factors present on admission and outcomes after surgical and non-surgical procedures, that can be integrated within patient flow pathways through the Australian healthcare system to improve healthcare equity.

Surgery's Rosetta Stone: Natural language processing to predict discharge and readmission after general surgery.

BACKGROUND: This study aimed to examine the accuracy with which multiple natural language processing artificial intelligence models could predict discharge and readmissions after general surgery. METHODS: Natural language processing models were derived and validated to predict discharge within the next 48 hours and 7 days and readmission within 30 days (based on daily ward round notes and discharge summaries, respectively) for general surgery inpatients at 2 South Australian hospitals. Natural language processing models included logistic regression, artificial neural networks, and Bidirectional Encoder Representations from Transformers. RESULTS: For discharge prediction analyses, 14,690 admissions were included. For readmission prediction analyses, 12,457 patients were included. For prediction of discharge within 48 hours, derivation and validation data set area under the receiver operator characteristic curves were, respectively: 0.86 and 0.86 for Bidirectional Encoder Representations from Transformers, 0.82 and 0.81 for logistic regression, and 0.82 and 0.81 for artificial neural networks. For prediction of discharge within 7 days, derivation and validation data set area under the receiver operator characteristic curves were, respectively: 0.82 and 0.81 for Bidirectional Encoder Representations from Transformers, 0.75 and 0.72 for logistic regression, and 0.68 and 0.67 for artificial neural networks. For readmission prediction within 30 days, derivation and validation data set area under the receiver operator characteristic curves were, respectively: 0.55 and 0.59 for Bidirectional Encoder Representations from Transformers and 0.77 and 0.62 for logistic regression. CONCLUSION: Modern natural language processing models, particularly Bidirectional Encoder Representations from Transformers, can effectively and accurately identify general surgery patients who will be discharged in the next 48 hours. However, these approaches are less capable of identifying general surgery patients who will be discharged within the next 7 days or who will experience readmission within 30 days of discharge.

Sociocultural and Demographic Factors Predict Readmissions for General Surgery Patients.

INTRODUCTION: Readmission is a poor outcome for both patients and healthcare systems. The association of certain sociocultural and demographic characteristics with likelihood of readmission is uncertain in general surgical patients. METHOD: A multi-centre retrospective cohort study of consecutive unique individuals who survived to discharge during general surgical admissions was conducted. Sociocultural and demographic variables were evaluated alongside clinical parameters (considered both as raw values and their proportion of change in the 1-2 days prior to admission) for their association with 7 and 30 days readmission using logistic regression. RESULTS: There were 12,701 individuals included, with 304 (2.4%) individuals readmitted within 7 days, and 921 (7.3%) readmitted within 30 days. When incorporating absolute values of clinical parameters in the model, age was the only variable significantly associated with 7-day readmission, and primary language and presence of religion were the only variables significantly associated with 30-day readmission. When incorporating change in clinical parameters between the 1-2 days prior to discharge, primary language and religion were predictive of 30-day readmission. When controlling for changes in clinical parameters, only higher comorbidity burden (represented by higher Charlson comorbidity index score) was associated with increased likelihood of 30-day readmission. CONCLUSIONS: Sociocultural and demographic patient factors such as primary language, presence of religion, age, and comorbidity burden predict the likelihood of 7 and 30-day hospital readmission after general surgery. These findings support early implementation a postoperative care model that integrates all biopsychosocial domains across multiple disciplines of healthcare.

Vital signs and medical emergency response (MER) activation predict in-hospital mortality in general surgery patients: a study of 15 969 admissions.

BACKGROUND: The applicability of the vital signs prompting medical emergency response (MER) activation has not previously been examined specifically in a large general surgical cohort. This study aimed to characterize the distribution, and predictive performance, of four vital signs selected based on Australian guidelines (oxygen saturation, respiratory rate, systolic blood pressure and heart rate); with those of the MER activation criteria. METHODS: A retrospective cohort study was conducted including patients admitted under general surgical services of two hospitals in South Australia over 2 years. Likelihood ratios for patients meeting MER activation criteria, or a vital sign in the most extreme 1% for general surgery inpatients (<0.5th percentile or > 99.5th percentile), were calculated to predict in-hospital mortality. RESULTS: 15 969 inpatient admissions were included comprising 2 254 617 total vital sign observations. The 0.5th and 99.5th centile for heart rate was 48 and 133, systolic blood pressure 85 and 184, respiratory rate 10 and 31, and oxygen saturations 89% and 100%, respectively. MER activation criteria with the highest positive likelihood ratio for in-hospital mortality were heart rate ≤ 39 (37.65, 95% CI 27.71-49.51), respiratory rate ≥ 31 (15.79, 95% CI 12.82-19.07), and respiratory rate ≤ 7 (10.53, 95% CI 6.79-14.84). These MER activation criteria likelihood ratios were similar to those derived when applying a threshold of the most extreme 1% of vital signs. CONCLUSIONS: This study demonstrated that vital signs within Australian guidelines, and escalation to MER activation, appropriately predict in-hospital mortality in a large cohort of patients admitted to general surgical services in South Australia.

Depression after stoma surgery: a systematic review and meta-analysis.

BACKGROUND: Depression is the leading cause of global disability and can develop following the change in body image and functional capacity associated with stoma surgery. However, reported prevalence across the literature is unknown. Accordingly, we performed a systematic review and meta-analysis aiming to characterise depressive symptoms after stoma surgery and potential predictive factors. METHODS: PubMed/MEDLINE, Embase, CINAHL and Cochrane Library were searched from respective database inception to 6 March 2023 for studies reporting rates of depressive symptoms after stoma surgery. Risk of bias was assessed using the Downs and Black checklist for non-randomised studies of interventions (NRSIs), and Cochrane RoB2 tool for randomised controlled trials (RCTs). Meta-analysis incorporated meta-regressions and a random-effects model. REGISTRATION: PROSPERO, CRD42021262345. RESULTS: From 5,742 records, 68 studies were included. According to Downs and Black checklist, the 65 NRSIs were of low to moderate methodological quality. According to Cochrane RoB2, the three RCTs ranged from low risk of bias to some concerns of bias. Thirty-eight studies reported rates of depressive symptoms after stoma surgery as a proportion of the respective study populations, and from these, the median rate across all timepoints was 42.9% 42.9% (IQR: 24.2-58.9%). Pooled scores for respective validated depression measures (Hospital Anxiety and Depression Score (HADS), Beck Depression Inventory (BDI), and Patient Health Questionnaire-9 (PHQ-9)) across studies reporting those scores were below clinical thresholds for major depressive disorder according to severity criteria of the respective scores. In the three studies that used the HADS to compare non-stoma versus stoma surgical populations, depressive symptoms were 58% less frequent in non-stoma populations. Region (Asia-Pacific; Europe; Middle East/Africa; North America) was significantly associated with postoperative depressive symptoms (p = 0.002), whereas age (p = 0.592) and sex (p = 0.069) were not. CONCLUSIONS: Depressive symptoms occur in almost half of stoma surgery patients, which is higher than the general population, and many inflammatory bowel disease and colorectal cancer populations outlined in the literature. However, validated measures suggest this is mostly at a level of clinical severity below major depressive disorder. Stoma patient outcomes and postoperative psychosocial adjustment may be enhanced by increased psychological evaluation and care in the perioperative period.

In-hospital survival after pancreatoduodenectomy is greater in high-volume hospitals versus lower-volume hospitals: a meta-analysis.

BACKGROUND: Variation in cut-off values for what is considered a high volume (HV) hospital has made assessments of volume-outcome relationships for pancreaticoduodenectomy (PD) challenging. Accordingly, we performed a systematic review and meta-analysis comparing in-hospital mortality after PD in hospitals above and below HV thresholds of various cut-off values. METHOD: PubMed/MEDLINE, Embase and Cochrane Library were searched to 4 January 2021 for studies comparing in-hospital mortality after PD in hospitals above and below defined HV thresholds. After data extraction, risk of bias was assessed using the Downs and Black checklist. A random-effects model was used for meta-analysis, including meta-regressions. Registration: PROSPERO, CRD42021224432. RESULTS: From 1855 records, 17 observational studies of moderate quality were included. Median HV cut-off was 25 PDs/year (IQR: 20-32). Overall relative risk of in-hospital mortality was 0.37 (95% CI: 0.30, 0.45), that is, 63% less in HV hospitals. All subgroup analyses found an in-hospital survival benefit in performing PDs at HV hospitals. Meta-regressions from included studies found no statistically significant associations between relative risk of in-hospital mortality and region (USA vs. non-USA; p = 0.396); or 25th percentile (p = 0.231), median (p = 0.822) or 75th percentile (p = 0.469) HV cut-off values. Significant inverse relationships were found between PD hospital volume and other outcomes. CONCLUSION: In-hospital survival was significantly greater for patients undergoing PDs at HV hospitals, regardless of HV cut-off value or region. Future research is required to investigate regions where low-volume centres have specialized PD infrastructure and the potential impact on mortality.

Proposed delay for safe surgery after COVID-19.

BACKGROUND: Long-term effects after COVID-19 may affect surgical safety. This study aimed to evaluate the literature and produce evidence-based guidance regarding the period of delay necessary for adequate recovery of patients following COVID-19 infection before undergoing surgery. METHODS: A rapid review was combined with advice from a working group of 10 clinical experts across Australia and New Zealand. MEDLINE, medRxiv and grey literature were searched to 4 October 2020. The level of evidence was stratified according to the National Health and Medical Research Council evidence hierarchy. RESULTS: A total of 1020 records were identified, from which 20 studies (12 peer-reviewed) were included. None were randomized trials. The studies comprised one case-control study (level III-2 evidence), one prospective cohort study (level III-2) and 18 case-series studies (level IV). Follow-up periods containing observable clinical characteristics ranged from 3 to 16 weeks. New or excessive fatigue and breathlessness were the most frequently reported symptoms. SARS-CoV-2 may impact the immune system for multiple months after laboratory confirmation of infection. For patients with past COVID-19 undergoing elective curative surgery for cancer, risks of pulmonary complications and mortality may be lowest at 4 weeks or later after a positive swab. CONCLUSION: After laboratory confirmation of SARS-CoV-2 infection, minor surgery should be delayed for at least 4 weeks and major surgery for 8-12 weeks, if patient outcome is not compromised. Comprehensive preoperative and ongoing assessment must be carried out to ensure optimal clinical decision-making.

Screening and testing for COVID-19 before surgery.

BACKGROUND: Preoperative screening for coronavirus disease 2019 (COVID-19) aims to preserve surgical safety for both patients and surgical teams. This rapid review provides an evaluation of current evidence with input from clinical experts to produce guidance for screening for active COVID-19 in a low prevalence setting. METHODS: An initial search of PubMed (until 6 May 2020) was combined with targeted searches of both PubMed and Google Scholar until 1 July 2020. Findings were streamlined for clinical relevance through the advice of an expert working group that included seven senior surgeons and a senior medical virologist. RESULTS: Patient history should be examined for potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hyposmia and hypogeusia may present as early symptoms of COVID-19, and can potentially discriminate from other influenza-like illnesses. Reverse transcription-polymerase chain reaction is the gold standard diagnostic test to confirm SARS-CoV-2 infection, and although sensitivity can be improved with repeated testing, the decision to retest should incorporate clinical history and the local supply of diagnostic resources. At present, routine serological testing has little utility for diagnosing acute infection. To appropriately conduct preoperative testing, the temporal dynamics of SARS-CoV-2 must be considered. Relative to other thoracic imaging modalities, computed tomography has the greatest utility for characterizing pulmonary involvement in COVID-19 patients who have been diagnosed by reverse transcription-polymerase chain reaction. CONCLUSION: Through a rapid review of the literature and advice from a clinical expert working group, evidence-based recommendations have been produced for the preoperative screening of surgical patients with suspected COVID-19.

Personal protective equipment and evidence-based advice for surgical departments during COVID-19.

BACKGROUND: Inconsistencies regarding the use of appropriate personal protective equipment (PPE) have raised concerns for the safety of surgical staff during the coronavirus disease 2019 (COVID-19) pandemic. This rapid review synthesizes the literature and includes input from clinical experts to provide evidence-based guidance for surgical services. METHODS: The rapid review comprised of targeted searches in PubMed and grey literature. Pertinent findings were discussed by a working group of clinical experts, and consensus recommendations, consistent with Australian and New Zealand Government guidelines, were formulated. RESULTS: There was a paucity of high-quality primary studies specifically investigating appropriate surgical PPE for healthcare workers treating patients possibly infected with COVID-19. SARS-CoV-2 is capable of aerosol, droplet and fomite transmission, making it essential to augment standard infection control measures with appropriate PPE, especially during surgical emergencies and aerosol-generating procedures. All biological material should be treated a potential source of SARS-COV-2. Staff must have formal training in the use of PPE and should be supervised by a colleague during donning and doffing. Patients with suspected or confirmed COVID-19 should wear a surgical mask during transfer to and from theatre. Potential solutions exist in the literature to extend the use of surgical P2/N95 respirators in situations of limited supply. CONCLUSION: PPE is advised for all high-risk procedures and when a patient's COVID-19 status is unknown. Surgical departments should facilitate staggered rostering, remote meeting attendance, and self-isolation of symptomatic staff. Vulnerable surgical staff should be identified and excluded from operations with a high risk of COVID-19 infection.

Surgery triage during the COVID-19 pandemic.

BACKGROUND: The novel coronavirus, SARS-CoV-2, caused the COVID-19 global pandemic. In response, the Australian and New Zealand governments activated their respective emergency plans and hospital frameworks to deal with the potential increased demand on scarce resources. Surgical triage formed an important part of this response to protect the healthcare system's capacity to respond to COVID-19. METHOD: A rapid review methodology was adapted to search for all levels of evidence on triaging surgery during the current COVID-19 outbreak. Searches were limited to PubMed (inception to 10 April 2020) and supplemented with grey literature searches using the Google search engine. Further, relevant articles were also sourced through the Royal Australasian College of Surgeons COVID-19 Working Group. Recent government advice (May 2020) is also included. RESULTS: This rapid review is a summary of advice from Australian, New Zealand and international speciality groups regarding triaging of surgical cases, as well as the peer-reviewed literature. The key theme across all jurisdictions was to not compromise clinical judgement and to enable individualized, ethical and patient-centred care. The topics reported on include implications of COVID-19 on surgical triage, competing demands on healthcare resources (surgery versus COVID-19 cases), and the low incidence of COVID-19 resulting in a possibility to increase surgical caseloads over time. CONCLUSION: During the COVID-19 pandemic, urgent and emergency surgery must continue. A carefully staged return of elective surgery should align with a decrease in COVID-19 caseload. Combining evidence and expert opinion, schemas and recommendations have been proposed to guide this process in Australia and New Zealand.

Safe surgery during the coronavirus disease 2019 crisis.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has created a global pandemic. Surgical care has been impacted, with concerns raised around surgical safety, especially in terms of laparoscopic versus open surgery. Due to potential aerosol transmission of SARS-CoV-2, precautions during aerosol-generating procedures and production of surgical plume are paramount for the safety of surgical teams. METHODS: A rapid review methodology was used with evidence sourced from PubMed, Departments of Health, surgical colleges and other health authorities. From this, a working group of expert surgeons developed recommendations for surgical safety in the current environment. RESULTS: Pre-operative testing of surgical patients with reverse transcription-polymerase chain reaction does not guarantee lack of infectivity due to a demonstrated false-negative rate of up to 30%. All bodily tissues and fluids should therefore be treated as a potential source of COVID-19 infection during operative management. Caution must be taken, especially when using an energy source that produces surgical plumes, and an appropriate capture device should also be used. Limiting the use of such devices or using lower energy devices is desirable. To reduce perceived risks association with desufflation of pneumoperitoneum during laparoscopic surgery, an appropriate suction irrigator system, attached to a high-efficiency particulate air filter, should be used. Additionally, appropriate use of personal protective equipment by the surgical team is necessary during high-risk aerosol-generating procedures. CONCLUSIONS: As a result of the rapid review, evidence-based guidance has been produced to support safe surgical practice.

Intermittent ischemia enhances the uptake of indocyanine green to livers subject to ischemia and reperfusion.

BACKGROUND AND AIM: Intermittent ischemia is known to promote post perfusion bile flow, and hence recovery of liver function following ischemia reperfusion of the liver. However, the mechanisms involved are not well understood. The aim of this study was to identify the step(s) in the bile acid transport pathway altered by intermittent ischemia. METHODS: Arat model of segmental hepatic ischemia in which the bilateral median and left lateral lobes were made ischemic by clamping the blood vessels was used. Indocyanine green (ICG), infrared spectroscopy, and compartmental kinetic analysis, were used to indirectly monitor the movement of bile acids across hepatocytes in situ. Rates of bile flow were measured gravimetrically. RESULTS: In control livers (not subjected to ischemia), the movement of ICG from the blood to bile fluid could be described by a three compartment model comprising the blood, a rapidly-exchangeable compartment, and the hepatocyte cytoplasmic space. In livers subjected to continuous clamping, the rates of ICG uptake to the liver, and outflow from the liver, were greatly reduced compared with those in control livers. Intermittent clamping (three episodes of 15 min clamping) compared with continuous clamping substantially increased the rate of ICG uptake from the blood but had less effect on the rate of ICG outflow from hepatocytes. CONCLUSIONS: It is concluded that intermittent ischemia promotes post reperfusion bile flow in the early phase of ischemia reperfusion injury principally by enhancing the movement of bile acids from the blood to hepatocytes.

Oestrogen hormone receptors in focal nodular hyperplasia.

BACKGROUND: The role of hormones in focal nodular hyperplasia (FNH) has been investigated with conflicting results. OBJECTIVE: The aim of this study was to evaluate oestrogen and progesterone receptor immunohistochemical expression in FNH and surrounding normal liver (control material). METHODS: Biopsy materials from FNH and control tissue were investigated using an immunostainer. Receptor expression was graded as the proportion score (percentage of nuclear staining) and oestrogen receptor intensity score. RESULTS: Study material included tissue from 11 resected FNH lesions and two core biopsies in 13 patients (two male). Twelve samples showed oestrogen receptor expression. The percentage of nuclear oestrogen receptor staining was <33% in eight FNH biopsies, 34-66% in two FNH biopsies, and >67% in both core biopsies. The better staining in core biopsies relates to limitations of the staining technique imposed by the fibrous nature of larger resected FNH. Control samples from surrounding tissue were available for nine of the resected specimens and all showed oestrogen receptor expression. Progesterone receptor expression was negligible in FNH and control samples. CONCLUSIONS: By contrast with previous studies, the majority of FNH and surrounding liver in this cohort demonstrated oestrogen receptor nuclear staining. The implications of this for continued oral contraceptive use in women of reproductive age with FNH remain uncertain given the lack of consistent reported growth response to oestrogen stimulation or withdrawal.

Evidence that estrogen receptors play a limited role in mediating enhanced recovery of bile flow in female rats in the acute phase of liver ischemia reperfusion injury.

INTRODUCTION: Female patients exhibit better survival and less hepatic damage from ischemia reperfusion (IR) injury following surgery. However, the effects of sex and estrogens on liver function in the acute phase of IR are not well understood. Objective. The aim was to investigate this question. MATERIAL AND METHODS: A rat model of segmental hepatic ischemia was employed. Rats were pre-treated with the estrogen receptor antagonist ICI182,780 and/or the estrogen receptor agonist 17ß-estradiol. Bile flow, blood concentrations of bilirubin and liver enzymes were measured, and liver histology was assessed. RESULTS: Bile flow recovery immediately after the initiation of reperfusion was faster in females than in males. ICI182,780 reduced the rate of bile flow recovery in females but this reduction was not reversed by co-administration of 17 ß-estradiol. In males, 17 ß-estradiol alone did not enhance bile flow recovery. The changes in bile flow recovery observed under a given condition were correlated with small changes in blood liver enzymes and liver histology. CONCLUSIONS: Sex has a significant influence on the early recovery of liver function in the acute phase of IR injury. However, in female rats estrogen receptors play only a limited role in mediating enhanced recovery of liver function.

Cirrhosis and microvascular invasion predict outcomes in hepatocellular carcinoma.

BACKGROUND: Liver resection (LR) and liver transplantation (LT) are two modalities offering potential for cure in patients with hepatocellular carcinoma (HCC). The objective of this study was to evaluate the long-term survival of patients with HCC treated with LT and LR and to analyse variables influencing these outcomes. METHODS: Patients referred to the South Australian Liver Transplant Unit and Hepatopancreatobiliary Unit at Flinders Medical Centre from January 1992 to September 2009 with a diagnosis of HCC who underwent LT or LR were included in the study. Histopathological parameters analysed included size, number and grade of tumour, microscopic vascular invasion and presence or absence of cirrhosis in remnant liver. RESULTS: Eighty-five patients with a median age of 58 years (range 26-85 years) underwent LT or LR. Median follow-up was 40 months in both groups. Overall, 5-year actuarial survival for all patients with HCC in both groups was 55%. LR patients were significantly older (P < 0.001) than LT patients. Their tumours were larger (P < 001) and more often solitary (P < 0.001) compared with the LT group. In multivariate analysis, age >60 (P < 0.02), histopathological evidence of vascular invasion (P < 0.02) and presence of cirrhosis (P < 0.02) were associated with a significantly reduced survival. Patients without vascular invasion and cirrhosis had an actuarial 5-year survival >70%. CONCLUSIONS: Our study indicates that LT (within University of California, San Francisco criteria) and LR can lead to acceptable long-term survival outcomes in patients with HCC. Microscopic vascular invasion and cirrhosis were the most significant prognostic factors impacting on survival.