The carbon footprint of total knee replacements.

ObjectiveDetailed quantifications of the environmental footprint of operations that include surgery, anaesthesia, and engineering are rare. We examined all such aspects to find the greenhouse gas emissions of an operation.MethodsWe undertook a life cycle assessment of 10 patients undergoing total knee replacements, collecting data for all surgical equipment, energy requirements for cleaning, and operating room energy use. Data for anaesthesia were sourced from our prior study. We used life cycle assessment software to convert inputs of energy and material use into outputs in kg CO2e emissions, using Monte Carlo analyses with 95% confidence intervals.ResultsThe average carbon footprint was 131.7kg CO2e, (95% confidence interval: 117.7-148.5kg CO2e); surgery was foremost (104/131.7kg CO2e, 80%), with lesser contributions from anaesthesia (15.0/131.7kg CO2e, 11%), and engineering (11.9/131.7kg CO2e, 9%). The main surgical sources of greenhouse gas emissions were: energy used to disinfect and steam sterilise reusable equipment (43.4/131.7kg CO2e, 33%), single-use equipment (34.2/131.7kg CO2e, 26%), with polypropylene alone 13.7/131.7kg CO2e (11%), and the knee prosthesis 19.6kg CO2e (15%). For energy use, the main contributors were: gas heating (6.7kg CO2e) and heating, cooling, and fans (4kg CO2e).ConclusionsThe carbon footprint of a total knee replacement was equivalent to driving 914km in a standard 2022 Australian car, with surgery contributing 80%. Such data provide guidance in reducing an operation's carbon footprint through prudent equipment use, more efficient steam sterilisation with renewable electricity, and reduced single-use waste.

Environmental sustainability in cardiovascular practice: current challenges and future directions.

Cardiovascular disease is the leading cause of morbidity and mortality worldwide, with a substantial amount of health-care resources targeted towards its diagnosis and management. Environmental sustainability in cardiovascular care can have an important role in reducing greenhouse gas emissions and pollution and could be beneficial for improving health metrics and societal well-being and minimizing the cost of health care. In this Review, we discuss the motivations and frameworks for sustainable cardiovascular care with an emphasis on the reduction of the climate-related and environmental effects of cardiovascular care. We also provide an overview of greenhouse gas emissions related to the provision of health care, including their measurement and quantification, carbon accounting, carbon disclosures and climate effects. The principles of life-cycle assessment, waste prevention and circular economics in health care are discussed, and the emissions associated with various sectors of cardiovascular care as well as the rationale for prevention as a powerful approach to reduce these emissions are presented. Finally, we highlight the challenges in environmental sustainability and future directions as applicable to cardiovascular practice.

Single-use synthetic plastic and natural fibre anaesthetic drug trays: a comparative life cycle assessment of environmental impacts.

BACKGROUND: Single-use anaesthetic drug trays are used widely in Australia, but their environmental impact is unclear. METHODS: A life cycle assessment was completed for 10 different types of single-use anaesthetic drug trays made of four materials: the synthetic plastics polypropylene and polystyrene, and the natural fibres bagasse (sugarcane pulp) and cellulose pulp. RESULTS: Carbon emissions per tray from total life cycle with landfill disposal were 33-454 g CO2-eq, which equates to 152-2066 tonnes CO2-eq annually. Recycling mitigates this impact, reducing emissions per tray to 16-294 g CO2-eq. The tray with the least emissions for landfill and recycling was the small polystyrene injection tray. There was a significant linear relationship between the mass of a tray and its carbon emissions. For landfill, recycling, and incineration disposal, Pearson's r value was 0.98, 0.99, and 0.95, respectively. Composting natural fibres can give a carbon benefit over some synthetic plastics under specific disposal scenarios, but this benefit was not seen under all circumstances. There was a strong positive correlation between the increasing mass of a tray and its increasing environmental impacts for water consumption, particulate matter formation, and mineral depletion. CONCLUSIONS: Single-use trays with the lowest mass should be preferentially chosen. Recycling and composting will reduce environmental impacts. Natural fibre does not automatically confer any environmental benefit over plastic and sustainability claims should be carefully examined for accuracy. The practice of using a single-use drug tray for every procedure should be reconsidered.

A Randomized Noninferiority Trial to Compare Enteral to Parenteral Phosphate Replacement on Biochemistry, Waste, and Environmental Impact and Healthcare Cost in Critically Ill Patients With Mild to Moderate Hypophosphatemia.

OBJECTIVES: Hypophosphatemia occurs frequently. Enteral, rather than IV, phosphate replacement may reduce fluid replacement, cost, and waste. DESIGN: Prospective, randomized, parallel group, noninferiority clinical trial. SETTING: Single center, 42-bed state trauma, medical and surgical ICUs, from April 20, 2022, to July 1, 2022. PATIENTS: Patients with serum phosphate concentration between 0.3 and 0.75 mmol/L. INTERVENTIONS: We randomized patients to either enteral or IV phosphate replacement using electronic medical record-embedded program. MEASUREMENT AND MAIN RESULTS: Our primary outcome was serum phosphate at 24 hours with a noninferiority margin of 0.2 mmol/L. Secondary outcomes included cost savings and environmental waste reduction and additional IV fluid administered. The modified intention-to-treat cohort comprised 131 patients. Baseline phosphate concentrations were similar between the two groups. At 24 hours, mean ( sd ) serum phosphate concentration were enteral 0.89 mmol/L (0.24 mmol/L) and IV 0.82 mmol/L (0.28 mmol/L). This difference was noninferior at the margin of 0.2 mmol/L (difference, 0.07 mmol/L; 95% CI, -0.02 to 0.17 mmol/L). When assigned IV replacement, patients received 408 mL (372 mL) of solvent IV fluid. Compared with IV replacement, the mean cost per patient was ten-fold less with enteral replacement ($3.7 [$4.0] vs. IV: $37.7 [$31.4]; difference = $34.0 [95% CI, $26.3-$41.7]) and weight of waste was less (7.7 g [8.3 g] vs. 217 g [169 g]; difference = 209 g [95% CI, 168-250 g]). C O2 emissions were 60-fold less for comparable phosphate replacement (enteral: 2 g producing 14.2 g and 20 mmol of potassium dihydrogen phosphate producing 843 g of C O2 equivalents). CONCLUSIONS: Enteral phosphate replacement in ICU is noninferior to IV replacement at a margin of 0.2 mmol/L but leads to a substantial reduction in cost and waste.

Cutting back on low-value health care practices supports sustainable kidney care.

July 2023 marked the hottest month on record, underscoring the urgent need for action on climate change. The imperative to reduce carbon emissions extends to all sectors, including health care, with it being responsible for 5.5% of global emissions. In decarbonizing health care, although much attention has focused on greening health care infrastructure and procurement, less attention has focused on reducing emissions through demand-side management. An important key element of this is reducing low-value care, given that ≈20% of global health care expenditure is considered low value. "Value" in health care, however, is subjective and dependent on how health outcomes are regarded. This review, therefore, examines the 3 main value perspectives specific to health care. Clinical effectiveness defines low-value care as interventions that offer little to no benefit or have a risk of harm exceeding benefits. Cost-effectiveness compares health outcomes versus costs compared with an alternative treatment. In this case, low-value care is care greater than a societal willingness to pay for an additional unit of health (quality-adjusted life year). Last, community perspectives emphasize the value of shared decision-making and patient-centered care. These values sit within broader societal values of ethics and equity. Any reduction in low-value care should, therefore, also consider patient autonomy, societal value perspectives and opportunity costs, and equity. Deimplementing entrenched low-value care practices without unnecessarily compromising ethics and equity will require tailored strategies, education, and transparency.

How environmental impact is considered in economic evaluations of critical care: a scoping review.

PURPOSE: Health care is a major contributor to climate change, and critical care is one of the sector's highest carbon emitters. Health economic evaluations form an important component of critical care and may be useful in identifying economically efficient and environmentally sustainable strategies. The purpose of this scoping review was to synthesise available literature on whether and how environmental impact is considered in health economic evaluations of critical care. METHODS: A robust scoping review methodology was used to identify studies reporting on environmental impact in health economic evaluations of critical care. We searched six academic databases to locate health economic evaluations, costing studies and life cycle assessments of critical care from 1993 to present. RESULTS: Four studies met the review's inclusion criteria. Of the 278 health economic evaluations of critical care identified, none incorporated environmental impact into their assessments. Most included studies (n = 3/4) were life cycle assessments, and the remaining study was a prospective observational study. Life cycle assessments used a combination of process-based data collection and modelling to incorporate environmental impact into their economic assessments. CONCLUSIONS: Health economic evaluations of critical care have not yet incorporated environmental impact into their assessments, and few life cycle assessments exist that are specific to critical care therapies and treatments. Guidelines and standardisation regarding environmental data collection and reporting in health care are needed to support further research in the field. In the meantime, those planning health economic evaluations should include a process-based life cycle assessment to establish key environmental impacts specific to critical care.

Environmental and financial impacts of perioperative paracetamol use: a multicentre international life-cycle analysis.

BACKGROUND: Pharmaceuticals account for 19-32% of healthcare greenhouse gas (GHG) emissions. Paracetamol is a common perioperative analgesic agent. We estimated GHG emissions associated with i.v. and oral formulations of paracetamol used in the perioperative period. METHODS: Life-cycle assessment of GHG emissions (expressed as carbon dioxide equivalents CO2e) of i.v. and oral paracetamol preparations was performed. Perioperative paracetamol prescribing practices and costs for 26 hospitals in USA, UK, and Australia were retrospectively audited. For those surgical patients for whom oral formulations were indicated, CO2e and costs of actual prescribing practices for i.v. or oral doses were compared with optimal oral prescribing. RESULTS: The carbon footprint for a 1 g dose was 38 g CO2e (oral tablet), 151 g CO2e (oral liquid), and 310-628 g CO2e (i.v. dependent on type of packaging and administration supplies). Of the eligible USA patients, 37% received paracetamol (67% was i.v.). Of the eligible UK patients, 85% received paracetamol (80% was i.v.). Of the eligible Australian patients, 66% received paracetamol (70% was i.v.). If the emissions mitigation opportunity from substituting oral tablets for i.v. paracetamol is extrapolated to USA, UK, and Australia elective surgical encounters in 2019, ∼5.7 kt CO2e could have been avoided and would save 98.3% of financial costs. CONCLUSIONS: Intravenous paracetamol has 12-fold greater life-cycle carbon emissions than the oral tablet form. Glass vials have higher greenhouse gas emissions than plastic vials. Intravenous administration should be reserved for cases in which oral formulations are not feasible.

Environmental impact of cardiovascular healthcare.

IMPORTANCE: The healthcare sector is essential to human health and well-being, yet its significant carbon footprint contributes to climate change-related threats to health. OBJECTIVE: To review systematically published studies on environmental impacts, including carbon dioxide equivalent (CO2e) emissions, of contemporary cardiovascular healthcare of all types, from prevention through to treatment. EVIDENCE REVIEW: We followed the methods of systematic review and synthesis. We conducted searches in Medline, EMBASE and Scopus for primary studies and systematic reviews measuring environmental impacts of any type of cardiovascular healthcare published in 2011 and onwards. Studies were screened, selected and data were extracted by two independent reviewers. Studies were too heterogeneous for pooling in meta-analysis and were narratively synthesised with insights derived from content analysis. FINDINGS: A total of 12 studies estimating environmental impacts, including carbon emissions (8 studies), of cardiac imaging, pacemaker monitoring, pharmaceutical prescribing and in-hospital care including cardiac surgery were found. Of these, three studies used the gold-standard method of Life Cycle Assessment. One of these found the environmental impact of echocardiography was 1%-20% that of cardiac MR (CMR) imaging and Single Photon Emission Tomography (SPECT) scanning. Many opportunities to reduce environmental impacts were identified: carbon emissions can be reduced by choosing echocardiography as the first cardiac test before considering CT or CMR, remote monitoring of pacemaker devices and teleconsultations when clinically appropriate to do so. Several interventions may be effective for reducing waste, including rinsing bypass circuitry after cardiac surgery. Cobenefits included reduced costs, health benefits such as cell salvage blood available for perfusion, and social benefits such as reduced time away from work for patients and carers. Content analysis revealed concern about the environmental impact of cardiovascular healthcare, particularly carbon emissions and a desire for change. CONCLUSIONS AND RELEVANCE: Cardiac imaging, pharmaceutical prescribing and in-hospital care including cardiac surgery have significant environmental impacts, including CO2e emissions which contribute to climate-related threats to human health. Importantly, many opportunities to effectively reduce environmental impacts exist within cardiac care, and can provide economic, health and social cobenefits.

Carbon emissions and hospital pathology stewardship: a retrospective cohort analysis.

BACKGROUND: As healthcare is responsible for 7% of Australia's carbon emissions, it was recognised that a policy implemented at St George Hospital, Sydney, to reduce non-urgent pathology testing to 2 days per week and, on other days only if essential, would also result in a reduction in carbon emissions. The aim of the study was to measure the impact of this intervention on pathology collections and associated carbon emissions and pathology costs. AIMS: To measure the impact of an intervention to reduce unnecessary testing on pathology collections and associated carbon emissions and pathology costs. METHODS: The difference in the number of pathology collections, carbon dioxide equivalents (CO2 e) for five common blood tests and pathology cost per admission were compared between a 6-month reference period and 6-month intervention period. CO2 e were estimated from published pathology CO2 e impacts. Cost was derived from pathology billing records. Outcomes were modelled using multivariable negative binomial, generalised linear and logistic regression. RESULTS: In total, 24 585 pathology collections in 5695 patients were identified. In adjusted analysis, the rate of collections was lower during the intervention period (rate ratio 0.90; 95% confidence interval (CI), 0.86-0.95; P < 0.001). This resulted in a reduction of 53 g CO2 e (95% CI, 24-83 g; P < 0.001) and $22 (95% CI, $9-$34; P = 0.001) in pathology fees per admission. The intervention was estimated to have saved 132 kg CO2 e (95% CI, 59-205 kg) and $53 573 (95% CI, 22 076-85 096). CONCLUSIONS: Reduction in unnecessary hospital pathology collections was associated with both carbon emission and cost savings. Pathology stewardship warrants further study as a potentially scalable, cost-effective and incentivising pathway to lowering healthcare associated greenhouse gas emissions.

Incorporating carbon into health care: adding carbon emissions to health technology assessments.

At the UN Climate Change Conference 26 in Glasgow, 50 countries committed to low-carbon health services, with 14 countries further committing to net-zero carbon health services by 2050. Reaching this target will require decision makers to include carbon emissions when evaluating new and existing health technologies (tests and treatments). There is currently, however, a scarcity of data on the carbon footprint of health-care interventions, nor any means for decision makers to include and consider carbon emission health-care assessments. We therefore investigated how to integrate carbon emissions calculated by environmental life cycle assessment (LCA) into health technology assessments (HTA). HTAs are extensively used in developing clinical and policy guidelines by individual public or private payers, and by government organisations. In the first section we explain the methodological differences between environmentally extended input-output and process-based LCA. The second section outlines ways in which carbon emissions calculated by LCA could be integrated with HTAs, recognising that HTAs are done in several ways by different jurisdictions. International effort and processes will be needed to ensure that robust and comprehensive carbon footprints of commonly used health-care products are freely available. The technical and implementation challenges of incorporating carbon emissions into HTAs are considerable, but not unsurmountable. Our aim is to lay foundations for meeting these challenges.

Health, financial and environmental impacts of unnecessary vitamin D testing: a triple bottom line assessment adapted for healthcare.

OBJECTIVE: To undertake an assessment of the health, financial and environmental impacts of a well-recognised example of low-value care; inappropriate vitamin D testing. DESIGN: Combination of systematic literature search, analysis of routinely collected healthcare data and environmental analysis. SETTING: Australian healthcare system. PARTICIPANTS: Population of Australia. OUTCOME MEASURES: We took a sustainability approach, measuring the health, financial and environmental impacts of a specific healthcare activity. Unnecessary vitamin D testing rates were estimated from best available published literature; by definition, these provide no gain in health outcomes (in contrast to appropriate/necessary tests). Australian population-based test numbers and healthcare costs were obtained from Medicare for vitamin D pathology services. Carbon emissions in kg CO2e were estimated using data from our previous study of the carbon footprint of common pathology tests. We distinguished between tests ordered as the primary test and those ordered as an add-on to other tests, as many may be done in conjunction with other tests. We conducted base case (8% being the primary reason for the blood test) and sensitivity (12% primary test) analyses. RESULTS: There were a total of 4 457 657 Medicare-funded vitamin D tests in 2020, on average one test for every six Australians, an 11.8% increase from the mean 2018-2019 total. From our literature review, 76.5% of Australia's vitamin D tests provide no net health benefit, equating to 3 410 108 unnecessary tests in 2020. Total costs of unnecessary tests to Medicare amounted to >$A87 000 000. The 2020 carbon footprint of unnecessary vitamin D tests was 28 576 kg (base case) and 42 012 kg (sensitivity) CO2e, equivalent to driving ~160 000-230 000 km in a standard passenger car. CONCLUSIONS: Unnecessary vitamin D testing contributes to avoidable CO2e emissions and healthcare costs. While the footprint of this example is relatively small, the potential to realise environmental cobenefits by reducing low-value care more broadly is significant.

The carbon footprint of hospital diagnostic imaging in Australia.

Background: Pathology testing and diagnostic imaging together contribute 9% of healthcare's carbon footprint. Whilst the carbon footprint of pathology testing has been undertaken, to date, the carbon footprint of the four most common imaging modalities is unclear. Methods: We performed a prospective life cycle assessment at two Australian university-affiliated health services of five imaging modalities: chest X-ray (CXR), mobile chest X-ray (MCXR), computerised tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US). We included scanner electricity use and all consumables and associated waste, including bedding, imaging contrast, and gloves. Analysis was performed using both attributional and consequential life cycle assessment methods. The primary outcome was the greenhouse gas footprint, measured in carbon dioxide equivalent (CO2e) emissions. Findings: Mean CO2e emissions were 17·5 kg/scan for MRI; 9·2 kg/scan for CT; 0·8 kg/scan for CXR; 0·5 kg/scan for MCXR; and 0·5 kg/scan for US. Emissions from scanners from standby energy were substantial. When expressed as emissions per additional scan (results of consequential analysis) impacts were lower: 1·1 kg/scan for MRI; 1·1 kg/scan for CT; 0·6 kg/scan for CXR; 0·1 kg/scan for MCXR; and 0·1 kg/scan for US, due to emissions from standby power being excluded. Interpretation: Clinicians and administrators can reduce carbon emissions from diagnostic imaging, firstly by reducing the ordering of unnecessary imaging, or by ordering low-impact imaging (X-ray and US) in place of high-impact MRI and CT when clinically appropriate to do so. Secondly, whenever possible, scanners should be turned off to reduce emissions from standby power. Thirdly, ensuring high utilisation rates for scanners both reduces the time they spend in standby, and apportions the impacts of the reduced standby power of a greater number of scans. This therefore reduces the impact on any individual scan, maximising resource efficiency. Funding: Healthy Urban Environments (HUE) Collaboratory of the Maridulu Budyari Gumal Sydney Partnership for Health, Education, Research and Enterprise MBG SPHERE. The National Health and Medical Research Council (NHMRC) PhD scholarship.