The carbon footprint of acute care: how energy intensive is critical care?

Past, present, and future of sustainable intensive care: narrative review and a large hospital system experience

Healthcare systems are large contributors to global emissions, and intensive care units (ICUs) are a complex and resource-intensive component of these systems. Recent global movements in sustainability initiatives, led mostly by Europe and Oceania, have tried to mitigate ICUs' notable environmental impact with varying success. However, there exists a significant gap in the U.S. knowledge and published literature related to sustainability in the ICU. After a narrative review of the literature and related industry standards, we share our experience with a Green ICU initiative at a large hospital system in Texas. Our process has led to a 3-step pathway to inform similar initiatives for sustainable (green) critical care. This pathway involves (1) establishing a baseline by quantifying the status quo carbon footprint of the affected ICU as well as the cumulative footprint of all the ICUs in the healthcare system; (2) forming alliances and partnerships to target each major source of these pollutants and implement specific intervention programs that reduce the ICU-related greenhouse gas emissions and solid waste; and (3) finally to implement a systemwide Green ICU which requires the creation of multiple parallel pathways that marshal the resources at the grass-roots level to engage the ICU staff and institutionalize a mindset that recognizes and respects the impact of ICU functions on our environment. It is expected that such a systems-based multi-stakeholder approach would pave the way for improved sustainability in critical care.

The carbon footprint of critical care: a systematic review

PURPOSE

The provision of healthcare is a substantial global contributor to greenhouse gas (GHG) emissions. Several medical specialties and national health systems have begun evaluating their carbon emission contributions. The aim of this review is to summarise and describe the carbon footprint resulting from the provision of adult, paediatric and neonatal critical care.

METHODS

A systematic search of Embase, Cochrane and Web of Science was performed in January 2023. Studies reporting any assessment of the carbon footprint of critical care were included. No language restrictions were applied. GHG emissions from life cycle assessments (LCA) were reported, in addition to waste, electricity and water use. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline was followed.

RESULTS

In total, 13 studies assessing and describing the environmental impact of 36 adult or paediatric intensive care units (ICUs) were included. Two studies described full LCAs, seven reported waste only, two provided audits of unused medical supplies, one reported electricity use, and one study described a Material Flow Analysis. The estimated carbon emissions from critical care range between 88 kg CO2e/patient/day and 178 kg CO2e/patient/day. The two predominant sources of carbon emissions in critical care originate from electricity and gas use, as well as consumables. Waste production ranged from 1.1 to 13.7 kg/patient/day in the 6 studies where mean waste could be calculated.

CONCLUSION

There is a significant carbon footprint that results from intensive care provision. Consumables and waste constitute important, measurable, and modifiable components of anthropogenic emissions. There remains uncertainty due to a lack of literature, several unstudied areas of carbon emissions from critical care units, and within measured areas, measurement and reporting of carbon emissions are inconsistent.

Environmentally sustainable gastroenterology practice: Review of current state and future goals

OBJECTIVES

The health-care sector contributes 4.6% of global greenhouse gas emissions, with gastroenterology playing a significant role due to the widespread use of gastrointestinal (GI) endoscopy. In this review, we aim to understand the carbon footprint in gastroenterology practice associated with GI endoscopy, conferences and recruitment, identify barriers to change, and recommend mitigating strategies.

METHODS

A comprehensive search of PubMed, Embase, and the Cochrane Library was conducted to explore the carbon footprint in gastroenterology practice, focusing on endoscopy, inpatient and outpatient settings, and recruitment practices. Recommendations for mitigating the carbon footprint were derived.

RESULTS

This narrative review analyzed 34 articles on the carbon footprint in gastroenterology practice. Carbon footprint of endoscopy in the United States is approximately 85,768 metric tons of CO2 emission annually, equivalent to 9 million gallons of gasoline consumed, or 94 million pounds of coal burned. Each endoscopy generates 2.1 kg of disposable waste (46 L volume), of which 64% of waste goes to the landfill, 28% represents biohazard waste, and 9% is recycled. The per-case manufacturing carbon footprint for single-use devices and reusable devices is 1.37 kg CO2 and 0.0017 kg CO2, respectively. Inpatient and outpatient services contributed through unnecessary procedures, prolonged hospital stays, and excessive use of single-use items. Fellowship recruitment and gastrointestinal conferences added to the footprint, mainly due to air travel and hotel stays.

CONCLUSION

Gastrointestinal endoscopy and practice contribute to the carbon footprint through the use of disposables such as single-use endoscopes and waste generation. To achieve environmental sustainability, measures such as promoting reusable endoscopy equipment over single-use endoscopes, calculating institutional carbon footprints, establishing benchmarking standards, and embracing virtual platforms such as telemedicine and research meetings should be implemented.

[Sustainability in intensive and emergency care : A nationwide survey by the German Society of Medical Intensive Care and Emergency Medicine]

BACKGROUND

The impact of climate change on humans is well known. However, the health care system is also a relevant contributor, accounting for up to 5-7% of global greenhouse gas emissions, and work should be adapted to be more sustainable.

AIM

The survey investigated whether sustainability plays a role in hospitals and specifically in the field of emergency and intensive care. Concrete measures and which hurdles are already recognized were also inquired.

MATERIALS AND METHODS

The "AG Nachhaltigkeit" (working group on sustainability) of the "Deutschen Gesellschaft für Internistische Intensivmedizin und Notfallmedizin" (DGIIN) conducted an electronic survey among the staff of intensive care units, emergency rooms, and ambulance services in Germany.

RESULTS

In all, 218 survey results were included in the analysis: 108 (50%) participants were from the nursing sector and 98 (45%) belonged to the medical staff. The majority of participants work in an intensive care unit (181 [83%]) followed by intermediate care unit (52 [24%]). A total of 104 (47%) participants indicated that their workplace had already implemented sustainability measures. However, when asked whether decision-makers in the workplaces incorporate sustainability into their decisions, management scored highest with only 20%. Potential for improvement is seen in energy and waste management, among others.

CONCLUSION

The survey results show that (1) employees are highly motivated to address the issue of sustainability and to implement measures, (2) the potential to establish a resource-saving and environmentally friendly hospital is far from being exhausted, and (3) it must become a priority that decision-makers in the hospital propagate sustainability, make processes transparent, and support the motivation of employees on the subject of sustainability. In addition, this process must be supported by politicians and health insurance companies.

[The CO2 footprint of intensive care medicine-let's go green]

Climate change and global warming are facts, and actually they are a hot topic for politics, economics, and societies. Global healthcare contributes approximately 5% of worldwide anthropogenic emissions, and this fact might produce an ethical dilemma between the Hippocratic principles of 'beneficence' (promotion of health) and of 'non-maleficence' (avoiding reinforcement of the climate crisis). Intensive care medicine has continuous high staff activity, resource use, and energy demands, and it is clear that intensive care medicine must become green to commence with practical measures to reduce their intensive care unit (ICU) carbon footprint. In this article several strategies are introduced, beginning with the creation of green teams on the ICUs from the bottom. Furthermore, systematic recycle programs, and the assessment and control of energy use are required to make ICUs more sustainable. Strategies for avoiding futile treatment combined with a choose wisely philosophy might contribute to such projects. Immediate engagement of all healthcare staff, particularly those who work in the ICU, is necessary to join the 'race to zero carbon emissions'.

Using Residual Blood from the Arterial Blood Gas Test to Perform Therapeutic Drug Monitoring of Vancomycin: An Example of Good Clinical Practice Moving towards a Sustainable Intensive Care Unit

Background

Regarding sustainability in the intensive care unit (ICU), there is increasing interest in reducing material waste and avoiding unnecessary procedures. Therapeutic drug monitoring (TDM) of vancomycin, using a dedicated tube, is standard clinical care during treatment with vancomycin. Furthermore, in the ICU, on a daily basis, arterial blood gas (ABG) tests are frequently performed throughout the day. After analysis, a variable volume of blood is discarded. Lithium heparin (LiHep) syringes for ABG tests differ from normally used dipotassium ethylenediaminetetraacetic acid (K₂EDTA) tubes. The primary objective was to compare both containers and validate the use of LiHep syringes. Secondary objectives were to evaluate the potential impact on saving materials, nursing time, and costs when implementing vancomycin TDM via LiHep syringes.

Methods

Vancomycin analysis from sampling in lithium heparin (LiHep) syringes for ABG tests was validated and compared with the concentrations from conventional sampling in K₂EDTA tubes. For method comparison, a Bland-Altman plot and Deming regression analysis were performed. The method was validated for inter- and intra-day precision and accuracy. Vancomycin was analyzed by means of the validated method using a particle-enhanced turbidimetric inhibition immunoassay (PETINIA) autoanalyzer. Furthermore, an analysis was conducted to evaluate the potential impact of implementing vancomycin sampling via ABG tests on savings in materials, nursing time, and costs.

Results

From 18 patients, 24 plasma samples in both K₂EDTA tubes and LiHep syringes were obtained and compared. The mean relative difference between the two containers was -2.0% (-3.0 to -0.93%). Both the Deming regression analysis and the Bland-Altman plot met the acceptance criteria. Potentially, over 1000 blood draws and accompanying materials and packaging can be saved when vancomycin samples are obtained by means of scavenged LiHep syringes. The vancomycin analysis for LiHep syringes showed a total interday precision of 1.95% and an accuracy of 99.7%. The total intraday precision was 2.22%, and the accuracy was 99.2%. Accuracy and precision values were within the acceptance criteria of recovery 85 to 115% and ≤15%, respectively.

Conclusion

No significant differences were found in vancomycin concentration between the two analyses, and the LiHep analysis was validated for further implementation in clinical care. Residual blood from ABG test samples can be used for TDM of vancomycin, resulting in a potential reduction of materials used and the number of blood draws. These results will contribute to a more sustainable TDM process with benefits for the patient.

Application of job shop scheduling approach in green patient flow optimization using a hybrid swarm intelligence

With the increasing demand for hospital services amidst the COVID-19 pandemic, allocation of limited public resources and management of healthcare services are of paramount importance. In the field of patient flow scheduling, previous research primarily focused on classical-based objective functions, while ignoring environmental-based objective functions. This study presents a flexible job shop scheduling problem to optimize patient flow and, thereby, minimize the total carbon footprint, as the sustainability-based objective function. Since flexible job shop scheduling is an NP-hard problem, a metaheuristic optimization algorithm, called Chaotic Salp Swarm Algorithm Enhanced with Opposition-Based Learning and Sine Cosine (CSSAOS), was developed. The proposed algorithm integrates the Salp Swarm Algorithm (SSA) with chaotic maps to update the position of followers, the sine cosine algorithm to update the leader position, and opposition-based learning for a better exploration of the search space. generating more accurate solutions. The proposed method was successfully applied in a real-world case study and demonstrated better performance than other well-known metaheuristic algorithms, including differential evolution, genetic algorithm, grasshopper optimization algorithm, SSA based on opposition-based learning, quantum evolutionary SSA, and whale optimization algorithm. In addition, it was found that the proposed method is scalable to different sizes and complexities.

Environmental sustainability and the carbon emissions of pharmaceuticals

The US healthcare industry emits an estimated 479 million tonnes of carbon dioxide each year; nearly 8% of the country's total emissions. When assessed by sector, hospital care, clinical services, medical structures, and pharmaceuticals are the top emitters. For 15 years, research has been dedicated to the medical structures and equipment that contribute to carbon emissions. More recently, hospital care and clinical services have been examined. However, the carbon of pharmaceuticals is understudied. This article will focus on the carbon emissions of pharmaceuticals since they are consistently calculated to be among the top contributors to healthcare carbon and assess the factors that contribute to pharmaceutical carbon emissions. Specifically, overprescription, pharmaceutical waste, antibiotic resistance, routine prescriptions, non-adherence, drug dependency, lifestyle prescriptions, and drugs given due to a lack of preventive healthcare will be identified. Prescribing practices have environmental ramifications. Carbon reduction, when focused on pharmaceuticals, can lead to cleaner, more sustainable healthcare.

Medical conferences in the era of environmental conscientiousness and a global health crisis: The carbon footprint of presenter flights to pre-COVID pediatric urology conferences and a consideration of future options

INTRODUCTION

Medical conferences are integral to academic medicine, with academic posters being a well-established medium for presenting research. However, conferences carry an ecological footprint due to greenhouse gas emissions. Furthermore, traditional conference formats have recently not been possible due to the COVID-19 pandemic. Herein we examine the carbon footprint associated with travel by presenting delegates to the Fall SPU conferences from 2013 to 2019, and the 2015 ESPU conference.

METHODS

Online programs for the targeted SPU Fall meetings and the 2015 ESPU Annual Meeting were retrospectively reviewed. Variables collected included meeting location and presenter home base. Distance traveled by the presenter, and likely CO₂e of this return trip were estimated using online calculators. Analysis was performed using the Kruskal-Wallis-H test with pairwise comparisons to detect differences in round trip distances and CO₂e between meeting locations.

RESULTS

Six Fall SPU conferences and one ESPU conference were reviewed. The majority of presenters were from the region (North America and Europe, respectively), for both SPU and ESPU. The median round trip distance was 2596.34 miles (IQR 1420.96-4438.30), and the median CO₂e 0.61 metric tons (IQR 0.36-1.02). We found that the distances traveled to conferences in the Western USA and Europe were slightly further than those to conferences in Central Canada and the Southern US. The difference in CO₂e between these locations did not achieve statistical significance.

CONCLUSION

Presenter travel to and from pediatric urological conferences generates an important carbon footprint and may not be possible in the medium-term future due to a global pandemic. We should explore strategies to allow meetings and knowledge exchange to continue whilst reducing the need for travel and the ecological burden of conferences.

LEVEL OF EVIDENCE

Level III: Most comparative level of evidence.

Sustainability in dialysis therapy: Japanese local and global challenge

Human-induced climate change is considered the greatest health threat of the 21st century. The health effects of climate change are becoming increasingly apparent, and there is substantial evidence indicating increased risk of kidney injury due to heat illness and other climate change-related meteorological abnormalities. On the other hand, healthcare itself is responsible for environmental burdens and has been estimated to generate between 3 and 10% of total national CO2 equivalent emissions. Dialysis has been estimated as one of the major contributors to healthcare’s carbon footprint. Especially in Australia and the UK, nations that have high awareness regarding environmental research, “Green Nephrology” has emerged as a new discipline. From both of these countries, a series of papers have been produced outlining the carbon footprint of hemodialysis, the results of surveys of specialists’ awareness of environmental issues, and proposals for how to save resources in dialysis therapy. Following on from this, several national and international nephrology societies have committed themselves to a range of initiatives aiming at “greening” the kidney sector. In Japan, where water and electricity supplies currently are stable, we occasionally are reminded of the potential for shortages of water and energy and of waste disposal problems. These issues particularly come to the fore in times of disasters, when hemodialysis patients need to be evacuated to distant dialysis facilities. Irrespective of the current state of resource availability, however, continuous efforts and the establishment of resource-saving procedures as a part of Japanese culture are highly desirable and would contribute to environmentally friendly healthcare. Japan needs to build awareness of these issues before the country faces a catastrophic situation of resource shortages. This review is intended as a call to action regarding environmental sustainability in kidney healthcare in Japan and the world.

Can United States Healthcare Become Environmentally Sustainable? Towards Green Healthcare Reform

In 2014, the United States health care industry produced an estimated 480 million metric tons of carbon dioxide (CO2); nearly 8% of the country's total emissions. The importance of sustainability in health care - as a business reliant on fossil fuels for transportation, energy, and operational functioning - is slowly being recognized. These efforts to green health care are incomplete, since they only focus on health care structures. The therapeutic relationship is the essence of health care - not the buildings that contain the practice. As such, this article will first postulate reasons for a lack of environmental sustainability in US health care. Second, the article will focus on current green health care initiatives in the United States in which patients and physicians participate. Third, the rationale for participation in green initiatives will be explained. Fourth, the article will propose that, based on the environmental values of patients and physicians, health care insurance plans and health care insurance companies can be targeted for green health care reform, thereby closing the loop of sustainable health care delivery.

Environmental sustainability in anaesthesia and critical care

The detrimental health effects of climate change continue to increase. Although health systems respond to this disease burden, healthcare itself pollutes the atmosphere, land, and waterways. We surveyed the 'state of the art' environmental sustainability research in anaesthesia and critical care, addressing why it matters, what is known, and ideas for future work. Focus is placed upon the atmospheric chemistry of the anaesthetic gases, recent work clarifying their relative global warming potentials, and progress in waste anaesthetic gas treatment. Life cycle assessment (LCA; i.e. 'cradle to grave' analysis) is introduced as the definitive method used to compare and contrast ecological footprints of products, processes, and systems. The number of LCAs within medicine has gone from rare to an established body of knowledge in the past decade that can inform doctors of the relative ecological merits of different techniques. LCAs with practical outcomes are explored, such as the carbon footprint of reusable vs single-use anaesthetic devices (e.g. drug trays, laryngoscope blades, and handles), and the carbon footprint of treating an ICU patient with septic shock. Avoid, reduce, reuse, recycle, and reprocess are then explored. Moving beyond routine clinical care, the vital influences that the source of energy (renewables vs fossil fuels) and energy efficiency have in healthcare's ecological footprint are highlighted. Discussion of the integral roles of research translation, education, and advocacy in driving the perioperative and critical care environmental sustainability agenda completes this review.

Pediatric Critical Care and the Climate Emergency: Our Responsibilities and a Call for Change

Critical care is perhaps one of the most "climate-intensive" divisions of health care. As greenhouse gas emissions continue to rise, the unprecedented threat of climate change has belatedly prompted an increased awareness of critical care's environmental impact. Within our role as pediatric critical care providers, we have a dual responsibility not only to care for children at their most vulnerable, but also to advocate on their behalf. There are clear, demonstrable effects of our worsening climate on the health of children, with the resultant increased burden of pediatric critical illness and disruption to health care systems. From increasing wildfires and their effect on lung health, to the spread of vector-borne diseases such as dengue, and the increased migration of children due to a changing climate, the effects of a changing climate are here, and we are beginning to see the changing epidemiology of pediatric critical illness. Ensuring that the effects of ongoing changes are minimized, including its future effects on child health, requires a multifaceted approach. As part of this review, we will use the Lancet Countdown on Climate Change indicators to explore the impact of pediatric critical care on climate change and the inevitable influence climate change will have on the future practice of pediatric critical care globally.

Sustainability in critical care practice: A grounded theory study

BACKGROUND

Sustaining high-quality, critical care practice is challenging because of current limits to financial, environmental, and social resources. The National Health Service in England intends to be more sustainable, although there is minimal research into what sustainability means to people working in critical care, and a theoretical framework is lacking that explains the social processes influencing sustainability in critical care.

AIMS AND OBJECTIVES

This study aimed to explain the concept of sustainability from the perspective of practitioners caring for critically ill patients.

DESIGN

The qualitative research followed a Charmazian constructivist grounded theory approach, including concurrent data collection and interpretation through constant comparison analysis.

METHODS

In-depth interviews were conducted online or by telephone with 11 health care professionals working in critical care in the South of England (8 nurses, 2 physiotherapists, and 1 technician). Schatzman's dimensional analysis and Straussian grounded theory techniques supplemented the data analysis.

RESULTS

Sustainability was defined as maintaining financial, environmental, and social resources throughout the micro, meso, and macro systems of critical care practice. The most pertinent social process enabling sustainability of critical care was satisficing (satisfaction of achieving a goal of quality care while sufficing within the limits of available resources). Increased satisficing enabled practitioners to fulfil their sense of normative, responsible, sustainable, and flourishing practice. Satisficing was bounded by the cognitive and environmental influences on decisions and an ethical imperative to ensure resources were used wisely through stewarding.

CONCLUSIONS

An explanation of the concept of sustainability and significant social processes, in relation to critical care, are presented in a theoretical framework, with implications for how financial, environmental, and social resources for critical care practice can be maintained.

RELEVANCE TO CLINICAL PRACTICE

This theory offers clinicians, managers, educators, and researchers a definition of sustainability in critical care practice and provides a structured approach to addressing critical care sustainability issues.

Life cycle assessment as decision support tool for environmental management in hospitals: A literature review

BACKGROUND

Life cycle assessment (LCA) is an environmental accounting tool aimed at determining environmental impacts of products, processes, or organizational activities over the entire life cycle. Although this technique already provides decision-makers in other sectors with valuable information, its application in the health care setting has not yet been examined.

PURPOSE

The aim of this study was to provide a comprehensive overview of scientific research on the application of LCA in hospitals and its contribution to management decision-making.

METHOD

We perform a systematic literature review by searching a range of databases with synonyms of "LCA" in combination with the term "hospital" in order to identify peer-reviewed studies. The final sample of 43 studies were then subjected to a content analysis.

RESULTS

We categorize existing research and show that single and multi-indicator LCA approaches are used to examine several products and processes in hospitals. The various approaches are favored by different scientific communities. Whereas researchers from environmental sciences perform complex multi-indicator LCA studies, researchers from health care sciences focus on footprints. The studies compare alternatives and identify environmental impacts and harmful hotspots.

PRACTICE IMPLICATIONS

LCA results can support health care managers' traditional decision-making by providing environmental information. With this additional information regarding the environmental impacts of products and processes, managers can implement organizational changes to improve their environmental performance. Furthermore, they can influence upstream and downstream activities. However, we recommend more transdisciplinary cooperation for LCA studies and to place more focus on actionable recommendations when publishing the results.