Abstract
Clinical practice has inadvertently changed after the COVID-19 pandemic and currently the need to provide sustainable surgical services is more pressing than ever. The National Health Service has committed to a long-term efficient plan to reduce carbon footprint but there is no detailed plan for surgical practice, the domain that contributes the most to hospital-derived pollution. A series of consecutive steps and measures ought to be taken, starting from a hybrid approach quantifying surgically attributed carbon footprint. Then, a variety of suggested measures can be widely discussed and accordingly applied on a wider or more local level. Appropriate training should always precede implementing new practices to ensure that staff is familiar with these. These measures cover a broad range and should be arranged on a patient-centred basis from preoperative preconditioning to an effective follow-up. The need for more intense research and implementation of enhanced recovery protocols is widely discussed. Also, the necessity of green research and reinvestment of materials and resources is highlighted. A change of philosophy from a cradle-to-grave approach to a repurposing approach is suggested. We are confident that a new era is dawning in surgical practice and teamwork is the key for providing greener surgical services.
Keywords: Sustainability, green surgery, surgical practice, carbon footprint, enhanced recovery
Introduction
We have recently experienced radical changes in healthcare provision in an attempt to tackle the COVID-19 pandemic effectively, which will doubtlessly be integrated for the long run, in national healthcare systems. However, until recently, little has been done to address a more subtle issue, climate change. Surprisingly, several studies have shown healthcare systems to be responsible for 1%–5% of the national annual carbon footprint – in some cases surpassing 5% – with a concomitant increase in national health expenditures annually on a global scale. 1 On a worldwide scale, several nations have attempted to record their annual carbon footprint, with various limitations, as displayed in Table 1.
Table 1.
Comparison of healthcare carbon footprint across the globe.
Author | Country | Years | Carbon footprint | National contribution |
---|---|---|---|---|
Malik et al. 2 | Australia | 2014–2015 | 35,772 kilo tonnes CO2e | 7% |
Eckelman et al. 3 | Canada | 2009–2015 | 33 million tonnes CO2e | 4.6% |
Wu 4 | China | 2012 | 315 million tonnes of CO2e | 2.7% |
NHS Net Zero Expert Panel 5 | NHS | 2019 | 25 million tonnes of CO2e | 4% |
Eckelman et al. 6 | US | 2018 | 554 million tonnes of CO2e/1693 kg CO2e per capita | 9–10% |
Table 2.
Summary of specific measures to reduce carbon footprint.
Anaesthesia | Material use | HVAC – building energy | Individualised patient care |
---|---|---|---|
Minimise volatile gases/use sparingly | Reduce ‘overage’/unused surgical material | Maintain buildings aiming at energy efficiency | Carefully consider indications for procedures |
Increase usage of intravenous general anaesthesia, when feasible | Recycle effectively | New materials in self-sustainable buildings | Implement enhanced recovery protocols |
Substitute general with regional or local anaesthesia, where applicable | Minimise single-use device/Substitute with reusable, according to trust guidelines | Automated control of heating and ventilating of theatres | Consider different modalities of treatment |
Manage anaesthetic medication-derivedwaste properly | Segregate waste properly | Encourage telemedicine/Reduce patient and staff travel | |
Ethical purchasing/Work with industry for life cycle assessment |
HVAC: heating, ventilation and air conditioning.
Box 1.
Summary of strategy.
• Identify surgical practice-derived carbon footprint using a mixed approach. |
• Educate and involve staff in reducing carbon footprint. |
• Allocate funds to research and service improvement. |
• Encourage high-quality environmental-friendly research and implement relevant changes in related services. |
• Use appropriate clinical governance to measure impact of changes. |
The National Health Service – surgical practice
The National Health Service (NHS) is the biggest employer in the UK and its emissions account for 4% of the national total. Regular monitoring of carbon footprint, along with a set of measures to reduce it, were implemented in 2008, with the introduction of the Climate Change Act, when the NHS committed to two clear targets. 5 Carbon foot printing estimates the Greenhouse Gas emissions from a sector, process or product and rather sophisticated tools have been developed in order to provide analytical guidance as to how it can be calculated. 7 The Greenhouse Gas Protocol (GHGP) describes the different approaches to quantifying carbon footprint. The NHS Carbon Footprint consists of the emissions directly controlled by the NHS, which are divided in the three scopes, as per GHGP. For the emissions controlled directly by the NHS (NHS Carbon Footprint) the target is an 80% reduction by the years 2028–2032 and a net zero by 2040. In addition to these, patient- and travel-derived emissions to NHS facilities constitute the NHS Carbon Footprint Plus, and the targeted reduction is an 80% by the years 2036–2039 and a net zero by 2045. 5
The footprint of theatres and surgery (what do we do now?)
Several single or multiple centre studies prove that surgical practice is one of the main drivers of hospital-derived environmental pollution. Despite that, there are no clear national records of the annual waste attributed to surgery. Even in the NHS, where a detailed recording of carbon footprint has been undertaken for over a decade, the exact percentage of what surgery contributes to total healthcare carbon footprint is vaguely delineated and could be deduced by calculations. Thus, the first step towards a ‘greener’ surgical practice is a precise census of the exact carbon footprint it produces. 7
Some steps have been made towards this direction, as a small number of surgical units have attempted to document their carbon footprint utilising different approaches. The first study comparing the carbon footprint of the operating theatres in three hospitals (UK, USA and Canada) within the boundary of the surgical theatre follows the GHGP. 8 It is clearly displayed that the NHS scheme to reduce desflurane usage in general anaesthesia has yielded results, with the UK hospital being the least carbon intensive; this being attributed to anaesthetic gas usage. However, it should be underlined that failing to modernise operating theatre energy management systems and to purchase energy from eco-friendly resources can dramatically increase the environmental impact of surgery. While anaesthesia induction in a separate room before entering the operating theatre has been proven to increase efficiency in delivery of surgical service, this leads to a higher environmental burden from heating, ventilation and air conditioning (HVAC). 8
Surgical carbon footprint has been assessed on a smaller scale in Australia, where the carbon footprint of a single private outpatient facility was compared to that of a public hospital, using a bottom-up approach. In 2014–2015 skin malignancy-related procedures, Australia led to the production of 8461 tonnes of CO2e, and 22.25% of these were produced by hospitals, which conduct approximately 10% of these procedures, thus emphasising the energy-wasting practices still in place. 9
Several attempts have been undertaken to quantify the carbon footprint of specific surgical procedures. In the UK, 57,000 tonsillectomy procedures were conducted in the year 2019. The ear, nose and throat team from Alder Hey Children’s Hospital recorded the approximate weight of orange bags per adenotonsillar procedure, which was a mean of 1.86 kg, and extrapolated to a national 106 tonnes of waste for incineration on an annual basis. 10
Another study quantified the environmental impact of discarded drugs in cataract surgery from four centres in the USA. Surprisingly, it was reported that 45.3% of medication was discarded unused, with eyedrops reaching a 65.7%. Antibiotic drops were the most abundantly consumed type of unused medication resulting in a discard of 80%–100% volume of unused antibiotics and the need for a new prescription. The authors have highlighted the lack of current evidence on the benefit of local antibiotics in the reduction of endopthalmitis. 11 All the above-mentioned clinical studies have followed a bottom-up analysis to evaluate the carbon footprint of particular surgical procedures in single or small number of centres and extrapolate to the total national of procedures, assuming homogeneity of practice across the country, which itself constitutes a severe limitation.
What can we do? (measures)
In the spirit of greening surgical practice, it must be underlined that a holistic approach should be applied, not only implementing measures that can maximise emissions reduction, but introducing policies that will guide staff towards adopting more sustainable clinical pathways.
Anaesthesia
Commonly used volatile anaesthetics, including sevoflurane and desflurane, have a high heat-trapping capacity, measured in global warming potential over 100 years (GWP100). For sevoflurane and desflurane, GWP100 is 130 and 2540, respectively. Thus, restricting desflurane usage can drastically reduce the carbon footprint of any operation. 12 Anaesthetic gases account for 2% of total NHS carbon footprint. 5 When volatile anaesthetics cannot be avoided, there are disposal systems for these gases, which involve adsorption on specially designed materials. 12
Nitrous oxide, apart from its heat-trapping properties, can also irreversibly damage the ozone layer. Mask induction with nitrous oxide is used in paediatric anaesthesia and it does not increase induction speed when used as supplement to sevoflurane induction. It can be substituted, when clinically indicated, by distraction techniques. 12
In terms of pharmaceutical waste, propofol is the most wasted, by volume, anaesthetic medication, while emergency medications are quite often opened but remain unused. Multiple measures can be adopted such as use of prefilled syringes, splitting of vials and the role of hospital pharmacy can be vital to the matter at hand.
Finally, avoiding general anaesthesia whenever possible, by substituting it with local or regional, can drastically reduce the carbon footprint of an operation. This has been observed in the ‘Lean and Green’ initiative, endorsed by the American Association for Hand Surgery, with the implementation of the ‘Wide Awake Local Anaesthesia No Tourniquet’ protocol. Not only can multiple procedures be carried out using lidocaine with epinephrine, instead of general anaesthesia, but this has been well received by patients (96% satisfaction rate). 13
Material use
The actions by which a significant reduction in carbon footprint can be achieved by means of better material usage are summarised in the 5 Rs: reduce, reuse, recycle, rethink and research. 14 As highlighted by Thiel et al., combining multiple interventions in the material usage sector yields maximum results. 15
In this study, minimising material use, by preparing sets with the minimum required instruments for specific procedures, and substituting single- for multiple- use devices, led to significant reduction of carbon footprint by simultaneously addressing the issue of ‘overage’. This is frequently linked with surgeons’ preferences while conducting an operation and pre-labelled surgical trays can help increase the life span of surgical instruments by avoiding pointless resterilisation. 16 Well-established policies, such as increased recycling, lead to smaller reductions in carbon footprint. 15
Waste segregation is an effective way to reduce the volume of waste that will be led to incineration. 17 It has been proven that even up to 90% of the waste classified as infectious does not fall in this category. 18 Misplacement of waste can be the result of multiple factors, such as staff being unaware of waste segregation policies or fear of being reprimanded in case of misplacing clinically hazardous waste to general waste, lack of appropriate bags and so on. 17 Expert panels have arbitrarily set the percentage of clinical waste produced by theatres at 15% of the total waste, a target that hospitals often fail to achieve. 19 One efficient measure to that end would be to avoid installing hazardous clinical waste bags in the theatre space before patients are transferred inside. 18
Materials purchased in large amounts by the NHS should have a clearly documented and well-known life cycle assessment, readily accessible by the public. The organisation could largely benefit financially by purchasing from providers with low environmental impact. This policy is known as environmentally preferable purchasing and guarantees a more sustainable workplace for staff and less impact on patient health. To that end, the NHS and other relevant organisations, on a worldwide level, should engage in discussion with the industry to encourage a more detailed life cycle assessment of multiple products.17,20
Shifting daily practice from a cradle-to-grave approach, in life cycle assessment, to cradle-to-cradle should become the new standard. In that, waste from usage of materials could be recycled or their purpose redefined. This principle particularly applies to surgical instruments and devices. 21 First, reusable devices can lead to huge cost savings, even when accounting for the resterilisation, being mindful of chronic usage wear. Another measure would be reusing disposables, a practice not widely accepted in many healthcare systems. 22 Despite lack of hard evidence against reusing single-use devices, concerns have been expressed by healthcare practitioners against resterilising them. 18
Another issue is material packaging. It has been observed that packaging disposal increases dramatically the volume and weight of operating theatre-derived waste. Furthermore, it should be underlined that not all packaging materials are recyclable; this increases the volume of landfill-dedicated waste, especially when they are mixed with recyclables or clinical waste, skyrocketing the environmental impact and financial burden to the hospital. Many efforts have focused on studying the impact of minimising packaging; of specific interest is the combination of ‘wide awake hand surgery’ protocols with simplified packaging. This protocol led to reduced expenses and waste quantity, without an impact on patient outcomes or satisfaction, proving that combined measures significantly improve procedure-related carbon footprint. 23
HVAC – building energy
Surgical units, not only theatres, but also recovery rooms, wards and outpatient clinics consume a rather large amount of the energy distributed to hospitals. ‘Greening the theatres’ as parts of the facilities takes multiple measures that do not fall within the expertise of healthcare staff. In the NHS, 10% of the organisation’s carbon footprint is attributable to building energy expenses and, in the USA, hospitals were found to consume 5.5% of the energy consumed by the commercial sector, while accounting for less than 1% of all commercial buildings.
Multiple steps can be taken towards reducing emissions from building utilisation. Since healthcare accounts for 17% of the US gross domestic product, it has significant ability in negotiating its sources of electricity, advocating for a shift from fossil fuels to sustainable sources. 20 Another solution is transforming hospitals into self-sustainable buildings that can partly generate their own electricity, i.e. with solar panels. Also, renovating NHS buildings, by upgrading their energy class, with newer insulation materials or novel energy distribution systems, could make them more efficient. 5 Focusing on theatres, anaesthetic rooms increase the number of procedures offered. However, the increased combined area of theatres and anaesthetic rooms increases the energy consumption in this section of the hospital. 8 Interestingly, theatres are occupied approximately 40% of the time, 19 thus an automated heating and ventilation system with sensors could reduce energy consumption, when staff does not occupy these spaces. 15 These investments are expected to be costly and will yield results in the long term.
Outpatient telemedicine appointments have been shown to reduce building-related costs without an impact on patient satisfaction. The necessity to follow up patients during the pandemic has led to wider adoption of this outpatients’ clinic modality. In the setting of vascular surgery, in a series of 87 unique patients who had 146 telemedicine encounters, a clear environmental benefit was shown in comparison to hypothetical face-to-face patient appointments. 24
Patient-specific considerations
All the above recommended measures are always suggested in the context of maximum patient beneficence. Thus, any clinical decision making should first address delivering optimal patient care; that should be ideally combined with offering environmentally friendly health services, meaning that if a suitable sustainable alternative can be offered, then it should be strongly considered. This entails both clinical excellence and appropriate training in sustainable healthcare provision.
Moreover, when clinically acceptable, the carbon footprint of equally effective therapeutic modalities should be considered in decision making, when surgical intervention is offered to a patient. In a study of 150 staging procedures for endometrial cancer, open versus laparoscopic versus robotic-assisted laparoscopic procedures were compared with respect to their carbon footprint. Open procedures marked minimal operative time, waste production, energy use and single-use device, with robotic assisted procedures scoring the highest carbon footprint in all but the single-use device domain. A significant limitation of this study was that it did not consider patients’ postoperative course and its respective carbon footprint. Naturally, one can only assume that a robotic approach could minimise postoperative resource usage, compensating for intraoperative high emission rates. No clinical studies have been conducted to prove such a hypothesis. 25
While international literature focuses on reducing the environmental impact of the operating theatre, it is imperative that we realise the necessity for standardised ‘green’ surgical pathways. That begins with identifying patient-customised appropriate indications for surgical intervention. In this spirit, an overall reduction in the number of surgical procedures offered to patients should be examined, taking into consideration current guidelines and protocols, coupled with balancing the benefits of having or not every procedure for each patient individually. As surgical practice changes, the environmental impact of a procedure could be integrated in the list of factors that surgeons consider, when offering patients specific procedures, without ever compromising patients’ beneficence. 26
Designing these pathways can prove to be a difficult task. An element to consider is the minimisation of preoperative evaluation by incorporating all the essential preoperative assessments (surgical, anaesthetic, cardiac and so forth) in a single visit, together with the minimum of laboratory investigations to ensure a safe anaesthetic and operative outcome. Surprisingly, despite the well-established multiple benefits of Enhanced Recovery after Surgery (ERAS) protocols, a quick literature research yields no results on the environmental benefits of their implementation. Along with their individual patient-centred benefits, one could argue that these protocols can reduce carbon footprint. Dedicated research in this field could prove fruitful, especially if it could prove that implementing ERAS protocols – which advocate for minimally invasive procedures – can outbalance these more carbon-intensive surgical modalities. Surgical care ends with a patient-tailored follow-up. Video follow-up has been shown to be highly efficient both on resource allocating and environmental costs, without compromising healthcare delivery. 24
How to bridge the gap?
After having identified the appropriate set of measures to achieve a more sustainable surgical practice (Table 2), there is a need for a structured plan for their implementation. It has been shown clinical leaders can heavily impact surgical practice in their institutions by introducing sets of measures. A simplified approach to this matter would be recruiting surgeons and other healthcare specialists to their respective fields, which can facilitate the application of energy- and resource-saving policies and act as an example for the staff, within the limits of their organisations. They could help with measures ranging from choosing the minimum number of surgical instruments per tray to facilitating environmentally friendly purchasing.5,15
The first step to establish pathways of sustainable development is accurate clinical governance. All sectors contributing to carbon footprint have to be documented, not only using a top-down analysis, but involving particular institutions and services both within and outside the NHS that can act as pioneers in the detailed record of carbon footprint. At this stage, apart from accounting for the logistics, staff training and awareness of sustainable development must be evaluated in order to assess the areas in which further training is needed in order to implement the necessary changes.
Another important pathway that can facilitate the way towards a zero net carbon footprint is research. Currently, there are noticeable heterogeneity and significant gaps in reporting life cycle assessments and carbon footprint in surgical and anaesthetic practice, as shown in a recent systematic review. 27 As previously shown, strong interest in research leads to easier recruitment and reduced research cost and time. The comparison of CRASH-1 and CRASH-2 studies is an excellent example of ways to reduce research carbon footprint and obtain results faster, thus being of double significance. First, these principles of sustainability ought to be applied in relevant research; and secondl they should be followed by trusts within the NHS in all clinical and basic science fields, to tackle the environmental impact of research itself, a crucial component of surgical practice.28,29
Staff education is fundamental to implementing environmental policies in healthcare facilities. That has been clearly shown in the paper by Botelho, in which compliance of private outpatient practices in the EU with waste disposal legislation has been surveyed. While segregation policies at the site were followed by all the 741 healthcare facilities, only 30% succeeded in disposing the appropriate space for waste segregation before collection. As displayed in the statistical analysis of this paper, one of the most effective ways to increase compliance with legislation is through staff training, leading to significantly smaller amounts of misclassified ‘hazardous’ waste. 30
To bridge the gap between the current situation and ‘greener’ surgical services, appropriate funding has to be allocated in the aforementioned activities. As it has been shown, many European countries have achieved providing a good portion of national expenditure on healthcare without increasing its relative carbon footprint. 1 Thus, one could argue that a source of funding for implementing surgical sustainability is applying green policies. However, understandable reluctancy against these investments could be justified by some, as their benefits could be harvested in the long term. 5 Sources of funding sustainability research could be sought after within the academia. Transforming practices and developing new techniques and materials can be the trigger for much-needed research and what better source of funding than the university itself.
Conclusions
Despite the NHS having a solid plan for minimising its carbon footprint, much could be improved in the domain of surgical practice. A precise record of the carbon footprint of surgical practice using hybrid approaches, involving pillars of provision of surgical service, could be a first step, identifying the domains in which measures ought to be taken. As evidenced, there is increased need for high-quality studies to identify current ‘weak’ spots and implement appropriate pathways. A bundle of measures for ‘greener’ surgery should be developed in accordance with these research findings and introduced in NHS trusts by specialised leadership clinical teams in collaboration with senior managerial staff, who will help implement the new measures and train staff appropriately in complying with these novel practices. Many questions remain unanswered regarding how sustainability can be integrated in the everyday surgical practice of all specialties, underlining the necessity for ‘eco-friendly’ research on such a thought-provoking topic.
Declarations
Competing Interests: None declared.
Funding: None declared.
Ethics approval: Not applicable.
Guarantor: VP.
Contributorship: NAA drafted the original manuscript, VP conceptualised and provided critical corrections.
Acknowledgements: None.
Provenance: Not commissioned; peer-reviewed by Qing-Wei Chen, Pirot Florent and James Smith.
ORCID iD: Nikolaos-Andreas Anastasopoulos https://orcid.org/0000-0003-1048-0960
References
- 1.Lenzen M, Malik A, Li M, et al. The environmental footprint of health care: a global assessment. Lancet Planet Heal 2020; 4: e271–e279. [DOI] [PubMed] [Google Scholar]
- 2.Malik A, Lenzen M, McAlister S, et al. The carbon footprint of Australian health care. Lancet Planet Heal 2018; 2: e2–e3. [DOI] [PubMed] [Google Scholar]
- 3.Eckelman MJ, Sherman JD, MacNeill AJ. Life cycle environmental emissions and health damages from the Canadian healthcare system: an economic-environmental-epidemiological analysis. PLoS Med 2018; 15: 1–16. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Wu R. The carbon footprint of the Chinese health-care system: an environmentally extended input–output and structural path analysis study. Lancet Planet Heal 2019; 3: e413–e419. [DOI] [PubMed] [Google Scholar]
- 5.The NHS Net Zero Expert Panel. Delivering a ‘net zero’ National Health Service. NHS 2020; 12: 1–76. [Google Scholar]
- 6.Eckelman MJ, Huang K, Lagasse R, et al. Health care pollution and public health damage in the united states: an update. Health Aff 2020; 39: 2071–2079. [DOI] [PubMed] [Google Scholar]
- 7.Salas RN, Maibach E, Pencheon D, et al. A pathway to net zero emissions for healthcare. BMJ 2020; 371: m3785. [DOI] [PubMed] [Google Scholar]
- 8.MacNeill AJ, Lillywhite R, Brown CJ. The impact of surgery on global climate: a carbon footprinting study of operating theatres in three health systems. Lancet Planet Heal 2017; 1: e360–e367. [DOI] [PubMed] [Google Scholar]
- 9.Tan E, Lim D. Carbon footprint of dermatologic surgery. Australas J Dermatol 2021; 62: e170–e177. [DOI] [PubMed]
- 10.Gill AS, Hampton T, Sharma R. Activism for health: green surgery. BMJ 2020; 368: 2020. [DOI] [PubMed] [Google Scholar]
- 11.Lee P. Challenging considerations regarding waste and potential environmental effects in cataract surgery. JAMA Ophthalmol 2019; 137: 1163–1664. [DOI] [PubMed] [Google Scholar]
- 12.Gordon D. Sustainability in the operating room: reducing our impact on the planet. Anesthesiol Clin 2020; 38: 679–692. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Van Demark RE, Smith VJS, Fiegen A. Lean and green hand surgery. J Hand Surg Am 2018; 43: 179–181. [DOI] [PubMed] [Google Scholar]
- 14.Laustsen G. Reduce–recycle–reuse: guidelines for promoting perioperative waste management. AORN J 2007; 85: 717–722,724,726–728. [DOI] [PubMed] [Google Scholar]
- 15.Thiel CL, Woods NC, Bilec MM. Strategies to reduce greenhouse gas emissions from laparoscopic surgery. Am J Public Health 2018; 108: S158–S164. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Laustsen G. Greening in healthcare. Nurs Manage 2010; 41: 26–31. [DOI] [PubMed] [Google Scholar]
- 17.Wyssusek KH, Keys MT, van Zundert AAJ. Operating room greening initiatives – the old, the new, and the way forward: a narrative review. Waste Manag Res 2019; 37: 3–19. [DOI] [PubMed] [Google Scholar]
- 18.Kwakye G, Brat GA, Makary MA. Green surgical practices for health care. Arch Surg 2011; 146: 131–136. [DOI] [PubMed] [Google Scholar]
- 19.Kagoma Y, Stall N, Rubinstein E, et al. People, planet and profits: the case for greening operating rooms. Can Med Assoc J 2012; 184: 1905–1911. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Hensher BM, Mcgain F. Health care sustainability metrics: building a safer, low-carbon health system. Health Aff (Millwood) 2020; 12: 2080–2087. [DOI] [PubMed]
- 21.Barraclough KA, Agar JWM. Green nephrology. Nat Rev Nephrol 2020; 16: 257–268. [DOI] [PubMed] [Google Scholar]
- 22.Siu J, Hill AG, MacCormick AD. Systematic review of reusable versus disposable laparoscopic instruments: costs and safety. ANZ J Surg 2017; 87: 28–33. [DOI] [PubMed] [Google Scholar]
- 23.Thiel CL, Fiorin Carvalho R, Hess L, et al. Minimal custom pack design and wide-awake hand surgery: reducing waste and spending in the orthopedic operating room. Hand 2019; 14: 271–276. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Paquette S, Lin JC. Outpatient telemedicine program in vascular surgery reduces patient travel time, cost, and environmental pollutant emissions. Ann Vasc Surg 2019; 59: 167–172. [DOI] [PubMed] [Google Scholar]
- 25.Woods DL, McAndrew T, Nevadunsky N, et al. Carbon footprint of robotically-assisted laparoscopy, laparoscopy and laparotomy: a comparison. Int J Med Robot Comput Assist Surg 2015; 11: 406–412. [DOI] [PubMed] [Google Scholar]
- 26.Maurice JB, Siau K, Sebastian S, et al. Green endoscopy: a call for sustainability in the midst of COVID-19. Lancet Gastroenterol Hepatol 2020; 5: 636–638. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Drew J, Christie SD, Tyedmers P, et al. Operating in a climate crisis : a state-of-the-science review of life cycle assessment within surgical and anesthetic care. Environ Health Perspect 2021; 129: 76001. doi: 10.1289/EHP8666. [DOI] [PMC free article] [PubMed]
- 28.Subaiya S, Hogg E, Roberts I. Reducing the environmental impact of trials: a comparison of the carbon footprint of the CRASH-1 and CRASH-2 clinical trials. Trials 2011; 12: 1–5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Ligozat AL, Névéol A, Daly B, et al. Ten simple rules to make your research more sustainable. PLoS Comput Biol 2020; 16: 1–11. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Botelho A. The impact of education and training on compliance behavior and waste generation in European private healthcare facilities. J Environ Manage 2012; 98: 5–10. [DOI] [PubMed] [Google Scholar]