How often are infusion sets for central venous catheters changed in Australian and New Zealand Intensive Care Units? A point prevalence survey

BACKGROUND

Infusion sets (comprising the tubing, measuring burettes, fluid containers, transducers) that are connected to invasive vascular devices are changed on a regular basis in an effort to reduce bacterial colonisation and bloodstream infection. There is a balance between reducing infection and creating unnecessary waste. Current evidence suggests that for central venous catheters (CVCs), changing infusion sets at 7 days does not increase infection risks.

OBJECTIVES

The objective of this study was to describe the current unit guidelines in Australian and New Zealand intensive care units (ICUs) for changing infusion sets for CVCs.

METHODS

prospective cross-sectional point prevalence study, as a part of the 2021 Australian and New Zealand Intensive Care Society Point Prevalence Program.

PARTICIPANTS

Australia and New Zealand (ANZ) adult ICUs and their patients on the day of the study.

RESULTS

Data were collected from 51 ICUs across ANZ. One-third of these (16/49) ICUs had a guideline that specified a 7-day replacement period, with the rest having a more frequent replacement period.

CONCLUSION

Most ICUs participating in this survey had policies to change their CVC infusion tubing in 3-4 days, and recent high-level evidence supports an update to extend this to 7 days. There remains work to be done to spread this evidence to ANZ ICUs and improve environmental sustainability initiatives.

The Carbon Footprint of Peritoneal Dialysis in Australia

BACKGROUND

As climate change escalates with increasing health impacts, healthcare must address its carbon footprint. A critical first step is understanding the sources and extent of emissions from commonly utilised clinical care pathways.

METHODS

We used attributional process-based life cycle analysis to quantify CO2 equivalent emissions associated with the delivery of Baxter home automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD) in Australia.

RESULTS

Annual per patient carbon emissions attributable to the manufacture and disposal of PD fluids and consumables were 1,992 kg CO2equivalent emissions for APD and 1,245 kg CO2equivalent emissions for CAPD. Transport impacts varied depending on the distance between site of manufacture of PD fluids and consumables and the home state of the patient. As a result, the total impact of providing PD also differed by Australian state, ranging from 2,350-4,503 kg CO2 equivalent emissions for APD and from 1,455-2,716 kg CO2 equivalent emissions for CAPD. Recycling of polyvinyl chloride (PVC) could reduce emissions by up to 14 per cent for APD and 30 per cent for CAPD, depending on the distance between the site of PVC waste generation and the recycling centre.

CONCLUSIONS

This study demonstrated higher per patient carbon emissions from APD compared to CAPD, due to both higher fluid and consumable requirements, and the consequent higher transport impacts. PVC recycling can partially mitigate PD associated carbon emissions.

Blood gas sampling in the intensive care unit: A prospective before-and-after interventional study on the effect of an educational program on blood gas testing frequency

BACKGROUND

Blood gas analysis is the most commonly ordered test in the intensive care unit. Each investigation, however, comes with risks and costs to the patient and healthcare system. Evidence suggests that many tests are performed with no appropriate clinical indication.

OBJECTIVES

The primary aim of our prospective interventional study was to investigate the proportion of blood gases undertaken with a valid clinical indication before and after an educational intervention. A secondary aim was to examine sleep interruption secondary to blood gas sampling.

METHODS

A prospective, before-and-after interventional study was conducted across two metropolitan intensive care units in Melbourne, Australia. Adults aged ≥18 years who were admitted to intensive care were eligible for inclusion. Two observation periods were conducted across a 2-week period in May and September 2022 (Periods 1 and 2), where clinicians were encouraged to record the purpose of blood gas sampling and other relevant data via an electronic questionnaire. These data were reviewed with corresponding electronic medical records. In between these periods, an interventional educational program to inform the clinical rationale for blood gas testing was delivered during July and August 2022, including introduction of a clinical guideline.

RESULTS

There were 68 patients with 688 tests included in Period 1 compared to 69 patients with 756 tests in Period 2. There was no significant difference between the median number of blood gas analyses performed per patient before and after the educational intervention (6.0 tests per patient vs 5.0 tests per patient, p = 0.609). However, there was a significant increase in the percentage of tests with a valid clinical indication (49.0% vs 59.7%, p = 0.0025). The most common indications selected were routine measurement, monitoring a clinical value, change in ventilator settings/oxygen therapy, and clinical deterioration. In addition, there were a large number of patients who were awakened upon drawing of a blood sample for analysis (26.1% for Period 1 and 37.6% for Period 2, p = 0.06).

CONCLUSION

The implementation of an educational program resulted in a significant increase in the proportion of blood gases performed with an appropriate clinical indication. There was, however, no reduction in the overall number of blood gases performed.

Structured Weaning From the Impella Left Ventricular Micro-Axial Pump in Acute Myocardial Infarction With Cardiogenic Shock and Protected Percutaneous Coronary Intervention: Experience From a Non-Cardiac Surgical Centre

BACKGROUND

The Impella (Abiomed, Danvers, MA, USA) temporary percutaneous left ventricular assist device is increasingly used as mechanical circulatory support in patients with acute myocardial infarction-cardiogenic shock (AMICS) or those undergoing high-risk protected percutaneous coronary intervention (PCI). The optimal weaning regimen remains to be defined.

METHOD

We implemented a structured weaning protocol in a series of 10 consecutive patients receiving Impella support for protected PCI or AMICS treated with PCI in a high volume non-cardiac surgery centre. Weaning after revascularisation was titrated to native heart recovery using both haemodynamic and echocardiographic parameters.

RESULTS

Ten patients (eight male, two female; aged 43-70 years) received Impella support for AMICS (80%) or protected PCI (20%). Cardiogenic shock was of Society for Cardiac Angiography & Interventions grade C-E of severity in 80%, and median left ventricular end-diastolic pressure was 31 mmHg. Protocol implementation allowed successful weaning in eight of 10 patients with a median support time of 29 hours (range, 4-48 hours). Explantation was associated with an increase in heart rate (81 vs 88 bpm; p=0.005), but no significant change in Cardiac Index (2.9 vs 2.9 L/min/m2), mean arterial pressure (79 vs 82 mmHg), vasopressor requirement (10% vs 10%), or serum lactate (1.0 vs 1.0). Median durations of intensive care and hospital stay were 3 and 6 days, respectively. At 30 days, the mortality rate was 20%, with median left ventricular ejection fraction of 40%.

CONCLUSIONS

A structured and dynamic weaning protocol for patients with AMICS and protected PCI supported by the Impella device is feasible in a non-cardiac surgery centre. Larger studies are needed to assess generalisability of such a weaning protocol.

Exploring anaesthetists' views on the carbon footprint of anaesthesia and identifying opportunities and challenges for reducing its impact on the environment

A shift in practice by anaesthetists away from anaesthetic gases with high global warming potential towards lower emission techniques (e.g. total intravenous anaesthesia) could result in significant carbon savings for the health system. The purpose of this qualitative interview study was to understand anaesthetists' perspectives on the carbon footprint of anaesthesia, and views on shifting practice towards more environmentally sustainable options. Anaesthetists were recruited from four hospitals in Western Sydney, Australia. Data were organised according to the capability-opportunity-motivation model of behaviour change. Twenty-eight anaesthetists were interviewed (July-September 2021). Participants' age ranged from 29 to 62 years (mean 43 years), 39% were female, and half had completed their anaesthesia training between 2010 and 2019. Challenges to the wider use of greener anaesthetic agents were identified across all components of the capability-opportunity-motivation model: capability (gaps in clinician skills and experience, uncertainty regarding research evidence); opportunity (norms, time, and resource pressures); and motivation (beliefs, habits, responsibility and guilt). Suggestions for encouraging a shift to more environmentally friendly anaesthesia included access to education and training, implementing guidelines and audit/feedback models, environmental restructuring, improving resource availability, reducing low value care, and building the research evidence base on the safety of alternative agents and their impacts on patient outcomes. We identified opportunities and challenges to reducing the carbon footprint of anaesthesia in Australian hospitals by way of system-level and individual behavioural change. Our findings will be used to inform the development of communication and behavioural interventions aiming to mitigate carbon emissions of healthcare.

Magnitude and time to peak oxygenation effect of prone positioning in ventilated adults with COVID-19 related acute hypoxemic respiratory failure

BACKGROUND

Prone positioning may improve oxygenation in acute hypoxemic respiratory failure and was widely adopted in COVID-19 patients. However, the magnitude and timing of its peak oxygenation effect remain uncertain with the optimum dosage unknown. Therefore, we aimed to investigate the magnitude of the peak effect of prone positioning on the PaO2 :FiO2 ratio during prone and secondly, the time to peak oxygenation.

METHODS

Multi-centre, observational study of invasively ventilated adults with acute hypoxemic respiratory failure secondary to COVID-19 treated with prone positioning. Baseline characteristics, prone positioning and patient outcome data were collected. All arterial blood gas (ABG) data during supine, prone and after return to supine position were analysed. The magnitude of peak PaO2 :FiO2 ratio effect and time to peak PaO2 :FIO2 ratio effect was measured.

RESULTS

We studied 220 patients (mean age 54 years) and 548 prone episodes. Prone positioning was applied for a mean (±SD) 3 (±2) times and 16 (±3) hours per episode. Pre-proning PaO2 :FIO2 ratio was 137 (±49) for all prone episodes. During the first episode. the mean PaO2 :FIO2 ratio increased from 125 to a peak of 196 (p < .001). Peak effect was achieved during the first episode, after 9 (±5) hours in prone position and maintained until return to supine position.

CONCLUSIONS

In ventilated adults with COVID-19 acute hypoxemic respiratory failure, peak PaO2 :FIO2 ratio effect occurred during the first prone positioning episode and after 9 h. Subsequent episodes also improved oxygenation but with diminished effect on PaO2 :FIO2 ratio. This information can help guide the number and duration of prone positioning episodes.

It's time to stop using nitrous oxide for pediatric mask induction

BACKGROUND

Mask induction of anesthesia for pediatric patients has included the use of nitrous oxide since the inception of pediatric anesthesia. However, the use of nitrous oxide precludes adequate preoxygenation. Additionally, pediatric physiology (less Functional Residual Capacity, higher oxygen consumption), increased risk of laryngospasm and lack of intravenous access increase the risk of a severe airway complication in the event of airway occlusion. Nitrous oxide does not facilitate tranquil mask placement on an unwilling child and does not meaningfully speed mask induction. Exposure to nitrous oxide has potential occupational health concerns and nitrous oxide has significant environmental detriment.

CONCLUSION

Utilizing other, evidence-based, techniques to facilitate tranquil mask placement will assure that patients have a pleasant induction experience and avoiding nitrous oxide will reduce the environmental impact, as well as improve the safety of, pediatric mask induction.

Neuromuscular blockade and oxygenation changes during prone positioning in COVID-19

PURPOSE

Neuromuscular blockers (NMBs) are often used during prone positioning to facilitate mechanical ventilation in COVID-19 related ARDS. However, their impact on oxygenation is uncertain.

METHODS

Multi-centre observational study of invasively ventilated COVID-19 ARDS adults treated with prone positioning. We collected data on baseline characteristics, prone positioning, NMB use and patient outcome. We assessed arterial blood gas data during supine and prone positioning and after return to the supine position.

RESULTS

We studied 548 prone episodes in 220 patients (mean age 54 years, 61% male) of whom 164 (75%) received NMBs. Mean PaO2:FiO2 (P/F ratio) during the first prone episode with NMBs reached 208 ± 63 mmHg compared with 161 ± 66 mmHg without NMBs (Δmean = 47 ± 5 mmHg) for an absolute increase from baseline of 76 ± 56 mmHg versus 55 ± 56 mmHg (padj < 0.001). The mean P/F ratio on return to the supine position was 190 ± 63 mmHg in the NMB group versus 141 ± 64 mmHg in the non-NMB group for an absolute increase from baseline of 59 ± 58 mmHg versus 34 ± 56 mmHg (padj < 0.001).

CONCLUSION

During prone positioning, NMB is associated with increased oxygenation compared to non-NMB therapy, with a sustained effect on return to the supine position. These findings may help guide the use of NMB during prone positioning in COVID-19 ARDS.

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.

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.

Nitrous Oxide Use in Australian Health Care: Strategies to Reduce the Climate Impact

Nitrous oxide is a useful inhaled analgesic. Due to its high global warming potential and ozone-depleting properties, the nitrous oxide emissions related to health care are being increasingly scrutinized. In this narrative review, we will discuss the clinical uses of nitrous oxide relevant to anesthetists, in addition to its contribution as a greenhouse gas. Using available data from Australia, we will explore potential strategies for reducing the impact of those emissions, which are likely to be applicable in other countries. These include destruction of captured nitrous oxide, minimizing nitrous oxide waste and reducing clinical use. Anesthesia clinicians are well placed to raise awareness with colleagues and consumers regarding the environmental impact of nitrous oxide and to promote cleaner alternatives. Reducing use is likely to be the most promising reduction strategy without large-scale changes to infrastructure and subsequent delay in action.

Implementation approaches to improve environmental sustainability in operating theatres: a systematic review

Operating theatres consume large amounts of energy and consumables and produce large amounts of waste. There is an increasing evidence base for reducing the climate impacts of healthcare that could be enacted into routine practice; yet, healthcare-associated emissions increase annually. Implementation science aims to improve the systematic uptake of evidence-based care into practice and could, therefore, assist in addressing the environmental impacts of healthcare. The aim of this systematic search with narrative synthesis was to explore what implementation approaches have been applied to reduce the environmental impact of operating theatre activities, described by implementation phases and methodologies. A search was conducted in EMBASE, PubMed, and CINAHL, limited to English and publication since 2010. In total, 3886 articles were retrieved and 11 were included. All were in the exploratory phase (seven of 11) or initial implementation phase (four of 11), but none were in the installation or full implementation phase. Three studies utilised a recognised implementation theory, model, or framework in the design. Four studies used interprofessional education to influence individuals' behaviour to reduce waste, improve waste segregation, or reduce anaesthetic gases. Of those that utilised behaviour change interventions, all were qualitatively successful in achieving environmental improvement. There was an absence of evidence for sustained effects in the intervention studies and little follow-up from studies that explored barriers to innovation. This review demonstrates a gap between evidence for reducing environmental impacts and uptake of proposed practice changes to deliver low-carbon healthcare. Future research into 'greening' healthcare should use implementation research methods to establish a solid implementation evidence base. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42022342786.

How much do we throw away in the intensive care unit? An observational point prevalence study of Australian and New Zealand ICUs

Objective

During the current COVID pandemic, waste generation has been more evident with increased use of single use masks, gowns and other personal protective equipment. We aimed to understand the scale of waste generation, recycling rates and participation in Australian and New Zealand (ANZ) ICUs.

Design

This is a prospective cross-sectional point prevalence study, as part of the 2021 ANZICS Point Prevalence Program. Specific questions related to waste and sustainability practices were asked at the site and patient level.

Setting and participants

ANZ adult ICUs and their patients on the day of the study.

Main outcome measures

Amount of single use items disposed of per shift, as well as the engagement of the site with sustainability and recycling practices.

Results

In total, 712 patients (median number of patients per ICU = 17, IQR 11-30) from 51 ICUs across ANZ were included in our study; 55% of hospitals had a sustainability officer, and recycling paper (86%) and plastics (65%) were frequent, but metal recycling was limited (27%). Per patient bed space per 12-h shift there was recycling of less than 40% paper, glass, intravenous fluid bags, medication cups and metal instruments. A median of 10 gowns (IQR 3-19.5), 10 syringes (4.5-18) and gloves 30 (18-49) were disposed of per bed space, per 12-h shift. These numbers increased significantly when comparing patients with and without infection control precautions in place.

Conclusions

In ANZ ICUs, we found utilisation of common ICU consumables to be high and associated with low recycling rates. Interventions to abate resource utilisation and augment recycling are required to improve environmental sustainability in intensive care units.

Quantifying the reduction of airborne infectious virus load using a ventilated patient hood

BACKGROUND

Healthcare workers treating SARS-CoV-2 patients are at risk of infection by respiratory exposure to patient-emitted, virus-laden aerosols. Source control devices such as ventilated patient isolation hoods have been shown to limit the dissemination of non-infectious airborne particles in laboratory tests, but data on their performance in mitigating the airborne transmission risk of infectious viruses are lacking.

AIM

We used an infectious airborne virus to quantify the ability of a ventilated hood to reduce infectious virus exposure in indoor environments.

METHODS

We nebulized 10⁹ plaque forming units (pfu) of bacteriophage PhiX174 virus into a ∼30-m³ room when the hood was active or inactive. The airborne concentration of infectious virus was measured by BioSpot-VIVAS and settle plates using plaque assay quantification on the bacterial host Escherichia coli C. The airborne particle number concentration (PNC) was also monitored continuously using an optical particle sizer.

FINDINGS

The median airborne viral concentration in the room reached 1.41 × 10⁵ pfu/m³ with the hood inactive. When active, the hood reduced infectious virus concentration in air samples by 374-fold. The deposition of infectious virus on the surface of settle plates was reduced by 87-fold. This was associated with a 109-fold reduction in total airborne particle number escape rate.

CONCLUSION

A personal ventilation hood significantly reduced airborne particle escape, considerably lowering infectious virus contamination in an indoor environment. Our findings support the further development of source control devices to mitigate nosocomial infection risk among healthcare workers exposed to airborne viruses in clinical settings.

Behavioural change interventions encouraging clinicians to reduce carbon emissions in clinical activity: a systematic review

BACKGROUND

Clinical activity accounts for 70-80% of the carbon footprint of healthcare. A critical component of reducing emissions is shifting clinical behaviour towards reducing, avoiding, or replacing carbon-intensive healthcare. The objective of this systematic review was to find, map and assess behaviour change interventions that have been implemented in healthcare settings to encourage clinicians to reduce greenhouse gas emissions from their clinical activity.

METHODS

Studies eligible for inclusion were those reporting on a behaviour change intervention to reduce carbon emissions via changes in healthcare workplace behaviour. Six databases were searched in November 2021 (updated February 2022). A pre-determined template was used to extract data from the studies, and risk of bias was assessed. The behaviour change techniques (BCTs) used in the interventions were coded using the BCT Taxonomy.

RESULTS

Six full-text studies were included in this review, and 14 conference abstracts. All studies used a before-after intervention design. The majority were UK studies (n = 15), followed by US (n = 3) and Australia (n = 2). Of the full-text studies, four focused on reducing the emissions associated with anaesthesia, and two aimed at reducing unnecessary test ordering. Of the conference abstracts, 13 focused on anaesthetic gas usage, and one on respiratory inhalers. The most common BCTs used were social support, salience of consequences, restructuring the physical environment, prompts and cues, feedback on outcome of behaviour, and information about environmental consequences. All studies reported success of their interventions in reducing carbon emissions, prescribing, ordering, and financial costs; however, only two studies reported the magnitude and significance of their intervention's success. All studies scored at least one item as unclear or at risk of bias.

CONCLUSION

Most interventions to date have targeted anaesthesia or pathology test ordering in hospital settings. Due to the diverse study outcomes and consequent inability to pool the results, this review is descriptive only, limiting our ability to conclude the effectiveness of interventions. Multiple BCTs were used in each study but these were not compared, evaluated, or used systematically. All studies lacked rigour in study design and measurement of outcomes.

REVIEW REGISTRATION

The study was registered on Prospero (ID number CRD42021272526) (Breth-Petersen et al., Prospero 2021: CRD42021272526).

Learning to treat the climate emergency together: social tipping interventions by the health community

Accelerating the decarbonisation of local and national economies is a profound public health imperative. As trusted voices within communities around the world, health professionals and health organisations have enormous potential to influence the social and policy landscape in support of decarbonisation. We assembled a multidisciplinary, gender-balanced group of experts from six continents to develop a framework for maximising the social and policy influence of the health community on decarbonisation at the micro levels, meso levels, and macro levels of society. We identify practical, learning-by-doing approaches and networks to implement this strategic framework. Collectively, the actions of health-care workers can shift practice, finance, and power in ways that can transform the public narrative and influence investment, activate socioeconomic tipping points, and catalyse the rapid decarbonisation needed to protect health and health systems.

Consensus on Prioritisation of Actions for Reducing the Environmental Impact of a Large Tertiary Hospital: Application of the Nominal Group Technique

Hospitals are the largest greenhouse gas producers within the Australian healthcare sector due to the large amounts of energy, resource utilization, equipment and pharmaceuticals required to deliver care. In order to reduce healthcare emissions, healthcare services must take multiple actions to address the broad range of emissions produced when delivering patient care. The goal of this study was to seek consensus on the priority actions needed to reduce the environmental impact of a tertiary Australian hospital. A nominal group technique was utilized within a multidisciplinary, executive-led environmental sustainability committee to find consensus on the 62 proposed actions to reduce the environmental impact of a tertiary Australian hospital. Thirteen participants joined an online workshop during which an educational presentation was delivered, 62 potential actions were privately ranked according to two domains of 'amenability to change' and 'scale of climate impact' and a moderated group discussion ensued. The group achieved verbal consensus on 16 actions that span staff education, procurement, pharmaceuticals, waste, transport and advocacy on all-electric capital works upgrades. In addition, the individual ratings of potential actions according to each domain were ranked and shared with the group. Despite a large number of actions and varied perspectives within the group, the nominal group technique can be used to focus a hospital leadership group on priority actions to improve environmental sustainability.

Aerosol Generation During High Intensity Exercise-Implications for COVID-19 Transmission

BACKGROUND AND AIM

COVID-19 can be transmitted through aerosolised respiratory particles. The degree to which exercise enhances aerosol production has not been previously assessed. We aimed to quantify the size and concentration of aerosol particles and evaluate the impact of physical distance and surgical mask wearing during high intensity exercise (HIE).

METHODS

Using a prospective observational crossover study, three healthy volunteers performed high intensity cardiopulmonary exercise testing at 80% of peak capacity in repeated 5-minute bouts on a cycle ergometer. Aerosol size and concentration was measured at 35, 150 and 300 cm from the participants in an anterior and lateral direction, with and without a surgical face mask, using an Aerodynamic Particle Sizer (APS) and a Mini Wide Range Aerosol Spectrometer (MiniWRAS), with over 10,000 sample points.

RESULTS

High intensity exercise generates aerosol in the 0.2-1 micrometre range. Increasing distance from the rider reduces aerosol concentrations measured by both MiniWRAS (p=0.003 for interaction) and APS (p=0.041). However, aerosol concentrations remained significantly increased above baseline measures at 300 cm from the rider. A surgical face mask reduced submicron aerosol concentrations measured anteriorly to the rider (p=0.031 for interaction) but not when measured laterally (p=0.64 for interaction).

CONCLUSIONS

High intensity exercise is an aerosol generating activity. Significant concentrations of aerosol particles are measurable well beyond the commonly recommended 150 cm of physical distancing. A surgical face mask reduces aerosol concentration anteriorly but not laterally to an exercising individual. Measures for safer exercise should emphasise distance and airflow and not rely solely on mask wearing.

Violence in intensive care: a point prevalence study

Introduction: Violence in the intensive care unit (ICU) is poorly characterised and its incidence is largely extrapolated from studies in the emergency department. Policy requirements vary between jurisdictions and have not been formally evaluated. Methods: A multisite, single-time point observational study was conducted across Australasian ICUs which focused on the incidence of violence in the previous 24 hours, the characteristics of patients displaying violent behaviour, the perceived contributors, and the management strategies implemented. Unit policies were surveyed across a range of domains relevant to violence management. Results: Data were available for 627 patients admitted to 44 ICUs on one of 2 days in June 2019. Four per cent (25/627) displayed at least one episode of violent behaviour in the previous 24 hours. Violent behaviour was more likely in individuals after a greater length of stay in hospital (incidence, 2%, 4% and 7% for day 0-2, 3-7 and > 7 days respectively; P = 0.01) and in the ICU (2%, 4% and 9% for day 0-2, 3-7 and > 7 of ICU stay respectively; P < 0.01). The most common perceived contributors to violence were confusion (64%), physical illness (40%), and psychiatric illness (34%). Management with chemical sedation (72%) and physical restraint (28%) was commonly required. Clinicians assessed an additional 53 patients (53/627, 9%) as at risk of displaying violence in the next 24 hours. Of the 44 participating ICUs, 30 (68%) had a documented violence procedure. Conclusion: Violence in the ICU was common and frequently required intervention. In this study, one-third of ICUs did not have formal violence procedures, and in those with violence procedures, considerable variation was observed.

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.

Vented Individual Patient (VIP) Hoods for the Control of Infectious Airborne Diseases in Healthcare Facilities

By providing a means of separating the airborne emissions of patients from the air breathed by healthcare workers (HCWs), vented individual patient (VIP) hoods, a form of local exhaust ventilation (LEV), offer a new approach to reduce hospital-acquired infection (HAI). Results from recent studies have demonstrated that, for typical patient-emitted aerosols, VIP hoods provide protection at least equivalent to that of an N95 mask. Unlike a mask, hood performance can be easily monitored and HCWs can be alerted to failure by alarms. The appropriate use of these relatively simple devices could both reduce the reliance on personal protective equipment (PPE) for infection control and provide a low-cost and energy-efficient form of protection for hospitals and clinics. Although the development and deployment of VIP hoods has been accelerated by the coronavirus disease 2019 (COVID-19) pandemic, these devices are currently an immature technology. In this review, we describe the state of the art of VIP hoods and identify aspects in need of further development, both in terms of device design and the protocols associated with their use. The broader concept of individual patient hoods has the potential to be expanded beyond ventilation to the provision of clean conditions for individual patients and personalized control over other environmental factors such as temperature and humidity.

Everyone's a winner if we test less: the CODA action plan

In this era of 'Choosing Wisely,' we present a four-step action plan to reduce unnecessary pathology testing and the associated patient harm (blood loss through repeated phlebotomy), economic cost and environmental impact. The authors are experts from the CODA group; a medical education and health-promotion charity that aims to build on the Choosing Wisely initiative to provide meaningful and sustainable actions to reduce the carbon footprint of healthcare, globally. Pathology testing is expensive and carbon-intensive, with as many as half of all tests being not clinically indicated. Reducing unnecessary testing is the only effective way to decrease the carbon footprint and other associated costs, as opportunities to reuse and recycle pathology specimens are limited. The four key steps for action are (i) auditing local practice; (ii) defining unnecessary testing including developing a clinical guideline for rational ordering; (iii) educating stakeholders; and (iv) measuring the impact of the intervention through re-audit. This proven method is designed to be used in any healthcare setting around the world; having a small group of passionate 'champions' is thought to be as important as strong clinical governance and more important than access to sophisticated equipment. Electronic medical record systems and other technological solutions offer new ways to help establish a sustainability mindset and reduce unnecessary testing. The Codachange.org/coda-earth/ website provides a dynamic crowdsourcing platform through which we can collectively learn to meet the diverse needs of our international medical community. Self-reported outcomes are gamified through collaborative feedback, amplification via social media and the ability to earn rewards, be uploaded to the CODA website, or added to the template as a success story. By combining our existing local networks with the emerging international CODA community, we can initiate meaningful change now and enter the era of environmental stewardship.

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.

Action guidance for addressing pollution from inhalational anaesthetics

Climate change is a real and accelerating existential danger. Urgent action is required to halt its progression, and everyone can contribute. Pollution mitigation represents an important opportunity for much needed leadership from the health community, addressing a threat that will directly and seriously impact the health and well‐being of current and future generations. Inhalational anaesthetics are a significant contributor to healthcare‐related greenhouse gas emissions and minimising their climate impact represents a meaningful and achievable intervention. A challenge exists in translating well‐established knowledge about inhalational anaesthetic pollution into practical action. CODA is a medical education and health promotion charity that aims to deliver climate action‐oriented recommendations, supported by useful resources and success stories. The CODA‐hosted platform is designed to maximise engagement of the global healthcare community and draws upon diverse experiences to develop global solutions and accelerate action. The action guidance for addressing pollution from inhalational anaesthetics is the subject of this article. These are practical, evidence‐based actions that can be undertaken to reduce the impact of pollution from inhalational anaesthetics, without compromising patient care and include: removal of desflurane from drug formularies; decommissioning central nitrous oxide piping; avoidance of nitrous oxide use; minimising fresh gas flows during anaesthesia; and prioritising total intravenous anaesthesia and regional anaesthesia when clinically safe to do so. Guidance on how to educate, implement, measure and review progress on these mitigation actions is provided, along with means to share successes and contribute to the essential, global transition towards environmentally sustainable anaesthesia.

Principles of environmentally-sustainable anaesthesia: a global consensus statement from the World Federation of Societies of Anaesthesiologists

The Earth's mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists' education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.

Quantitative evaluation of aerosol generation during manual facemask ventilation

Manual facemask ventilation, a core component of elective and emergency airway management, is classified as an aerosol-generating procedure. This designation is based on one epidemiological study suggesting an association between facemask ventilation and transmission during the SARS-CoV-1 outbreak in 2003. There is no direct evidence to indicate whether facemask ventilation is a high-risk procedure for aerosol generation. We conducted aerosol monitoring during routine facemask ventilation and facemask ventilation with an intentionally generated leak in anaesthetised patients. Recordings were made in ultraclean operating theatres and compared against the aerosol generated by tidal breathing and cough manoeuvres. Respiratory aerosol from tidal breathing in 11 patients was reliably detected above the very low background particle concentrations with median [IQR (range)] particle counts of 191 (77-486 [4-1313]) and 2 (1-5 [0-13]) particles.l-1 , respectively, p = 0.002. The median (IQR [range]) aerosol concentration detected during facemask ventilation without a leak (3 (0-9 [0-43]) particles.l-1 ) and with an intentional leak (11 (7-26 [1-62]) particles.l-1 ) was 64-fold (p = 0.001) and 17-fold (p = 0.002) lower than that of tidal breathing, respectively. Median (IQR [range]) peak particle concentration during facemask ventilation both without a leak (60 (0-60 [0-120]) particles.l-1 ) and with a leak (120 (60-180 [60-480]) particles.l-1 ) were 20-fold (p = 0.002) and 10-fold (0.001) lower than a cough (1260 (800-3242 [100-3682]) particles.l-1 ), respectively. This study demonstrates that facemask ventilation, even when performed with an intentional leak, does not generate high levels of bioaerosol. On the basis of this evidence, we argue facemask ventilation should not be considered an aerosol-generating procedure.

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 two 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.

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 5,695 patients were identified. In adjusted analysis, the rate of collections was lower during the intervention period (rate ratio 0.90, 95% CI, 0.86 to 0.95; P<0.001). This resulted in a reduction of 53 g CO₂ e (95% CI, 24 to 83g; P<0.001) and $22 (95% CI, $9 to $34; P=0.001) in pathology fees per admission. The intervention was estimated to have saved 132kg CO₂ e (95% CI, 59 to 205kg) and $53,573 (95% CI, 22,076 to 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. This article is protected by copyright. All rights reserved.

Net zero healthcare: a call for clinician action

Health professionals are well positioned to effect change by reshaping individual practice, influencing healthcare organisations, and setting clinical standards, argue Jodi Sherman and colleagues

Victorian public healthcare Chief Executive Officers' views on renewable energy supply

Objective Identify the views of healthcare leaders towards public healthcare's carbon footprint; the importance or not of healthcare energy supply and sources and; the perceived key barriers for Victorian health care to show leadership on renewable energy sources and supply. Methods Self-administered questionnaire (10 Likert scale, two open-ended questions) among 24 Victorian Health Chief Executive Officers (CEOs). Responses were anonymous. Descriptive analysis was conducted. Results Overall, 13/24 (54%) of CEOs responded. A majority (11/13) agreed that climate change is causing real and accelerating harm to health and the environment, with impacts on patients, staff and services a current issue. One hundred percent (13/13) saw leadership by the public healthcare sector on environmental sustainability as an important responsibility (strongly agreed, 9/13 (69%); agreed, 4/13 (31%)), with most CEOs supporting their institution increasing the amount of renewable electricity supply over-and-above grid levels (strongly agreed, 3/13 (23%); agreed, 9/13 (69%)). However, support for renewable electricity was, for the most part, aspirational and not perceived as a current priority. The key perceived barriers to increasing renewable electricity supply were Health Purchasing Victoria contract and financial constraints. Conclusions Health care itself has a carbon footprint. Public healthcare CEOs are supportive of their institutions increasing use of renewable electricity supply, yet perceived barriers regarding inflexible and poorly transparent purchasing contracts and financial cost exist. What is known about the topic? Australian health care contributes ~7 percent to Australia's total carbon emissions, with hospital energy consumption (coal-generated electricity and natural/fossil gas) a large majority. An executive level champion is a consistent factor across health services that are taking the lead on environmental sustainability. What does this paper add? Our research is original in understanding the views of Victorian public healthcare CEOs on climate change, renewable energy supply and key barriers to increasing uptake. A majority of public healthcare CEOs see energy choices as an important issue for their patients, staff and institution, and that greater leadership should be shown by health care in light of the urgency required to address greenhouse gas emissions. However, support for renewable electricity was, for the most part, aspirational, with specific barriers identified across the healthcare network. What are the implications for practitioners? This research provides information that can inform a pathway to healthcare decarbonisation via sector-wide action.

Characteristics, presentation and outcomes of music festival patrons with stimulant drug-induced serotonin toxicity

OBJECTIVE

A large number of stimulant drug-associated deaths at music festivals in Australia were reported during the southern hemisphere summer of 2018-2019. This led to the prehospital deployment of healthcare professional-led critical care response teams. We aimed to describe the characteristics, clinical presentation, management and outcomes of music festival patrons with stimulant drug-induced serotonin toxicity managed using this model during the study period.

METHODS

We performed a retrospective observational study of patients presenting with stimulant drug-induced serotonin toxicity and/or drug-induced hyperthermia who presented between December 2017 and December 2019. Comprehensive follow-up data were collected for those patients who required hospital admission. Data included demographics, clinical features, management and disposition, hospital outcomes and laboratory data, stratified by severity of presentation.

RESULTS

Forty-seven patients were included. Median age was 21.9 years (interquartile range 19.6-22.2). 3,4-Methylenedioxymetamphetamine was the most frequently reported agent ingested (32/47). After stratification, 13 of 47 patients were classified as mild, 20 of 47 as moderate and 14 of 47 as severe. Median presenting temperature in this latter cohort was 41.1°C (40.5-42.0°C). All severely ill patients required intensive care unit admission, with a median hospital stay of 4.63 days (interquartile range 2.08-8.36). End-organ complications were reported in 11 of 14 patients. No mortalities were reported. All patients (13/13) from the mild cohort and 15 of 20 patients from the moderate cohort were treated and discharged on-site.

CONCLUSIONS

Severe illness was associated with a high incidence of end-organ impairment. A high proportion of patients without severe disease were able to be successfully managed at the event without transport to hospital. No deaths are reported in this series.