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.

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.

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.

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.

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.

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.

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.

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.

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.

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.