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.
Severely ill patients with COVID-19 are challenging to sedate and often require high-dose sedation and analgesic regimens. Ketamine can be an effective adjunct to facilitate sedation of critically ill patients but its effects on sedation level and inflammation in COVID-19 patients have not been studied. This retrospective, observational cohort study evaluated the effect of ketamine infusions on inflammatory biomarkers and clinical outcomes in mechanically ventilated patients with SARS-CoV-2 infection. A total of 186 patients were identified (47 received ketamine, 139 did not). Patients who received ketamine were significantly younger than those who did not (mean (standard deviation) 59.2 (14.2) years versus 66.3 (14.4) years; P = 0.004), but there was no statistically significant difference in body mass index (P = 0.25) or sex distribution (P = 0.91) between groups. Mechanically ventilated patients who received ketamine infusions had a statistically significant reduction in Richmond Agitation-Sedation Scale score (-3.0 versus -2.0, P < 0.001). Regarding inflammatory biomarkers, ketamine was associated with a reduction in ferritin (P = 0.02) and lactate (P = 0.01), but no such association was observed for C-reactive protein (P = 0.27), lactate dehydrogenase (P = 0.64) or interleukin-6 (P = 0.87). No significant association was observed between ketamine administration and mortality (odds ratio 0.971; 95% confidence interval 0.501 to 1.882; P = 0.93). Ketamine infusion was associated with improved sedation depth in mechanically ventilated COVID-19 patients and provided a modest anti-inflammatory benefit but did not confer benefit with respect to mortality or intensive care unit length of stay.
Nitrous oxide is a potent greenhouse gas and ozone-depleting agent with a long atmospheric lifetime. Several previous reports indicate that over half of supplied nitrous oxide is wasted from leaking manifold-pipeline systems infrastructure prior to patient use, and that remediating leaks can have significant environmental benefits. We describe an accurate, simple and cost-effective cylinder weighing method to quantify nitrous oxide leak from the manifold-pipeline network at our tertiary non-obstetric facility. Nitrous oxide cylinder depletion was prospectively compared with clinical usage derived from the electronic medical record over an 18-day period. A total of 1932 l (3.62 kg) of nitrous oxide was used in 35 operating theatre cases during the period. This was only 16.5% of actual cylinder depletion (11,686 l; 21.88 kg), indicating that 83.5% (9754 l; 18.26 kg) of nitrous oxide had leaked to the atmosphere (376 ml/minute; 22.6 l/hour; 542 l/day). The fraction of nitrous oxide wasted was consistent with a retrospective analysis of the previous 2-year period at the site that compared purchasing records with estimated clinical use. If maintained over a year, the leak would be equivalent to 101 tonnes of carbon dioxide per annum.
Post-mastectomy pain syndrome (PMPS) is a type of chronic postsurgical pain that can be severe, debilitating and frequently encountered in clinical practice. Multiple studies have focused on prevention, identifying risk factors and treating this condition. Nonetheless, PMPS remains a complex condition to treat effectively. In this case report, we describe the use of percutaneous electrical nerve stimulation in a breast cancer patient who experienced PMPS refractory to conventional treatments.