Anaesthesia and Intensive Care最新文献

Nitrous oxide (N₂O) is a potent greenhouse gas used to provide analgesia and anaesthesia in healthcare. Leaks from the manifold-pipeline systems may result in significant losses of N₂O before delivery to the patient. The provision of N₂O by cylinder at point-of-care is proposed as a leak-reducing alternative to manifold-pipeline systems. The primary endpoint of this study was to determine the percentage of anaesthetists who considered it acceptable for N₂O to be supplied by cylinder rather than a manifold-pipeline system. It also explored the current application of N₂O and prevailing attitudes toward its environmental impact and future role in anaesthetic practice. A cross-sectional survey was administered in 2023 among anaesthetists working across seven metropolitan hospitals in New South Wales, Australia. Participants provided self-reported information on demographics, practice characteristics, views on climate change, the role of anaesthetists in addressing environmental concerns, routine N₂O usage, and the potential shift to cylinder supply of N₂O. Among the 287 respondents, the majority (n=241, 84.6%) were current users of N₂O, although most administered it infrequently (71.5% used it in less than 25% of cases). Attitudes regarding N₂O's environmental impact varied irrespective of career stage. Notably, 219 of 287 (76.3%) favoured using cylinders over the manifold-pipeline network. These findings indicate a decreasing trend in N₂O usage, especially among early career anaesthetists, and suggest that transitioning to cylinder supply is acceptable, provided that strategies are in place to manage supply disruptions without compromising patient care.

Remifentanil and dexmedetomidine are sedative agents used both in anaesthetic and critical care practice. Their effects on the gastro-oesophageal pressure gradient and hence on the potential risk for regurgitation have not been quantified. The aim of this study was to measure and compare the effects of both agents on the gastro-oesophageal pressure gradient. The study used a randomised, double blinded crossover study design, and 16 healthy volunteers were sedated on two separate occasions. Baseline lower oesophageal sphincter pressure (26 and 28 mmHg for dexmedetomidine and remifentanil, respectively) and gastro-oesophageal pressure gradient (20 mmHg for both dexmedetomidine and reminfentanil) were recorded. Then, each volunteer received increasing doses of target-controlled infusions of dexmedetomidine (1, 2, 4, 6 ng/ml) or remifentanil (1, 2, 3, 4 ng/ml). Each dose level was maintained for 20 minutes, and both lower oesophageal sphincter pressure and gastro-oesophageal pressure gradient were continuously recorded. Measurements were averaged. Out of 16 subjects recruited, data were analysable from 11 (aged 18-54 years, body mass index 17.7-27.9 kg/m², five men and six women). The dose regimens of both agents provided similar profiles of progressive sedation over time, with sedation scores reaching a minimum of -2 on the 'observer's assessment of alertness and sedation score' with both medications. With dexmedetomidine, the bispectral index gradually decreased in line with sedation scores (P<0.05), but remifentanil produced little change in the bispectral index from baseline. Both agents decreased gastro-oesophageal pressure gradient (P<0.001) similarly, (P=0.199), in line with the decreases in sedation scores. In conclusion, when remifentanil or dexmedetomidine are administered to provide sedation they induce similar decreases in gastro-oesophageal pressure gradient. This may put patients at comparable risk of gastro-oesophageal reflux.

2,4-Dinitrophenol (DNP), previously used as a weight loss drug, was banned owing to its narrow therapeutic index and severe side effects. DNP disrupts mitochondrial oxidative phosphorylation and inhibits adenosine triphosphate synthesis, causing heat production, increased basal metabolic rate and enhanced glycolysis. Despite bans, unregulated online and darknet sales have led to a rise in DNP toxicity cases. We report a case of a young man who survived a deliberate, highly lethal DNP overdose through coordinated team-based care including early aggressive cooling and high-volume mechanical ventilation, crucial in maintaining normothermia and normocapnia. This case adds valuable insights to the literature on DNP toxicity management.

Fellowship selection interviews evaluate candidates' suitability for specialised anaesthesia training. Applicants are not commonly provided with specific details of questions or topics although these are often sourced from previous applicants. This study explored whether increased transparency in the interview process, by providing a list of discussion topics beforehand, impacts applicant performance and experience. Data from 91 applicant interviews over four years (2021-2024) were analysed. The traditional interview format was employed in 2021 and 2022. A novel format was introduced in 2023, in which applicants were provided with a list of 14 discussion topics 3 weeks before the interview. 2024 interviews reverted to the traditional format. Applicant performance was compared across the study period, with feedback collected from the 2023 cohort. No significant difference in mean interview scores or variance ratios was found between the novel and traditional formats, nor between local and non-local applicants. A total of 58.3% of applicants preferred the novel format, citing reduced anxiety and improved preparation. One-third preferred the traditional format, arguing that transparency might disadvantage those who typically prepare for interviews independently. Interviewer feedback indicated no perceived disadvantages from increased transparency, and probing questions effectively elicited detailed responses without making answers seem rehearsed. Providing applicants with interview topics in advance did not impact overall ratings but positively affected their experience by reducing anxiety and improving perceptions of the interview process. The findings support the implementation of transparency in selection interviews to enhance fairness and candidate experience without compromising the validity of the selection process.

Nitrous oxide (N₂O) is ozone-depleting and a greenhouse gas. Studies have shown a high wastage of N₂O from leaking hospital infrastructure. Identifying leaks is a priority action in the Australian national health and climate strategy. Four possible methods to identify leaks have been described: the discrepancy method, cylinder weighing, pressure testing, and flow monitoring. We used the discrepancy and pressure testing methods to investigate possible N₂O leaks at St George Hospital, a large tertiary hospital in Sydney providing medical, surgical, birthing, paediatric, and trauma care. Our investigation was in four steps: (a) to determine how much N₂O is procured and calculate the associated carbon emissions; (b) to outline the location of pipeline supply; (c) to determine how much N₂O is used clinically (operating theatres, delivery suite, other areas); and (d) to assess for leaks throughout the pipeline using pressure testing. We estimated a total annual 'worst case' estimate of maximum possible clinical N₂O use of approximately 801,866 litres at St George Hospital in 2021, with 14,846 litres used in the operating theatres and 787,020 litres used in the delivery suite. This estimate was approximately 319,534 litres (or 28%) less than the 1,121,400 litres procured N₂O used to supply the manifold, indicating leaks at least this large. Pressure testing of the full manifold system identified leaks in three operating theatres. A substantial amount of the N₂O procured by St George Hospital is leaking to the atmosphere causing unnecessary emissions. This N₂O provides no benefits to clinical care, has financial costs, and may pose potential occupational exposure risks to clinicians.

Background: Arterial haemoglobin oxygen desaturation is common during gastroscopy and is associated with patient harm. Obesity increases the risk of desaturation during gastroscopy. High-flow nasal oxygen may reduce the risk of desaturation, but data are lacking.

Methods: We conducted a single-centre, parallel group, randomised controlled trial of high-flow nasal oxygen at 50-70 l/min compared with oxygen via nasal prongs 4-10 l/min, enrolling adults having gastroscopy procedures who had a body mass index greater than 30 kg/m². The primary outcome was the incidence of desaturation, defined as any peripheral oxygen saturation less than 90% during the procedure.

Results: We recruited 150 participants (75 in each group). The mean body mass index was similar in each group (35 vs. 36 kg/m²). High-flow nasal oxygen reduced the incidence of desaturation compared with standard oxygen therapy (three (4%) vs. 14 (19%), P = 0.005), and increased the median minimum peripheral oxygen saturation (98% (interquartile range 92-97%) vs. 94% (interquartile range 97-100%), P < 0.001). Fewer patients administered high-flow oxygen required airway interventions (39 (52%) vs. 58 (77%), P < 0.001), while the number of patients requiring interruption to the procedure for airway management were similar in each group (seven (9%) vs. five (7%), P = 0.57). High-flow nasal oxygen was associated with a higher risk of apnoea compared with standard oxygen delivery (17 (23%) vs. six (8%), P = 0.013), and a similar risk of arrhythmias existed between the groups (two (3%) vs. one (1%), P = 0.56).

Conclusion: High-flow nasal oxygen reduced the incidence of desaturation during gastroscopy in obese patients.

Acute kidney injury is a frequent complication in critically ill patients and often necessitates kidney replacement therapy. Optimising antimicrobial dosing in this population is essential yet challenging owing to altered pharmacokinetics in critical illness and the wide variability of prescriptions utilised in kidney replacement therapy. This case report investigates the pharmacokinetics of cefazolin in a critically ill patient receiving prolonged intermittent kidney replacement therapy, offering insights into dosing considerations in this clinical setting.

Airway management in critically ill patients remains an essential component of intensive care medicine and is associated with significant patient risks. We conducted a 6-year follow-up survey among intensive care unit (ICU) medical staff in Australia and New Zealand (ANZ) from June to September 2024 which explored current ICU airway management practices and compared these with our previous survey in 2019. Among 211 respondents (26% response rate), 79.6% were male and 70.6% were intensivists. Video laryngoscopy (VL) availability increased significantly to 100% (P=0.005). VL was the first-line choice for 82% of respondents (adjusted odd ratio (aOR) = 7.41; 95% confidence interval (CI): 4.33 to 12.67) and there was an increase in intubation checklist usage (aOR = 3.32; 95%CI: 1.88 to 5.86). The use of ketamine for induction doubled (33.2% versus 15.3%; aOR = 2.96; 95%CI: 1.65 to 5.31), and rocuronium (89.6%) was the most used neuromuscular-blocking agent. Only 15.1% consistently used a bougie or stylet, and half used bag-mask ventilation post-induction and prior to intubation. Only 54% of respondents were familiar with any guidelines, and less than half of respondents (46.4%) reported having any formal airway management training in the past 3 years. A majority (81%) supports mandatory airway management continuing professional development (CPD) for fellows of the College of Intensive Care Medicine of ANZ (CICM). Despite improvements in airway management among ANZ ICU clinicians, notable gaps persist between current practices and recent trial evidence and guideline recommendations, supporting the need for airway management CPD for CICM fellows.

Failing high-stakes examinations in specialist medical training has devastating effects on trainees, both personally and professionally, with some trainees requiring multiple attempts. Factors enabling the transition from failure to success are under-explored. This study aims to understand how intensive care trainees, taking multiple attempts at the final high-stakes exam for progression to specialist, made the transition from failure to success, and their lived experience of the journey. This qualitative study applied grounded theory design, conducting 11 in-depth interviews. All participants had had two or more failed attempts before achieving success in the final high-stakes examination, a critical hurdle in achieving Fellowship with the College of Intensive Care Medicine. Additional data included exam reports, an external review of the exam processes, and research notes. To achieve exam success participants needed to reconstruct their sense of self, develop a growth mindset and identify as a competent intensivist. The constructed theory, 'Identifying as an intensivist', relates to professional identity formation and 'thinking, acting and feeling' as an intensivist. 'Identifying as an intensivist' was integral to overcoming exam failure for intensive care trainees. Professional identity formation as an aspect of remediation for high-stakes assessments in medical specialty training has not been well described. Furthermore, assessment processes should be constructed to align with a professional identity reflecting the values and diversity of the specialty.