British journal of anaesthesia
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Editorial Randomized Controlled Trial
Should renin-angiotensin system inhibitors be held prior to major surgery?
Many patients undergoing surgical procedures have a history of hypertension, diabetes mellitus, heart failure, or a combination. Often, these conditions involve the chronic use of a renin-angiotensin system inhibitor, including angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). Observational studies have suggested that continuing ACEIs/ARBs before major noncardiac surgery can increase the risk of intraoperative hypotension, which might drive postoperative complications such as acute kidney injury, myocardial injury, or stroke. ⋯ Patients randomised to the 'Stop' group experienced more postoperative hypertension. In a post hoc analysis, patients randomised to the 'Continue' group with low preoperative NT-proBNP concentrations (<100 pg ml-1) experienced less myocardial injury after surgery than the 'Stop' group, whereas no significant difference was observed in patients with elevated preoperative NT-proBNP concentrations. The SPACE trial provides important and new reassuring data on the safety of continuing ACEIs/ARBs before major surgery, challenging previous beliefs.
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Patients who undergo laparotomy for major trauma are amongst the most critically unwell patients, and they have high morbidity and mortality rates. Despite 20 yr of improvements in resuscitation practices, those who present with hypotension continue to have mortality rates of up to 50%. Currently there is no mechanism for capturing national audit data on these patients, leading to their exclusion from potential quality improvement initiatives. We argue that there is an unmet need for quality assurance in this patient cohort and outline possible mechanisms to address this.
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Artificial intelligence (AI) for ultrasound scanning in regional anaesthesia is a rapidly developing interdisciplinary field. There is a risk that work could be undertaken in parallel by different elements of the community but with a lack of knowledge transfer between disciplines, leading to repetition and diverging methodologies. This scoping review aimed to identify and map the available literature on the accuracy and utility of AI systems for ultrasound scanning in regional anaesthesia. ⋯ There is a lack of structure to the evaluation of accuracy and utility of AI for ultrasound scanning in regional anaesthesia, which hinders rigorous appraisal and clinical uptake. A framework for consistent evaluation is needed to inform model evaluation, allow comparison between approaches/models, and facilitate appropriate clinical adoption.
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Pulse oximetry uses noninvasive optical measurements of light transmission from each of two sources through vascularised living tissue over the cardiac cycle (SpO2). From those measurements, the relative amount of oxygenated haemoglobin (SaO2) in circulating blood can be deduced. Recent reports have shown that, compared with SaO2 measurements from blood samples, SpO2 measurements are biased erroneously high for patients with dark skin. ⋯ To eliminate melanin bias, pulse oximeters should use much narrower spectral bandwidths than those used in current models.