AnaesthesiaPub Date : 2025-01-24DOI: 10.1111/anae.16547
Rosalyn Boyd, James E. Dinsmore
{"title":"Incomplete Optiflow™ switching and the potential for confusion","authors":"Rosalyn Boyd, James E. Dinsmore","doi":"10.1111/anae.16547","DOIUrl":"https://doi.org/10.1111/anae.16547","url":null,"abstract":"<p>As the evidence base supporting the use of peri-intubation high-flow nasal oxygen (HFNO) continues to expand [<span>1</span>], there have been advances in the design of the latest generation of systems for use in operating theatres. We would like to highlight several practice point considerations relating to use of such systems.</p>\u0000<p>A limitation of previous designs is that applying a tight-fitting anaesthetic facemask over the incompressible nasal prongs is contraindicated due to the risks of gastric insufflation and barotrauma. The Fisher and Paykel Optiflow™ Switch (Fisher and Paykel, Auckland, New Zealand) modification [<span>2</span>] incorporates a flow-regulated pressure relief valve and a compressible inflow to the nasal prongs so that there is interruption of the 100% oxygen nasal prong gas flow when a tight-fitting facemask is applied. This allows safe and seamless transitions from anaesthetic mask pre-oxygenation and facemask ventilation to HFNO and vice versa.</p>\u0000<p>The user should be aware that, even when a firmly applied facemask is applied over the nasal prongs, the nasal oxygen flow is not completely ‘switched off’. It is likely to be variable but with Optiflow Switch flows above 10 l.min<sup>-1</sup> it is apparent that there is ongoing oxygen ingress via the nasal prongs into the facemask during pre-oxygenation and facemask ventilation. The product literature details that the pressure delivered to the patient will be limited to 30 cmH<sub>2</sub>O between flows of 30–70 l.min<sup>-1</sup> [<span>3</span>].</p>\u0000<p>Figure 1 shows the gas analyser data observed when a firmly applied facemask connected to a circle anaesthetic circuit with flow rates 10 l.min<sup>-1</sup> of room air (F<sub>I</sub>O<sub>2</sub> 0.21) is applied over the Optiflow Switch nasal prongs and the HFNO flow rate is increased. The analyser measures increasing levels of inspired and end-tidal oxygen consistent with increasing oxygen ingress via the nasal prongs. Additionally, the capnography trace is attenuated, the extent of which is related to the HFNO flow rate. It does not appear to make a significant difference if the mask is a cushion design (e.g. Ambu® King; Ambu A/S, Ballerup, Denmark) or anatomical (e.g. Meditech Anatomical Eco; Meditech Systems Limited, Shaftesbury, UK).</p>\u0000<figure><picture>\u0000<source media=\"(min-width: 1650px)\" srcset=\"/cms/asset/4281cadf-7e16-42ba-9ad4-786dd478abb4/anae16547-fig-0001-m.jpg\"/><img alt=\"Details are in the caption following the image\" data-lg-src=\"/cms/asset/4281cadf-7e16-42ba-9ad4-786dd478abb4/anae16547-fig-0001-m.jpg\" loading=\"lazy\" src=\"/cms/asset/89be1ca2-6d77-48de-8576-478a34442fb5/anae16547-fig-0001-m.png\" title=\"Details are in the caption following the image\"/></picture><figcaption>\u0000<div><strong>Figure 1<span style=\"font-weight:normal\"></span></strong><div>Open in figure viewer<i aria-hidden=\"true\"></i><span>PowerPoint</span></div>\u0000</div>\u0000<div>Photos stitched together show representative gas analyser readi","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"34 1","pages":""},"PeriodicalIF":10.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaesthesiaPub Date : 2025-01-23DOI: 10.1111/anae.16546
Chin Wen Tan, Rehena Sultana, Mary C. Wright, Ban Leong Sng, Ashraf S. Habib
{"title":"Persistent pain six months after breast cancer surgery: a multicentre follow-up study","authors":"Chin Wen Tan, Rehena Sultana, Mary C. Wright, Ban Leong Sng, Ashraf S. Habib","doi":"10.1111/anae.16546","DOIUrl":"10.1111/anae.16546","url":null,"abstract":"<p>Persistent postoperative pain, defined as surgical site pain lasting beyond 3 months with other causes of pain excluded, can have adverse physical and psychological consequences [<span>1</span>]. We developed a multivariable model for persistent pain at 4 months after breast cancer surgery based on baseline and peri-operative factors [<span>2</span>]. A significant number of women who develop persistent pain 4 months after surgery may continue to have persistent pain at 6 months. Hence, we further evaluated risk factors for persistent pain at 6 months, encompassing patients' characteristics and information available from the 4-month follow-up.</p><p>This study is a secondary analysis of a prospective study investigating factors for persistent pain after breast cancer surgery at 4 months at two specialist centres (KK Women's and Children's Hospital, Singapore and Duke University Medical Centre, Durham, NC, USA), from January 2018 to March 2021 [<span>2</span>]. After ethical approval, written informed consent was obtained from English-speaking patients scheduled for elective breast cancer surgery. Patients with a history of intravenous drug abuse, chronic opioid use, receiving chronic corticosteroid therapy or who were pregnant were not studied. Pre-operative baseline information was collected and is available in online Supporting Information Tables S1 and S2. Patients were further assessed for postoperative pain and analgesic use in the post-anaesthesia care unit and at 24–72 h post-surgery. Patients were followed-up via telephone or online survey at 4 and 6 months using a validated pain questionnaire [<span>3</span>].</p><p>The primary outcome of persistent pain at 6 months was defined as the presence of one of either a pain score ≥ 3 on a numerical pain rating scale of 0 (no pain) to 10 (worst pain imaginable); or pain affecting daily life activities via indication of ‘yes’ on any of the seven questions that evaluated the impact of pain at 6 months on daily life activities in the Brief Pain Inventory Short-Form [<span>4</span>].</p><p>The main objective was to develop a multivariable model for factors associated with persistent pain 6 months after breast cancer surgery. We also identified factors associated with persistent pain at both 4 and 6 months. The multivariable model was finalised using a stepwise variable selection method, incorporating clinically relevant variables with a p value < 0.20 from the univariable logistic regression analyses.</p><p>Among the 233 recruited patients, 209 completed the follow-up at 6 months with an incidence of persistent pain of 57.4% (95%CI 50.4–64.2, n = 120). By selecting factors with p < 0.20 in the univariable analysis, we identified the optimal multivariable model for the primary outcome, which contained the following independent risk factors: pain at 4 months after surgery; history of hypertension; axillary surgery; lower pain pressure threshold; and greater pre-operative perceived stress (AUC","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"80 4","pages":"448-450"},"PeriodicalIF":7.5,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/anae.16546","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaesthesiaPub Date : 2025-01-23DOI: 10.1111/anae.16552
Christopher Frerk, Genevieve Evans
{"title":"Mandatory training for rare anaesthetic events – a philosophical view","authors":"Christopher Frerk, Genevieve Evans","doi":"10.1111/anae.16552","DOIUrl":"10.1111/anae.16552","url":null,"abstract":"<p>Murphy's letter opposing the call for mandatory training for rare anaesthetic events [<span>1</span>] challenges issues inferred, but not contained, in the editorial by Nathanson et al. [<span>2</span>]. For example, Nathanson et al. did not suggest that training would make individual humans less error prone. They proposed that we should be training staff to work in multidisciplinary teams, as teamwork can help us identify and correct the inevitable errors of our colleagues and can help them identify and correct ours. While the concepts of teamwork can, and should, be learned through lectures and reading existing literature, developing and refining the non-technical skills required for good teamwork requires training and deliberate practice, with targeted positive feedback. Simulation is the ideal learning environment for this, allowing non-technical skills to be observed, practised and improved. Murphy also seemed particularly concerned about the possibility of sanctions for failing to meet standards, but sanctions do not have a role in simulation training, and they were not mentioned by Nathanson et al.</p><p>In response to Murphy's philosophical position that we should view this issue through a utilitarian lens, we believe that a Kantian perspective would be much more appropriate. Utilitarianism can be summarised as the greatest good for the greatest number of people; it is important to recognise that this is based on consequentialism, meaning that, when we act, we are trying to predict how much good the act will produce, as opposed to whether the act is good [<span>3</span>]. The Kantian approach is deontological in nature. This means our actions are judged as objectively good or bad based on ethical values and principles, rather than predicted consequences [<span>4</span>]. According to Kant, what matters is the ethical or moral value of an action. While outcomes are important, it is vital to recognise that, instead of trying to anticipate the optimal outcomes for all parties involved, we have a duty to act in the most ethically correct way for our patients. This includes supporting all measures to ensure that we, as doctors, are appropriately trained to deal with serious rare events that we know cause death and disability. This, therefore, includes supporting the call by Nathanson et al. for mandatory training [<span>2</span>].</p><p>The second relevant element of Kantian ethics is found within his categorical imperative, which boils down to the principle of universalisation [<span>5</span>]: “<i>if I act in a certain way, I should be content with everyone else also acting in this way</i>”. This mirrors the question posed by Nathanson et al.: “<i>would we be happy if a member of our family were under the care of an anaesthetist who was unable to demonstrate they could safely manage inadvertent oesophageal intubation or acute anaphylaxis to a neuromuscular blocking drug?</i>” [<span>2</span>]. We believe anaesthetists would answer this qu","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"80 5","pages":"590-591"},"PeriodicalIF":7.5,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/anae.16552","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaesthesiaPub Date : 2025-01-23DOI: 10.1111/anae.16544
Benjamin Stretch, Paola Eiben, James O'Carroll
{"title":"Similarities and differences between maternal and major traumatic haemorrhage – what can we learn?","authors":"Benjamin Stretch, Paola Eiben, James O'Carroll","doi":"10.1111/anae.16544","DOIUrl":"10.1111/anae.16544","url":null,"abstract":"<p>We read the correspondence from Margiotta and Plaat with interest [<span>1</span>]. There could be much gained by comparing major obstetric and traumatic haemorrhage. Three areas that we believe are particularly relevant are identification of hypovolaemia and coagulopathy, and the impact of human factors.</p><p>The 7th National Audit Project (NAP7) authors identified that hypovolaemia was under-recognised and inadequately treated in obstetric patients who had a cardiac arrest [<span>2</span>]. Trauma research suggests multimodal assessments of volume status are important, as individual parameters and scoring systems lack sensitivity and specificity. In addition to heart rate and blood pressure, capillary refill, pulse pressure, base deficit and lactate, coagulopathy and estimated blood loss may be most useful and should be used in combination. Shock index can be a predictor of the severity of shock in trauma, but not in the obstetric population.</p><p>The NAP7 authors recommended the use of fluid resuscitation and vasopressor use in obstetric haemorrhage [<span>2</span>]. In the major trauma setting, acidaemia, hypothermia, hyperkalaemia, hypocalcaemia and coagulopathy are associated with worse outcomes. Consequently, early transfusion of blood products and management of metabolic disturbance are of the upmost importance. Viscoelastic haemostatic assay-driven therapy represents the ‘gold standard’ in trauma care and is recommended by international guidelines [<span>3</span>]. The importance of targeted therapy was emphasised by CRYOSTAT-2, showing no advantage to empirical cryoprecipitate use in major trauma and worse outcomes if given before depletion of fibrinogen [<span>4</span>]. Pregnancy is accompanied by significant changes in the coagulation and fibrinolytic systems including increased fibrinogen concentrations (3.5–6.5 g.l<sup>-1</sup>) [<span>5</span>]. Hypofibrinogenaemia is associated with poor outcomes and, as a result, a higher fibrinogen target of 2 g.l<sup>-1</sup> is recommended.</p><p>We must also consider fetal wellbeing. To preserve uterine blood flow, maternal systemic blood pressure should be maintained near normal before delivery. As such, hypotensive resuscitation, which can be an advantageous approach in damage control resuscitation in trauma [<span>3</span>], is not the mainstay in obstetrics.</p><p>Multidisciplinary teamwork, effective communication and human factors are key in managing both obstetric and traumatic major haemorrhage, with failure of these recognised as a contributor to maternal morbidity and mortality by MBRRACE-UK [<span>6</span>]. Non-technical skills including situational awareness, appropriate role allocation and performance under pressure in stressful situations are important.</p><p>Comparing obstetric and traumatic haemorrhage highlights that not all bleeding is the same, as they differ significantly in physiological response and risk of coagulopathy. These differences are influenced by a patie","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"80 4","pages":"456-457"},"PeriodicalIF":7.5,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/anae.16544","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pre-operative subjective functional capacity and postoperative outcomes in adult non-cardiac surgery: a systematic review and meta-analysis","authors":"Kyosuke Takahashi, Kyoko Chiba, Ayano Honda, Yusuke Iizuka, Koichi Yoshinaga, Alka Sachin Deo, Tokujiro Uchida","doi":"10.1111/anae.16543","DOIUrl":"10.1111/anae.16543","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>Assessment of functional capacity is an essential part of peri-operative risk stratification. Subjective functional capacity is easier to examine than objective tests of patient fitness. However, the association between subjective functional capacity and postoperative outcomes has not been established.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Four databases were searched for studies describing the associations between subjective functional capacity and postoperative outcomes in adults undergoing non-cardiac surgery. Meta-analysis was conducted among studies where functional capacity was expressed in metabolic equivalents. The primary outcome was postoperative major adverse cardiovascular events. Secondary outcomes were mortality and postoperative overall complications. We estimated the ORs of the outcomes in patients with poor functional capacity (< 4 metabolic equivalents) as compared with those with good functional capacity (≥ 4 metabolic equivalents). Random-effects models were used for the meta-analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We identified 7835 abstracts. After screening and a full-text review, 23 studies were selected. Evaluation methods of functional capacity included: questionnaires (n = 7); specific questions (n = 6); and subjective assessment by anaesthetists (n = 5). The probability of major postoperative adverse cardiovascular events was significantly higher in patients with poor functional capacity (OR 1.84, 95%CI 1.62–2.08) than in those with good functional capacity. Patients with poor functional capacity also had higher odds of mortality (OR 2.48, 95%CI 1.45–4.25) and postoperative complications (OR 1.85, 95%CI 1.34–2.55).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>Subjective functional capacity of < 4 metabolic equivalents was associated with postoperative complications including cardiovascular events and other serious outcomes. The results need to be interpreted with caution due to the diverse measures used to assess functional capacity.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"80 5","pages":"561-571"},"PeriodicalIF":7.5,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaesthesiaPub Date : 2025-01-23DOI: 10.1111/anae.16545
Ting Li, Jun Li, Chenchen Jiang, Liyong Yuan, Jinze Wu, Ali Mazaheri, Mingcang Wang, Shengwei Jin, Paul S. Myles, Yinguang Yao, Jimin Wu, Junping Chen, Fang G. Smith
{"title":"Incidence of 12-month postoperative cognitive decline following regional vs. general anaesthesia in older patients undergoing hip fracture surgery: follow-up of the RAGA trial","authors":"Ting Li, Jun Li, Chenchen Jiang, Liyong Yuan, Jinze Wu, Ali Mazaheri, Mingcang Wang, Shengwei Jin, Paul S. Myles, Yinguang Yao, Jimin Wu, Junping Chen, Fang G. Smith","doi":"10.1111/anae.16545","DOIUrl":"https://doi.org/10.1111/anae.16545","url":null,"abstract":"Data regarding the incidence of 12-month postoperative cognitive decline following regional or general anaesthesia in older patients undergoing hip fracture surgery remain observational. Compared with general anaesthesia, we hypothesised that regional anaesthesia would decrease the incidence of 12-month postoperative cognitive decline.","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"49 1","pages":""},"PeriodicalIF":10.7,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaesthesiaPub Date : 2025-01-16DOI: 10.1111/anae.16549
Siu-Wai Choi
{"title":"Instrumental variable analyses – an alternative to regression?","authors":"Siu-Wai Choi","doi":"10.1111/anae.16549","DOIUrl":"10.1111/anae.16549","url":null,"abstract":"","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"80 3","pages":"327-329"},"PeriodicalIF":7.5,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaesthesiaPub Date : 2025-01-15DOI: 10.1111/anae.16548
Dáire N. Kelly, Sai Pentyala, Stephen C. Haskins
{"title":"Gastric point-of-care ultrasound in the GLP-1 receptor agonist era: clinical impact and competency","authors":"Dáire N. Kelly, Sai Pentyala, Stephen C. Haskins","doi":"10.1111/anae.16548","DOIUrl":"10.1111/anae.16548","url":null,"abstract":"","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"80 4","pages":"362-365"},"PeriodicalIF":7.5,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaesthesiaPub Date : 2025-01-13DOI: 10.1111/anae.16537
Laura A. Buiteman-Kruizinga, David M. P. van Meenen, Ary Serpa Neto, Guido Mazzinari, Lieuwe D. J. Bos, Pim L. J. van der Heiden, Frederique Paulus, Marcus J. Schultz, for the NEBULAE, PReVENT, RELAx, investigators
{"title":"Association of ventilation volumes, pressures and rates with the mechanical power of ventilation in patients without acute respiratory distress syndrome: exploring the impact of rate reduction","authors":"Laura A. Buiteman-Kruizinga, David M. P. van Meenen, Ary Serpa Neto, Guido Mazzinari, Lieuwe D. J. Bos, Pim L. J. van der Heiden, Frederique Paulus, Marcus J. Schultz, for the NEBULAE, PReVENT, RELAx, investigators","doi":"10.1111/anae.16537","DOIUrl":"10.1111/anae.16537","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>High mechanical power is associated with mortality in patients who are critically ill and require invasive ventilation. It remains uncertain which components of mechanical power – volume, pressure or rate – increase mechanical power the most.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We conducted a post hoc analysis of a database containing individual patient data from three randomised clinical trials of ventilation in patients without acute respiratory distress syndrome. The primary endpoint was mechanical power. We used linear regression; double stratification to create subgroups of participants; and mediation analysis to assess the impact of changes in volumes, pressures and rates on mechanical power.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 1732 patients were included and analysed. The median (IQR [range]) mechanical power was 12.3 (9.3–17.1 [3.7–50.1]) J.min<sup>-1</sup>. In linear regression, respiratory rate (36%) and peak pressure (51%) explained most of the increase in mechanical power. Increasing quintiles of peak pressure stratified on constant levels of respiratory rate resulted in higher risks of high mechanical power (relative risk 2.2 (95%CI 1.8–2.6), p < 0.01), while decreasing quintiles of respiratory rate stratified on constant levels of peak pressure resulted in lower risks of high mechanical power (relative risk 0.2 (95%CI 0.2–0.3), p < 0.01). Mediation analysis showed that a reduction in respiratory rate, with the increase in tidal volume, partially mediates an effect of reduction in mechanical power (average causal mediation effect -0.10, 95%CI -0.12 to -0.09, p < 0.01), but still with a direct effect of tidal volume on mechanical power (average direct effect 0.15, 95%CI 0.11–0.19, p < 0.01).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>In this cohort of patients without acute respiratory distress syndrome, pressure and respiratory rate were the most important determinants of mechanical power. The respiratory rate may be the most attractive ventilator setting to adjust when targeting a lower mechanical power.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7742,"journal":{"name":"Anaesthesia","volume":"80 5","pages":"533-542"},"PeriodicalIF":7.5,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/anae.16537","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}