BJA openPub Date : 2024-12-01DOI: 10.1016/j.bjao.2024.100358
Steven McGuigan , Andria Pelentritou , David A. Scott , Jamie Sleigh
{"title":"Xenon anaesthesia is associated with a reduction in frontal electroencephalogram peak alpha frequency","authors":"Steven McGuigan , Andria Pelentritou , David A. Scott , Jamie Sleigh","doi":"10.1016/j.bjao.2024.100358","DOIUrl":"10.1016/j.bjao.2024.100358","url":null,"abstract":"<div><h3>Background</h3><div>Administration of conventional anaesthetic agents is associated with changes in electroencephalogram (EEG) oscillatory dynamics, including a reduction in the peak alpha frequency. Computational models of neurones can reproduce such phenomena and are valuable tools for investigating their underlying mechanisms. We hypothesised that EEG data acquired during xenon anaesthesia in humans would show similar changes in peak alpha frequency and that computational neuronal models of recognised cellular actions of xenon would be consistent with the observed changes.</div></div><div><h3>Methods</h3><div>EEG recordings were obtained for 11 participants from a randomised controlled trial of xenon anaesthesia and for 21 participants from a volunteer study of xenon administration. The frontal peak alpha frequency was calculated for both cohorts at awake baseline and during xenon administration. <em>In silico</em> simulations with two computational models of neurones were performed to investigate how xenon antagonism of hyperpolarisation-activated cyclic nucleotide-gated channel 2 (HCN2) and glutamatergic excitatory neurotransmission would influence peak alpha frequency.</div></div><div><h3>Results</h3><div>Compared with awake baseline, frontal peak alpha frequency was significantly lower during xenon administration in the randomised controlled trial cohort, median (inter-quartile range) frequency 7.73 Hz (7.27–8.08 Hz) <em>vs</em> 8.81 Hz (8.35–9.03 Hz), <em>P</em>=0.012, and the volunteer cohort, 8.69 Hz (8.34–8.98 Hz) <em>vs</em> 9.41 Hz (9.11–9.92 Hz), <em>P</em>=0.001. <em>In silico</em> simulations with both computational models suggest that antagonism of HCN2 and glutamatergic excitatory neurotransmission are associated with a reduction in peak alpha frequency.</div></div><div><h3>Conclusions</h3><div>Xenon administration is associated with a reduction of peak alpha frequency in the frontal EEG. <em>In silico</em> simulations utilising two computational models of neurones suggest that these changes are consistent with antagonism of HCN2 and glutamatergic excitatory neurotransmission.</div></div><div><h3>Clinical trial registration</h3><div>The Australian New Zealand Clinical Trials Registry: ANZCTR number 12618000916246.</div></div>","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100358"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BJA openPub Date : 2024-12-01DOI: 10.1016/j.bjao.2024.100361
Andy Yuet Meng Ng, Thomas Emery
{"title":"Moderate or severe pain in recovery after major elective surgery: A pilot retrospective analysis to identify those at risk","authors":"Andy Yuet Meng Ng, Thomas Emery","doi":"10.1016/j.bjao.2024.100361","DOIUrl":"10.1016/j.bjao.2024.100361","url":null,"abstract":"","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100361"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Association between plasma-free haemoglobin and postoperative acute kidney injury in paediatric cardiac surgery: a prospective observational study","authors":"Takanobu Sakura, Tomoyuki Kanazawa, Tatsuhiko Shimizu, Kazuyoshi Shimizu, Tatsuo Iwasaki, Hiroshi Morimatsu","doi":"10.1016/j.bjao.2024.100348","DOIUrl":"10.1016/j.bjao.2024.100348","url":null,"abstract":"<div><h3>Background</h3><div>Acute kidney injury (AKI) is a common complication among patients requiring cardiopulmonary bypass (CPB) during paediatric cardiac surgery. Plasma-free haemoglobin (PFH) produced by haemolysis during CPB contributes to AKI. This study aimed to determine the association between PFH and postoperative AKI during paediatric cardiac surgery requiring CPB.</div></div><div><h3>Methods</h3><div>This prospective, single-centre, observational study included children aged <5 yr who underwent cardiac surgery requiring CPB. PFH was measured pre-CPB, every 30 min during CPB, after modified ultrafiltration, on ICU admission, and once a day at 1–3 days after surgery. The study outcome included the relationship between peak PFH concentrations and the development of postoperative AKI up to 3 days after surgery. Additionally, multivariable analysis was performed to determine the risk factors for AKI.</div></div><div><h3>Results</h3><div>Of 179 patients, 74 (41%) developed postoperative AKI. Patients who developed AKI had significantly higher peak PFH concentrations (80 mg dl<sup>−1</sup> [inter-quartile range, 50–132.5] <em>vs</em> 60 mg dl<sup>−1</sup> [40–100]; <em>P</em>=0.006). Multivariable analysis did not identify peak PFH concentrations as an independent risk factor for postoperative AKI (odds ratio [OR] 1.00; 95% confidence interval [CI]: 0.99–1.00; <em>P</em>=0.268). Factors associated with postoperative AKI were age in months (OR 0.96; 95% CI: 0.94–0.99; <em>P</em>=0.007) and CPB duration (OR 1.02; 95% CI: 1.01–1.02; <em>P</em><0.001).</div></div><div><h3>Conclusions</h3><div>There was an association between postoperative AKI and CPB time rather than PFH. Perioperative peak PFH concentrations were significantly higher in patients with postoperative AKI after paediatric cardiac surgery requiring CPB.</div></div>","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100348"},"PeriodicalIF":0.0,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BJA openPub Date : 2024-10-17DOI: 10.1016/j.bjao.2024.100346
Alexandre Garioud, Michael Seltz Kristensen
{"title":"Oxygen insufflation via the working channel during tracheal intubation guided by a flexible optical scope and benefits, dangers, and future of the method: a narrative review","authors":"Alexandre Garioud, Michael Seltz Kristensen","doi":"10.1016/j.bjao.2024.100346","DOIUrl":"10.1016/j.bjao.2024.100346","url":null,"abstract":"<div><div>When performing tracheal intubation guided by a flexible optical scope, the operator may lose the anatomical orientation and hypoxia may occur. Oxygen insufflation through the working channel of the flexible optical scope is used by anaesthetists to prevent blurring of the lens and to prevent hypoxia. However, fatal iatrogenic injuries from this method are reported. Our aim is to review the current literature on oxygen insufflation through the working channel during tracheal intubation guided by a flexible optical scope, to identify its benefits and the source of its dangers, and ultimately to provide a basis for the development of a safer technique. We conducted a literature search of databases, guidelines, and textbooks using search terms related to oxygen insufflation through the working channel during intubation guided by a flexible optical scope. Clinical trials confirm that the technique results in better visibility and better oxygenation during intubation. Gastric rupture and pneumothorax were the most frequent types of injury. We identified that oxygen insufflation without pressure limitation during accidental misplacement of the flexible optical scope in the oesophagus, deep in the lower airways, or via a tear of the airway mucosa was the cause of barotrauma. We conclude that a delivered pressure below 40 cm H<sub>2</sub>O will likely carry a low risk of serious adverse outcomes. The technique in its current form seems unsafe, and future research should aim at developing a system that delivers oxygen at pressures respecting gastric and airway physiologic pressure thresholds with a flow sufficient to obtain the documented advantages of the technique.</div></div>","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100346"},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BJA openPub Date : 2024-10-14DOI: 10.1016/j.bjao.2024.100345
Jakob Zeuchner , Louise Elander , Jessica Frisk , Michelle S. Chew
{"title":"Incidence and trajectories of subclinical and KDIGO-defined postoperative acute kidney injury in patients undergoing major abdominal surgery","authors":"Jakob Zeuchner , Louise Elander , Jessica Frisk , Michelle S. Chew","doi":"10.1016/j.bjao.2024.100345","DOIUrl":"10.1016/j.bjao.2024.100345","url":null,"abstract":"<div><h3>Background</h3><div>Postoperative acute kidney injury is a common occurrence among patients undergoing major abdominal surgery and is associated with adverse outcomes. The effect of an incremental increase in serum creatinine concentration not meeting the KDIGO criteria for acute kidney injury is poorly studied. We evaluated the incidence and trajectories of postoperative subclinical acute kidney injury (sPO-AKI), acute kidney injury (PO-AKI), acute kidney disease (PO-AKD), and their relationships with chronic kidney disease (CKD), major adverse kidney events (MAKE30), and all-cause mortality at 30 days after surgery.</div></div><div><h3>Methods</h3><div>In a pre-planned, nested cohort sub study of the Myocardial Injury in Noncardiac Surgery in Sweden (MINSS) study, we included 588 patients from two hospitals. We determined the incidence of PO-AKI, PO-AKD, and CKD according to the ADQI-POQI consensus criteria. sPO-AKI was defined as a 25–49% increase in serum creatinine concentration within 7 days of surgery.</div></div><div><h3>Results</h3><div>A total of 59 (10.2%) patients fulfilled the criteria for sPO-AKI, 41 (7.1%) patients for PO-AKI, 29 (6.2%) for PO-AKD, and 6 (1.2%) for CKD. Similar proportions of patients with sPO-AKI and PO-AKI developed PO-AKD. An association was identified between the combined group of sPO-AKI and PO-AKI and 30-day mortality (Cramer's V: 0.1, <em>P</em>=0.037). PO-AKD (Cramer's V: 0.4, <em>P</em><0.001) was associated with MAKE30 and 30-day mortality. All patients with CKD had pre-existing PO-AKD.</div></div><div><h3>Conclusions</h3><div>Subclinical postoperative kidney injury not fulfilling the KDIGO criteria occurred in every 10th patient, and one in 14 suffered from PO-AKI after major abdominal surgery. A majority of PO-AKD cases was preceded by sPO-AKI and PO-AKI. Early kidney injuries were associated with longer-term adverse outcomes including MAKE30, 30-day mortality, and CKD.</div></div>","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100345"},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BJA openPub Date : 2024-10-12DOI: 10.1016/j.bjao.2024.100347
Lichy Han , David A. Purger , Sarah L. Eagleman , Casey H. Halpern , Vivek Buch , Samantha M. Gaston , Babak Razavi , Kimford Meador , David R. Drover
{"title":"Deep learning models using intracranial and scalp EEG for predicting sedation level during emergence from anaesthesia","authors":"Lichy Han , David A. Purger , Sarah L. Eagleman , Casey H. Halpern , Vivek Buch , Samantha M. Gaston , Babak Razavi , Kimford Meador , David R. Drover","doi":"10.1016/j.bjao.2024.100347","DOIUrl":"10.1016/j.bjao.2024.100347","url":null,"abstract":"<div><h3>Background</h3><div>Maintaining an appropriate depth of anaesthesia is important for avoiding adverse effects from undermedication or overmedication during surgery. Electroencephalography (EEG) has become increasingly used to achieve this balance. Investigating the predictive power of intracranial EEG (iEEG) and scalp EEG for different levels of sedation could increase the utility of EEG monitoring.</div></div><div><h3>Methods</h3><div>Simultaneous iEEG, scalp EEG, and Observer's Assessment of Alertness/Sedation (OAA/S) scores were recorded during emergence from anaesthesia in seven patients undergoing placement of intracranial electrodes for medically refractory epilepsy. A deep learning model was constructed to predict an OAA/S score of 0–2 <em>vs</em> 3–5 using iEEG, scalp EEG, and their combination. An additional five patients with only scalp EEG data were used for independent validation. Models were evaluated using the area under the receiver-operating characteristic curve (AUC).</div></div><div><h3>Results</h3><div>Combining scalp EEG and iEEG yielded significantly better prediction (AUC=0.795, <em>P</em><0.001) compared with iEEG only (AUC=0.750, <em>P</em>=0.02) or scalp EEG only (AUC=0.764, <em>P</em><0.001). The validation scalp EEG only data resulted in an AUC of 0.844. Combining the two modalities appeared to capture spatiotemporal advantages from both modalities.</div></div><div><h3>Conclusions</h3><div>The combination of iEEG and scalp EEG better predicted sedation level than either modality alone. The scalp EEG only model achieved a similar AUC to the combined model and maintained its performance in additional patients, suggesting that scalp EEG models are likely sufficient for real-time monitoring. Deep learning approaches using multiple leads to capture a wider area of brain activity may help augment existing EEG monitors for prediction of sedation.</div></div>","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100347"},"PeriodicalIF":0.0,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BJA openPub Date : 2024-10-05DOI: 10.1016/j.bjao.2024.100349
Thomas Payne , Jennifer Taylor , David Kunkel , Katherine Konieczka , Frankie Ingram , Kaj Blennow , Henrik Zetterberg , Robert A. Pearce , Anke Meyer-Franke , Niccolò Terrando , Katerina Akassoglou , Robert D. Sanders , Richard C. Lennertz
{"title":"Association of preoperative to postoperative change in cerebrospinal fluid fibrinogen with postoperative delirium","authors":"Thomas Payne , Jennifer Taylor , David Kunkel , Katherine Konieczka , Frankie Ingram , Kaj Blennow , Henrik Zetterberg , Robert A. Pearce , Anke Meyer-Franke , Niccolò Terrando , Katerina Akassoglou , Robert D. Sanders , Richard C. Lennertz","doi":"10.1016/j.bjao.2024.100349","DOIUrl":"10.1016/j.bjao.2024.100349","url":null,"abstract":"<div><h3>Background</h3><div>We aimed to assess perioperative changes in fibrinogen in the cerebrospinal fluid (CSF), their association with markers of blood–brain barrier breakdown and neuroinflammation, and their association with postoperative delirium severity.</div></div><div><h3>Methods</h3><div>We conducted a secondary analysis of the Interventions for Postoperative Delirium-Biomarker 2 (IPOD-B2, NCT02926417) study, a prospective observational cohort study. We included 24 patients aged >21 yr undergoing aortic aneurysm repair. CSF samples were obtained before (<em>n</em>=24) and after surgery (<em>n</em>=13), with some participants having multiple postoperative samples. Our primary outcome was the perioperative change in CSF fibrinogen. Delirium was assessed using the Delirium Rating Scale-Revised-98.</div></div><div><h3>Results</h3><div>CSF fibrinogen increased after surgery (<em>P</em><0.001), and this was associated with an increase in CSF/plasma albumin ratio (β=1.09, 95% CI 0.47–1.71, <em>P</em>=0.004). The peak change in CSF fibrinogen was associated with the change in CSF interleukin (IL)-10 and IL-12p70. The peak change in CSF fibrinogen was associated with the change in CSF total tau (β=0.47, 95% CI 0.24–0.71, <em>P</em>=0.002); however, we did not observe an association with postoperative delirium severity (incidence rate ratio = 1.20, 95% CI 0.66–2.17, <em>P</em>=0.540).</div></div><div><h3>Conclusions</h3><div>Our preliminary findings support the hypothesis that fibrinogen enters the brain via blood-brain barrier disruption, promoting neuroinflammation and neuronal injury. However, we did not observe an association between cerebrospinal fluid fibrinogen and peak delirium severity in this limited cohort.</div></div>","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100349"},"PeriodicalIF":0.0,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BJA openPub Date : 2024-10-01DOI: 10.1016/j.bjao.2024.100316
A. Phillips, F. Breckenridge
{"title":"Impact of introduction of point-of-care viscoelastic testing on transfusion practice in major obstetric haemorrhage","authors":"A. Phillips, F. Breckenridge","doi":"10.1016/j.bjao.2024.100316","DOIUrl":"10.1016/j.bjao.2024.100316","url":null,"abstract":"","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100316"},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Incidence of early postoperative cognitive dysfunction and overall patient and surgical risks in older patients undergoing cardiac surgery","authors":"Chyanis Vongseenin, Nicha Wongratanakarn, Wacharin Sindhvananda","doi":"10.1016/j.bjao.2024.100317","DOIUrl":"10.1016/j.bjao.2024.100317","url":null,"abstract":"","PeriodicalId":72418,"journal":{"name":"BJA open","volume":"12 ","pages":"Article 100317"},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}