Predicting postoperative complications with the respiratory exchange ratio after high-risk noncardiac surgery: A prospective cohort study BACKGROUND The respiratory exchange ratio (RER), defined as the ratio of CO2 production (VCO2) to O2 consumption (VO2), is reported to be a noninvasive marker of anaerobic metabolism. The intubated, ventilated patient's inspired and expired fractions of O2 and CO2 (FiO2, FeO2, FiCO2 and FeCO2) are monitored in the operating room and can be used to calculate RER. OBJECTIVE To investigating the ability of the RER to predict postoperative complications. DESIGN An observational, prospective study. SETTING Two French university hospitals between March 2017 and September 2018. PATIENTS A total of 110 patients undergoing noncardiac high-risk surgery. MAIN OUTCOME MEASURES The RER was calculated as (FeCO2 − FiCO2)/(FiO2 − FeO2) at five time points during the operation. The primary endpoint was at the end of the surgery. The secondary endpoints were systemic oxygenation indices (pCO2 gap, pCO2 gap/arteriovenous difference in O2 ratio, central venous oxygen saturation) and the arterial lactate level at the end of the surgery. Complications were classified according to the European Peri-operative Clinical Outcome definitions. RESULTS Postoperative complications occurred in 35 patients (34%). The median [interquartile range] RER at the end of surgery was significantly greater in the subgroup with complications, 1.06 [0.84 to 1.35] than in the subgroup without complications, 0.81 [0.75 to 0.91], and correlated significantly with the arterial lactate (r = 0.31, P < 0.001) and VO2 (r = −0.23, P = 0.001). Analysis of the area under the receiver operating characteristic curve for the predictive value of RER for postoperative complications revealed a value of 0.77 [95% confidence interval (CI) 0.69 to 0.88, P = 0.001]. The best cut-off for the RER was 0.94, with a sensitivity of 71% (95% CI 54 to 85) and a specificity of 79% (95% CI 68 to 88). CONCLUSION As a putative noninvasive marker of tissue hypoperfusion and anaerobic metabolism, the RER can be used to predict complications following high-risk surgery. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT03471962. Correspondence to Stéphane Bar, Anaesthesiology and Critical Care Department, Amiens University Hospital, Rond-Point Fernand Leger, F-80054 Amiens, France Tel: +33 621841562; e-mail: stephane.bar.sb@gmail.com Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (www.ejanaesthesiology.com). © 2019 European Society of Anaesthesiology

Preventive effect of dexmedetomidine on postictal delirium after electroconvulsive therapy: A randomised controlled study BACKGROUND Postictal delirium (PID) is a relatively common complication following electroconvulsive therapy (ECT). OBJECTIVE We investigated whether prophylactic dexmedetomidine administration would safely decrease the incidence of PID in psychiatric patients after ECT. DESIGN A randomised, double-blind, placebo-controlled trial. PATIENTS A total of 223 patients undergoing ECT were randomly allocated to two groups. INTERVENTIONS Patients received 0.5 μg kg−1 dexmedetomidine (Dex group, n=111) or 0.9% sodium chloride (Con group, n=112) before ECT. Propofol was used for anaesthesia and succinylcholine for muscle relaxation. The incidence of PID was measured using the Confusion Assessment Method for the Intensive Care Unit. MAIN OUTCOME MEASURES The percentage of patients who were diagnosed with PID at any ECT session during the whole treatment. RESULTS PID occurred in 76 (67.9%) of 112 patients given saline (0.9% sodium chloride), and in 49 (44.1%) of 111 patients given dexmedetomidine during the whole treatment. There was a significant difference in the incidence of PID between two groups (P < 0.001). Post hoc analyses showed that the incidence of PID was significantly lower in the Dex group than in the Con group from the first to the seventh ECT session (P < 0.005). There were no significant differences in seizure duration or recovery time between the two groups. Heart rate and mean arterial pressure in the Dex group were significantly lower than in the Con group at 0, 5 and 15 min after electrical stimulation. No patients developed bradycardia, hypotension or respiratory depression during recovery. CONCLUSION Pretreatment with dexmedetomidine leads to a significant reduction in the incidence of PID with no respiratory depressant effect. Dexmedetomidine might be considered an effective method for the prevention of PID post-ECT. TRIAL REGISTRATION Chinese Clinical Trial Registry ChiCTR-IOR-17012306. Correspondence to Xiang Li, PhD, Department of Anesthesiology, The Third Affiliated Hospital, Sun Yat-sen University, No. 600, Tianhe Road, Tianhe Sistrict, 510630 Guangzhou, China Tel: +86 20 85253132; e-mail: lixiang27@mail.sysu.edu.cn Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (www.ejanaesthesiology.com). © 2019 European Society of Anaesthesiology

Hypoxia, hypercarbia, and mortality reporting in studies of anaesthesia-related neonatal neurodevelopmental delay in rodent models: A systematic review BACKGROUND The concept of anaesthesia-related neonatal neurotoxicity originated in neonatal rodent models, yet prospective clinical studies have largely not supported this concern. OBJECTIVES To determine the frequency and magnitude of hypercarbia, hypoxia and death in rodent models of neonatal anaesthetic toxicity and neurodevelopmental delay. DESIGN Systematic review of published rodent studies of neonatal anaesthesia neurotoxicity. We documented anaesthetic, route, dose, frequency and duration of exposures. We further report ventilation method, documentation of adequacy of ventilation [arterial blood gas (ABG), other], mortality and the reporting of mortality. DATA SOURCES A PubMed literature search from 2003 to 2017 was conducted to identify studies on neurotoxicity in neonatal rodent models. ELIGIBILITY Studies were included when at least one group of animals fell within the postnatal age range of 3 to 15 days. Only English language original studies published as full-length articles in peer reviewed journals were included in the final analysis. RESULTS One hundred and three manuscripts were included. Ninety-eight percent of studies were conducted using spontaneous ventilation (101/103), with ABG monitoring used in only 33% of studies and visual monitoring alone for respiratory distress or cyanosis was employed in 60%. Of the 33% who reported ABG results, there were widely divergent values, with most reporting modest-to-severe hypercarbia. Mortality (median 11%, range of 0 to 40%), which infers severe hypoxia, was documented in only 36/103 (35%) reports. CONCLUSION Hypoxia and hypercarbia have known apoptotic effects on developing brains. Hence, the inadequate control of hypercarbia and hypoxia in neonatal rodent models of anaesthetic exposure during spontaneous ventilation suggests that the evidence for developmental delay and neurotoxicity attributed to anaesthesia may not be valid in humans. Correspondence to Thomas F. Floyd, Department of Anesthesiology and Pain Management, The University of Texas Southwestern, 5323 Harry Hines Blvd, Dallas, TX 75390-9068, USA Tel: +1 469 900 5509; e-mail: thomas.floyd@utsouthwestern.edu © 2019 European Society of Anaesthesiology

Intranasal dexmedetomidine premedication in children with recent upper respiratory tract infection undergoing interventional cardiac catheterisation: A randomised controlled trial BACKGROUND Recent upper respiratory tract infection (URI) is a risk factor for the occurrence of peri-operative respiratory adverse events (PRAE). This risk may be higher in children with congenital heart disease (CHD), particularly in those undergoing interventional cardiac catheterisation. It is therefore essential to adapt the anaesthetic strategy in these children to prevent from the occurrence of PRAE. OBJECTIVE To determine whether intranasal dexmedetomidine (DEX) premedication can reduce the incidence of PRAE in children with recent URI undergoing interventional cardiac catheterisation. DESIGN Randomised controlled trial. SETTING Single-centre study based at a tertiary care centre in Shanghai, China. PATIENTS A total of 134 children with CHD aged 0 to 16 years with recent URI undergoing interventional cardiac catheterisation. INTERVENTIONS Children were randomised to receive either intranasal DEX 1.5 μg kg−1 (DEX group) or intranasal saline (Placebo group) 30 to 45 min before anaesthesia induction. MAIN OUTCOME MEASURES The incidence of PRAE. RESULTS Intranasal DEX significantly reduced the incidence of PRAE (P = 0.001), particularly oxygen desaturation (P = 0.012). Most PRAE were observed during the emergence phase. The incidence of PRAE was comparable among the three types of left–right shunt CHD children in both groups. In children aged less than 3 years, the incidence of PRAE was significantly lower in the DEX group (P = 0.003). In contrast, the incidence of PRAE was comparable between the two groups in children aged at least 3 years. No differences in the incidence of emergence agitation, fever and vomiting between the two groups were noted. CONCLUSION Administration of intranasal DEX 1.5 μg kg−1 30 to 45 min before induction led to a reduction in the incidence of PRAE in children aged less than 3 years with recent URI undergoing interventional cardiac catheterisation. TRIAL REGISTRATION chictr.org.cn identifier: ChiCTR-RRC-17012519. Correspondence to Jijian Zheng, MD, PhD, Department of Anaesthesiology, Shanghai Children's Medical Centre, School of Medicine, Shanghai Jiao Tong University, Shanghai, China Tel: +86 18964853803; fax: +86 021 38626161; e-mail: zhengjijian626@sina.com © 2019 European Society of Anaesthesiology

Anaesthesiology: a problem-based learning approach No abstract available

A comparison between the flexor hallucis brevis and adductor pollicis muscles in atracurium-induced neuromuscular blockade using acceleromyography: A prospective observational study BACKGROUND Neuromuscular blockade (NMB) monitoring is essential to avoid residual NMB. While the adductor pollicis is the recommended site for monitoring recovery, it is not always accessible. The flexor hallucis brevis could be an interesting alternative. OBJECTIVE The aim of our study was to compare NMB onset and recovery at both sites. DESIGN Prospective observational study. SETTING Operating rooms at the University Hospital of Poitiers, France. PATIENTS Sixty patients scheduled for surgery under general anaesthesia with neuromuscular blocking agents were enrolled from January 2016 to September 2017. Data from 56 patients were finally analysed. Among these, 11 patients received pharmacological reversal with neostigmine and atropine before emergence from anaesthesia. INTERVENTION After atracurium injection, NMB onset and recovery at the adductor pollicis and flexor hallucis brevis were monitored simultaneously. MAIN OUTCOME MEASURES The time to NMB onset, defined as a train-of-four (TOF) count equal to 0, and the times to NMB recovery: TOF = 1, TOF = 4, T4/T1 ratio = 0.75 and T4/T1 ratio more than 0.90. RESULTS NMB onset was significantly slower at the flexor hallucis brevis with a mean onset time of 4.4 ± 1.5 versus 3.7 ± 1.2 min at adductor pollicis (P = 0.0001). Recovery to TOF = 1 was significantly slower at flexor hallucis brevis. No difference was found for TOF = 4. The full recovery of NMB (T4/T1 > 0.90) was significantly faster at flexor hallucis brevis with a mean time to recovery of 59.5 ± 9.9 versus 64.5 ± 10.7 min at adductor pollicis (P < 0.0001), a difference of 4.9 min between both sites. This difference was not present after pharmacological reversal with a mean time to recovery of 53.0 ± 12.2 min at flexor hallucis brevis versus 54.0 ± 12.4 min at adductor pollicis (P = 0.28). However, NMB onset and recovery did not follow the same pattern in individual patients. CONCLUSION Flexor hallucis brevis could be an interesting alternative site for NMB monitoring when the adductor pollicis is not accessible. However, in the absence of pharmacological reversal, monitoring at the hallucis brevis muscle should be used with caution for the detection of residual paralysis. TRIAL REGISTRATION ClinicalTrials.gov (NCT02825121). Correspondence to Matthieu Boisson, Service d’anesthésie-réanimation, CHU de Poitiers, 2 rue de la Milétrie, 86021 Poitiers Cedex, France E-mail: matthieu.boisson@chu-poitiers.fr © 2019 European Society of Anaesthesiology

Fibrinolytic shutdown diagnosed with rotational thromboelastometry represents a moderate form of coagulopathy associated with transfusion requirement and mortality: A retrospective analysis BACKGROUND Viscoelastic techniques have made it possible to describe specific fibrinolytic phenotypes (physiological, hyperfibrinolysis and shutdown) and to establish a relationship of these phenotypes with outcome. However, there remains a debate as to whether shutdown is a state of hypercoagulability or rather a coagulopathy with moderate fibrinolysis and fibrinogen consumption. OBJECTIVES Our objectives were to describe the relationship between fibrinolytic phenotypes and outcomes, and to report the effects of tranexamic acid (TXA) administration. DESIGN This was a retrospective analysis of prospectively acquired data from a trauma registry. SETTING An academic level 1 trauma centre in the Lyon Region, from March 2011 to December 2016. PATIENTS We included all injured patients who had a rotational thromboelastometry analysis at admission. Fibrinolytic phenotypes were determined according to the maximum lysis: shutdown less than 3%, physiological 3 to 15%, hyperfibrinolysis more than 15%. MAIN OUTCOME MEASURE Mortality at 24 h and at hospital discharge. RESULTS During the study period, 473 patients were included with the following phenotypes: physiological (344 patients, 73%), shutdown (107 patients, 23%) and hyperfibrinolysis (22 patients, 5%). There was an increase in injury severity, prothrombin time ratio, fibrin degradation products and transfusion requirements from the physiological to the shutdown and hyperfibrinolysis phenotypes. Prehospital TXA administration increased the rate of shutdown and decreased the maximum lysis value at admission. After adjustment, multivariate analysis showed that fibrinolytic phenotypes, but not TXA, were independently associated with an increased risk of early death and death before hospital discharge: shutdown [odds ratio (95% confidence interval)] 2.4 (1.2 to 4.8) and hyperfibrinolysis 67.9 (7.4 to 624.2). CONCLUSION The results of the current study suggest that shutdown, which is associated with injury severity and mortality, probably reflects a moderate form of coagulopathy and fibrinolysis rather than a hypercoagulopathy. Therefore, the observation of shutdown fibrinolysis on thromboelastography/rotational thromboelastometry should not lead to withholding but rather to the administration of TXA. Correspondence to Jean-Stephane David, Département d’Anesthésie Réanimation, Centre Hospitalier Lyon Sud, F-69495 Lyon, France E-mail: js-david@univ-lyon1.fr © 2019 European Society of Anaesthesiology

A novel method for ultrasound-guided radial artery cannulation in neonates by trainee anaesthesiologists: A randomised controlled trial BACKGROUND The modified dynamic needle tip positioning (MDNTP) technique for ultrasound-guided radial artery cannulation (MDNTP-US technique) in neonates can be technically challenging for trainee anaesthesiologists. We hypothesised that by associating the MDNTP-US technique with hypodermic 0.9% sodium chloride (Saline MDNTP-US technique), which increases the subcutaneous radial artery depth, the procedure would become easier for trainee anaesthesiologists. OBJECTIVE To compare the Saline MDNTP-US technique, with the MDNTP-US technique for radial artery catheterisation in neonates by trainee anaesthesiologists with limited experience. DESIGN Randomised controlled trial. PATIENTS Ninety-six neonates scheduled to undergo major abdominal surgery requiring continuous arterial pressure monitoring between May 2018 and December 2018 at the Children's Hospital of Chongqing Medical University were enrolled. Neonates with signs of skin erosions or haematomas at or near the insertion site, as well as those with low noninvasive blood pressure values, were excluded. INTERVENTION Neonates were randomised to the Saline MDNTP-US and MDNTP-US groups in a 1 : 1 ratio. Twelve trainees performed the cannulation procedures. MAIN OUTCOME MEASURES Duration of procedure, first attempt success rate, rate of success within 10 min, and the incidence of haematoma and thrombosis. RESULTS The median [IQR] time to perform cannulation was less for the Saline MDNTP-US technique than for the MDNTP-US technique: 203 [160 to 600] vs. 600 s [220 to 600]; P = 0.005. The rate of success within 10 min, 72.9 vs. 47.9%; P = 0.012, was higher in the Saline MDNTP-US group than in the MDNTP-US group. The incidence of haematoma on postoperative day 1 was lower in the Saline MDNTP-US group than in the MDNTP-US group: 8.3 vs. 22.9%; P = 0.049. CONCLUSION Trainee anaesthesiologists can achieve higher success rates by using the Saline MDNTP-US technique instead of the MDNTP-US technique for radial artery catheterisation in neonates, taking less time with a lower incidence of complications. TRIAL REGISTRATION ChiCTR-IOR-17014119 (Chinese Clinical Trial Registry). Correspondence to Dr Lifei Liu, Department of Anesthesiology, Children's Hospital of Chongqing Medical University, 136 Zhongshan Er Road, Yu Zhong District, Chongqing 400014, PR China Tel: +86 18996218065; fax: +86 2363632143; e-mail: lifeiliu@hospital.cqmu.edu.cn © 2019 European Society of Anaesthesiology

Incidence and risk factors of postoperative delirium in patients admitted to the ICU after elective intracranial surgery: A prospective cohort study BACKGROUND Postoperative delirium (POD) has been confirmed as an important complication after major surgery. However, neurosurgical patients have usually been excluded in previous studies. To date, data on POD and risk factors in patients after intracranial surgery are scarce. OBJECTIVES To determine the incidence and risk factors of POD in patients after intracranial surgery. DESIGN Prospective cohort study. SETTING A neurosurgical ICU of a university-affiliated hospital, Beijing, China. INTERVENTIONS Adult patients admitted to the ICU after elective intracranial surgery under general anaesthesia were consecutively enrolled between 1 March 2017 and 2 February 2018. Delirium was assessed using the Confusion Assessment Method for the ICU. POD was diagnosed as Confusion Assessment Method for the ICU positive on either postoperative day 1 or day 3. Patients were classified into groups with or without POD. Data were collected for univariate and multivariate analyses to determine the risk factors for POD. RESULTS A total of 800 patients were included. POD was diagnosed in 157 patients (19.6%, 95% confidence interval 16.9 to 22.4%). Independent risk factors for POD included age, nature of intracranial lesion, frontal approach craniotomy, duration of surgery, presence of an episode of low pulse oxygenation at ICU admission, presence of inadequate emergence and emergence delirium, postoperative pain and presence of immobilising events. POD was associated with adverse outcomes and high costs. CONCLUSION POD is prevalent in patients after elective intracranial surgery. The identified risk factors for and the potential association of POD with adverse outcomes suggest that a comprehensive strategy involving screening for predisposing factors and early prevention of modifiable factors should be established in this population. TRIAL REGISTRATION The study was registered at ClinicalTrials.gov (NCT03087838). Correspondence to Jian-Xin Zhou, Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, No 6, Tiantan Xili, Dongcheng District, Beijing 100050, China Tel: +86 10 67098019; fax: +86 10 67098019; e-mail: zhoujx.cn@icloud.com Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (www.ejanaesthesiology.com). © 2019 European Society of Anaesthesiology

Comparison of neostigmine vs. sugammadex for recovery of muscle function after neuromuscular block by means of diaphragm ultrasonography in microlaryngeal surgery: A randomised controlled trial BACKGROUND Postoperative residual neuromuscular blockade or curarisation (PORC) is a risk directly related to the use of neuromuscular blocking agents during surgical procedures. Acceleromyography is distressing for conscious patients when assessing PORC. Diaphragm ultrasonography could be a valid alternative. OBJECTIVES The primary objective was to achieve a 28% lower incidence of PORC in patients who, after rocuronium administration, received neostigmine or sugammadex at 30 min after surgery. To assess PORC, diaphragm ultrasonography was used, and thickening fractioning [the difference of thickness at the end of inspiration (TEI) and at the end of expiration (TEE), normalised for TEE (TEI − TEE/TEE)] was measured. PORC was defined as thickening fractioning of 0.36 or less. The secondary object was the comparison, in the two treatment groups, of the return to baseline thickening fractioning at 30 min after surgery (ΔTF30). DESIGN Prospective, double-blind, single-centre randomised study. SETTING University Hospital Careggi, Florence, Italy. PATIENTS Patients of American Society Anesthesiologists’ physical status 1 or 2, 18 to 80 years, receiving rocuronium during microlaryngeal surgery. INTERVENTIONS At the end of surgery participants were randomised to receive neostigmine (NEO group) or sugammadex (SUG group) as the reversal drug. Thickening fractioning and ΔTF30 were evaluated at baseline and at 0, 10 and 30 min after surgery. MAIN OUTCOME MEASURES TEE and TEI at each time point. RESULTS A total of 59 patients with similar demographic characteristics were enrolled. An association between lack of recovery (thickening fractioning ≤0.36) and drug treatment was only observed at 0 min (SUG vs. NEO, P < 0.05). Concerning ΔTF, at 30 min more patients in the SUG group returned to baseline than those in the NEO group (P < 0.001), after adjusting for side (P = 0.52), baseline thickening fractioning (P < 0.0001) and time of measurement (P < 0.01). CONCLUSION We found an early (0 min) but not long-lasting (30 min) association between diaphragm failure and treatment allocation; a full recovery in baseline diaphragm function was observed only in patients receiving sugammadex. We cannot exclude that further differences have not been found due to interpatients variability in assessing diaphragm contractility by ultrasonography. TRIAL REGISTRATION EudraCT Identifier: 2013-004787-62, Clinicaltrials.gov Identifier: NCT02698969. Correspondence to Iacopo Cappellini, Section of Anesthesiology and Intensive Care, Department of Health Sciences, University of Florence, Largo Brambilla 3, 50134 Florence, Italy E-mail: jacopocappellini@gmail.com © 2019 European Society of Anaesthesiology