Dexmedetomidine for adult cardiac surgery: a systematic review,meta-analysis and trial sequential analysis

The effects of dexmedetomidine in adults undergoing cardiac surgery are inconsistent. We conducted a systematic review and meta-analysis to analyse the effects of peri-operative dexmedetomidine in adults undergoing cardiac surgery. We searched MEDLINE via Pubmed, EMBASE, Scopus and Cochrane for relevant randomised controlled trials between 1 January 1990 and 1 March 2022. We used the Joanna Briggs Institute methodology checklist to assess study quality and the GRADE approach to certainty of evidence. We assessed the sensitivity of results to false data. We used random-effects meta-analyses to analyse the primary outcomes: durations of intensive care and tracheal intubation. We included 48 trials of 6273 participants. Dexmedetomidine reduced the mean (95%CI) duration of intensive care by 5.0 (2.2–7.7) h, p = 0.001, and tracheal intubation by 1.6 (0.6–2.7) h, p = 0.003. The relative risk (95%CI) for postoperative delirium was 0.58 (0.43–0.78), p = 0.001; 0.76 (0.61–0.95) for atrial fibrillation, p = 0.015; and 0.49 (0.25–0.97) for short-term mortality, p = 0.041. Bradycardia and hypotension were not significantly affected. Trial sequential analysis was consistent with the primary meta-analysis. Adjustments for possible false data reduced the mean (95%CI) reduction in duration of intensive care and tracheal intubation by dexmedetomidine to 3.6 (1.8–5.4) h and 0.8 (0.2–1.4) h, respectively. Binary adjustment for methodological quality at a Joanna Briggs Institute score threshold of 10 did not alter the results significantly. In summary, peri-operative dexmedetomidine reduced the durations of intensive care and tracheal intubation and the incidence of short-term mortality after adult cardiac surgery. The reductions in intensive care stay and tracheal intubation may or may not be considered clinically useful, particularly after adjustment for possible false data.     

The effect of intraoperative dexmedetomidine administration on length of stay in the post-anesthesia care unit in ambulatory surgery: A hospital registry study

Study objectiveDexmedetomidine, which is commonly used for procedural sedation and as adjunct to general anesthesia for ambulatory procedures, may affect patient discharge from the post-anesthesia care unit (PACU). We hypothesized that intraoperative dexmedetomidine use in ambulatory surgery is associated with delayed discharge from the PACU and that this is modified by surgical duration and anesthesia type.DesignRetrospective cohort study.SettingAcademic medical center.Patients130,854 adult patients undergoing ambulatory surgery between 2008 and 2018.InterventionsIntraoperative administration of dexmedetomidine.MeasurementsThe primary outcome was PACU length of stay. In secondary and exploratory analyses, we examined dose-dependency, effect modification by duration of surgery and anesthesia type, effects of timing of dexmedetomidine administration, and PACU discharge delays.Main resultsDexmedetomidine was associated with a prolonged PACU length of stay (adjusted absolute difference [AD_adj] 15.0 min; 95%CI 12.7–17.3; p < 0.001). This effect was dose-dependent (p-for-trend < 0.001), magnified in surgeries of less than one hour (AD_adj 20.7 min; 95%CI 16.7–24.7; p < 0.001) and in patients undergoing monitored anesthesia care compared to general anesthesia (AD_adj 16.8 min; 95%CI 14.1–19.6; p < 0.001). The effect was more pronounced if dexmedetomidine was administered within the last 60 min of surgery (AD_adj 18.7 min; 95%CI 15.7–21.7; p < 0.001). Dexmedetomidine was associated with discharge delays due to cardiovascular complications (OR_adj 2.27; 95%CI 1.59–3.24; p < 0.001) and over-sedation (OR_adj 1.28; 95%CI 1.11–1.48; p < 0.001). In patients who received dexmedetomidine (n = 2901), the use of bolus doses only versus the combination of bolus and infusions, magnified the effects on PACU length of stay (AD_adj 29.5 min per μg/kg; 95%CI 17.3–41.8 versus 18.1 min per μg/kg; 95%CI 11.4–24.8; p < 0.001).ConclusionsThe intraoperative administration of dexmedetomidine was dose-dependently associated with a prolonged PACU length of stay. Clinicians should judiciously titrate dexmedetomidine, especially when using this long-acting drug for monitored anesthesia care for shorter procedures.     

Right ventricular failure after implantation of continuous flow left ventricular assist device: analysis of predictors and outcomes

Postoperative right ventricular failure is a serious complication for up to 50% of patients following LVAD insertion. Predicting RV failure is an important factor for patients as planned BiVAD support has been shown to correlate with better outcomes compared to delayed BiVAD to LVAD conversion. This retrospective study examined prospectively collected data for 101 patients implanted with an LVAD between 2003 and 2013, aiming to establish preoperative predictive factors for RVF post‐LVAD insertion, analyze outcomes, and validate existing RVF scoring systems. In our cohort, 63 patients (62.4%) developed RV failure and consequently demonstrated consistently poorer survival throughout the follow‐up period (log‐rank p = 0.01). Multivariable logistic regression identified two significant variables: cardiac index <2.2 preoperatively despite inotropic support (OR 4.6 [95%CI 1.8–11.8]; p = 0.001) and preoperative tricuspid regurgitation (OR 8.1 [95%CI 1.9–34]; p = 0.004). Patients who developed RV failure had more complicated postoperative courses including longer ICU stay (p < 0.001), higher incidence of transfusions (p = 0.03) and re‐intubation (p = 0.001), longer ventilation duration (p < 0.001), and higher incidence of returning to theater (p = 0.0008). This study found that previous validation models had only moderate correlation with our population emphasizing the need for prospective validation of these scores in the current era of continuous flow devices.     

Association between anaesthetic technique and unplanned admission to intensive care after thoracic lung resection surgery: the second Association of Cardiothoracic Anaesthesia and Critical Care (ACTACC) National Audit

Unplanned intensive care admission is a devastating complication of lung resection and is associated with significantly increased mortality. We carried out a two-year retrospective national multicentre cohort study to investigate the influence of anaesthetic and analgesic technique on the need for unplanned postoperative intensive care admission. All patients undergoing lung resection surgery in 16 thoracic surgical centres in the UK in the calendar years 2013 and 2014 were included. We defined critical care admission as the unplanned need for either tracheal intubation and mechanical ventilation or renal replacement therapy, and sought an association between mode of anaesthesia (total intravenous anaesthesia vs. volatile) and analgesic technique (epidural vs. paravertebral) and need for intensive care admission. A total of 253 out of 11,208 patients undergoing lung resection in the study period had an unplanned admission to intensive care in the postoperative period, giving an incidence of intensive care unit admission of 2.3% (95%CI 2.0–2.6%). Patients who had an unplanned admission to intensive care unit had a higher mortality (29.00% vs. 0.03%, p < 0.001), and hospital length of stay was increased (26 vs. 6 days, p < 0.001). Across univariate, complete case and multiple imputation (multivariate) models, there was a strong and significant effect of both anaesthetic and analgesic technique on the need for intensive care admission. Patients receiving total intravenous anaesthesia (OR 0.50 (95%CI 0.34–0.70)), and patients receiving epidural analgesia (OR 0.56 (95%CI 0.41–0.78)) were less likely to have an unplanned admission to intensive care after thoracic surgery. This large retrospective study suggests a significant effect of both anaesthetic and analgesic technique on outcome in patients undergoing lung resection. We must emphasise that the observed association does not directly imply causation, and suggest that well-conducted, large-scale randomised controlled trials are required to address these fundamental questions.     

The effect of a multidisciplinary care bundle on the incidence of delirium after hip fracture surgery: a quality improvement study

Delirium is a common complication following hip fracture surgery. We introduced a peri-operative care bundle that standardised management in the emergency department, operating theatre and ward. This incorporated: use of fascia iliaca blocks; rationalisation of analgesia; avoidance of drugs known to trigger delirium; a regular education program for staff; and continuous auditing of compliance. The study was conducted between June 2017 and December 2018. We recruited 150 patients before (control group) and 150 patients after (care bundle group) the introduction of the care bundle. In patients having surgery for a hip fracture, there was a lower incidence of delirium on the third postoperative day in the care bundle group compared with the control group (33 patients (22%) vs. 49 patients (33%)), respectively; p = 0.04). Patients in the care bundle group had an adjusted OR of 2.2 (95%CI 1.1–4.4) (p = 0.03) for the avoidance of delirium on the third postoperative day. There was no difference between groups for the secondary outcome measures (measured at 30 days postoperatively) including: all-cause mortality; composite morbidity; institutionalisation; and walking status. During the study period, compliance with elements of the care bundle improved in the emergency department (49 patients (33%) compared with 85 patients (59%); p < 0.001) and anaesthetic department (40 patients (27%) compared with 104 patients (69%); p < 0.001), while orthogeriatrics maintained a high level of compliance (140 patients (93%) compared with 143 patients (95%); p = 0.45). There was a clinically and statistically significant reduction in the incidence of delirium following hip fracture surgery in patients treated with a multidisciplinary care bundle.     

A randomised controlled trial of dexmedetomidine for delirium in adults undergoing heart valve surgery

Dexmedetomidine might reduce delirium after cardiac surgery. We allocated 326 participants to an infusion of dexmedetomidine at a rate of 0.6 μg kg⁻¹ for 10 min and then at 0.4 μg.kg⁻¹.h⁻¹ until the end of surgery; 326 control participants received comparable volumes of saline. We detected delirium in 98/652 (15%) participants during the first seven postoperative days: 47/326 after dexmedetomidine vs. 51/326 after placebo, p = 0.62, adjusted relative risk (95%CI) 0.86 (0.56–1.33), p = 0.51. Postoperative renal impairment (Kidney Disease Improving Global Outcomes stages 1, 2 and 3) was detected in 46, 9 and 2 participants after dexmedetomidine and 25, 7 and 4 control participants, p = 0.040. Intra-operative dexmedetomidine infusion did not reduce the incidence of delirium after cardiac valve surgery but might impair renal function.     

Incidence of severe critical events in paediatric anaesthesia in the United Kingdom: secondary analysis of the anaesthesia practice in children observational trial (APRICOT study)

The anaesthesia practice in children observational trial of 31,127 patients in 261 European hospitals revealed a high (5.2%) incidence of severe critical events in the peri-operative period and wide variability in practice. A sub-analysis of the UK data was undertaken to investigate differences compared with the non-UK cohort in the incidence and nature of peri-operative severe critical events and to attempt to identify areas for quality improvement. In the UK cohort of 7040 paediatric patients from 43 hospitals, the overall incidence of peri-operative severe critical events was lower than in the non-UK cohort (3.3%, 95%CI: 2.9–3.8 vs. 5.8%, 95%CI: 5.5–6.1, RR 0.57, p < 0.001). There was a lower rate of bronchospasm (RR 0.22, 95%CI: 0.14–0.33; p < 0.001), stridor (RR 0.42, 95%CI: 0.28–0.65; p < 0.001) and cardiovascular instability (RR 0.69, 95%CI: 0.55–0.86; p = 0.001) than in the non-UK cohort. The proportion of sicker patients where less experienced teams were managing care was lower in the UK than in the non-UK cohort (10.4% vs. 20.4% of the ASA physical status 3 and 9% vs. 12.9% of the ASA physical status 4 patients). Differences in work-load between centres did not affect the incidence and outcomes of severe critical events when stratified for age and ASA physical status. The lower incidence of cardiovascular and respiratory complications could be partly attributed to more experienced dedicated paediatric anaesthesia providers managing the higher risk patients in the UK. Areas for quality improvement include: standardisation of serious critical event definitions; increased reporting; development of evidence-based protocols for management of serious critical events; development and rational use of paediatric peri-operative risk assessment scores; implementation of current best practice in provision of competent paediatric anaesthesia services in Europe; development of specific training in the management of severe peri-operative critical events; and implementation of systems for ensuring maintenance of skills.     

Renal impairment and its impact on clinical outcomes in patients who are critically ill with COVID-19: a multicentre observational study

Renal impairment is common in patients who are critically ill with coronavirus disease-19 (COVID-19). We examined the association between acute and chronic kidney disease with clinical outcomes in 372 patients with coronavirus disease-19 admitted to four regional intensive care units between 10 March 2020 and 31 July 2020. A total of 216 (58%) patients presented with COVID-19 and renal impairment. Acute kidney injury and/or chronic kidney disease was associated with greater in-hospital mortality compared with patients with preserved renal function (107/216 patients (50%) (95%CI 44–57) vs. 32/156 (21%) (95%CI 15–28), respectively; p < 0.001, relative risk 2.4 (95%CI 1.7–3.4)). Mortality was greatest in patients with renal transplants (6/7 patients (86%) (95%CI 47–100)). Mortality rates increased in patients with worsening renal injury according to the Kidney Disease: Improving Global Outcomes classification: stage 0 mortality 33/157 patients (21%) (95%CI 15–28) vs. stages 1–3 mortality 91/186 patients (49%) (95%CI 42–56); p < 0.001, relative risk 2.3 (95%CI 1.7–3.3). Survivors were less likely to require renal replacement therapy compared with non-survivors (57/233 patients (24%) vs. 64/139 patients (46%), respectively; p < 0.001, relative risk 1.9 (95%CI 1.4–2.5)). One-fifth of survivors who required renal replacement therapy acutely in intensive care continued to require renal support following discharge. Our data demonstrate that renal impairment in patients admitted to intensive care with COVID-19 is common and is associated with a high mortality and requirement for on-going renal support after discharge from critical care. Our findings have important implications for future pandemic planning in this patient cohort.     

The effect of a multicomponent multidisciplinary bundle of interventions on sleep and delirium in medical and surgical intensive care patients

Sleep deprivation is common among intensive care patients and may be associated with delirium. We investigated whether the implementation of a bundle of non‐pharmacological interventions, consisting of environmental noise and light reduction designed to reduce disturbing patients during the night, was associated with improved sleep and a reduced incidence of delirium. The study was divided into two parts, before and after changing our practice. One hundred and sixty‐seven and 171 patients were screened for delirium pre‐ and post‐intervention, respectively. Compliance with the interventions was > 90%. The bundle of interventions led to an increased mean (SD) sleep efficiency index (60.8 (3.5) before vs 75.9 (2.2) after, p = 0.031); reduced mean sound (68.8 (4.2) dB before vs 61.8 (9.1) dB after, p = 0.002) and light levels (594 (88.2) lux before vs 301 (53.5) lux after, p = 0.003); and reduced number of awakenings caused by care activities overnight (11.0 (1.1) before vs 9.0 (1.2) after, p = 0.003). In addition, the introduction of the care bundle led to a reduced incidence of delirium (55/167 (33%) before vs 24/171 (14%) after, p < 0.001), and less time spent in delirium (3.4 (1.4) days before vs 1.2 (0.9) days after, p = 0.021). Increases in sleep efficiency index were associated with a lower odds ratio of developing delirium (OR 0.90, 95% CI 0.84–0.97). The introduction of an environmental noise and light reduction programme as a bundle of non‐pharmacological interventions in the intensive care unit was effective in reducing sleep deprivation and delirium, and we propose a similar programme should be implemented more widely.     

Postoperative delirium: An independent risk factor for poorer quality of life with long-term cognitive and functional decline after cardiac surgery

Study objectiveTo evaluate the influence of delirium on the functional and cognitive capacity of patients included in the DELIPRECAS study, as well as on their quality of life, in the 3–4 years after cardiac surgery.DesignProspective observational study.SettingAssessment of cognitive and functional status from hospital discharge to the present, 3 years after cardiac surgery.Patients313 patients undergoing cardiac surgery consecutively, aged 18 years or over.MeasurementsThe primary outcome measure was the cognitive and functional status of the patients 3 years after cardiac surgery, evaluated by telephone interview, and the possible influence on them of delirium diagnosed by the Confusion Assessment Method in Intensive Care Units (CAM-ICU) during their stay in the intensive care unit after cardiac surgery.Main resultsPostoperative delirium acts as an independent risk factor for the long-term development of memory problems (OR 6.11, 95% CI 2.54 to 14.68, p < 0.001), concentration (OR 11.20, 95% CI 3.58 to 35.09, p > 0.001), confusion/disorientation (OR 10.93, 95% CI 3.61 to 33.12, p > 0.001), sleep problems (OR 5.21, 95% CI 2 0.29 to 11.84, p < 0.001), nightmares (OR 8.99, 95% CI 1.98 to 40.90, p = 0.004), emotional problems (OR 4.30, 95% CI 1.87 to 9.91, p = 0.001) and poorer mobility after hospital discharge (OR 2.436, 95% CI 1.06 to 5.61, p = 0.037). The number of hospital readmissions was also significantly higher in those patients who developed delirium after cardiac surgery (27% vs 13.8%, p = 0.022).ConclusionPostoperative delirium is a risk factor for decreased quality of life in patients 3 years after heart surgery, being associated with greater cognitive and functional deterioration, as well as greater risk of hospital readmission. Therefore, emphasis should be placed on both prevention and early recognition and treatment of delirium to improve long-term outcomes for patients after cardiac surgery.     

The association of pre-operative anaemia with morbidity and mortality after emergency laparotomy

Pre-operative anaemia is associated with poor outcomes after elective surgery but its relationship with outcomes after emergency surgery is unclear. We analysed National Emergency Laparotomy Audit data from 1 December 2013 to 30 November 2017, excluding laparotomy for haemorrhage. Anaemia was classified as ‘mild’ 129–110 g.l−1; ‘moderate’ 109–80 g.l−1; or ‘severe’ ≤ 79 g.l−1. The primary outcome was 90-day mortality. Secondary outcomes were 30-day mortality, return to theatre and postoperative hospital stay. The primary outcome was available for 86,763 patients, of whom 45,306 (52%) were anaemic. There were 12,667 (15%) deaths at 90 postoperative days and 9246 (11%) deaths at 30 postoperative days. Anaemia was associated with increased 90-day and 30-day mortality, odds ratio (95%CI): mild, 1.15 (1.09–1.21); moderate, 1.44 (1.36–1.52); and severe, 1.42 (1.24–1.63), p < 0.001 for all; mild, 1.07 (1.00–1.12), p = 0.030; moderate, 1.30 (1.21–1.38), p < 0.001; and severe, 1.22 (1.05–1.43), p = 0.010, respectively. All categories of anaemia were associated with prolonged hospital stay, adjusted coefficient (95%CI): mild, 1.31 (1.01–1.62); moderate, 3.41 (3.04–3.77); severe, 2.80 (1.83–3.77), p < 0.001 for all. Moderate and severe anaemia were associated with increased risk of return to the operating theatre, odds ratio (95%CI): moderate 1.13 (1.06–1.21), p < 0.001; and severe 1.23 (1.06–1.43), p = 0.006. Pre-operative anaemia is common in patients undergoing emergency laparotomy and is associated with increased postoperative mortality and morbidity.     

Prolonged Mechanical Ventilation After Lung Transplantation—A Single‐Center Study

This single‐center study examines the incidence, etiology, and outcomes associated with prolonged mechanical ventilation (PMV), defined as time to definite spontaneous ventilation >21 days after double lung transplantation (LTx). A total of 690 LTx recipients between January 2005 and December 2012 were analyzed. PMV was necessary in 95 (13.8%) patients with decreasing incidence during the observation period (p < 0.001). Independent predictors of PMV were renal replacement therapy (odds ratio [OR] 11.13 [95% CI, 5.82–21.29], p < 0.001), anastomotic dehiscence (OR 8.74 [95% CI 2.42–31.58], p = 0.001), autoimmune comorbidity (OR 5.52 [95% CI 1.86–16.41], p = 0.002), and postoperative neurologic complications (OR 5.03 [95% CI 1.98–12.81], p = 0.001), among others. Overall 1‐year survival was 86.0% (90.4% for LTx between 2010 and 2012); it was 60.7% after PMV and 90.0% in controls (p < 0.001). Conditional long‐term outcome among hospital survivors, however, did not differ between the groups (p = 0.78). Multivariate analysis identified renal replacement therapy (hazard ratio [HR] 3.55 [95% CI 2.40–5.25], p < 0.001), post‐LTx extracorporeal membrane oxygenation (HR 3.47 [95% CI 2.06–5.83], p < 0.001), and prolonged inotropic support (HR 1.95 [95% CI 1.39–2.75], p < 0.001), among others, as independent predictors of mortality. In conclusion, PMV complicated 14% of LTx procedures and, although associated with increased in‐hospital mortality, outcomes among patients surviving to hospital discharge were unaffected.     

Spinal or general anaesthesia for surgical repair of hip fracture and subsequent risk of mortality and morbidity: a database analysis using propensity score-matching

Around 76,000 people fracture their hip annually in the UK at a considerable personal, social and financial cost. Despite longstanding debate, the optimal mode of anaesthesia (general or spinal) remains unclear. Our aim was to assess whether there is a significant difference in mortality and morbidity between patients undergoing spinal anaesthesia compared with general anaesthesia during hip fracture surgery. A secondary analysis examined whether a difference exists in mortality for patients with pre-existing cardiovascular disease or chronic obstructive pulmonary disease. This was a clinical database analysis of patients treated for hip fracture in Nottingham, UK between 2004 and 2015. Propensity score-matching was used to generate matched pairs of patients, one of whom underwent each mode of anaesthesia. Data were analysed using conditional logistic regression, with 7164 patients successfully matched. There was no difference in 30- or 90-day mortality in patients who had spinal rather than general anaesthesia (OR [95%CI] 0.97 [0.8–1.15]; p = 0.764 and 0.93 [0.82–1.05]; p = 0.247 respectively). Patients who had a spinal anaesthetic had a lower-risk of blood transfusion (OR [95%CI] 0.84 [0.75–0.94]; p = 0.003) and urinary tract infection (OR [95%CI] 0.72 [0.61–0.84]; p < 0.001), but were more likely to develop a chest infection (OR [95%CI] 1.23 [1.07–1.42]; p = 0.004), deep vein thrombosis (OR [95%CI] 2.18 [1.07–4.45]; p = 0.032) or pulmonary embolism (OR [95%CI] 2.23 [1.16–4.29]; p = 0.016). The mode of anaesthesia for hip fracture surgery resulted in no significant difference in mortality, but there was a significant difference in several measures of postoperative morbidity.     

An international survey about rapid sequence intubation of 10,003 anaesthetists and 16 airway experts

Pulmonary aspiration of gastric content is a significant cause of anaesthesia-related morbidity and mortality. High-quality prospective randomised evidence to support prevention strategies, such as rapid sequence intubation, is difficult to generate due to well-described practical, ethical and methodological barriers. We aimed to generate an understanding of worldwide practice through surveying clinically practicing anaesthetists and airway experts. Our survey was designed to assess the influence of: departmental standards; patient factors; socio-economic factors; training; and supervision. We surveyed 10,003 anaesthetists who responded to an invitation to participate on LinkedIn. We then surveyed 16 international airway experts on the same content. When asked about a hypothetical patient with intestinal obstruction, respondents expressed preferences for [OR (95%CI)]: the head-up or -down position 4.26 (3.98–4.55), p < 0.001; nasogastric tube insertion 29.5 (26.9–32.3), p < 0.001; and the use of cricoid force 2.80 (2.62–3.00), p < 0.001, as compared with a hypothetical patient without intestinal obstruction also requiring rapid sequence intubation. Respondents from lower income countries were more likely to prefer [OR (95%CI]: the supine position 2.33 (2.00–2.63), p < 0.001; nasogastric tube insertion 1.29 (1.09–1.51), p = 0.002; and cricoid force application 2.54 (2.09–3.09), p < 0.001 as compared with respondents from higher income countries for a hypothetical patient with intestinal obstruction. This survey, which we believe is the largest of its kind, demonstrates that preferences for positioning, nasogastric tube use and cricoid force application during rapid sequence intubation vary substantially. Achieving agreed consensus may yield better training in the principles of rapid sequence intubation.     

Factors associated with time to defecate and outcomes in critically ill patients: a prospective,multicentre, observational study

Delayed defecation is common in patients on intensive care. We aimed to determine factors associated with time to defecation after admission to intensive care and in turn its association with length of stay and mortality. We studied 396 adults admitted to one of five intensive care units in whom at least 2 days’ invasive ventilation was anticipated during an expected stay of at least 3 days. The median (IQR [range]) time to defecate by the 336 out of 396 (84%) patients who did so before intensive care discharge was 6 (4-8 [1–18]) days. Defecation was independently associated with five factors, hazard ratio (95%CI), higher values indicating more rapid defecation: alcoholism, 1.32 (1.05–1.66), p = 0.02; laxatives before admission, 2.35 (1.79–3.07), p < 0.001; non-invasive ventilation, 0.54 (0.36–0.82), p = 0.004; duration of ventilation, 0.78 (0.74–0.82), p < 0.001; laxatives after admission, 1.67 (1.23–2.26), p < 0.001; and enteral nutrition within 48 h of admission, 1.43 (1.07–1.90), p = 0.01. Delayed defecation was associated with prolonged intensive care stay but not mortality.     

Effect of dexmedetomidine on delirium during sedation in adult patients in intensive care units: A systematic review and meta-analysis

Study objectiveTo compare the effect of sedation protocols with and without dexmedetomidine on delirium risk and duration in adult patients in intensive care units (ICUs).DesignA meta-analysis of randomized controlled trials.Review methodsWe searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and ISI Web of Science from inception to September 3, 2020. We included studies comparing the effect of dexmedetomidine-based sedation on delirium risk with non-dexmedetomidine-based sedation in adult patients in ICUs. We pooled the data using a random-effects model using Review Manager 5.2, and assessed publication bias using Stata 11.0. The quality of evidence was rated using the Grading of Recommendations, Assessment, Development and Evaluation system.Main resultsWe included 36 studies involving 9623 participants. The use of dexmedetomidine was associated with reduced risk of delirium (risk ratio [RR], 0.63; 95% confidence interval [CI], 0.54–0.75; very low-quality evidence), but higher incidences of hypotension and bradycardia during hospital stay. Dexmedetomidine was also associated with shorter durations of ICU stay, hospital stay and mechanical ventilation. Dexmedetomidine did not affect ICU mortality (RR, 1.01; 95% CI, 0.89–1.14; low-quality evidence), hospital mortality (RR, 1.01; 95% CI, 0.91–1.12; very low-quality evidence), or 30-day mortality (RR, 0.77; 95% CI, 0.58–1.01; moderate-quality evidence), or duration of delirium (mean difference, −0.74 days; 95% CI, −1.83 to 0.36 days; very low-quality evidence). We identified publication bias for risk and duration of delirium, length of ICU stay, and hospital stay.ConclusionsLow- or very low-quality evidence suggests that dexmedetomidine was associated with a clinically-small reduction of delirium risk, ICU/hospital stay and mechanical ventilation duration, but were not associated with improved mortality or shorter delirium duration in ICU patients. These findings were inconclusive because of publication bias, heterogeneity, and limited sample size. Significant adverse effects of dexmedetomidine include hypotension and bradycardia.PROSPERO registration number: CRD42018095358.     

The association of pre-operative anaemia with survival after orthotopic liver transplantation

Anaemia is common in patients with end-stage liver disease. Pre-operative anaemia is associated with greater mortality after major surgery. We analysed the association of pre-operative anaemia (World Health Organization classification) with survival and complications after orthotopic liver transplantation using Cox and logistic regression models. We included patients undergoing their first orthotopic liver transplantation between 2004 and 2016. Out of 599 included patients, 455 (76%) were anaemic before transplantation. Pre-operative anaemia was not associated with the survival of 485/599 (81%) patients to 1 year after liver transplantation, OR (95%CI) 1.04 (0.64–1.68), p = 0.88. Pre-operative anaemia was associated with higher rates of intra-operative blood transfusions and acute postoperative kidney injury on multivariable analysis, OR (95%CI) 1.70 (0.82–2.59) and 1.72 (1.11–2.67), respectively, p < 0.001 for both. Postoperative renal replacement therapy was associated with pre-operative anaemia on univariate analysis, OR (95%CI) 1.87 (1.11–3.15), p = 0.018.     

Postoperative outcomes in surgical patients with obstructive sleep apnoea diagnosed by sleep studies: a meta-analysis and trial sequential analysis

Identifying surgical patients with obstructive sleep apnoea may assist with anaesthetic management to minimise postoperative complications. Using trial sequential analysis, we evaluated the impact of obstructive sleep apnoea diagnosed by polysomnography or home sleep apnoea testing on postoperative outcomes in surgical patients. Multiple databases were systematically searched. Outcomes included: total postoperative complications, systemic complications (cardiovascular, respiratory, neurological, renal, infectious) and specific complications (atrial fibrillation, myocardial infarction, combined hospital and intensive care unit re-admission, mortality). The pooled odds ratios of postoperative complications were evaluated by the Mantel–Haenszel method random-effects model. Meta-analysis and meta-regression were conducted, and the GRADE approach was used to evaluate the certainty of evidence. Twenty prospective cohort studies with 3756 patients (2127 obstructive sleep apnoea and 1629 non-obstructive sleep apnoea) were included (9 in non-cardiac surgery and 11 in cardiac surgery). Postoperative complications were almost two-fold higher with obstructive sleep apnoea, OR (95%CI) 1.92 (1.52–2.42), p < 0.001; certainty of evidence, moderate. Obstructive sleep apnoea was associated with a 1.5 times increased risk of postoperative cardiovascular complications, OR (95%CI) 1.56 (1.20–2.02), p = 0.001; certainty of evidence, moderate; an almost two-fold increase in respiratory complications, OR (95%CI) 1.91 (1.39–2.62), p < 0.001; certainty of evidence, moderate; and hospital and ICU re-admission, OR (95%CI) 2.25 (1.21–4.19), p = 0.01; certainty of evidence, low. Trial sequential analysis showed adequate information size for postoperative complications. Baseline confounding factors were adjusted by meta-regression, and the sub-group analysis did not materially change our results. This increased risk occurred especially in patients in whom obstructive sleep apnoea had been newly diagnosed, emphasising the importance of pre-operative screening.     

Pre-operative voice evaluation as a hypothetical predictor of difficult laryngoscopy

We examined the potential for voice sounds to predict a difficult airway as compared with prediction by the modified Mallampati test. A total of 453 patients scheduled for elective surgery under general anaesthesia with tracheal intubation were studied. Five phonemes were recorded and their formants analysed. Difficult laryngoscopy was defined as the Cormack–Lehane grade 3 or 4. Univariate and multivariate logistic regression were used to examine the association between some variables (mouth opening, sternomental distance, modified Mallampati and formants) and difficult laryngoscopy. Difficult laryngoscopy was reported in 29/453 (6.4%) patients. Among five regression models evaluated, the model achieving better performance to predict difficult laryngoscopy, after a variable selection criteria (stepwise, multivariate) and included a modified Mallampati classification (OR 2.920; 95%CI 1.992–4.279; p < 0.001), first formant of /i/(iF1) (OR 1.003; 95%CI 1.002–1.04; p < 0.001), and second formant of /i/(iF2) (OR 0.998; 95%CI 0.997–0.998; p < 0.001). The receiver operating curve for a regression model that included both formants and Mallampati showed an area under curve of 0.918, higher than formants alone (area under curve 0.761) and modified Mallampati alone (area under curve 0.874). Voice presented a significant association with difficult laryngoscopy during general anaesthesia showing a 76.1% probability of correctly classifying a randomly selected patient.     

Risk factors for children requiring adenotonsillectomy and their impact on postoperative complications: a retrospective analysis of 2000 patients

Adenotonsillectomies are commonly performed procedures and sleep-disordered breathing is becoming increasingly important as an indication for surgery. Because of the higher risks in patients with obstructive sleep apnoea, the required level of postoperative care for these patients is currently under discussion, and better identification of patients at risk may reduce unnecessary postoperative monitoring. To evaluate the influence of obstructive sleep apnoea, and other risk factors, on peri-operative complications in children requiring adenotonsillectomy, we performed a retrospective case-control study that included 1995 patients treated between January 2009 and June 2017. In our analysis, young age (OR 3.8, 95%CI 2.1–7.1), low body weight (OR 2.6, 95%CI 1.5–4.4), obstructive sleep apnoea (OR 2.4, 95%CI 1.5–3.8), pre-existing craniofacial or syndromal disorders (OR 2.3, 95%CI 1.4–3.8) and adenotonsillectomy, compared with adenoidectomy alone, (OR 7.9, 95%CI 4.7–13.1) were identified as risk factors for complications during or after surgery, p < 0.001. All 13 patients suffering from complications more than 3 h postoperatively had obstructive sleep apnoea plus at least one more of these risk factors. Patients at risk of postoperative complications can therefore be identified by several criteria pre-operatively, and should be monitored postoperatively using pulse oximetry overnight. For all other patients, postoperative observation on a surgical ward without extra monitoring is sufficient. Admission to paediatric intensive care should be reserved for patients suffering serious intra-operative complications.