Differential effects of sevoflurane and desflurane on frontal intraoperative electroencephalogram dynamics associated with postoperative delirium

STUDY OBJECTIVE

Intraoperative electroencephalogram (EEG) patterns associated with postoperative delirium (POD) development have been studied, but the differences in EEG recordings between sevoflurane- and desflurane-induced anesthesia have not been clarified. We aimed to distinguish the EEG characteristics of sevoflurane and desflurane in relation to POD development.

DESIGN AND PATIENTS

We collected frontal four-channel EEG data during the maintenance of anesthesia from 148 elderly patients who received sevoflurane (n = 77) or desflurane (n = 71); 30 patients were diagnosed with delirium postoperatively. The patients were divided into four subgroups based on anesthetics and delirium status: sevoflurane delirium (n = 17), sevoflurane non-delirium (n = 60), desflurane delirium (n = 13), and desflurane non-delirium (n = 58). We compared spectral power, coherence, and pairwise phase consistency (PPC) between sevoflurane and desflurane, and between non-delirium and delirium groups for each anesthetic.

MAIN RESULTS

In patients without POD, the sevoflurane non-delirium group exhibited higher EEG spectral power across 8.5-35 Hz (99.5% CI bootstrap analysis) and higher PPC from alpha to gamma bands (p < 0.005) compared to the desflurane non-delirium group. Conversely, in patients with POD, no significant EEG differences were observed between the sevoflurane and desflurane delirium groups. For the sevoflurane-induced patients, the sevoflurane delirium group had significantly lower power within 7.5-31.5 Hz (99.5% CI bootstrap analysis), reduced coherence over 8.9-23.8 Hz (99.5% CI bootstrap analysis), and lower PPC values in the alpha band (p < 0.005) compared with the sevoflurane non-delirium group. For the desflurane-induced patients, there were no significant differences in the EEG patterns between delirium and non-delirium groups.

CONCLUSIONS

In normal patients without POD, sevoflurane demonstrates a higher power spectrum and prefrontal connectivity than desflurane. Furthermore, reduced frontal alpha power, coherence, and connectivity of intraoperative EEG could be associated with an increased risk of POD. These intraoperative EEG characteristics associated with POD are more noticeable in sevoflurane-induced anesthesia than in desflurane-induced anesthesia.

Comparison of Remimazolam and Propofol on Postoperative Delirium in Elderly Patients Undergoing Radical Resection of Colon Cancer: A Single-Center Prospective Randomized Controlled Study

BACKGROUND We compared the effect of remimazolam and propofol intravenous anesthesia on postoperative delirium in elderly patients undergoing laparoscopic radical resection of colon cancer. MATERIAL AND METHODS One hundred patients undergoing elective radical operation of colon cancer under general anesthesia were divided into a remimazolam group (group R) and propofol group (group P) by a random number table method. During anesthesia induction and maintenance, group R was intravenously injected with remimazolam to exert sedation; however, in group P, propofol was injected instead of remimazolam. The occurrence of postoperative delirium was assessed with the Confusion Assessment Method for the Intensive Care Unit scale and postoperative pain was assessed with the visual analogue score (VAS). The primary outcome measures were the incidence and duration of delirium within 7 days following surgery. Secondary outcome measures included postoperative VAS scores, intraoperative anesthetic drug dosage, and adverse reactions, including nausea and vomiting, hypoxemia, and respiratory depression. RESULTS There was no significant difference in baseline data between the 2 groups (P>0.05). There was no statistically significant difference in the incidence and duration of postoperative delirium between the 2 groups (P>0.05). There were no significant differences in VAS scores, remifentanil consumption, and adverse reactions, including nausea and vomiting, hypoxemia, and respiratory depression between the 2 groups (P>0.05). CONCLUSIONS In elderly patients undergoing radical colon cancer surgery, remimazolam administration did not improve or aggravate the incidence and duration of delirium, compared with propofol.

Prevention of post-operative delirium using an overnight infusion of dexmedetomidine in patients undergoing cardiac surgery: a pragmatic, randomized, double-blind, placebo-controlled trial

BACKGROUND

After cardiac surgery, post-operative delirium (PoD) is acknowledged to have a significant negative impact on patient outcome. To date, there is no valuable and specific treatment for PoD. Critically ill patients often suffer from poor sleep condition. There is an association between delirium and sleep quality after cardiac surgery. This study aimed to establish whether promoting sleep using an overnight infusion of dexmedetomidine reduces the incidence of delirium after cardiac surgery.

METHODS

Randomized, pragmatic, multicentre, double-blind, placebo controlled trial from January 2019 to July 2021. All adult patients aged 65 years or older requiring elective cardiac surgery were randomly assigned 1:1 either to the dexmedetomidine group or the placebo group on the day of surgery. Dexmedetomidine or matched placebo infusion was started the night after surgery from 8 pm to 8 am and administered every night while the patient remained in ICU, or for a maximum of 7 days. Primary outcome was the occurrence of postoperative delirium (PoD) within the 7 days after surgery.

RESULTS

A total of 348 patients provided informed consent, of whom 333 were randomized: 331 patients underwent surgery and were analysed (165 assigned to dexmedetomidine and 166 assigned to placebo). The incidence of PoD was not significantly different between the two groups (12.6% vs. 12.4%, p = 0.97). Patients treated with dexmedetomidine had significantly more hypotensive events (7.3% vs 0.6%; p < 0.01). At 3 months, functional outcomes (Short-form 36, Cognitive failure questionnaire, PCL-5) were comparable between the two groups.

CONCLUSION

In patients recovering from an elective cardiac surgery, an overnight infusion of dexmedetomidine did not decrease postoperative delirium. Trial registration This trial was registered on ClinicalTrials.gov (number: NCT03477344; date: 26th March 2018).

Comparison of dexmedetomidine and a dexmedetomidine-esketamine combination for reducing dental anxiety in preschool children undergoing dental treatment under general anesthesia: A randomized controlled trial

BACKGROUND

Dental anxiety is a widespread complication occurring in pediatric patients during dental visits and may lead to undesirable complications. Esketamine may be effective in anxiety.

OBJECTIVE

The objective of this study was to investigate the effect of premedication with a dexmedetomidine-esketamine combination compared with dexmedetomidine alone on dental anxiety in preschool children undergoing dental treatment under general anesthesia.

METHODS

This is a prospective, double-blinded, randomized controlled trial. A total of 84 patients were scheduled for elective outpatient dental caries treatment under general anesthesia. Patients were randomly premedicated with intranasal dexmedetomidine (group D) or intranasal dexmedetomidine-esketamine (group DS). The primary outcome was the level of dental anxiety assessed by the Modified Child Dental Anxiety Scale (MCDAS) at 2 h after surgery. Secondary outcomes included level of dental anxiety at 1 day and 7 days after surgery, the incidence of dental anxiety at 2 h, 1 day, and 7 days after surgery, sedation onset time, overall success of sedation, acceptance of mask induction, postoperative pain intensity, incidence of emergence agitation in PACU, adverse reactions, HR, and SpO2 before premedication (baseline) and at 10, 20, and 30 min after the end of study drug delivery.

RESULTS

The dental anxiety in group DS was lower than that in group D at 2 h, 1 day, and 7 days postoperatively (P = 0.04, 0.004, and 0.006, respectively). The incidences of dental anxiety in group DS were lower than those in group D at 2 h (53 % vs 76 %, P = 0.03), 1 day (47 % vs 71 %, P = 0.04), and 7 days (44 % vs 71 %, P = 0.02) after surgery. Group DS had a higher success rate of sedation (P = 0.03) but showed a lower MAS score (P = 0.005) and smoother hemodynamics (P < 0.01) after drug administration than group D. Group DS showed a significantly lower incidence rate of emergence agitation (P = 0.03) and postoperative pain intensity (P = 0.006) than that in group D during the anesthesia recovery time. The occurrence of adverse reactions was similar in both groups (P > 0.05).

LIMITATIONS

We did not analyze and correct for the learning effect caused by repeated applications of the MCDAS and MCDAS scores on the 1 day after surgery were obtained by telephone follow-up.

CONCLUSIONS

Compared to premedication with dexmedetomidine alone, premedication with intranasal dexmedetomidine combined with esketamine could significantly improve dental anxiety in preschool children undergoing dental treatment under general anesthesia.

The association between midazolam premedication and postoperative delirium - a retrospective cohort study

STUDY OBJECTIVE

To evaluate the association between midazolam premedication and postoperative delirium in a large retrospective cohort of patients ≥70 years.

DESIGN

Retrospective cohort study.

SETTING

A single tertiary academic medical center.

PATIENTS

Patients ≥70 years having elective non-cardiac surgery under general anesthesia from 2020 to 2021.

INTERVENTIONS

Midazolam premedication, defined as intravenous midazolam administration prior to induction of general anesthesia.

MEASUREMENTS

The primary outcome, postoperative delirium, was a collapsed composite outcome including at least one of the following: a positive 4A's test during post-anesthesia care unit stay and/or the initial 2 postoperative days; physician or nursing records reporting new-onset confusion as captured by the CHART-DEL instrument; or a positive 3D-CAM test. The association between midazolam premedication and postoperative delirium was assessed using multivariable logistic regression, adjusting for potential confounding variables. As secondary analysis, we investigated the association between midazolam premedication and a composite of other postoperative complications. Several sensitivity analyses were performed using similar regression models.

MAIN RESULTS

In total, 1973 patients were analyzed (median age 75 years, 47% women, 50% ASA score ≥ 3, 32% high risk surgery). The overall incidence of postoperative delirium was 15.3% (302/1973). Midazolam premedication was administered to 782 (40%) patients (median [IQR] dose 2 [1,2] mg). After adjustment for potential confounding variables, midazolam premedication was not associated with increased odds of postoperative delirium, with adjusted odds ratio of 1.09 (95% confidence interval 0.82-1.45; P = 0.538). Midazolam premedication was also not associated with the composite of other postoperative complications. Furthermore, no association was found between midazolam premedication and postoperative delirium in any of the sensitivity analyses preformed.

CONCLUSIONS

Our results suggest that low doses of midazolam can be safely used to pre-medicate elective surgical patients 70 years or older before non-cardiac surgery, without significant effect on the risk of developing postoperative delirium.

Perioperative Management and Outcomes in Patients With Autism Spectrum Disorder: A Retrospective Cohort Study

BACKGROUND

Autism spectrum disorder (ASD) is a neurocognitive disorder characterized by impairments in communication and socialization. There are little data comparing the differences in perioperative outcomes in children with and without ASD. We hypothesized that children with ASD would have higher postoperative pain scores than those without ASD.

METHODS

Pediatric patients undergoing ambulatory tonsillectomy/adenoidectomy, ophthalmological surgery, general surgery, and urologic procedures between 2016 and 2021 were included in this retrospective cohort study. ASD patients, defined by International Classification of Diseases-9/10 codes, were compared to controls utilizing inverse probability of treatment weighting based on surgical category/duration, age, sex, race and ethnicity, anesthetizing location, American Society of Anesthesiology physical status, intraoperative opioid dose, and intraoperative dexmedetomidine dose. The primary outcome was the maximum postanesthesia care unit (PACU) pain score, and secondary outcomes included premedication administration, behavior at induction, PACU opioid administration, postoperative vomiting, emergence delirium, and PACU length of stay.

RESULTS

Three hundred thirty-five children with ASD and 11,551 non-ASD controls were included. Maximum PACU pain scores in the ASD group were not significantly higher than controls (median, 5; interquartile range [IQR], 0-8; ASD versus median, 5; IQR, 0-8 controls; median difference [95% confidence interval {CI}] of 0 [-1.1 to 1.1]; P = .66). There was no significant difference in the use of premedication (96% ASD versus 95% controls; odds ratio [OR], 1.5; [95% CI, 0.9-2.7]; P = .12), but the ASD cohort had significantly higher odds of receiving an intranasal premedication (4.2% ASD versus 1.2% controls; OR, 3.5 [95% CI, 1.8-6.8]; P < .001) and received ketamine significantly more frequently (0.3% ASD versus <0.1% controls; P < .001). Children with ASD were more likely to have parental (4.9% ASD versus 1.0% controls; OR, 5 [95% CI, 2.1-12]; P < .001) and child life specialist (1.3% ASD versus 0.1% controls; OR, 9.9 [95% CI, 2.3-43]; P < .001) presence at induction, but were more likely to have a difficult induction (11% ASD versus 3.4% controls; OR, 3.42 [95% CI, 1.7-6.7]; P < .001). There were no significant differences in postoperative opioid administration, emergence delirium, vomiting, or PACU length of stay between cohorts.

CONCLUSIONS

We found no difference in maximum PACU pain scores in children with ASD compared to a similarly weighted cohort without ASD. Children with ASD had higher odds of a difficult induction despite similar rates of premedication administration, and significantly higher parental and child life specialist presence at induction. These findings highlight the need for future research to develop evidence-based interventions to optimize the perioperative care of this population.

Postoperative Use of the Muscle Relaxants Baclofen and/or Cyclobenzaprine Associated With an Increased Risk of Delirium Following Lumbar Fusion

STUDY DESIGN

Retrospective, single-center, cohort study.

OBJECTIVE

Investigate whether the incidence of postoperative delirium in older adults undergoing spinal fusion surgery is associated with postoperative muscle relaxant administration.

SUMMARY OF BACKGROUND DATA

Baclofen and cyclobenzaprine are muscle relaxants frequently used for pain management following spine surgery. Muscle relaxants are known to cause central nervous system side effects in the outpatient setting and are relatively contraindicated in individuals at high risk for delirium. However, there are no known studies investigating their side effects in the postoperative setting.

METHODS

Patients over 65 years of age who underwent elective posterior lumbar fusion for degenerative spine disease were stratified into two treatment groups based on whether postoperative muscle relaxants were administered on postoperative day one as part of a multimodal analgesia regimen. Doubly robust inverse probability weighting with cox regression for time-dependent covariates was used to examine the association between postoperative muscle relaxant use and the risk of delirium while controlling for variation in baseline characteristics.

RESULTS

The incidence of delirium was 17.6% in the 250 patients who received postoperative muscle relaxants compared with 7.9% in the 280 patients who did not receive muscle relaxants ( P=0.001 ). Multivariate analysis to control for variation in baseline characteristics between treatment groups found that patients who received muscle relaxants had a 2.00 (95% CI: 1.14-3.49) times higher risk of delirium compared with controls ( P=0.015 ).

CONCLUSION

Postoperative use of muscle relaxants as part of a multimodal analgesia regimen was associated with an increased risk of delirium in older adults after lumber fusion surgery. Although muscle relaxants may be beneficial in select patients, they should be used with caution in individuals at high risk for postoperative delirium.

The Efficacy of Ramelteon to Prevent Postoperative Delirium After General Anesthesia in the Elderly: A Double-Blind, Randomized, Placebo-Controlled Trial

OBJECTIVE

Postoperative delirium is common and serious in elderly patients. Several drugs have been proposed as potential prophylactic agents for postoperative delirium. Studies on melatonin receptor agonists showed heterogeneity in age, cognitive function, anesthesia, surgery, interventions, methodologies for assessing outcomes, and results. Our objective was to examine the effect of ramelteon to prevent postoperative delirium in elderly patients, including those with dementia.

DESIGN

A stratified, double-blind, randomized, placebo-controlled trial (UMIN000028436, jRCTs031180054).

SETTING

Tertiary medical center.

PARTICIPANTS

Patients aged older than or equal to 65 years undergoing elective surgery under general anesthesia.

INTERVENTION

Ramelteon (8 mg orally) or placebo (lactose) for six nights (the preoperative night and five consecutive nights from postoperative day 1 to 5) at around 9 P.M.

MEASUREMENTS

Patients were screened for postoperative delirium using the Confusion Assessment Method for the Intensive Care Unit twice daily until the sixth postoperative day. Patients with positive results were referred to a consultant psychiatrist to establish the diagnosis of delirium.

RESULTS

A total of 108 patients were randomly assigned to receive ramelteon (n = 55) or placebo (n = 53). Most of the patients' characteristics were reasonably well-balanced between the two groups. The stratified log-rank test showed no significant difference in preventing postoperative delirium between ramelteon and placebo (χ2 = 0.30, degrees of freedom = 1, p = 0.60). The Cox proportional hazard ratio for ramelteon compared to placebo was 1.40 (95% confidence interval: 0.40-4.85, χ2 for likelihood ratio test = 0.29, degrees of freedom = 1, p = 0.60).

CONCLUSION

There was no significant difference in the incidence of postoperative delirium between ramelteon and placebo after general anesthesia in elderly patients.

Prevalence and risk factors of emergence agitation among pediatric patients undergo ophthalmic and ENT Surgery: a cross-sectional study

BACKGROUND

Some studies reported that pediatric patients undergoing otorhinolaryngology (ENT) and ophthalmic surgeries have higher incidences of emergence agitation (EA). Children with EA tend to carry the risk of self-harm, have longer periods of recovery and delayed hospital discharge. Consequently, EA needs to be monitored and risk factors ought to be emphasized to implement preventative measures. The objective of this study was to describe EA and to identify risk factors after pediatric ophthalmic or ENT surgery.

METHODS

Between September 2021 and December 2021, a cross-sectional study was conducted in 100 children aged of 0-12 years who underwent ophthalmic or ENT surgery. The Watcha scale was used to observe and record EA, which was defined at levels of 3 or 4 at any time in the post-anesthesia care unit (PACU). The pain intensity was graded with the Face, Legs, Activity, Cry, Consolability (FLACC) Scale after surgery. Patient and surgery-related characteristics, the behavioral criteria of EA, the pharmacologic and non-pharmacologic interventions and recovery outcomes were objectively recorded. A binary logistic regression model was constructed to identify the associated factors of EA.

RESULTS

From the 100 analyzed children, 58 were males and 42 were females, and 44 patients received ophthalmic surgery and 56 ENT surgery. The median age was 6 (IQR 4-7) years. The overall incidence of EA among pediatrics was 30% (34.5% for ENT and 24.4% for ophthalmic surgery). High preoperative modified Yale Preoperative Anxiety scale (m-YPAS) grade (OR = 1.19, 95%CI 1.06-1.33, P = 0.003) and high postoperative FLACC score (OR = 3.36, 95%CI 1.88-6.02, P < 0.001) were risk factors for EA.

CONCLUSIONS

This study identified that preoperative anxiety and postoperative pain are associated with EA in children after ophthalmic or ENT surgery. Preoperative anxiety assessment and management, and administration of adjunct analgesic treatments should be considered in the routine care.

Benzodiazepines and postoperative delirium: should we be as cautious as we are?

A recent systematic review and meta-analysis by Wang and colleagues in the British Journal of Anaesthesia calls into question the concept that perioperative benzodiazepine administration is associated with development of postoperative delirium in older individuals after anaesthesia and surgery. This editorial focuses on potential bias within the systematic review and addresses major concerns surrounding benzodiazepine use in the older perioperative population.

Delirium in older patients given propofol or sevoflurane anaesthesia for major cancer surgery: a multicentre randomised trial

BACKGROUND

Delirium is a common and disturbing postoperative complication that might be ameliorated by propofol-based anaesthesia. We therefore tested the primary hypothesis that there is less delirium after propofol-based than after sevoflurane-based anaesthesia within 7 days of major cancer surgery.

METHODS

This multicentre randomised trial was conducted in 14 tertiary care hospitals in China. Patients aged 65-90 yr undergoing major cancer surgery were randomised to either propofol-based anaesthesia or to sevoflurane-based anaesthesia. The primary endpoint was the incidence of delirium within 7 postoperative days.

RESULTS

A total of 1228 subjects were enrolled and randomised, with 1195 subjects included in the modified intention-to-treat analysis (mean age 71 yr; 422 [35%] women); one subject died before delirium assessment. Delirium occurred in 8.4% (50/597) of subjects given propofol-based anaesthesia vs 12.4% (74/597) of subjects given sevoflurane-based anaesthesia (relative risk 0.68 [95% confidence interval {CI}: 0.48-0.95]; P=0.023; adjusted relative risk 0.59 [95% CI: 0.39-0.90]; P=0.014). Delirium reduction mainly occurred on the first day after surgery, with a prevalence of 5.4% (32/597) with propofol anaesthesia vs 10.7% (64/597) with sevoflurane anaesthesia (relative risk 0.50 [95% CI: 0.33-0.75]; P=0.001). Secondary endpoints, including ICU admission, postoperative duration of hospitalisation, major complications within 30 days, cognitive function at 30 days and 3 yr, and safety outcomes, did not differ significantly between groups.

CONCLUSIONS

Delirium was a third less common after propofol than sevoflurane anaesthesia in older patients having major cancer surgery. Clinicians might therefore reasonably select propofol-based anaesthesia in patients at high risk of postoperative delirium.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR-IPR-15006209) and ClinicalTrials.gov (NCT02662257).

Effect of Dexmedetomidine on Posttraumatic Stress Disorder in Patients Undergoing Emergency Trauma Surgery: A Randomized Clinical Trial

Importance

Posttraumatic stress disorder (PTSD) is common in people who have experienced trauma, especially those hospitalized for surgery. Dexmedetomidine may reduce or reverse the early consolidation and formation of conditioned fear memory and prevent the occurrence of postoperative PTSD.

Objective

To evaluate the effects of intraoperative and postoperative low-dose intravenous pumping dexmedetomidine on PTSD among patients with trauma undergoing emergency surgery.

Design, Setting, and Participants

This double-blind, randomized clinical trial was conducted from January 22 to October 20, 2022, with follow-up 1 month postoperatively, in patients with trauma undergoing emergency surgery at 4 hospital centers in Jiangsu Province, China. A total of 477 participants were screened. The observers were blinded to patient groupings, particularly for subjective measurements.

Interventions

Dexmedetomidine or placebo (normal saline) was administered at a maintenance dose of 0.1 μg/kg hourly from the start of anesthesia until the end of surgery and at the same rate after surgery from 9 pm to 7 am on days 1 to 3.

Main Outcomes and Measures

The primary outcome was the difference in the incidence of PTSD 1 month after surgery in the 2 groups. This outcome was assessed with the Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (CAPS-5). The secondary outcomes were the pain score within 48 hours and 1 month postoperatively; incidence of postoperative delirium, nausea, and pruritus; subjective sleep quality; anxiety; and occurrence of adverse events.

Results

A total of 310 patients (154 in the normal saline group and 156 in the dexmedetomidine group) were included in the modified intention-to-treat analysis (mean [SD] age, 40.2 [10.3] years; 179 men [57.7%]). The incidence of PTSD was significantly lower in the dexmedetomidine group than in the control group 1 month postoperatively (14.1% vs 24.0%; P = .03). The participants in the dexmedetomidine group had a significantly lower CAPS-5 score than those in the control group (17.3 [5.3] vs 18.9 [6.6]; mean difference, 1.65; 95% CI, 0.31-2.99; P = .02). After adjusting for potential confounders, the patients in the dexmedetomidine group were less likely to develop PTSD than those in the control group 1 month postoperatively (adjusted odds ratio, 0.51; 95% CI, 0.27-0.94; P = .03).

Conclusions and Relevance

In this randomized clinical trial, the administration of intraoperative and postoperative dexmedetomidine reduced the incidence of PTSD among patients with trauma. The findings of this trial support the use of dexmedetomidine in emergency trauma surgery.

Trial Registration

Chinese Clinical Trial Register Identifier: ChiCTR2200056162.

Postoperative Delirium after Dexmedetomidine versus Propofol Sedation in Healthy Older Adults Undergoing Orthopedic Lower Limb Surgery with Spinal Anesthesia: A Randomized Controlled Trial

BACKGROUND

Delirium is a critical postoperative complication in older patients. Based on the hypothesis that intraoperative dexmedetomidine sedation would lower postoperative delirium than propofol sedation would, the authors compared the incidence of postoperative delirium in older adults, using the mentioned sedatives.

METHODS

This double-blinded, randomized controlled study included 748 patients, aged 65 yr or older, who were scheduled for elective lower extremity orthopedic surgery, between June 2017 and October 2021. Patients were randomized equally into two groups in a 1:1 ratio according to the intraoperative sedative used (dexmedetomidine vs. propofol). The postoperative delirium incidence was considered the primary outcome measure; it was determined using the confusion assessment method, on the first three postoperative days. The mean arterial pressure and heart rate were evaluated as secondary outcomes.

RESULTS

The authors enrolled 732 patients in the intention-to-treat analyses. The delirium incidence was lower in the dexmedetomidine group than in the propofol group (11 [3.0%] vs. 24 [6.6%]; odds ratio, 0.42; 95% CI, 0.201 to 0.86; P = 0.036). During sedation, the mean arterial pressure (median [interquartile range] mmHg) was higher in the dexmedetomidine group (77 [71 to 84]) than in the propofol group (74 [69 to 79]; P < 0.001); however, it significantly fell lower (74 [68 to 80]) than that of the propofol group (80 [74 to 87]) in the postanesthesia care unit (P < 0.001). Lower heart rates (beats/min) were recorded with the use of dexmedetomidine than with propofol, both during sedation (60 [55 to 66] vs. 63 [58 to 70]) and in the postanesthesia care unit (64 [58 to 72] vs. 68 [62-77]; P < 0.001).

CONCLUSIONS

Dexmedetomidine showed a lower incidence of postoperative delirium than propofol in healthy older adults undergoing lower extremity orthopedic surgery.

EDITOR’S PERSPECTIVE

Intraoperative infusion of dexmedetomidine for prevention of postoperative delirium in elderly patients undergoing craniotomy: a protocol of randomised clinical trial

INTRODUCTION

Postoperative delirium (POD) is a common surgical complication. The incidence is 19% in neurological procedures, and advanced age is a risk factor for neurological procedures. Many studies have shown that dexmedetomidine (DEX) reduced the incidence of delirium after non-cardiac surgery in elderly patients. However, there are few studies focus on the effect of DEX on POD in elderly patients undergoing neurosurgery.

METHODS AND ANALYSIS

This is a randomised, double-blinded, paralleled-group and controlled trial. Patients older than 65 years and scheduled for elective craniotomy will be randomly assigned to the DEX group and the control group. After endotracheal intubation, patients in the DEX group will be administered with continuous DEX infusion at rate of 0.4 µg/kg/hour until the surgical haemostasis. In the control group, patients will receive the identical volume of normal saline in the same setting. The primary outcome is the incidence of POD during the first 5 days. Delirium will be evaluated through a combination of three methods, including the Richmond Agitation Sedation Scale (RASS), the confusion assessment method for ICU (CAM-ICU) and the 3 min diagnostic interview for CAM (3D-CAM). The RASS, CAM-ICU and 3D-CAM will be evaluated two times per day (08:00-10:00 and 18:00-20:00 hours) during the first postoperative 5 days. Secondary outcomes include pain severity score, quality of recovery, quality of sleep, cognitive function, psychological health state, intraoperative data, physiological status, length of stay in ICU and hospital, hospitalisation costs, non-delirium complications, and 30-day all-cause mortality.

ETHICS AND DISSEMINATION

The protocol (V.4.0) has been approved by the medical ethics committee of Beijing Tiantan Hospital, Capital Medical University (KY2021-194-03). The findings of the study will be disseminated in a peer-reviewed journal and at a scientific conference.

TRIAL REGISTRATION NUMBER

NCT05168280.

Safety implications of concomitant administration of antidepressants and opioid analgesics in surgical patients

BACKGROUND

Commonly prescribed antidepressants (paroxetine, fluoxetine, duloxetine, bupropion) inhibit bioconversion of several prodrug opioid medications to their active metabolite, potentially decreasing analgesic effect. There is a paucity of studies assessing the risk-benefit of concomitant administration of antidepressants and opioids.

RESEARCH DESIGN AND METHODS

Observational study of adult patients taking antidepressants prior to scheduled surgery using 2017-2019 electronic medical record data to assess perioperative use of opioids and to determine the incidence and risk factors for developing postoperative delirium. We conducted a generalized linear regression with the Gamma log-link to assess the association between use of antidepressants and opioids and a logistic regression to assess the association between antidepressants use and the likelihood of developing postoperative delirium.

RESULTS

After controlling for patient demographic and clinical characteristics, and postoperative pain, use of inhibiting antidepressants was associated with 1.67 times greater use of opioids per hospitalization day (p = 0.00154), a two-fold increase in the risk for developing postoperative delirium (p = 0.0224), and an estimated average of four additional days of hospitalization (p < 0.00001) compared to use of non-inhibiting antidepressants.

CONCLUSIONS

Careful consideration to drug-drug interactions and risk of related adverse events remains critical in the safe and optimal management of postoperative pain in patients taking concomitantly antidepressants.

The frequency of emergence delirium in children undergoing outpatient anaesthesia for magnetic resonance imaging

AIM

The aim of this study was to investigate the effect on the occurrence of emergence delirium of propofol and ketofol with intranasal dexmedetomidine and midazolam applied as premedication to paediatric patients during magnetic resonance imaging (MRI).

METHODS

The study included children aged 2-10 years who received sedation for MRI, separated into four groups. Group MP (midazolam-propofol) received intranasal midazolam (0.2 mg/kg) for premedication and intravenous (IV) propofol (1 mg/kg) as the anaesthetic agent. Group MK (midazolam-ketofol) received intranasal midazolam (0.2 mg/kg) for premedication and IV ketofol (1 mg/kg) as the anaesthetic agent. Group DP (dexmedetomidine-propofol) received intranasal dexmedetomidine (1 mcg/kg) for premedication and IV propofol (1 mg/kg) as the anaesthetic agent. Group DK (dexmedetomidine-ketofol) received intranasal dexmedetomidine (1 mcg/kg) for premedication and IV ketofol (1 mg/kg) as the anaesthetic agent. The Paediatric Anaesthesia Emergence Delirium (PAED) scale was used to evaluate delirium. A PAED score ≥ 10 was accepted as delirium.

RESULTS

Statistical analysis was made of 140 paediatric patients. Delirium developed in 1.42% of all the patients, and in 5.7% of Group MP. The mean Aldrete and PAED scores were lower and the length of stay in the recovery room was shorter in Group DP than in the other groups. The need for additional anaesthetic was highest in Group DP at 94.3% and lowest in Group DK at 14.3%. The groups administered ketofol were observed to have a lower requirement for additional anaesthetic.

CONCLUSION

Delirium was seen at a very low rate only in the Group MP and it is difficult to say the best combination in terms of delirium frequency. However, intranasal dexmedetomidine and IV ketofol seem to be better and safer than the other groups in terms of the need for additional doses and the number of side effects. The addition of ketamine to propofol reduces the need for additional doses with a synergistic effect.

Risk prediction models for emergence delirium in paediatric general anaesthesia: a systematic review

OBJECTIVES

Emergence delirium (ED) occurs in approximately 25% of paediatric general anaesthetics and has significant adverse effects. The goal of the current systematic review was to identify the existing literature investigating performance of predictive models for the development of paediatric ED following general anaesthesia and to determine their usability.

DESIGN

Systematic review using the Prediction model study Risk Of Bias Assessment Tool (PROBAST) framework.

DATA SOURCES

Medline (Ovid), PubMed, Embase (Ovid), Cochrane Database of Systematic Reviews (Ovid), Cochrane CENTRAL (Ovid), PsycINFO (Ovid), Scopus (Elsevier) and Web of Science (Clarivate Analytics), ClinicalTrials.gov, International Clinical Trials Registry Platform and ProQuest Digital Dissertations and Theses International through 17 November 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

All randomised controlled trials and cohort studies investigating predictive models for the development of ED in children undergoing general anaesthesia.

DATA EXTRACTION AND SYNTHESIS

Following title, abstract and full-text screening by two reviewers, data were extracted from all eligible studies, including demographic parameters, details of anaesthetics and performance characteristics of the predictive scores for ED. Evidence quality and predictive score usability were assessed according to the PROBAST framework.

RESULTS

The current systematic review yielded 9242 abstracts, of which only one study detailing the development and validation of the Emergence Agitation Risk Scale (EARS) met the inclusion criteria. EARS had good discrimination with c-index of 0.81 (95% CI 0.72 to 0.89). Calibration showed a non-significant Homer-Lemeshow goodness-of-fit test (p=0.97). Although the EARS demonstrated low concern of applicability, the high risk of bias compromised the overall usability of this model.

CONCLUSIONS

The current systematic review concluded that EARS has good discrimination performance but low usability to predict ED in a paediatric population. Further research is warranted to develop novel models for the prediction of ED in paediatric anaesthesia.

PROSPERO REGISTRATION NUMBER

CRD42019141950.

Intraoperative clonidine to prevent postoperative emergence delirium following sevoflurane anesthesia in pediatric patients: a randomized clinical trial

Introduction and objective

Emergence Delirium (ED), particularly in children, is characterized by mental confusion, irritability, disorientation, and inconsolable crying. ED prolongs the time required in the Post-Anesthesia Care Unit (PACU) and increases concern and anxiety in parents. The present study aimed to determine the effectiveness and safety of low-dose clonidine in preventing ED in children receiving sevoflurane anesthesia for tonsillectomy/adenotonsillectomy.

Methods

A randomized, double-blind clinical trial was conducted between November 2013 and January 2014. Sixty-two children aged 2–12 years, scheduled to undergo tonsillectomy/adenotonsillectomy, and classified as American Society of Anesthesiologists (ASA) physical status I/II were included, with 29 being randomized to receive 1 μg.kg^-1 clonidine intravenously, and 33 allocated to a control group that received no clonidine. Anesthesia was induced and maintained with sevoflurane. Children with altered state of consciousness, neurological deficit, history of allergy to dipyrone, or receiving other drugs such as preanesthetic agents were excluded from the study. The primary outcome was the presence of ED in the initial 20 minutes in the PACU according to the Pediatric Anesthesia Emergence Delirium (PAED) scale. The Chi-Square test and Fisher’s two-tailed exact test were used for statistical analysis, as applicable. Significance level was set at 5%, and Risk Ratios (RR) and their 95% Confidence Intervals (95% CI) were calculated.

Results

The frequency of ED was significantly decreased in the group of children who received clonidine (17.2% vs. 57.6%; RR = 0.30; 95% CI 0.13–0.70; p =  0.001). There was no difference between groups with respect to the frequency of postoperative self-harm (falls and bruises), dislodged catheters, and for most of the other adverse events evaluated.

Conclusions

The use of 1 μg.kg^-1 intravenous clonidine during anesthesia induction can effectively reduce the incidence of ED in children undergoing elective tonsillectomy/adenotonsillectomy under general inhalation anesthesia with sevoflurane.

ClinicalTrials.gov Identifier

NCT02181543.

Effect of Tropisetron on Prevention of Emergence Delirium in Patients After Noncardiac Surgery: A Trial Protocol

IMPORTANCE

Postoperative delirium is a frequent disorder for patients undergoing surgery and is associated with poor outcomes. Delirium may occur in the immediate period after anesthesia administration and surgery. Tropisetron, which is frequently administrated for postoperative nausea and vomiting, is also a partial agonist of α7 nicotinic acetylcholine receptors associated with neuroprotective effects. Tropisetron may be the potential pharmacological treatment to decrease delirium after noncardiac surgery.

OBJECTIVE

To perform a randomized clinical trial to determine the efficacy and safety of tropisetron for prevention of emergence delirium in patients undergoing noncardiac surgery.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, 2-arm randomized, double-blind, placebo-controlled trial will include 1508 patients undergoing noncardiac surgery. The intervention group will receive 5 mg of intravenous tropisetron before anesthesia induction, and patients in the control group will receive a placebo. The primary end point is the incidence of emergence delirium within 1 hour after tracheal tube removal, measured by the Confusion Assessment Method for the Intensive Care Unit score. The main secondary outcome is the incidence of postoperative delirium measured at 3 days of follow-up. An intention-to-treat principle will be used for all analyses.

DISCUSSION

Delirium remains the most common neuropsychiatric complication for patients after surgery. This will be the first randomized clinical study to evaluate whether tropisetron is effective in preventing emergence delirium. Results from this study will provide evidence for alteration of daily practice.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04027751.

Current Evidence-Based Practice for Pediatric Emergence Agitation

This article provides a systematic review of pediatric emergence agitation, also known as emergence delirium. Major topics of this review include the incidence, risk factors, and impact of the phenomenon, in addition to current evidence-based strategies for prevention of pediatric emergence agitation. Emergence agitation causes tremendous psychological distress for the patient, family, and healthcare providers, as well as concerns for physical safety. Risk factors for pediatric emergence agitation are the child's age, genetic profile, length and type of surgical procedure, and use of inhalational anesthesia. In an attempt to prevent this problem, anesthesia providers should consider these factors and possible interventions when implementing an anesthetic plan. Evidence-based interventions that may decrease the incidence of pediatric emergence agitation include technology, familial involvement, pharmacologic adjuncts, and alternative methods of general anesthesia.

Comparison of effects of propofol and ketofol (Ketamine-Propofol mixture) on emergence agitation in children undergoing tonsillectomy

BACKGROUND

The aim of this study was to compare the effect of propofol and ketofol (ketamine-propofol mixture) on EA in children undergoing tonsillectomy.

METHOD

In this randomized clinical trial, 87 ASA class I and II patients, aged 3-12 years, who underwent tonsillectomy, were divided into two groups to receive either propofol 100 µg/kg/min (group p, n=44) or ketofol : ketamine 25 µg/kg/min + propofol 75 µg/kg/min (group k, n= 43). Incidence and severity of EA was evaluated using the Pediatric Anesthesia Emergence Delirium (PAED) scales on arrival at the recovery room, and 10 and 30 min after that time.

RESULTS

There was no statistically significant difference in demographic data between the two groups. In the ketofol group, the need for agitation treatment and also mean recovery duration were lower than in the propofol group (30 and 41%, and 29.9 and 32.7 min), without statistically significant difference (P value=0.143 and P value=0.187). Laryngospasm or bronchospasm occurred in 2 patients in each group and bleeding was observed in only one individual in the ketofol group.

CONCLUSION

Infusion of ketofol in children undergoing tonsillectomy provides shorter recovery time and lower incidence of EA despite the non significant difference with propofol.

The influence of analgesic-based sedation protocols on delirium and outcomes in critically ill patients: A randomized controlled trial

OBJECTIVE

To investigate the influence of analgesic-based midazolam sedation on delirium and outcomes in critically ill patients and to analyze the risk factors of delirium.

DESIGN

Single center, prospective randomized controlled trial.

SETTING

A surgical intensive care unit (ICU) in a tertiary care hospital in China.

PATIENTS

Mechanically ventilated patients requiring sedation.

MEASUREMENTS AND MAIN RESULTS

Patients admitted to the surgical intensive care unit who required sedation and were undergoing mechanical ventilation for longer than 24 hours were randomly divided into three groups: 1) the remifentanil group received remifentanil and midazolam, 2) the fentanyl group received fentanyl and midazolam, and 3) the control group received only midazolam. The analgesic effect, sedation depth, and presence of delirium were evaluated. To compare the effect of different therapies on the occurrence of delirium, days of mechanical ventilation, length of the ICU stay, and 28-day mortality were measured along with the risk factors for delirium. A total of 105 patients were enrolled, and 35 patients were included in each group. Compared to the control group, patients who received remifentanil and fentanyl required less midazolam each day (P = 0.038 and <0.001, respectively). Remifentanil has a significant effect on reducing the occurrence of delirium (P = 0.007). The logistic regression analysis of delirium demonstrated that remifentanil (OR 0.230, 95%Cl 0.074-0.711, P = 0.011) is independent protective factors for delirium, and high APACHE II score (OR 1.103, 95%Cl 1.007-1.208, P = 0.036) is the independent risk factor for delirium.

CONCLUSION

Remifentanil and fentanyl can reduce the amount of midazolam required, and remifentanil could further reduce the occurrence of delirium.

Impact of dexmedetomidine on the incidence of delirium in elderly patients after cardiac surgery: A randomized controlled trial

Background

Delirium is a frequent complication after cardiac surgery and its occurrence is associated with poor outcomes. The purpose of this study was to investigate the impact of perioperative dexmedetomidine administration on the incidence of delirium in elderly patients after cardiac surgery.

Methods

This randomized, double-blinded, and placebo-controlled trial was conducted in two tertiary hospitals in Beijing between December 1, 2014 and July 19, 2015. Eligible patients were randomized into two groups. Dexmedetomidine (DEX) was administered during anesthesia and early postoperative period for patients in the DEX group, whereas normal saline was administered in the same rate for the same duration for patients in the control (CTRL) group. The primary endpoint was the incidence of delirium during the first five days after surgery. Secondary endpoints included the cognitive function assessed on postoperative days 6 and 30, the overall incidence of non-delirium complications within 30 days after surgery, and the all-cause 30-day mortality.

Results

Two hundred eighty-five patients were enrolled and randomized. Dexmedetomidine did not decrease the incidence of delirium (4.9% [7/142] in the DEX group vs 7.7% [11/143] in the CTRL group; OR 0.62, 95% CI 0.23 to 1.65, p = 0.341). Secondary endpoints were similar between the two groups; however, the incidence of pulmonary complications was slightly decreased (OR 0.51, 95% CI 0.26 to 1.00, p = 0.050) and the percentage of early extubation was significantly increased (OR 3.32, 95% CI 1.36 to 8.08, p = 0.008) in the DEX group. Dexmedetomidine decreased the required treatment for intraoperative tachycardia (21.1% [30/142] in the DEX group vs 33.6% [48/143] in the CTRL group, p = 0.019), but increased the required treatment for postoperative hypotension (84.5% [120/142] in the DEX group vs 69.9% [100/143] in the CTRL group, p = 0.003).

Conclusions

Dexmedetomidine administered during anesthesia and early postoperative period did not decrease the incidence of postoperative delirium in elderly patients undergoing elective cardiac surgery. However, considering the low delirium incidence, the trial might have been underpowered.

Trial Registration

ClinicalTrials.gov NCT02267538