Efficacy of perioperative dexmedetomidine on postoperative delirium: systematic review and meta-analysis with trial sequential analysis of randomised controlled trials

Development and validation of a machine learning model to predict postoperative delirium using a nationwide database: A retrospective, observational study

STUDY OBJECTIVE

Postoperative delirium is a neuropsychological syndrome that typically occurs in surgical patients. Its onset can lead to prolonged hospitalization as well as increased morbidity and mortality. Therefore, it is important to promptly identify its signs. This study aimed to develop and validate a machine learning predictive model for postoperative delirium using extensive population data.

DESIGN

Retrospective observational study.

SETTING

Japanese Diagnosis Procedure Combination inpatient data. Data were used for internal (2016.4-2018.12) and temporal validation (2019.01-2019.10).

PATIENTS

Patients aged ≥65 years who underwent general anesthesia for surgical procedure.

MEASUREMENTS

The primary outcome was postoperative delirium, which was defined as a condition requiring newly prescribed antipsychotic drugs or assignment of the corresponding insurance claim code after the date of surgery. We trained and tuned the optimal machine-learning model through 10-fold cross-validation using the selected optimal area under the receiver operating characteristic curve (AUC) value. In the temporal validation, we measured the performance of our model.

MAIN RESULTS

The analysis included 557,990 patients. The light-gradient boosting machine models showed a higher AUC value (0.826 [95% confidence interval (CI): 0.822-0.829]) than the other models. Regarding performance, the model had a recall value of 0.124 (95% CI: 0.119-0.129) and precision value of 0.659 (95% CI: 0.641-0.677]). This performance was sustained in the temporal validation (AUC, 0.815 [95% CI: 0.811-0.818]). At a sensitivity of 0.80, the model achieved a specificity of 0.672 (95% CI: 0.670-0.674]), a negative predictive value of 0.975 (95% CI: 0.974-0.975), and a positive predictive value of 0.176 (95% CI: 0.176-0.179).

CONCLUSIONS

Using extensive Diagnostic Procedure Combination data, we successfully created and validated a machine learning model for predicting postoperative delirium. This model may facilitate prediction of postoperative delirium.

Dexmedetomidine-mediated improvement of perioperative neurocognitive disorders by miR-184-3p-mediated NLRP3

BACKGROUND

Perioperative neurocognitive disorders (PND) is a neurological complication in the perioperative period, which may lead to severe poor prognosis. Dexmedetomidine (Dex) is a commonly used sedative in the perioperative period. However, the effect of intraoperative anesthetic Dex on PND remain complicated and confusing.

METHODS

PND model was established using aged male mice, treated with Dex, and subjected to behavioral tests. The effect of Dex on pyroptosis was assessed by western blot, enzyme-linked immunosorbent assay and immunofluorescence. In addition, the miRNA expression profile of PND mice was identified by small RNA sequencing and performed PCR to detect miRNAs. Finally, the effect of miRNA on mice neuron pyroptosis was verified in vitro.

RESULTS

We found postoperative cognitive was declined in PND mice compared with control group, while preoperative injection of Dex improved short-term working memory and anxious exploration behavior, alleviated the cognitive impairment. Intriguingly, Dex ameliorated hippocampal inflammation and neuron pyroptosis in PND mice as evidenced by the reduced GSDMD, NLRP3, IL-1β and IL-18. The miRNA expression profile of PND mice hippocampus was disordered, including 5 miRNAs up-regulated and 17 miRNAs down-regulated, compared to the sham group. Dysregulated miRNAs were mainly enriched in biological functions related to neuronal development and signaling pathways related to pyroptosis. MiR-184-3p was the key miRNA, overexpression of miR-184-3p blocked the inhibitory effect of Dex on neuron pyroptosis, which was manifested as increased expression of GSDMD and NLRP3, increased inflammatory factors IL-1β and IL-18.

CONCLUSIONS

This study revealed that miR-184-3p may mediate NLRP3 to prevent the alleviate effect of Dex on PND, which provides a new potential way to improve the therapeutic intervention of PND.

Dexmedetomidine Attenuates Inflammation in Elderly Patients Following Major Hepatobiliary and Pancreatic Surgery: A Randomized Clinical Trial

Background

Dexmedetomidine (Dex) may have anti-inflammatory properties and potentially reduce the incidence of postoperative organ injury.

Objective

To investigate whether Dex protects pulmonary and renal function via its anti-inflammatory effects in elderly patients undergoing prolonged major hepatobiliary and pancreatic surgery.

Design and Setting

Between October 2019 and December 2020, this randomized controlled trial was carried out at a tertiary hospital in Chongqing, China.

Patients

86 patients aged 60-75 who underwent long-duration (> 4 hrs) hepatobiliary and pancreatic surgery without significant comorbidities were enrolled and randomly assigned into two groups at a 1:1 ratio.

Interventions

Patients were given either Dex or an equivalent volume of 0.9% saline (Placebo) with a loading dose of 1 μg kg-1 for 10 min, followed by 0.5 μg kg-1 hr-1 for maintenance until the end of surgery.

Main Outcome Measures

The changes in serum concentrations of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were primary outcomes.

Results

At one hour postoperatively, serum IL-6 displayed a nine-fold increase (P<0.05) in the Placebo group. Administration of Dex decreased IL-6 to 278.09 ± 45.43 pg/mL (95% CI: 187.75 to 368.43) compared to the Placebo group (P=0.019; 432.16 ± 45.43 pg/mL, 95% CI: 341.82 to 522.50). However, no significant differences in TNF-α were observed between the two groups. The incidence of postoperative acute kidney injury was twice as high in the Placebo group (9.30%) compared to the Dex group (4.65%), and the incidence of postoperative acute lung injury was 23.26% in the Dex group, lower than that in the Placebo group (30.23%), although there was no statistical significance between the two groups.

Conclusion

Dex administration in elderly patients undergoing major hepatobiliary and pancreatic surgery reduces inflammation and potentially protects kidneys and lungs.

Registration

Chinese Clinical Trials Registry, identifier: ChiCTR1900024162, on 28 June 2019.

The influence of dexmedetomidine added to ropivacaine for transversus abdominis plane block on perioperative neurocognitive disorders after radical colorectal cancer surgery: randomized, double-blind, controlled trial

OBJECTIVE

Perioperative Neurocognitive Disorders (PND) is a common neurological complication after radical colorectal cancer surgery, which increases adverse outcomes. So, our objective is to explore the influence of dexmedetomidine added to ropivacaine for transversus abdominis plane block (TAPB) on perioperative neurocognitive disorders, and to provide a new way to reduce the incidence of PND.

METHODS

One hundred and eighty patients submitted to radical laparoscopic colorectal cancer surgery were randomly divided into Control group and Dex group. Ultrasound guided TAPB was performed after anesthesia induction: 0.5% ropivacaine 20 ml was injected into each transversus abdominis plane in Control group, 0.5% ropivacaine + 1 μg/kg dexmedetomidine (amounting to 20 ml) in Dex group. We observed the incidence of PND within 30 days after surgery.

RESULTS

One hundred and sixty-nine cases were finally analyzed, including 84 cases in Control group and 85 cases in Dex group. Compared with Control group, there was no significant difference in terms of the incidence of PND on the 3rd day and the 7th day (P > 0.05), but the incidence significantly decreased at the 6th hour, at the 24th hour and on the 30th day after surgery (P < 0.05) in Dex group.

CONCLUSION

Dexmedetomidine added to ropivacaine for TAPB can reduce the incidence of PND in the first 24 h after surgery and on the 30th postoperative day, which may be related to reduce the consumption of general anesthetics and provide satisfactory postoperative analgesia.

TRIAL REGISTRATION

29 /05/ 2021, ChiCTR2100046876.

The effectiveness of dexmedetomidine for preventing acute kidney injury after surgery: a systematic review and meta-analysis

Background

Postoperative acute kidney injury (AKI) is a serious and distressing complication connected to various adverse outcomes following the surgical operation. Controversy remains regarding the dexmedetomidine's preventive impact on postoperative AKI. Therefore, this investigation aims to explore the efficiency and safety of dexmedetomidine in preventing AKI after surgical operation.

Methods

We systematically searched electronic databases such as PubMed, Embase, Web of Science, and the Cochrane Library to detect eligible randomized controlled studies that used dexmedetomidine for the prevention of AKI following operation up to April 30, 2023. The main outcome evaluated was AKI incidence. The evidence quality was assessed employing the Grading of Recommendations Assessment, Development, and Evaluation.

Results

The meta-analysis included 25 trials, including 3,997 individuals. Of these, 2,028 were in the dexmedetomidine group, and 1,969 were in the control group. The result showed that patients administered dexmedetomidine significantly decreased the AKI incidence following surgical operation in contrast to the control group (risk ratio, 0.60; 95% confidence intervals, 0.45-0.78; p < 0.05; I 2 = 46%). In addition, dexmedetomidine decreased the period of hospitalization in both the intensive care unit (ICU) and the hospital while also reducing postoperative delirium (POD) occurrence. However, dexmedetomidine elevated the incidence of bradycardia but did not have a significant impact on other indicators.

Conclusion

Our meta-analysis indicates that the dexmedetomidine treatment reduces the postoperative AKI and POD risk while also shortening the time of hospitalization in the ICU and hospital. However, it is connected to an increased bradycardia risk.

Relationship Between Coronary Artery Revascularization and Postoperative Delirium: Progress and Perspectives

Brain dysfunction resulting from damage to the heart-brain link leads to a decline in cognitive function. This, in turn, gives rise to the clinical symptom of perioperative delirium in patients undergoing coronary artery revascularization. Those affected are provided symptomatic treatment, but many do not recover fully. Thus, medium- and long-term mortality and adverse event rates remain relatively high in patients with perioperative delirium. Despite the relatively high incidence of perioperative delirium in patients undergoing coronary artery revascularization, it has not been systematically investigated. Inflammation, vascular damage, neuronal damage, and embolism are all involved in the injury process. Here, we discuss the incidence rate, pathological mechanisms, and prognosis of delirium after coronary artery revascularization. We also discuss in detail the risk factors for delirium after coronary artery revascularization, such as anxiety, depression, mode of operation, and drug use. We hope that prevention, early diagnosis, assessment, and potential treatment can be achieved by cardiologists to improve patient prognosis.

Is the Use of Dexmedetomidine Upon Emergence From Anesthesia Associated With Neck Hematoma Formation Following Head and Neck Microvascular Reconstruction?

BACKGROUND

Dexmedetomidine (DEX) is a highly selective alpha-2-receptor agonist, and its use has not been well studied in major microvascular reconstructive surgery of the head and neck.

PURPOSE

The purpose is to measure the association between DEX and neck hematoma formation in subjects undergoing head and neck microvascular reconstructive surgery.

STUDY DESIGN, SETTING, SAMPLE

The investigators implemented a retrospective cohort study on subjects undergoing microvascular head and neck reconstruction for benign and malignant pathology at the University of Alabama at Birmingham from 2014 to 2021. Patients with unresectable tumors were excluded.

PREDICTOR VARIABLE

The predictor variable was the intraoperative use of DEX upon emergence from general anesthesia. Subjects received standard anesthetic drugs and DEX, while control subjects received only standard anesthetic drugs.

MAIN OUTCOME VARIABLE(S)

The primary outcome was postoperative neck hematoma formation necessitating a return to the operating theater. The secondary outcome was the length of stay (LOS).

COVARIATES

The covariates were demographic, operative, and oral morphine equivalents of anesthesia drugs.

ANALYSES

Bivariate analyses were performed using the Student's t-test and the χ2 test for continuous and categorical variables. Multivariate regression analyses were conducted to assess for associations between DEX and the outcomes adjusted for confounding variables when present. P values of < .05 were regarded as statistically significant.

RESULTS

A total of 297 subjects (mean age, 59.6 years, and standard deviation [SD], 14.9) with 61.6% male received DEX, and 304 subjects (mean age, 58.9 years, and SD, 14.6) with 60.2% male served as controls (P > .5). A total of 11 postoperative neck hematoma occurred in the control group when compared to 2 in the DEX (relative risk = 5.4, 95% confidence interval [CI], 1.2 to 24, P = .02). The mean LOS was 7.7 (SD, 4.3) and 9.4 (SD, 8.1) for the DEX and control groups (95% CI, 0.7 to 2.8, P < .01). After adjusting for tobacco history, tracheostomy, and neck dissection, DEX (Beta coefficient (B) = -1.7, 95% CI -2.7 to -0.7, P < .01) and neck dissection (B = 2.2, 95% CI 1.0 to 3.4, P < .01) were statistically associated with LOS.

CONCLUSION AND RELEVANCE

The use of intraoperative DEX upon emergence from general anesthesia was associated with lower postoperative neck hematoma formation and a shorter length of stay following microvascular head and neck reconstruction.

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).

Electroencephalographic spectrogram-guided total intravenous anesthesia using dexmedetomidine and propofol prevents unnecessary anesthetic dosing during craniotomy: a propensity score-matched analysis

BACKGROUND

The bispectral index (BIS) may be unreliable to gauge anesthetic depth when dexmedetomidine is administered. By comparison, the electroencephalogram (EEG) spectrogram enables the visualization of the brain response during anesthesia and may prevent unnecessary anesthetic consumption.

METHODS

This retrospective study included 140 adult patients undergoing elective craniotomy who received total intravenous anesthesia using a combination of propofol and dexmedetomidine infusions. Patients were equally matched to the spectrogram group (maintaining the robust EEG alpha power during surgery) or the index group (maintaining the BIS score between 40 and 60 during surgery) based on the propensity score of age and surgical type. The primary outcome was the propofol dose. Secondary outcome was the postoperative neurological profile.

RESULTS

Patients in the spectrogram group received significantly less propofol (1585 ± 581 vs. 2314 ± 810 mg, P < 0.001). Fewer patients in the spectrogram group exhibited delayed emergence (1.4% vs. 11.4%, P = 0.033). The postoperative delirium profile was similar between the groups (profile P = 0.227). Patients in the spectrogram group exhibited better in-hospital Barthel's index scores changes (admission state: 83.6 ± 27.6 vs. 91.6 ± 17.1; discharge state: 86.4 ± 24.3 vs. 85.1 ± 21.5; group-time interaction P = 0.008). However, the incidence of postoperative neurological complications was similar between the groups.

CONCLUSIONS

EEG spectrogram-guided anesthesia prevents unnecessary anesthetic consumption during elective craniotomy. This may also prevent delayed emergence and improve postoperative Barthel index scores.

Determination of the 90% Effective Dose of Dexmedetomidine for Treating Postoperative Catheter‑related Bladder Discomfort During Recovery: An Open-label, Single-group Study

PURPOSE

Catheter-related bladder discomfort (CRBD) is an unpleasant experience for patients during postoperative recovery. Dexmedetomidine is an effective therapy for CRBD; however, little is known about dexmedetomidine administration for treating CRBD during recovery. This study was conducted to determine the 90% effective dose (ED90) of dexmedetomidine to provide adequate treatment for CRBD during recovery.

DESIGN

Prospective, single-blind dose-finding study.

METHODS

This open-label, single-group trial included severe postoperative CRBD patients aged 18 to 80 years and the American Society of Anesthesiologists' physical status class I or II in the postanesthesia care unit. All patients were assigned to receive intravenous dexmedetomidine. The dose of dexmedetomidine was determined using the modified Dixon's up-and-down method. The first patient was treated with 0.4 mcg/kg dexmedetomidine. An increment or decrement of 0.05 mcg/kg dexmedetomidine was used based on the response of the previous patient. A successful treatment was defined as the transition from severe CRBD to mild CRBD. Probit regression was applied to calculate the ED90 of dexmedetomidine.

FINDINGS

A total of 29 patients were recruited, of whom 14 patients (48.3%) underwent successful treatment. The ED90 of dexmedetomidine required for successfully treating postoperative CRBD was 0.55 mcg/kg (95% confidence interval: 0.49-1.54 mcg/kg).

CONCLUSIONS

The ED90 of dexmedetomidine for the successful treatment of severe postoperative CRBD during recovery is 0.55 mcg/kg.

Clinical Use of Adrenergic Receptor Ligands in Acute Care Settings

In this chapter, we review how ligands, both agonists and antagonists, for the major classes of adrenoreceptors, are utilized in acute care clinical settings. Adrenergic ligands exert their effects by interacting with the three major classes of adrenoceptors. Adrenoceptor agonists and antagonists have important applications, ranging from treatment of hypotension to asthma, and have proven to be extremely useful in a variety of clinical settings of acute care from the operating room to the critical care environment. Continued research interpreting the mechanisms of adrenoreceptors may help the discovery of new drugs with more desirable clinical profiles.

Different Sedation Strategies in Older Patients Receiving Spinal Anesthesia for Hip Surgery on Postoperative Delirium: A Randomized Clinical Trial

Background

Postoperative delirium (POD) is of great concern as a complication of surgery in older adult patients. Sedation strategies influence the development of POD. This study compared how sedation strategies administered during spinal anesthesia influenced POD in patients aged ≥65 years undergoing elective surgery for hip fracture repair.

Patients and Methods

A randomized clinical trial was conducted from 1 August 2021 to 30 June 2022 at a single academic medical center. Two hundred and twenty-six patients were randomly divided into four groups: lighter sedation with propofol (LP), heavier sedation with propofol (HP), lighter sedation with dexmedetomidine (LD), and heavier sedation with dexmedetomidine (HD). The incidence of delirium was the primary outcome and was assessed daily by the blinded Confusion Assessment Method.

Results

There was a significant association between dexmedetomidine (LD+HD group) and a lower incidence of delirium (11.9% [13/109] vs the propofol group (23.6% [26/110]; Risk ratio, 0.51; 95% CI, 0.274 to 0.929; p=0.024). In the propofol group, heavier sedation had a higher rate of POD (32.7% [18/55] vs the lighter sedation group (14.5% [8/55]; Risk ratio, 2.25; 95% CI, 1.069 to 4.736; p=0.025).

Conclusion

Dexmedetomidine was associated with a lower incidence of delirium than that with propofol among older patients with hip fractures. In patients that received propofol, heavier sedation was associated with high incidence of POD.

Application of Butorphanol versus Sufentanil in Multimode Analgesia via Patient Controlled Intravenous Analgesia After Hepatobiliary Surgery: A Retrospective Cohort Study

Purpose

We investigate the efficacy and safety of butorphanol in multimodal analgesia combined with dexmedetomidine and ketorolac via patient-controlled intravenous analgesia (PCIA) after hepatobiliary surgery, as compared with sufentanil.

Patients and Methods

Postoperative follow-up data of hepatobiliary surgery patients in Henan Provincial People's Hospital from March 2018 to June 2021 were collected retrospectively and divided into butorphanol group (group B) or sufentanil group (group S) according to the postoperative intravenous controlled analgesia scheme. The baseline characteristics and surgical information of the two groups were matched through propensity score matching (PSM).

Results

A total of 3437 patients were screened, and PSM yielded 1816 patients after matching, including 908 in the butorphanol group and 908 in the sufentanil group. Compared with group S, the incidence of moderate-to-severe pain on the first postoperative day and the second postoperative day was lower in group B during rest (3.2% vs 10.9%, P<0.001; 1.2% vs 4.6%, P<0.001), and during movement (7.0% vs 18.9%, P<0.001; 2.6% vs 8.7%, P<0.001). Patients receiving butorphanol had a lower morphine consumption (50mg vs 120mg, P<0.001). The bolus attempts of an analgesic pump in group B were significantly lower than in group S (1 vs 2, P<0.001). Postoperative hospital length of stay was shortened in group B (11d vs 12d, P=0.017). The occurrence of postoperative vomiting was lower in group B (1.4% vs 3.0%, P=0.025) than in group S. However, more patients in group B experienced dizziness (0.9% vs 0.1%, P=0.019).

Conclusion

Compared with sufentanil, the application of butorphanol in multimodal analgesia combined with dexmedetomidine and ketorolac via PCIA ameliorated postoperative pain after hepatobiliary surgery, with reduced opioid consumption and shorter postoperative hospital length of stay.

Effects of dexmedetomidine dosage on the short-term cognitive function of elderly patients undergoing cardiac surgery

BACKGROUND

This study aimed to investigate the effects of perioperative dexmedetomidine (DEX) infusion rates on the postoperative short-term cognitive function.

METHODS

A total of 88 patients aged ≥ 60 years who underwent cardiac surgery from January 2022 to November 2022 at the First Affiliated Hospital of The University of Science and Technology of China (USTC) were included. Based on a single-center pilot analysis, patients were divided into two groups according to the rate of intraoperative DEX infusion, which started after tracheal intubation and continued until 1 h before extubation in the cardiac surgery intensive care unit. In Group L (n = 44), the infusion rate was 0.1-0.5 µg/kg/h (low-dose group), whereas in Group H (n = 44), the infusion rate was 0.5-0.9 µg/kg/h (high-dose group). Clinical outcomes were then compared between the groups. The Mini-Mental State Evaluation (abbreviated as MMSE1, MMSE2, MMSE3, and MMSE4) scale was used for the assessment of cognitive function, which was conducted on postoperative Days 2 (T1), 7 (T2), 14 (T3), and 28 (T4), with the score from postoperative Day 2 (MMSE1) considered as the primary observation.

RESULTS

Patients in Group L had higher MMSE1 scores compared to those in Group H (26.0 [24.0, 27.0] vs. 24.5 [22.0, 26.0], p = 0.046), and there was no significant difference in the scores between the groups at all subsequent time points. Group H exhibited a higher incidence of hypotension and bradycardia compared to Group L (p = 0.044 and p = 0.047, respectively).

CONCLUSIONS

Compared to a high dose (0.5-0.9 µg/kg/h) of DEX infusion, a low-dose (0.1-0.5 µg/kg/h) infusion started after induction of anesthesia and continued until 1 h before extubation improved postoperative cognitive function scores on postoperative Day 2 in patients aged 60 years and older.

TRIAL REGISTRATION

URL: www.chictr.org.cn with registration number ChiCTR2100055093, registered on 31/12/2021.

Neurologic complications after cardiopulmonary bypass - A narrative review

Neurologic complications, associated with cardiac surgery and cardiopulmonary bypass (CPB) in adults, are common and can be devastating in some cases. This comprehensive review will not only consider the broad categories of stroke and neurocognitive dysfunction, but it also summarises other neurological complications associated with CPB, and it provides an update about risks, prevention and treatment. Where appropriate, we consider the impact of off-pump techniques upon our understanding of the contribution of CPB to adverse outcomes.

Ketamine: A Practical Review for the Consultation-Liaison Psychiatrist

BACKGROUND

Ketamine is a noncompetitive N-methyl-D-aspartate-receptor antagonist often used for sedation and management of acute agitation in general hospital settings. Many hospitals now include ketamine as part of their standard agitation protocol, and consultation-liaison psychiatrists frequently find themselves treating patients who have received ketamine, despite lack of clear recommendations for management.

OBJECTIVE

Conduct a nonsystematic narrative review regarding the use of ketamine for agitation and continuous sedation, including benefits and adverse psychiatric effects. Compare ketamine to more traditional agents of agitation control. Provide consultation-liaison psychiatrists with a summary of available knowledge and recommendations for managing patients receiving ketamine.

METHODS

A literature review was performed using PubMed, querying published articles from inception to March 2023 for articles related to use of ketamine for agitation or continuous sedation and side effects including psychosis and catatonia.

RESULTS

A total of 37 articles were included. Ketamine was found to have multiple benefits, including shorter time to adequate sedation for agitated patients when compared to haloperidol ± benzodiazepines and unique advantages for continuous sedation. However, ketamine carries significant medical risks including high rates of intubation. Ketamine appears to induce a syndrome that mimics schizophrenia in healthy controls, and such effects are more pronounced and longer-lasting in patients with schizophrenia. Evidence regarding rates of delirium with ketamine for continuous sedation is mixed and requires further investigation before the agent is widely adopted for this purpose. Finally, the diagnosis of "excited delirium syndrome" and use of ketamine to treat this controversial syndrome warrants critical evaluation.

CONCLUSIONS

Ketamine carries many potential benefits and can be an appropriate medication for patients with profound undifferentiated agitation. However, intubation rates remain high, and ketamine may worsen underlying psychotic disorders. It is essential that consultation-liaison psychiatrists understand the advantages, disadvantages, biased administration, and areas of limited knowledge regarding ketamine.

Analgesia for the Bayesian Brain: How Predictive Coding Offers Insights Into the Subjectivity of Pain

PURPOSE OF REVIEW

In order to better treat pain, we must understand its architecture and pathways. Many modulatory approaches of pain management strategies are only poorly understood. This review aims to provide a theoretical framework of pain perception and modulation in order to assist in clinical understanding and research of analgesia and anesthesia.

RECENT FINDINGS

Limitations of traditional models for pain have driven the application of new data analysis models. The Bayesian principle of predictive coding has found increasing application in neuroscientific research, providing a promising theoretical background for the principles of consciousness and perception. It can be applied to the subjective perception of pain. Pain perception can be viewed as a continuous hierarchical process of bottom-up sensory inputs colliding with top-down modulations and prior experiences, involving multiple cortical and subcortical hubs of the pain matrix. Predictive coding provides a mathematical model for this interplay.

Effects of neuraxial or general anaesthesia on postoperative adverse events in oldest-old patients (aged 90 years and older) with intertrochanteric fractures: a retrospective study

BACKGROUND

To retrospectively analyse postoperative adverse events in oldest-old patients (aged 90 years and older) with intertrochanteric fractures treated under various anaesthetic techniques.

METHODS

A total of 153 consecutive patients participated in this study, of which 127 patients who underwent surgery with neuraxial anaesthesia or general anaesthesia for intertrochanteric fractures between October 2019 and October 2022 were eligible and evaluated. They were divided into the neuraxial anaesthesia and general anaesthesia groups. The demographic characteristics and postoperative adverse events were compared between the two groups.

RESULTS

A total of 13 patients (10.24%), including 6 in the neuraxial anaesthesia group (8.22%) and 7 in the general anaesthesia group (12.96%), died within 30 days after surgery. No significant differences between the two groups were observed. Postoperative delirium occurred in 40 patients (31.49%), including 17 (23.29%) in the neuraxial anaesthesia group and 23 (42.59%) in the general anaesthesia group; there was a significant difference between the two groups [P = 0.02, odds ratio (OR) = 0.41]. The other postoperative adverse events, including heart failure, acute stroke, acute myocardial infarction, pulmonary disease, anaemia, deep vein thrombosis, hypoproteinaemia, and electrolyte disorders, were not significantly different between the two groups.

CONCLUSION

Our data suggest that different anaesthesia methods do not affect the incidence of adverse events, such as death within 30 days after surgery in oldest-old patients with intertrochanteric fractures. However, more patients developed delirium after surgery in the general anaesthesia group (23, 42.59%) than in the neuraxial anaesthesia group (17, 23.29%); this may indicate that spinal anaesthesia reduces the incidence of postoperative delirium (P = 0.02, OR = 0.41).

TRIAL REGISTRATION

Retrospectively registered.

The Effect of Dexmedetomidine on the Mini-Cog Score and High-Mobility Group Box 1 Levels in Elderly Patients with Postoperative Neurocognitive Disorders Undergoing Orthopedic Surgery

Dexmedetomidine prevents postoperative cognitive dysfunction by inhibiting high-mobility group box 1 (HMGB1), which acts as an inflammatory marker. This study investigated the HMGB1 levels and the cognitive function using a Mini-Cog© score in elderly patients undergoing orthopedic surgery with dexmedetomidine infusion. In total, 128 patients aged ≥ 65 years were analyzed. The patients received saline in the control group and dexmedetomidine in the dexmedetomidine group until the end of surgery. Blood sampling and the Mini-Cog© test were performed before the surgery and on postoperative days 1 and 3. The primary outcomes were the effect of dexmedetomidine on the HMGB1 levels and the Mini-Cog© score in terms of postoperative cognitive function. The Mini-Cog© score over time differed significantly between the groups (p = 0.008), with an increase in the dexmedetomidine group. The postoperative HMGB1 levels increased over time in both groups; however, there was no significant difference between the groups (p = 0.969). The probability of perioperative neurocognitive disorders decreased by 0.48 times as the Mini-Cog© score on postoperative day 3 increased by 1 point. Intraoperative dexmedetomidine has shown an increase in the postoperative Mini-Cog© score. Thus, the Mini-Cog© score is a potential tool for evaluating cognitive function in elderly patients.

Taming Postoperative Delirium with Dexmedetomidine: A Review of the Therapeutic Agent's Neuroprotective Effects following Surgery

Postoperative delirium (POD) represents a perioperative neurocognitive disorder that has dreaded ramifications on a patient's recovery from surgery. Dexmedetomidine displays multiple mechanisms of neuroprotection to assist in preventing POD as a part of a comprehensive anesthetic care plan. This review will cover dexmedetomidine's pharmacological overlap with the current etiological theories behind POD along with pre-clinical and clinical studies on POD prevention with dexmedetomidine. While the body of evidence surrounding the use of dexmedetomidine for POD prevention still requires further development, promising evidence exists for the use of dexmedetomidine in select dosing and circumstances to enhance recovery from surgery.

Depth of sedation with dexmedetomidine increases transcranial magnetic stimulation-evoked potential amplitude non-linearly

BACKGROUND

Cortical excitability is higher in unconsciousness than in wakefulness, but it is unclear how this relates to anaesthesia. We investigated cortical excitability in response to dexmedetomidine, the effects of which are not fully known.

METHODS

We recorded transcranial magnetic stimulation (TMS) and EEG in frontal and parietal cortex of 20 healthy subjects undergoing dexmedetomidine sedation in four conditions (baseline, light sedation, deep sedation, recovery). We used the first component (0-30 ms) of the TMS-evoked potential (TEP) to measure cortical excitability (amplitude), slope, and positive and negative peak latencies (collectively, TEP indices). We used generalised linear mixed models to test the effect of condition, brain region, and responsiveness on TEP indices.

RESULTS

Compared with baseline, amplitude in the frontal cortex increased by 6.52 μV (P<0.001) in light sedation, 4.55 μV (P=0.003) in deep sedation, and 5.03 μV (P<0.001) in recovery. Amplitude did not change in the parietal cortex. Compared with baseline, slope increased in all conditions (P<0.02) in the frontal but not parietal cortex. The frontal cortex showed 5.73 μV higher amplitude (P<0.001), 0.63 μV ms-1 higher slope (P<0.001), and 2.2 ms shorter negative peak latency (P=0.001) than parietal areas. Interactions between dexmedetomidine and region had effects over amplitude (P=0.004) and slope (P=0.009), with both being higher in light sedation, deep sedation, and recovery compared with baseline.

CONCLUSIONS

Transcranial magnetic stimulation-evoked potential amplitude changes non-linearly as a function of depth of sedation by dexmedetomidine, with a region-specific paradoxical increase. Future research should investigate other anaesthetics to elucidate the link between cortical excitability and depth of sedation.

Postoperative infusion of dexmedetomidine via intravenous patient-controlled analgesia for prevention of postoperative delirium in elderly patients undergoing surgery

BACKGROUND

Postoperative delirium (POD) is a common clinical complication in elderly patients after surgery and predicts poor outcomes.

AIM

We researched whether postoperative infusion of dexmedetomidine (DEX) had prophylactic effect on POD in elderly patients.

METHODS

A total of 236 patients over the age of 60 years undergoing thoracoabdominal tumor surgery were enrolled in Zhejiang Cancer Hospital from November 2016 to October 2020. The patients were randomly assigned into DEX group (group D) and control group (Group C). DEX was provided via PCIA pump 1-3 days after surgery, which consisted of 3 ug/kg sufentanil and 3 ug/kg DEX in group D, and 3 ug/kg sufentanil without DEX in group C. The PCIA parameters were programmed as follows: total amount 150 ml, 2 ml bolus dose with a lock-out of 10 min and background infusion rate 2 ml/h. The primary endpoint was the incidence of POD, assessed twice daily within 7 days after surgery by Richmond Agitation-Sedation Scale (RASS) and the Confusion Assessment Method-Intensive Care Unit (CAM-ICU). The secondary endpoint was postoperative hospitalization days, ICU stay time, adverse events and non-delirium complications.

RESULTS

The incidence of POD in all patients was 7%. The incidence of POD in group C was significantly higher than that in group D (10.1% vs 3.4%, P = 0.042). There were no significant differences in length of hospital stay after operation, ICU stay time, the percentage of patients discharged within 7 days after surgery, non-delirium complications, and 30-day all-cause deaths between the two groups. The incidence of hypertension in group D was lower than that in group C (P = 0.003), and there were no differences in other adverse events.

CONCLUSION

Patients aged over 60 years received DEX in addition to intravenous patient-controlled analgesia (PCIA) for major thoracoabdominal surgery experienced less delirium.

Effect of dexmedetomidine on postoperative delirium in patients undergoing awake craniotomies: study protocol of a randomized controlled trial

INTRODUCTION

Postoperative delirium (POD) is a common complication, and it has a high incidence in neurosurgery patients. Awake craniotomy (AC) has been widely performed in patients with glioma in eloquent and motor areas. Most of the surgical procedure is frontotemporal craniotomy, and the operation duration has been getting longer. Patients undergoing AC are high-risk populations for POD. Dexmedetomidine (Dex) administration perioperatively might help to reduce the incidence of POD. The purpose of this study is to investigate the effect of Dex on POD in patients undergoing AC.

METHODS

The study is a prospective, single-center, double-blinded, paralleled-group, randomized controlled trial. Patients undergoing elective AC will be randomly assigned to the Dex group and the control group. Ten minutes before urethral catheterization, patients in the Dex group will be administered with a continuous infusion at a rate of 0.2 µg/kg/h until the end of dural closure. In the control group, patients will receive an identical volume of normal saline in the same setting. The primary outcome will be the cumulative incidence and severity of POD. It will be performed by using the confusion assessment method in the first 5 consecutive days after surgery. Secondary outcomes include quality of intraoperative awareness, stimulus intensity of neurological examination, pain severity, quality of recovery and sleep, and safety outcomes.

DISCUSSION

This study is to investigate whether the application of Dex could prevent POD in patients after undergoing AC and will provide strong evidence-based clinical practice on the impact of intraoperative interventions on preventing POD in AC patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05195034. Registered on January 18, 2022.

Effect of Intraoperative Dexmedetomidine Use on Postoperative Delirium in the Elderly After Laryngectomy: A Randomized Controlled Clinical Trial

Purpose

To examine whether intraoperative dexmedetomidine reduces postoperative delirium (POD) in elderly patients who underwent a laryngectomy.

Methods

Patients were randomly assigned to receive dexmedetomidine or a saline placebo infused during surgery. The study period was July 2020 to January 2022. Participants were elderly individuals (≥65 years) who underwent a laryngectomy. Immediately after induction of anesthesia, a 0.5 μg.kg-1 bolus of study solution was administered for 10 min, followed by a maintenance infusion of 0.2 μg.kg-1.hr-1 until the end of surgery. Patients were assessed daily for POD (primary outcome). Plasma inflammatory factors were measured at baseline, on the first postoperative day, and on the third postoperative day.

Results

In total, 304 male patients were randomized; 299 patients [median (interquartile range) age, 69.0 (67.0-73.0) years] completed in-hospital delirium assessments. There was no difference in the incidence of POD between the dexmedetomidine and control groups (21.3% [32 of 150] vs 24.2% [36 of 149], P=0.560). However, dexmedetomidine reduced POD in patients with laryngeal cancer and a higher tumor stage (21.6% vs 38.5%; OR, 0.441; 95% CI, 0.209-0.979; P=0.039). Dexmedetomidine reduced levels of C-reactive protein (CRP) (P=0.0056) and interleukin 6 (IL-6) (P<0.001) on the first and third postoperative days, respectively. More patients had intraoperative hypotension in the dexmedetomidine group (29.3% [44 of 150] vs 17.4% [26 of 149], P=0.015).

Conclusion

Intraoperative dexmedetomidine administration did not prevent POD in patients with laryngeal cancer. Dexmedetomidine reduced serum CRP and IL-6 levels postoperatively but caused a higher occurrence of intraoperative hypotension in elderly patients after a laryngectomy.

[Special features of the perioperative course in patients with frailty syndrome]

The demographic change with an increase in the number of geriatric patients presents major challenges for perioperative medicine. Frailty is a multimorbidity complex that incorporates a combination of various factors, such as physical weakness, slower walking speed and unwanted weight loss. It is of great importance that these patients receive an individually adapted perioperative care. This includes, among others, a preoperative examination for frailty, a structured prehabilitation according to the concept of better in, better out, the compliance with the guidelines on prevention and timely treatment of postoperative delirium as well as the continuous maintenance of the body's homeostasis. By means of these measures the risk of complications in this patient group can be reduced and the best possible postoperative results can be achieved.

Comparison of the Effects of Dexmedetomidine and Lidocaine on Stress Response and Postoperative Delirium of Older Patients Undergoing Thoracoscopic Surgery: A Randomized Controlled Trial

Purpose

We investigated the effects of intraoperative intravenous lidocaine or dexmedetomidine infusion on inflammatory factors and cognitive function in patients undergoing thoracoscopic surgery.

Patients and Methods

Patients aged >65 years undergoing elective thoracoscopic lobectomy or segmentectomy were randomly grouped as dexmedetomidine group (group D), lidocaine group (group L), and control group (group C). The plasma cortisol, interleukin-6, and tumor necrosis factor-α concentrations were measured before anesthesia (T0) and immediately (T1), 24 h (T2), and 48 h postoperatively (T3). Postoperative delirium (POD) was assessed by 3D-CAM on days 2 and 7.

Results

The cortisol concentrations decreased for all groups at T1 from T0 although they were significantly higher at T2. Group L had significantly lower interleukin-6 concentrations at T1 and T2 than the other groups (P<0.05). The interleukin-6 concentrations were significantly higher at T1, T2, and T3 than at T0 for all the groups, significantly lower for groups D and L than for group C at T1 and T2 (P<0.05), and significantly lower for group L than for group D at T2 (P<0.05). The tumor necrosis factor-α concentrations were significantly higher at T1, T2, and T3 than at T0 for all the groups and significantly lower for groups D and L than for group C at T1 and T2 (P<0.05), although they were not statistically significantly different for groups D and L. There were no statistically significant differences in the postoperative incidence of POD between the three groups on days 2 and day 7.

Conclusion

Intraoperative continuous intravenous lidocaine or dexmedetomidine infusion reduced surgical stress and inflammatory responses. The inhibitory effect of lidocaine on surgical stress remained significant for up to 24 h postoperatively without affecting patient awakening. However, the administration of either drug failed to prevent postoperative POD.

The Efficacy of Dexmedetomidine alone or with Melatonin on Delirium after Coronary Artery Bypass Graft Surgery: A Randomized Clinical Trial

Background

One of the most common cognitive disorders after major surgery is delirium which can increase morbidity and mortality. This study compared the effect of dexmedetomidine with or without melatonin to reduce delirium following coronary artery bypass graft (CABG) surgery.

Methods

This trial was a double-blind, randomized, controlled clinical trial. Eighty patients in two different groups with the administration of dexmedetomidine alone or with melatonin undergoing CABG surgery in Golestan Hospital, Ahvaz, 2022 - 2023, were randomly allocated. This study evaluated the occurrence, onset, and length of delirium, haloperidol, the time required for weaning, and the duration of stays in the intensive care unit (ICU) and hospital.

Results

The occurrence of delirium was lower in the melatonin/dexmedetomidine group (15%) than in the dexmedetomidine group (30 %) (P = 0.09). Additionally, the melatonin/dexmedetomidine group had a significantly lower duration of delirium than the dexmedetomidine group (1.95 (0, 20) and 8.46 (0, 40) P = 0.04). However, no significant difference was observed in the onset of delirium between the two groups (P = 0.25). The length of hospital stays in the melatonin/dexmedetomidine group was significantly shorter than in the dexmedetomidine group (7.53 (7, 10) and 8.60 (7, 15), P = 0.03). However, the two groups demonstrated no significant difference between extubation (P = 0.38) and length of ICU stay (P = 0.19).

Conclusions

The administration of melatonin and dexmedetomidine reduced the incidence of post-cardiac surgery delirium, shortened its duration, and decreased the impact of many risk factors observed in those not receiving the added melatonin.

Pharmacological interventions for preventing opioid-induced hyperalgesia in adults after opioid-based anesthesia: a systematic review and network meta-analysis

Background: Opioid-induced hyperalgesia (OIH) is an adverse event of prolonged opioid use that increases pain intensity. The optimal drug to prevent these adverse effects is still unknown. We aimed to conduct a network meta-analysis to compare different pharmacological interventions for preventing the increase in postoperative pain intensity caused by OIH. Methods: Several databases were searched independently for randomized controlled trials (RCTs) comparing various pharmacological interventions to prevent OIH. The primary outcomes were postoperative pain intensity at rest after 24 h and the incidence of postoperative nausea and vomiting (PONV). Secondary outcomes included pain threshold at 24 h after surgery, total morphine consumption over 24 h, time to first postoperative analgesic requirement, and shivering incidence. Results: In total, 33 RCTs with 1711 patients were identified. In terms of postoperative pain intensity, amantadine, magnesium sulphate, pregabalin, dexmedetomidine, ibuprofen, flurbiprofen plus dexmedetomidine, parecoxib, parecoxib plus dexmedetomidine, and S (+)-ketamine plus methadone were all associated with milder pain intensity than placebo, with amantadine being the most effective (SUCRA values = 96.2). Regarding PONV incidence, intervention with dexmedetomidine or flurbiprofen plus dexmedetomidine resulted in a lower incidence than placebo, with dexmedetomidine showing the best result (SUCRA values = 90.3). Conclusion: Amantadine was identified as the best in controlling postoperative pain intensity and non-inferior to placebo in the incidence of PONV. Dexmedetomidine was the only intervention that outperformed placebo in all indicators. Clinical Trial Registration: https://www.crd.york.ac. uk/prospero/display_record.php?, CRD42021225361.

Effects of dexmedetomidine at different dosages on perioperative haemodynamics and postoperative recovery quality in elderly patients undergoing hip replacement surgery under general anaesthesia: a randomized controlled trial

BACKGROUND

Dexmedetomidine could provide some advantages to prevent postoperative complications in elderly patients undergoing under general anaesthesia. However, dexmedetomidine inhibits haemodynamics to some extent due to its sympathetic inhibition.

OBJECTIVE

To evaluate the effects of different doses of dexmedetomidine on haemodynamics during surgery and recovery after general anaesthesia in elderly patients undergoing hip replacement.

METHODS

This was a prospective randomized double-blind controlled clinical trial. Eligible patients were randomly allocated into comparative groups (normal saline (NS) and midazolam (MD), n = 30) and dexmedetomidine groups at different doses (D0.25/D0.5/D0.75, n = 30). In the D0.25/D0.5/D0.75 groups, dexmedetomidine was administered at different initial loading doses (0.25/0.5/0.75 μg/kg for 15 min) following 0.5 μg/kg/h continuous infusion until the end of the operation. In the MD group, patients were administered 0.03 mg/kg midazolam at the beginning of anaesthesia induction.

RESULTS

Compared to the MD and NS groups, there were significant decreases in MAP in the D0.5 and D0.75 groups at many time points, such as skin incision, end of operation, and from extubation until 30 min after extubation (P < 0.05); there were also significant decreases in HR in the D0.5 and D0.75 groups at time points including anaesthesia induction, end of operation, and from extubation to 2 h after operation (P < 0.05). In the D0.25 group, there were few differences in the changes in MAP and HR compared to the MD and NS groups during the entire perioperative period (P > 0.05). Moreover, the percentage of patients whose MAP and HR decreased > 20% of baseline was higher in the D0.75 and D0.5 groups than that in all other groups. Compared to the NS group, from the beginning to the end of the operation, the 95% confidence interval (CI) of RR for MAP below > 20% of baseline in the D0.5 and D0.75 groups was greater than 1. In particular, the CI of the RR in the D0.75 group was greater than 1 until the patient awoke from general anaesthesia (P < 0.05). In addition, the CI of the RR for HR below > 20% of baseline in the D0.5 group was greater than 1 compared to the NS group at the time of induction and extubation (P < 0.05). There was no significant difference in the possibility of developing hypotension or bradycardia in the MD or D0.25 groups compared to the NS group (P > 0.05). The recovery quality of patients during the post-anaesthesia period was also observed. No differences were observed among all the groups in the time to awakening or extubation after general anaesthesia (P > 0.05). According to the Riker Sedation-agitated Scale, dexmedetomidine significantly alleviated emergency agitation or delirium compared to NS (P < 0.05). In addition, the scores in the D0.5 and D0.75 groups were lower than those in the D0.25 group (P < 0.05).

CONCLUSION

Dexmedetomidine could alleviate the agitation of elderly patients undergoing hip replacement after intravenous general anaesthesia combined with inhaled sevoflurane without delayed recovery. However, it is necessary to be vigilant about the haemodynamic inhibition of the drug at high dosages throughout the perioperative period. Dexmedetomidine 0.25-0.5 μg/kg as the initial loading dose followed by 0.5 μg/kg/h continuous infusion might provide comfortable recovery after general anaesthesia with slight haemodynamic inhibition.

TRAIL REGISTRATION

ClinicalTrial.gov, No. NCT05567523. Registered 05 October 2022, https://clinicaltrials.gov/ct2/show/NCT05567523?term=NCT05567523&draw=2&rank=1 .

Anesthesia, the developing brain, and dexmedetomidine for neuroprotection

Anesthesia-induced neurotoxicity is a set of unfavorable adverse effects on central or peripheral nervous systems associated with administration of anesthesia. Several animal model studies from the early 2000's, from rodents to non-human primates, have shown that general anesthetics cause neuroapoptosis and impairment in neurodevelopment. It has been difficult to translate this evidence to clinical practice. However, some studies suggest lasting behavioral effects in humans due to early anesthesia exposure. Dexmedetomidine is a sedative and analgesic with agonist activities on the alpha-2 (ɑ₂) adrenoceptors as well as imidazoline type 2 (I2) receptors, allowing it to affect intracellular signaling and modulate cellular processes. In addition to being easily delivered, distributed, and eliminated from the body, dexmedetomidine stands out for its ability to offer neuroprotection against apoptosis, ischemia, and inflammation while preserving neuroplasticity, as demonstrated through many animal studies. This property puts dexmedetomidine in the unique position as an anesthetic that may circumvent the neurotoxicity potentially associated with anesthesia.

Effect of intraoperative dexmedetomidine on long-term survival in older patients after major noncardiac surgery: 3-year follow-up of a randomized trial

STUDY OBJECTIVE

To assess the impact of intraoperative dexmedetomidine on long-term outcomes of older patients following major noncardiac surgery mainly for cancer.

DESIGN

A long-term follow-up of patients enrolled in a randomized trial.

SETTING

The initial trial was performed in a tertiary care hospital in Beijing, China.

PARTICIPANTS

Patients aged 60 years or older who were scheduled for major noncardiac surgery.

INTERVENTION

Participants were randomized to receive either dexmedetomidine (a loading dose of 0.6 μg/kg over 10 min, followed by a continuous infusion of 0.5 μg/kg/h until 1 h before end of surgery) or placebo during anesthesia.

MEASUREMENTS

The primary endpoint was overall survival. Secondary endpoints included recurrence-free survival and event-free survival. Cox proportional hazard models were used to adjust for predefined confounding factors. Propensity score matching was employed for sensitive analysis.

RESULTS

Among 620 patients who were randomized in the initial trial, 619 were included in the long-term analysis (mean age 69 years, 40% female, 77% oncological surgery). The median follow-up duration was 42 months (interquartile range 41 to 45). Overall survival did not differ between the two groups: there were 49/309 (15.9%) deaths with dexmedetomidine versus 63/310 (20.3%) with placebo (adjusted hazard ratio [HR] 0.78, 95% CI 0.53-1.13, P = 0.187). Recurrence-free survival was improved with dexmedetomidine (68/309 [22.0%] events with dexmedetomidine versus 98/310 [31.6%] with placebo; adjusted HR 0.67, 95% CI 0.49-0.92, P = 0.012). Event-free survival was also improved with dexmedetomidine (120/309 [38.8%] events with dexmedetomidine versus 145/310 [46.8%] with placebo; adjusted HR 0.78, 95% CI 0.61-1.00, P = 0.047). Results were similar after propensity-score matching and in the subgroup of cancer patients.

CONCLUSIONS

In older patients having major noncardiac surgery mainly for cancer, intraoperative dexmedetomidine did not improve overall survival but was associated with improved recurrence-free and event-free survivals.

[Postoperative delirium in the recovery room]

Postoperative delirium during emergence from anesthesia is the most frequent neuropsychiatric complication in the post-anesthesia care unit. In addition to increased medical and especially nursing care efforts, affected patients are threatened with delayed rehabilitation with a longer hospital stay and an increased mortality. It is therefore essential to identify risk factors at an early stage and to implement preventive measures; however, should a postoperative delirium occur in the post-anesthesia care unit despite the use of these preventive measures, it should be detected and treated at an early stage using suitable screening procedures. In this context, working instructions for delirium prophylaxis and standardized test procedures for detection of delirium have been shown to be useful. An additional drug treatment can be indicated when all nonpharmacological options have been exhausted.

Adiponectin Attenuates Splenectomy-Induced Cognitive Deficits by Neuroinflammation and Oxidative Stress via TLR4/MyD88/NF-κb Signaling Pathway in Aged Rats

Perioperative neurocognitive disorder (PND) is a common adverse event after surgical trauma in elderly patients. The pathogenesis of PND is still unclear. Adiponectin (APN) is a plasma protein secreted by adipose tissue. We have reported that a decreased APN expression is associated with PND patients. APN may be a promising therapeutic agent for PND. However, the neuroprotective mechanism of APN in PND is still unclear. In this study, 18 month old male Sprague-Dawley rats were assigned to six groups: the sham, sham + APN (intragastric (i.g.) administration of 10 μg/kg/day for 20 days before splenectomy), PND (splenectomy), PND + APN, PND + TAK-242 (intraperitoneal (i.p.) administration of 3 mg/kg TAK-242), and PND + APN + lipopolysaccharide (LPS) (i.p. administration of 2 mg/kg LPS). We first found that APN gastric infusion significantly improved learning and cognitive function in the Morris water maze (MWM) test after surgical trauma. Further experiments indicated that APN could inhibit the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor kappa B (NF-κb) p65 pathway to decrease the degree of oxidative damage (malondialdehyde (MDA) and superoxide dismutase (SOD)), microglia-mediated neuroinflammation (ionized calcium binding adapter molecule 1 (IBA1), caspase-1, tumor necrosis factor (TNF)-α, interleukin-1β (IL-1β), and interleukin-6 (IL-6)), and apoptosis (p53, Bcl2, Bax, and caspase 3) in hippocampus. By using LPS-specific agonist and TAK-242-specific inhibitor, the involvement of TLR4 engagement was confirmed. APN intragastric administration exerts a neuroprotective effect against cognitive deficits induced by peripheral trauma, and the possible mechanisms include the inhibition of neuroinflammation, oxidative stress, and apoptosis, mediated by the suppression of the TLR4/MyD88/NF-κb signaling pathway. We propose that oral APN may be a promising candidate for PND treatment.

Dexmedetomidine for the prevention of delirium in adults admitted to the intensive care unit or post-operative care unit: A systematic review of randomised clinical trials with meta-analysis and Trial Sequential Analysis

OBJECTIVES

To assess any benefit or harm, we conducted a systematic review of randomised clinical trials (RCTs) allocating adults to dexmedetomidine versus placebo/no intervention for the prevention of delirium in intensive care or post-operative care units.

DATA SOURCES

We searched Medline, Embase, CENTRAL and other databases. The last search was 9 April 2022.

DATA EXTRACTION

Literature screening, data extraction and risk of bias volume 2 assessments were performed independently and in duplicate. Primary outcomes were occurrences of serious adverse events (SAEs), delirium and all-cause mortality. We used meta-analysis, Trial Sequential Analysis, and GRADE (Grading Recommendations Assessment, Development and Evaluation).

DATA SYNTHESIS

Eighty-one RCTs (15,745 patients) provided data for our primary outcomes. Results from trials at low risk of bias showed that dexmedetomidine may reduce the occurrence of the most frequently reported SAEs (relative risk [RR] 0.69; 95% CI 0.43-1.09), cumulated SAEs (RR 0.70; 95% CI 0.52-0.95) and the occurrence of delirium (RR 0.62; 95% CI 0.43-0.89). The certainty of evidence was very low for delirium. Mortality was very low in trials at low risk of bias (0.4% in the dexmedetomidine groups and 1.0% in the control groups) and meta-analysis did not provide conclusive evidence that dexmedetomidine may result in lower or higher all-cause mortality (RR 0.47; 95% CI 0.18-1.21). There was a lack of information from trial results at low risk of bias for all primary outcomes.

CONCLUSIONS

Trial results at low risk of bias showed that dexmedetomidine might reduce occurrences of SAEs and delirium, while no conclusive evidence was found for effects on all-cause mortality. The certainty of evidence ranged from very low for occurrence of delirium to low for the remaining outcomes.

Postoperative Application of Dexmedetomidine is the Optimal Strategy to Reduce the Incidence of Postoperative Delirium After Cardiac Surgery: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Previous pairwise meta-analyses demonstrated the efficacy and safety of dexmedetomidine in preventing postoperative delirium (POD) after cardiac surgery; however, the optimal time of applying dexmedetomidine remains unclear.

OBJECTIVE

This network meta-analysis aimed to determine the optimal time of using dexmedetomidine to reduce the incidence of POD following cardiac surgery.

METHODS

We first retrieved eligible randomized controlled trials (RCTs) from previous meta-analyses, and then an updated search was performed to identify additional RCTs in PubMed, Embase, and the Cochrane library from January 1, 2021 to October 31, 2021. Two authors screened literature, collected data, and evaluated bias risk of eligible studies. Finally, we performed Bayesian network analysis using R version 3.6.1 with the "gemtc" and "rjags" package.

RESULTS

Eighteen studies with 2636 patients were included, and all studies were identified from previous meta-analyses. Results showed that postoperative dexmedetomidine reduced the risk of POD compared with normal saline (NS) (odds ratio [OR], 0.13; 95% credible interval [CrI], 0.03-0.35) and propofol (PRO) (OR, 0.19; 95%CrI, 0.04-0.66). Postoperative dexmedetomidine was associated with a lower incidence of POD compared with perioperative dexmedetomidine (OR, 0.21; 95% CrI, 0.04-0.82). Moreover, postoperative dexmedetomidine had the highest probability of ranking best (90.98%), followed by intraoperative dexmedetomidine (46.83%), PRO (36.94%), perioperative dexmedetomidine (30.85%), and NS (60.02%).

CONCLUSION AND RELEVANCE

Dexmedetomidine reduces the incidence of POD compared with PRO and NS in patients undergoing cardiac surgery, and postoperative application of dexmedetomidine is the optimal time.

Cardiac surgery, ICU sedation, and delirium: is dexmedetomidine the silver bullet?

PURPOSE OF REVIEW

Delirium is a marker of acute brain insufficiency and a harbinger of poor outcomes and increased healthcare costs. Despite success preventing delirium by nonpharmacologic measures, the incidence in the postcardiac surgical ICU population remains high. Dexmedetomidine, a selective alpha-2 agonist, is a plausible preventive agent with sedative, anxiolytic, analgesic, sympatholytic and anti-inflammatory properties, and is the subject of very active study in cardiac surgery populations.

RECENT FINDINGS

Recent trials, including DEXACET (2019), DECADE (2020), LOWDEXDEL (2021), and DIRECT (2022) individually, failed to show a benefit for dexmedetomidine and highlighted associated risks. Meta-analyses have offered conflicting results, highlighting the complexity of delirium, and likely interaction of multiple etiological pathways; those that concluded benefit often were driven by trials at high risk of bias. Meta-analyses excluding biased trials currently suggest no benefit for dexmedetomidine over control in unselected cardiac surgical populations.

SUMMARY

Although using dexmedetomidine to prevent delirium in unselected cardiac surgical patients is not supported by current evidence, there remains hope that it may offer benefits in highly selected populations, and further trials are ongoing.

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.

Research progress on perioperative blood-brain barrier damage and its potential mechanism

The blood-brain barrier (BBB) is an important barrier separating the central nervous system from the periphery. The composition includes endothelial cells, pericytes, astrocytes, synapses and tight junction proteins. During the perioperative period, anesthesia and surgical operations are also a kind of stress to the body, which may be accompanied by blood-brain barrier damage and brain metabolism dysfunction. Perioperative blood-brain barrier destruction is closely associated with cognitive impairment and may increase the risk of postoperative mortality, which is not conducive to enhanced recovery after surgery. However, the potential pathophysiological process and specific mechanism of blood-brain barrier damage during the perioperative period have not been fully elucidated. Changes in blood-brain barrier permeability, inflammation and neuroinflammation, oxidative stress, ferroptosis, and intestinal dysbiosis may be involved in blood-brain barrier damage. We aim to review the research progress of perioperative blood-brain barrier damage and its potential adverse effects and potential molecular mechanisms, and provide ideas for the study of homeostasis maintenance of brain function and precision anesthesia.

Determination of the effective dose of dexmedetomidine to achieve loss of consciousness during anesthesia induction

Background

Dexmedetomidine (DEX) is a sedative with greater preservation of cognitive function, reduced respiratory depression, and improved patient arousability. This study was designed to investigate the performance of DEX during anesthesia induction and to establish an effective DEX induction strategy, which could be valuable for multiple clinical conditions.

Methods

Patients undergoing abdominal surgery were involved in this dose-finding trial. Dixon's up-and-down sequential method was employed to determine the effective dose of DEX to achieve the state of "loss of consciousness", and an effective induction strategy was established with continuous infusion of DEX and remifentanil. The effects of DEX on hemodynamics, respiratory state, EEG, and anesthetic depth were monitored and analyzed.

Results

Through the strategy mentioned, the depth of surgical anesthesia was successfully achieved by DEX-led anesthesia induction. The ED50 and ED95 of the initial infusion rate of DEX were 0.115 and 0.200 μg/kg/min, respectively, and the mean induction time was 18.3 min. The ED50 and ED95 of DEX to achieve the state of "loss of consciousness" were 2.899 (95% CI: 2.703-3.115) and 5.001 (95% CI: 4.544-5.700) μg/kg, respectively. The mean PSI on the loss of consciousness was 42.8 among the patients. During anesthesia induction, the hemodynamics including BP and HR were stable, and the EEG monitor showed decreased α and β powers and increased θ and δ in the frontal and pre-frontal cortices of the brain.

Conclusion

This study indicated that continuous infusion of combined DEX and remifentanil could be an effective strategy for anesthesia induction. The EEG during the induction was similar to the physiological sleep process.

Pre-anesthetic use of butorphanol for the prevention of emergence agitation in thoracic surgery: A multicenter, randomized controlled trial

Background

Emergence agitation (EA) is common in patients after general anesthesia (GA) and is associated with poor outcomes. Patients with thoracic surgery have a higher incidence of EA compared with other surgery. This study aimed to investigate the impact of pre-anesthetic butorphanol infusion on the incidence of EA in patients undergoing thoracic surgery with GA.

Materials and methods

This prospective randomized controlled trial (RCT) was conducted in 20 tertiary hospitals in China. A total of 668 patients undergoing elective video-assisted thoracoscopic lobectomy/segmentectomy for lung cancer were assessed for eligibility, and 620 patients were enrolled. In total, 296 patients who received butorphanol and 306 control patients were included in the intention-to-treat analysis. Patients in the intervention group received butorphanol 0.02 mg/kg 15 min before induction of anesthesia. Patients in the control group received volume-matched normal saline in the same schedule. The primary outcome was the incidence of EA after 5 min of extubation, and EA was evaluated using the Riker Sedation-Agitation Scale (RSAS). The incidence of EA was determined by the chi-square test, with a significance of P < 0.05.

Results

In total, 296 patients who received butorphanol and 306 control patients were included in the intention-to-treat analysis. The incidence of EA 5 min after extubation was lower with butorphanol treatment: 9.8% (29 of 296) vs. 24.5% (75 of 306) in the control group (P = 0.0001). Patients who received butorphanol had a lower incidence of drug-related complications (including injecting propofol pain and coughing with sufentanil): 112 of 296 vs. 199 of 306 in the control group (P = 0.001) and 3 of 296 vs. 35 of 306 in the control group (P = 0.0001).

Conclusion

The pre-anesthetic administration of butorphanol reduced the incidence of EA after thoracic surgery under GA.

Clinical trial registration

[http://www.chictr.org.cn/showproj.aspx?proj=42684], identifier [ChiCTR1900025705].

Effects of Dexmedetomidine on Postoperative Pain and Recovery Time in Obese Patients

Objective

The objective of this study is to investigate the effect of dexmedetomidine on postoperative pain and recovery time in obese patients.

Methods

A total of 100 obese patients with body mass index (BMI) ≥ 30 kg/m² who underwent laparoscopic sleeve gastrectomy under general anesthesia in our hospital from January 2019 to December 2021 were included and assigned into DEX group (dexmedetomidine group) and NS group (normal saline group). The bariatric surgery patients who were given normal saline pump were the NS group (n = 50), and the bariatric surgery patients who were given the dexmedetomidine pump were the DEX group (n = 50). The patients in the DEX group were given continuous intravenous infusion of dexmedetomidine before, during, and after induction of anesthesia at a dose of 0.4 μg. kg-1. h-1, 0.4 μg·kg-1. h-1, 0.2 μg·kg-1. h-1, respectively. The NS group was infused with the same volume of normal saline for the same time. The two groups of patients were treated with the same anesthesia induction and maintenance program. By comparing the operation, anesthesia, postoperative extubation, and recovery time of the two groups of patients, the effect of dexmedetomidine on the postoperative recovery time of obese patients was analyzed. Visual analogue scale (VAS) and adverse reactions were compared to analyze the effect of dexmedetomidine on postoperative pain in obese patients.

Results

The operation, anesthesia, postoperative extubation, and recovery time of the DEX group were significantly lower than those of the NS group, whereas the VAS and adverse reactions were significantly lower than those in the NS group (P < 0.05).

Conclusion

An appropriate dose of dexmedetomidine in bariatric surgery for morbidly obese patients can effectively shorten the recovery time and extubation time of patients, reduce postoperative pain and the incidence of adverse reactions, and is worthy of clinical application. Dexmedetomidine 2 μg/kg has promising anesthesia benefits in bariatric surgery of obese patients, can provide favorable analgesia and quality of recovery, help reduce the degree of stress response of patients, and does not increase the risk of adverse events. However, this study has certain limitations, so physicians should tailor the dosage according to the patient's physical condition in clinical practice.

Effects of subanaesthetic S-ketamine on postoperative delirium and cognitive function in elderly patients undergoing non-cardiac thoracic surgery: a protocol for a randomised, double-blinded, placebo-controlled and positive-controlled, non-inferiority trial (SKED trial)

INTRODUCTION

Postoperative delirium (POD) is a common and distressing complication after thoracic surgery. S-ketamine has neuroprotective properties as a dissociative anaesthetic. Emerging literature has indicated that S-ketamine can reduce cognitive impairment in patients with depression. However, the role of S-ketamine in preventing POD remains unknown. Therefore, this study aims to evaluate the effect of intraoperative prophylactic S-ketamine compared with that of dexmedetomidine on the incidence of POD in elderly patients undergoing non-cardiac thoracic surgery.

METHODS AND ANALYSIS

This will be a randomised, double-blinded, placebo-controlled, positive-controlled, non-inferiority trial that enrolled patients aged 60-90 years undergoing thoracic surgery. The patients will be randomly allocated in a ratio of 1:1:1 to S-ketamine, dexmedetomidine or normal saline placebo groups using computer-generated randomisation with a block size of six. The primary outcome will be the incidence of POD within 4 days after surgery and this will be assessed using a 3-Minute Diagnostic Confusion Assessment Method two times per day. The severity and duration of POD, the incidence of emergence delirium, postoperative pain, quality of sleep, cognitive function, and the plasma concentrations of acetylcholine, brain-derived neurotrophic factor, tumour necrosis factor-α and incidence of adverse events will be evaluated as secondary outcomes.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Institutional Review Board of the Cancer Hospital and the Institute of Guangzhou Medical University (ZN202119). At the end of the trial, we commit to making a public disclosure available, regardless of the outcome. The public disclosure will include a publication in an appropriate journal and an oral presentation at academic meetings.

TRIAL REGISTRATION NUMBER

ChiCTR2100052750 (NCT05242692).

The Role of Dexmedetomidine in Tumor-Progressive Factors in the Perioperative Period and Cancer Recurrence: A Narrative Review

Dexmedetomidine, a specific α2 adrenergic receptor agonist, is highly frequently used in the perioperatively for its favorable pharmacology, such as mitigating postoperative cognitive dysfunction. Increasing attention has been recently focused on the effect of whether dexmedetomidine influences cancer recurrence, which urges the discussion of the role of dexmedetomidine in tumor-progressive factors. The pharmacologic characteristics of dexmedetomidine, the tumor-progressive factors in the perioperative period, and the relationships between dexmedetomidine and tumor-progressive factors were described in this review. Available evidence suggests that dexmedetomidine could reduce the degree of immune function suppression, such as keeping the number of CD3+ cells, NK cells, CD4+/CD8+ ratio, and Th1/Th2 ratio stable and decreasing the level of proinflammatory cytokine (interleukin 6 and tumor necrosis factor-alpha) during cancer operations. However, dexmedetomidine exhibits different roles in cell biological behavior depending on cancer cell types. The conclusions on whether dexmedetomidine would influence cancer recurrence could not be currently drawn for the lack of strong clinical evidence. Therefore, this is still a new area that needs further exploration.

Anaesthetic Approach to Enhanced Recovery after Surgery for Kidney Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) protocols are designed to reduce medical complications, the length of hospital stays (LoS), and healthcare costs. ERAS is considered safe and effective for kidney transplant (KTx) surgery. KTx recipients are often frail with multiple comorbidities. As these patients follow an extensive diagnostic pathway preoperatively, the ERAS protocol can ideally be implemented at this stage. Small singular changes in a long perioperative pathway can result in significant positive outcomes. We have investigated the current evidence for an ERAS pathway related to anaesthetic considerations in renal transplant surgery for adult recipients.

Dexmedetomidine in Prevention of Postoperative Delirium: A Systematic Review

Delirium is defined by the DSM-5 as a fluctuating course of disturbance in attention, cognition, and awareness that develops over a short period without any pre-existing neurocognitive disorder. As people age, there is an increased risk of complications that may occur following a surgical procedure and one such acute complication is delirium. Studies are emerging to reduce the incidence of postoperative delirium, and one such preventive measures implemented in recent years include the administration of dexmedetomidine, a high selectivity α-2 adrenoceptor agonist. This study aims to review the efficacy of Dexmedetomidine in the prevention of postoperative delirium in randomized controlled trials in patients older than 18 years of age. The literature was explored in three online databases, namely, PubMed, Science Direct, and Scopus. Appropriate keywords and MesH terms were employed to scrutinize relevant articles that demonstrated the effects of dexmedetomidine in the prevention of postoperative delirium. The data was restricted to randomized controlled trials and clinical trials published from 2017 to 2021 in human patients older than >18 years of age undergoing non-cardiac-related procedures. The randomized clinical trials were critically assessed with the Cochrane risk of bias tool. We proceeded to screen 428 records with the assessment of the PRISMA chart and filtered out 420 papers to obtain a total of eight studies where we identified data such as sample size, types of surgeries in which the patients were involved, the delirium assessment tool, the plan of the administration of dexmedetomidine and the outcomes evaluated in each study. The Confusion Assessment Method (CAM) was the prevailing assessment tool used with the sole purpose to evaluate the incidence of postoperative delirium as the primary outcome, and assessment of inflammatory cytokines, sleep quality, and pain scales were considered as secondary outcomes. The dosage of dexmedetomidine varied among studies, and it displayed varying impacts on postoperative delirium and the secondary outcomes as well. Limitations include varying ages and ethnicities of the population. It was concluded that dexmedetomidine prevents the development of postoperative delirium in elderly patients undergoing non-cardiac surgical interventions by modulating important predisposing factors such as neuroinflammation, pain, and sleep quality. No funding was made for this study.

Postoperative management of children after lung transplantation

Pediatric lung transplantation is a highly specialized treatment option at a select few hospitals caring for children. Advancements in surgical and medical approaches in the care of these children have improved their care with only minimal improvement in outcomes which remain the lowest of all solid organ transplants. A crucial time period in the management of these children is in the perioperative period after performance of the lung transplant. Supporting allograft function, preventing infection, maintaining fluid balance, achieving pain control, and providing optimal respiratory support are all key factors required for this highly complex pediatric patient population. We review commonly encountered complications that these patients often experience and provide strategies for management.

Dexmedetomidine vs other sedatives in critically ill mechanically ventilated adults: a systematic review and meta-analysis of randomized trials

Conventional gabaminergic sedatives such as benzodiazepines and propofol are commonly used in mechanically ventilated patients in the intensive care unit (ICU). Dexmedetomidine is an alternative sedative that may achieve lighter sedation, reduce delirium, and provide analgesia. Our objective was to perform a comprehensive systematic review summarizing the large body of evidence, determining if dexmedetomidine reduces delirium compared to conventional sedatives. We searched MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov and the WHO ICTRP from inception to October 2021. Independent pairs of reviewers identified randomized clinical trials comparing dexmedetomidine to other sedatives for mechanically ventilated adults in the ICU. We conducted meta-analyses using random-effects models. The results were reported as relative risks (RRs) for binary outcomes and mean differences (MDs) for continuous outcomes, with corresponding 95% confidence intervals (CIs). In total, 77 randomized trials (n = 11,997) were included. Compared to other sedatives, dexmedetomidine reduced the risk of delirium (RR 0.67, 95% CI 0.55 to 0.81; moderate certainty), the duration of mechanical ventilation (MD - 1.8 h, 95% CI  - 2.89 to  - 0.71; low certainty), and ICU length of stay (MD  - 0.32 days, 95% CI  - 0.42 to  - 0.22; low certainty). Dexmedetomidine use increased the risk of bradycardia (RR 2.39, 95% CI 1.82 to 3.13; moderate certainty) and hypotension (RR 1.32, 95% CI 1.07 to 1.63; low certainty). In mechanically ventilated adults, the use of dexmedetomidine compared to other sedatives, resulted in a lower risk of delirium, and a modest reduction in duration of mechanical ventilation and ICU stay, but increased the risks of bradycardia and hypotension.

Impact of perioperative inflammation on days alive and at home after surgery

Background

Perioperative inflammation is associated with perioperative complications, including delirium, that are associated with a reduced number of postoperative days alive and at home at 90 days (DAH90). We tested whether inflammation was associated with DAH90 even when adjusting for perioperative factors, and whether inflammation independently was associated with DAH90 when adjusting for delirium.

Methods

We conducted a prospective cohort study of major, non-intracranial surgical patients who were older than 65 yr (n=134). We measured postoperative delirium incidence and severity, and changes in interleukin (IL)-8 and IL-10 in blood plasma. Our primary outcome, DAH90, was analysed using quantile regression.

Results

Before adjusting for delirium, a postoperative day 1 increased IL-8 was associated with fewer DAH90 at the 0.75 quantile (β=-0.082; 95% confidence interval [CI], -0.19 to -0.006) after adjusting for demographic (age and sex) and perioperative factors (cardiovascular surgery, National Surgical Quality Improvement Program risk of death, and operative time). IL-10 was similarly associated with DAH90 at the 0.5 (β=-0.026; 95% CI, -0.19 to -0.001) and 0.75 (β= -0.035; 95% CI, -0.07 to -0.006) quantiles. Neither cytokine was significantly associated with DAH90 once delirium and baseline Trail Making Test B were added to the models.

Conclusions

Perioperative inflammation predicts DAH90, but when delirium is added to the model inflammation loses significance as a predictor, whereas delirium is significant. Targeting perioperative inflammation may reduce delirium and moderate hospital readmission and mortality.

Clinical trial registration

NCT03124303.