Propofol and the risk of delirium: Exploring the anticholinergic properties of propofol

Postoperative delirium under general anaesthesia by remimazolam versus propofol: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Remimazolam, an ultra-short-acting benzodiazepine, has similar clinical effects to propofol for sedation in general anaesthesia. However, it remains uncertain whether remimazolam could increase postoperative delirium (POD) compared with propofol.

OBJECTIVES

The purpose of our study was to compare the incidence of POD between remimazolam and propofol as sedative agents in general anaesthesia.

STUDY DESIGN

Systematic review and meta-analysis of randomised controlled trials (RCTs).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched for prospective RCTs published through September 16, 2024. RCTs reporting the incidence of POD and comparing remimazolam with propofol for general anaesthesia were included. Odds ratio (ORs) were calculated using a random-effects model. The primary outcome was the incidence of POD. The secondary outcomes included time to extubation, awakening time, and adverse events such as intraoperative hypotension.

RESULTS

A total of six RCTs involving 1107 patients were included in this meta-analysis. For the primary outcome, the incidence of POD did not differ between the remimazolam and propofol groups (OR, 0.92; 95 % confidence interval [CI], 0.58-1.44). Regarding the secondary outcomes, remimazolam was associated with a lower incidence of intraoperative hypotension compared with propofol (OR, 0.31; 95 % CI, 0.21-0.46). There were no significant differences in other secondary outcomes. In the sensitivity analysis on three RCTs including only older patients (≥60 years old), there was no significant difference in the incidence of POD (OR, 1.00; 95 % CI, 0.52-1.93).

CONCLUSION

Perioperative remimazolam administration did not increase POD and reduced the risk of intraoperative hypotension compared to propofol. Further large-scale RCTs are warranted to explore the association of remimazolam and POD. Systematic review protocol: PROSPERO CRD42024544122.

Electroencephalographic guided propofol-remifentanil TCI anesthesia with and without dexmedetomidine in a geriatric population: electroencephalographic signatures and clinical evaluation

Elderly and multimorbid patients are at high risk for developing unfavorable postoperative neurocognitive outcomes; however, well-adjusted and EEG-guided anesthesia may help titrate anesthesia and improve postoperative outcomes. Over the last decade, dexmedetomidine has been increasingly used as an adjunct in the perioperative setting. Its synergistic effect with propofol decreases the dose of propofol needed to induce and maintain general anesthesia. In this pilot study, we evaluate two highly standardized anesthetic regimens for their potential to prevent burst suppression and postoperative neurocognitive dysfunction in a high-risk population. Prospective, randomized clinical trial with non-blinded intervention. Operating room and post anesthesia care unit at Hospital Base San José, Osorno/Universidad Austral, Valdivia, Chile. 23 patients with scheduled non-neurologic, non-cardiac surgeries with age > 69 years and a planned intervention time > 60 min. Patients were randomly assigned to receive either a propofol-remifentanil based anesthesia or an anesthetic regimen with dexmedetomidine-propofol-remifentanil. All patients underwent a slow titrated induction, followed by a target controlled infusion (TCI) of propofol and remifentanil (n = 10) or propofol, remifentanil and continuous dexmedetomidine infusion (n = 13). We compared the perioperative EEG signatures, drug-induced changes, and neurocognitive outcomes between two anesthetic regimens in geriatric patients. We conducted a pre- and postoperative Montreal Cognitive Assessment (MoCa) test and measured the level of alertness postoperatively using a sedation agitation scale to assess neurocognitive status. During slow induction, maintenance, and emergence, burst suppression was not observed in either group; however, EEG signatures differed significantly between the two groups. In general, EEG activity in the propofol group was dominated by faster rhythms than in the dexmedetomidine group. Time to responsiveness was not significantly different between the two groups (p = 0.352). Finally, no significant differences were found in postoperative cognitive outcomes evaluated by the MoCa test nor sedation agitation scale up to one hour after extubation. This pilot study demonstrates that the two proposed anesthetic regimens can be safely used to slowly induce anesthesia and avoid EEG burst suppression patterns. Despite the patients being elderly and at high risk, we did not observe postoperative neurocognitive deficits. The reduced alpha power in the dexmedetomidine-treated group was not associated with adverse neurocognitive outcomes.

Benefits of remimazolam as an anesthetic sedative for older patients: A review

Owing to the decreased levels of receptors in the peripheral and central nervous systems, the functions of various organ systems decline in older patients. When administering anesthesia to older patients, it is necessary to consider the effects of medication on the homeostatic balance. Remimazolam, a new benzodiazepine, was recently developed as an anesthetic drug that has shown promise in clinical anesthesia application owing to its molecular structure, targets, pharmacodynamics, and pharmacokinetic characteristics. Remimazolam exhibits a rapid onset and metabolism, with minor effects on liver and kidney functions. Moreover, the drug has a specific antagonist, flumazenil. It is safer to use in older patients than other anesthetic sedatives and has been widely used since its introduction. Comparisons of the pharmacokinetics, metabolic pathways, effects on target organs, and hemodynamics of different drugs with those of commonly used anesthetic sedative drugs are useful to inform clinical practice. This article elaborates on the benefits of remimazolam compared with those of other anesthetic sedatives for sedation in older patients to demonstrate how it offers a new option for anesthetics in older patients. In cases involving older patients with increased clinical complexities or very old patients requiring anesthesia, remimazolam can be selected as the preferred anesthetic sedative, as outlined in this review.

Comparison of the effects of remimazolam tosylate and propofol on postoperative delirium among older adults undergoing major non-cardiac surgery: protocol for a randomised controlled trial

INTRODUCTION

Postoperative delirium (POD) is a common cognitive disturbance in elderly individuals that is characterised by acute and fluctuating impairments in attention and awareness. Remimazolam tosylate is a novel, ultrashort-acting benzodiazepine, and there is limited evidence of its correlation with the incidence of early POD. The aim of this study is to evaluate the incidence of POD after anaesthesia induction and maintenance with remimazolam tosylate or propofol in elderly patients undergoing major non-cardiac surgery.

METHODS AND ANALYSIS

This is a single-centre, randomised controlled trial. 636 elderly patients undergoing major non-cardiac surgery will be enrolled and randomised at a 1:1 ratio to receive total intravenous anaesthesia with either remimazolam tosylate or propofol. The primary outcome is the incidence of POD within 5 days after surgery. Delirium will be assessed twice daily by the 3 min Diagnostic Interview for the Confusion Assessment Method or the Confusion Assessment Method for the intensive care unit (ICU) for ICU patients. Secondary outcomes are the onset and duration of delirium, cognitive function at discharge and within 1-year postoperatively, postoperative analgesia within 5 days, chronic pain at 3 months, quality of recovery and postoperative inflammatory biomarker levels.

ETHICS AND DISSEMINATION

The study was approved by the institutional ethics committee of the National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences (approval No. 22/520-3722). Written informed consent will be obtained from each patient before enrolment. The results of this trial will be presented at scientific conferences and in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ChiCTR2300067368.

Identification of risk factors for postoperative delirium in elderly patients with hip fractures by a risk stratification index model: A retrospective study

INTRODUCTION

Postoperative delirium is one of the most common and dangerous psychiatric complications after hip surgery. The aim of this study was to investigate the incidence of postoperative delirium in elderly patients after hip fracture surgery and to identify risk factors for such, as part of developing a risk stratification index (RSI) system to predict a patient's risk of postoperative delirium.

METHODS

Elderly patients (aged 65 years or older) with hip fractures who had received surgical treatment in our hospital between March 2018 and December 2019 were retrospectively included. Clinical data were collected, and multivariate logistic regression analysis was performed to investigate the relevant risk factors of postoperative delirium. An RSI system was developed based on factors identified in the regression analysis.

RESULTS

Of 272 patients included, 52 (19.12%) experienced postoperative delirium. Drinking history (> 3/ week), the perioperative lactic acid level (Lac > 2 mmol/L), postoperative visual analog score (VAS) > 3, American Society of Anesthesiologists (ASA) physical status > II, application of the bispectral index, and preoperative diabetes were independent risk factors of postoperative delirium. When RSI ≥ 5, the rate of postoperative delirium significantly increased (p < .05).

CONCLUSION

The RSI system developed here can safely guide postoperative outcomes of elderly patients with hip fractures, and RSI ≥ 5 may be able to predict the onset of postoperative delirium.

Effect of remimazolam besylate compared with propofol on the incidence of delirium after cardiac surgery: study protocol for a randomized trial

Background

Delirium is an acute cognitive disorder that presents with fluctuation in cognition, apathy, and non-organized thinking, resulting in increased morbidity, mortality, intensive care unit (ICU) stay, and total healthcare costs. In patients undergoing cardiac surgery, delirium also increases the risk of postoperative complications, such as respiratory insufficiency, sternum instability, and need for re-operation of the sternum. This study aims to understand the incidence of delirium in patients after cardiac surgery in patients sedated with remimazolam besylate versus propofol.

Methods

In this prospective, double-blind, randomized controlled clinical trial, we aim to recruit 200 patients undergoing cardiac surgery between January 1, 2021, and December 31, 2021, who will be randomized to receive either remimazolam besylate or propofol infusions postoperatively, until they are extubated. The primary outcome is the incidence of delirium within 5 days after surgery. Secondary outcomes include the time of delirium onset, duration of delirium, ICU length of stay, hospital length of stay, and mechanical ventilation time.

Discussion

The key objective of this study is to assess whether remimazolam besylate reduces the incidence of delirium in patients after cardiac surgery compared to propofol sedation. In this preliminary randomized controlled clinical trial, we will test the hypothesis that the use of remimazolam besylate lowers the incidence of delirium when compared to propofol in patients undergoing cardiac surgery.

Trial registration

chictr.org.cn ChiCTR2000038976. Registered on October 11, 2020

Iatrogenic Delirium in Patients on Symptom-Triggered Alcohol Withdrawal Protocol: A Case Series

In this report, we present a case series involving four patients placed on the Clinical Institute Withdrawal Assessment for Alcohol, Revised (CIWA-Ar) protocol for alcohol or sedative-hypnotic withdrawal syndromes, who developed delirium on sustained or increasing symptom-triggered benzodiazepine dosages. In each of the four cases, delirium was not present on admission and resolved in the hospital itself with fixed benzodiazepine tapers. Cases were selected from an electronic medical record database of patients admitted to a United States-based university hospital and placed on CIWA-Ar between 2017 and 2018. This case series illustrates the major limitations of CIWA-Ar including its subjective nature, its susceptibility to inappropriate patient selection, and its requirement for providers to consider alternative etiologies to alcohol and benzodiazepine withdrawal syndromes. These cases demonstrate the necessity of considering other assessment and treatment options such as objective alcohol withdrawal scales, fixed benzodiazepine tapers, and even antiepileptics. An effective systems-based approach to overcoming these challenges may include setting time limits on CIWA-Ar orders within the electronic health record (EHR) system.

Pharmacological strategies to prevent postoperative delirium: a systematic review and network meta-analysis

Background

Postoperative delirium (POD) is a condition of cerebral dysfunction and a common complication after surgery. This study aimed to compare and determine the relative efficacy of pharmacological interventions for preventing POD using a network meta-analysis.

Methods

We performed a systematic and comprehensive search to identify and analyze all randomized controlled trials until June 29, 2020, comparing two or more pharmacological interventions, including placebo, to prevent or reduce POD. The primary outcome was the incidence of POD. We performed a network meta-analysis and used the surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of the pharmacological interventions evaluated.

Results

According to the SUCRA value, the incidence of POD decreased in the following order: the combination of propofol and acetaminophen (86.1%), combination of ketamine and dexmedetomidine (86.0%), combination of diazepam, flunitrazepam, and pethidine (84.8%), and olanzapine (75.6%) after all types of anesthesia; combination of propofol and acetaminophen (85.9%), combination of ketamine and dexmedetomidine (83.2%), gabapentin (82.2%), and combination of diazepam, flunitrazepam, and pethidine (79.7%) after general anesthesia; and ketamine (87.1%), combination of propofol and acetaminophen (86.0%), and combination of dexmedetomidine and acetaminophen (66.3%) after cardiac surgery. However, only the dexmedetomidine group showed a lower incidence of POD than the control group after all types of anesthesia and after general anesthesia.

Conclusions

Dexmedetomidine reduced POD compared with the control group. The combination of propofol and acetaminophen and the combination of ketamine and dexmedetomidine seemed to be effective in preventing POD. However, further studies are needed to determine the optimal pharmacological intervention to prevent POD.

Propofol plus low-dose dexmedetomidine infusion and postoperative delirium in older patients undergoing cardiac surgery

BACKGROUND

Postoperative delirium (POD) is a frequent complication in older patients. Dexmedetomidine might be effective in decreasing the incidence of POD. We hypothesised that adding low-dose rate dexmedetomidine infusion to a propofol sedation regimen would have fewer side-effects and would counteract the possible delirium producing properties of propofol, resulting in a lower risk of POD than propofol with placebo.

METHODS

In this double-blind placebo-controlled trial, patients ≥60 yr old undergoing on-pump cardiac surgery were randomised 1:1 to the following postoperative sedative regimens: a propofol infusion and dexmedetomidine (0.4 μg kg^-1 h^-1) or a propofol infusion and saline 0.9% (placebo group). The study drug was started at chest closure and continued for 10 h. The primary endpoint was in-hospital POD, assessed using the Confusion Assessment Method and chart review method.

RESULTS

POD over the course of hospital stay occurred in 31/177 (18%) and 33/172 (19%) patients in the dexmedetomidine and placebo arm, respectively (P=0.687; odds ratio=0.89; 95% confidence interval, 0.52-1.54). The incidence of POD in the intensive care alone, or on the ward alone, was also not significantly different between the groups. Subjects in the dexmedetomidine group spent less median time in a delirious state (P=0.026). Median administered postoperative norepinephrine was significantly higher in the dexmedetomidine group (P<0.001). One patient in the dexmedetomidine group and 10 patients in the placebo group died in the hospital.

CONCLUSIONS

Adding low-dose rate dexmedetomidine to a sedative regimen based on propofol did not result in a different risk of in-hospital delirium in older patients undergoing cardiac surgery. With a suggestion of both harm and benefit in secondary outcomes, supplementing postoperative propofol with dexmedetomidine cannot be recommended based on this study.

CLINICAL TRIAL REGISTRATION

NCT03388541.

The pharmacotherapeutic management of postoperative delirium: an expert update

INTRODUCTION

Postoperative delirium is a common sequela in older adults in the peri-operative period leading to poor outcomes with a complex pathophysiology which has led to a variety of different pharmacologic agents employed in attempts to prevent and treat this syndrome. No pharmacologic agent has been approved to treat this disorder, but this review discusses the pharmacologic strategies which have been tried based on the hypotheses of the causation of the syndrome including neurotransmitter imbalance, inflammation, and oxidative stress.

AREAS COVERED

Systematic reviews and meta-analyses of randomized clinical trials (RCTs) were included via search of electronic databases specifically for the terms postoperative delirium and pharmacologic treatments. With this approach, the recurrent topics of analgesia and sedation, antipsychotics, acetylcholinesterase inhibitors (AchE-Is), inflammation, and melatonin were emphasized and provided the outline for this review.

EXPERT OPINION

Research evidence does not support any particular agent in any of the pharmacologic classes reviewed. However, there is some potential benefit with dexmedetomidine, melatonin, and the monitoring of anesthetic agents all of which need further clinical trials to validate these conclusions. Exploration of ways to improve studies and the application of novel pharmacologic agents may offer future benefit.

Delirium screening in the intensive care unit using emerging QEEG techniques: A pilot study

Delirium is an under-diagnosed yet frequently occurring clinical complication with potentially serious consequences for intensive care unit (ICU) patients. Diagnosis is currently reactive and based upon qualitative assessment of the patient's cognitive status by ICU staff. Here, we conducted a preliminary investigation into whether emerging quantitative electroencephalography (QEEG) analysis techniques can accurately discriminate between delirious and non-delirious patients in an ICU setting. Resting EEG recordings from 5 ICU patients in a state of delirium and 5 age matched control patients were analyzed using autoregressive spectral estimation for quantification of EEG power and renormalized partial directed coherence for analysis of directed functional connectivity. Delirious subjects exhibited pronounced EEG slowing as well as severe general loss of directed functional connectivity between recording sites. Distinction between groups based on these parameters was surprisingly clear given the low sample size employed. Furthermore, by targeting the electrode positions where effects were most apparent it was possible to clearly segregate patients using only 3 scalp electrodes. These findings indicate that quantitative diagnosis and monitoring of delirium is not only possible using emerging QEEG methods but is also accomplishable using very low-density electrode systems.

Risk Factors for Patient-Ventilator Asynchrony and Its Impact on Clinical Outcomes: Analytics Based on Deep Learning Algorithm

Background and objectives: Patient-ventilator asynchronies (PVAs) are common in mechanically ventilated patients. However, the epidemiology of PVAs and its impact on clinical outcome remains controversial. The current study aims to evaluate the epidemiology and risk factors of PVAs and their impact on clinical outcomes using big data analytics. Methods: The study was conducted in a tertiary care hospital; all patients with mechanical ventilation from June to December 2019 were included for analysis. Negative binomial regression and distributed lag non-linear models (DLNM) were used to explore risk factors for PVAs. PVAs were included as a time-varying covariate into Cox regression models to investigate its influence on the hazard of mortality and ventilator-associated events (VAEs). Results: A total of 146 patients involving 50,124 h and 51,451,138 respiratory cycles were analyzed. The overall mortality rate was 15.6%. Double triggering was less likely to occur during day hours (RR: 0.88; 95% CI: 0.85-0.90; p < 0.001) and occurred most frequently in pressure control ventilation (PCV) mode (median: 3; IQR: 1-9 per hour). Ineffective effort was more likely to occur during day time (RR: 1.09; 95% CI: 1.05-1.13; p < 0.001), and occurred most frequently in PSV mode (median: 8; IQR: 2-29 per hour). The effect of sedatives and analgesics showed temporal patterns in DLNM. PVAs were not associated mortality and VAE in Cox regression models with time-varying covariates. Conclusions: Our study showed that counts of PVAs were significantly influenced by time of the day, ventilation mode, ventilation settings (e.g., tidal volume and plateau pressure), and sedatives and analgesics. However, PVAs were not associated with the hazard of VAE or mortality after adjusting for protective ventilation strategies such as tidal volume, plateau pressure, and positive end expiratory pressure (PEEP).

Effect of Depth of Sedation in Older Patients Undergoing Hip Fracture Repair on Postoperative Delirium: The STRIDE Randomized Clinical Trial

Importance

Postoperative delirium is the most common complication following major surgery in older patients. Intraoperative sedation levels are a possible modifiable risk factor for postoperative delirium.

Objective

To determine whether limiting sedation levels during spinal anesthesia reduces incident delirium overall.

Design, Setting, and Participants

This double-blind randomized clinical trial (A Strategy to Reduce the Incidence of Postoperative Delirum in Elderly Patients [STRIDE]) was conducted from November 18, 2011, to May 19, 2016, at a single academic medical center and included a consecutive sample of older patients (≥65 years) who were undergoing nonelective hip fracture repair with spinal anesthesia and propofol sedation. Patients were excluded for preoperative delirium or severe dementia. Of 538 hip fractures screened, 225 patients (41.8%) were eligible, 10 (1.9%) declined participation, 15 (2.8%) became ineligible between the time of consent and surgery, and 200 (37.2%) were randomized. The follow-up included postoperative days 1 to 5 or until hospital discharge.

Interventions

Heavier (modified observer's assessment of sedation score of 0-2) or lighter (observer's assessment of sedation score of 3-5) propofol sedation levels intraoperatively.

Main Outcomes and Measures

Delirium on postoperative days 1 to 5 or until hospital discharge determined via consensus panel using Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) criteria. The incidence of delirium was compared between intervention groups with and without stratification by the Charlson comorbidity index (CCI).

Results

Of 200 participants, the mean (SD) age was 82 (8) years, 146 (73%) were women, 194 (97%) were white, and the mean (SD) CCI was 1.5 (1.8). One hundred participants each were randomized to receive lighter sedation levels or heavier sedation levels. A good separation of intraoperative sedation levels was confirmed by multiple indices. The overall incident delirium risk was 36.5% (n = 73) and 39% (n = 39) vs 34% (n = 34) in heavier and lighter sedation groups, respectively (P = .46). Intention-to-treat analyses indicated no statistically significant difference between groups in the risk of incident delirium (log-rank test χ2, 0.46; P = .46). However, in a prespecified subgroup analysis, when stratified by CCI, sedation levels did effect the delirium risk (P for interaction = .04); in low comorbid states (CCI = 0), heavier vs lighter sedation levels doubled the risk of delirium (hazard ratio, 2.3; 95% CI, 1.1- 4.9). The level of sedation did not affect delirium risk with a CCI of more than 0.

Conclusions and Relevance

In the primary analysis, limiting the level of sedation provided no significant benefit in reducing incident delirium. However, in a prespecified subgroup analysis, lighter sedation levels benefitted reducing postoperative delirium for persons with a CCI of 0.

Trial Registration

clinicaltrials.gov Identifier: NCT00590707.

Effect of Neuromuscular Blocking Agents on Sedation Requirements in Trauma Patients with an Open Abdomen

The appropriate level of sedation in patients with an open abdomen following damage control laparotomy (DCL) is debated. Chemical paralysis with neuromuscular blocking agents (NMBAs) has been used to decrease time to abdominal closure. We sought to evaluate the effect of NMBA use on sedation requirements in patients with an open abdomen and to determine the effect of sedation on patient outcomes. A retrospective cohort study was conducted at an American College of Surgeons' verified level 1 trauma center. Adult trauma patients who underwent DCL between 2009 and 2015 were included. Patients with an intensive care unit length of stay of less than 48 hours and those who died before abdominal closure were excluded. The NMBA+ group received continuous NMBA within 24 hours of DCL; the NMBA- group did not. The primary outcome was cumulative sedation dose during the 7 days following DCL. Secondary outcomes included Richmond Agitation-Sedation Scale (RASS) score, mechanical ventilation-free days, and delirium-coma-free days. Delirium-coma-free days were analyzed with linear regression. A total of 222 patients were included (NMBA+ 125; NMBA- 97). Demographics were similar between groups including age, Injury Severity Score, and mechanism of injury. The median time to closure in the overall cohort was 2 days (interquartile range [IQR] 1-2 days). Propofol and fentanyl were the primary sedatives used. The NMBA+ group received higher cumulative doses of propofol (NMBA+ 5405 mg, IQR 3103-10,573 mg; NMBA- 3601 mg, IQR 1605-6887 mg; p=0.007), but not of fentanyl. Time to abdominal closure, but not NMBA use, was associated with a higher cumulative propofol dose on multivariate analysis. The NMBA+ group had significantly lower RASS scores on the first 3 days following DCL. Mechanical ventilation-free days (NMBA+ 20 days vs NMBA- 18 days, p=0.960) and delirium-coma-free days (NMBA+ 18 days vs NMBA- 18 days, p=0.610) were similar between the groups. On linear regression, cumulative propofol dose was associated with fewer delirium-coma-free days (β-coefficient -0.007, 95% confidence interval -0.015 to -0.003). In trauma patients managed with DCL, higher cumulative sedative doses were administered in patients who received adjunctive NMBA, although NMBA therapy was not associated with a higher cumulative propofol dose on multivariate analysis. Consideration must be given to the potential effect of sedation on delirium and awakening following DCL.

Postoperative Delirium in Severely Burned Patients Undergoing Early Escharotomy: Incidence, Risk Factors, and Outcomes

The aim of this study is to investigate the incidence, related risk factors, and outcomes of postoperative delirium (POD) in severely burned patients undergoing early escharotomy. This study included 385 severely burned patients (injured <1 week; TBSA, 31-50% or 11-20%; American Society of Anesthesiologists physical status, II-IV) aged 18 to 65 years, who underwent early escharotomy between October 2014 and December 2015, and were selected by cluster sampling. The authors excluded patients with preoperative delirium or diagnosed dementia, depression, or cognitive dysfunction. Preoperative, perioperative, intraoperative, and postoperative information, such as demographic characteristics, vital signs, and health history were collected. The Confusion Assessment Method was used once daily for 5 days after surgery to identify POD. Stepwise binary logistic regression analysis was used to identify the risk factors for POD, t-tests, and χ tests were performed to compare the outcomes of patients with and without the condition. Fifty-six (14.55%) of the patients in the sample were diagnosed with POD. Stepwise binary logistic regression showed that the significant risk factors for POD in severely burned patients undergoing early escharotomy were advanced age (>50 years old), a history of alcohol consumption (>3/week), high American Society of Anesthesiologists classification (III or IV), time between injury and surgery (>2 days), number of previous escharotomies (>2), combined intravenous and inhalation anesthesia, no bispectral index applied, long duration surgery (>180 min), and intraoperative hypotension (mean arterial pressure < 55 mm Hg). On the basis of the different odds ratios, the authors established a weighted model. When the score of a patient's weighted odds ratios is more than 6, the incidence of POD increased significantly (P < .05). When the score of a patient's weighted odds ratios is more than 6, the incidence of POD increased significantly (P < .05). Further, POD was associated with more postoperative complications, including hepatic and renal function impairment and hypernatremia, as well as prolonged hospitalization, increased medical costs, and higher mortality.

Impact of Sedation on Cognitive Function in Mechanically Ventilated Patients

The practice of sedation dosing strategy in mechanically ventilated patient has a profound effect on cognitive function. We conducted a comprehensive review of outcome of sedation on mental health function in critically ill patients on mechanical ventilation in the intensive care unit (ICU). We specifically evaluated current sedative dosing strategy and the development of delirium, post-traumatic stress disorders (PTSDs) and agitation. Based on this review, heavy dosing sedation strategy with benzodiazepines contributes to cognitive dysfunction. However, outcome for mental health dysfunction is mixed in regard to newer sedatives agents such as dexmedetomidine and propofol. Moreover, studies that examine the impact of sedatives for persistence of PTSD/delirium and its long-term cognitive and functional outcomes for post-ICU patients are frequently underpowered. Most studies suffer from low sample sizes and methodological variations. Therefore, larger randomized controlled trials are needed to properly assess the impact of sedation dosing strategy on cognitive function.