Risk Factors of Delirium in Sequential Sedation Patients in Intensive Care Units

Comparative risks and clinical outcomes of midazolam versus other intravenous sedatives in critically ill mechanically ventilated patients: A systematic review and meta-analysis of randomized trials

OBJECTIVES

This systematic review synthesized literature evidence and compared midazolam's risks and clinical outcomes with other sedatives in critically ill mechanically ventilated patients.

METHODS

We included randomized controlled trials (RCTs) from databases of PubMed, Embase, Cochrane Library, Web of Science, and CINAHL without language restrictions. We used relative risk (RR) for binary outcomes and standardized mean difference (SMD) for continuous outcomes, with corresponding 95% confidence interval (CI).

RESULTS

17 RCTs involving 1509 patients were included. Compared to other sedatives, midazolam significantly increased the incidence of delirium (RR 2.39, 95 % CI, 1.75 to 3.26), the time up to extubation (SMD 1.99, 95 % CI, 0.81 to 3.16) and ICU length of stay (SMD 0.63, 95 % CI, 0.20 to 1.08), but significantly reduced the incidence of bradycardia (RR 0.52, 95 % CI, 0.36 to 0.76). No differences were identified in hypotension incidence (RR 0.69, 95 % CI, 0.37 to 1.31) or duration of mechanical ventilation (SMD 0.28, 95 % CI, -0.22 to 0.78).

CONCLUSIONS

Midazolam caused a higher risk of delirium, a longer time up to extubation, and ICU length of stay, but a lower incidence of bradycardia. No significant evidence indicated midazolam was associated with a higher risk of hypotension or increased duration of mechanical ventilation.

IMPLICATIONS FOR CLINICAL PRACTICE

Clinicians should balance midazolam's potential risks with its benefits. While other sedatives may be catering to patients at a higher delirium risk, midazolam remains indispensable for hemodynamically compromised patients, such as those with bradycardia. Precise sedation management is crucial for patient safety and outcomes.

Global Research Trends in Postoperative Delirium and Its Risk Factors: A Bibliometric and Visual Analysis

PURPOSE

Postoperative delirium (POD) is one of the most frequent complications after surgery which is closely associated with many adverse outcomes, including high mortality and low quality of life. This study aims to carry out a bibliometric analysis of POD and its risk factors from 2012 to 2022 to reveal the research status and hot spots.

DESIGN

This study is a bibliometric and visualized analysis.

METHODS

Relevant publications between 2012 and 2022 were extracted from the Web of Science Core Collection database. CiteSpace software (v6.1. R2, Drexel University), VOSviewer software (v1.6.18, Leiden University), and the Online Analysis Platform of Literature Metrology were used to analyze research attributes. These publications were used to analyze research attributes, including countries, journals, institutions, authors, keywords, and burst detection, to predict trends and hot spots.

FINDINGS

We included a total of 1,324 related documents from 2012 to 2022. The literature on POD has increased significantly since 2016. The United States and Harvard University were the leading literature publishing country (436/1324, 32.9%) and institution (112/1324, 8.5%). Anesthesia and Analgesia was the most frequently published journal. Keywords analysis with VOSviewer revealed that the keywords could be divided into five clusters, including anesthesia techniques, cardiac surgery, risk factors, intraoperative anesthesia monitoring, and postoperative cognitive dysfunction. We included a total of 198 POD risk factors documents, and the literature on POD risk factors increased. The People's Republic of China and Harvard University were the leading literature publishing country (53/198, 26.8%) and institution (12/198, 6.1%). Elderly, hip surgery, frailty, postoperative pain, cardiac surgery, dementia, and depression are keywords that are risk factors for POD.

CONCLUSIONS

The number of literature on POD in the field of anesthesia has increased significantly. Risk factors and anesthesia techniques are still key areas of research. Encephalogram, the use of sedatives, and perioperative nursing may be the new research focus. Older adults, hip fractures, cardiac surgery, liver transplants, dementia, and depression are hot words in the field of POD risk factors.

Investigating the Relationship Between Midazolam Serum Concentrations and Paediatric Delirium in Critically Ill Children

OBJECTIVES

Intravenous midazolam is widely used for sedation in critically ill children. Sometimes, these children develop a paediatric delirium (PD). Our aim was to determine the relationship between midazolam serum concentration and the development of new PD in critically ill children.

DESIGN

Prospective observational pilot study.

SETTING

Paediatric Intensive Care Unit (PICU), Groningen, the Netherlands.

PATIENTS

All children admitted to the PICU from October-December 2019 who received continuous midazolam administration.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Twenty-five percent (n = 7) of the included patients (n = 28) developed new PD. In most patients, PD occurred following midazolam dose reduction. The median cumulative midazolam dose was higher in patients who developed PD compared to those without PD. We analysed 104 blood samples to determine the midazolam concentrations. To determine whether patients had PD, the Sophia Observation withdrawal Symptoms-Paediatric Delirium (SOS-PD) score was used. Patients suffering PD (n = 7) had a lower median midazolam concentration on that day compared with the day prior to PD detection. Analysis of the active metabolites, 1-hydroxymidazolam and 1-hydroxymidazolam glucuronide, showed similar results.

CONCLUSIONS

PD may be linked to a sudden and significant reduction in the midazolam concentration in critically ill children. Further investigation in larger patient populations is necessary to validate our findings.

Association Between Verbal Communication With Families and Delirium in Mechanically Ventilated Patients: A Retrospective Study

Introduction Delirium in the intensive care unit (ICU) significantly impacts patient outcomes. While family involvement may help prevent delirium in ICU patients, its effect during mechanical ventilation remains unclear. This study investigated the association between verbal communication during family visits and early post-extubation delirium in mechanically ventilated ICU patients. Materials and methods This retrospective, analytical observational study used data from the hospital's standard electronic health record (EHR) system, which includes routine medical and nursing documentation. We conducted this study in a 10-bed emergency ICU at an academic hospital in rural Japan from April 1, 2019, to December 31, 2020. We included patients aged ≥18 years who received invasive positive pressure ventilation for >48 hours. We excluded patients who were discharged while intubated, required a tracheostomy, or were unable to be assessed using the intensive care delirium screening checklist (ICDSC). The primary outcome was the maximum ICDSC score within 24 hours post-extubation. We conducted multiple regression analyses with ICDSC as the outcome. Results A total of 110 patients were analyzed. The mean age was 64.7 years (standard deviation ± 14.3), and 73 patients were male (66.4%). The median duration of intubation was five days (interquartile range (IQR), 4-8), and the median sequential organ failure assessment (SOFA) score was 8 (IQR, 6-11). The median ICDSC within 24 hours post-extubation was 3 (IQR, 2-5). Of the total 110 patients, 28 (25.5%) could communicate verbally. Patients who could communicate verbally had lower SOFA scores, longer duration of intubation, more frequent family visits, and higher intensive care mobility scale (IMS) scores during intubation. Neither single nor multiple regression showed a significant association between verbal communication and post-extubation ICDSC. Conclusions We did not find a statistically significant association between verbal communication during family visits with patients and ICDSC within 24 hours post-extubation. Potential confounders and variations in care practices may have influenced the results. Further studies are needed to address these limitations.

Risk Factors Associated With Opioid/Benzodiazepine Iatrogenic Withdrawal Syndrome in COVID-19 Acute Respiratory Distress Syndrome

BackgroundMechanically ventilated COVID-19 acute respiratory distress syndrome (ARDS) patients often receive deeper sedation and analgesia to maintain respiratory compliance and minimize staff exposure, which incurs greater risk of iatrogenic withdrawal syndrome (IWS) and has been associated with worse patient outcomes. Objective: To identify potential risk factors and differences in patient outcomes associated with the development of IWS in COVID-19 ARDS patients. Methods: Retrospective analysis of ventilated COVID-19 ARDS intensive care unit (ICU) patients who received continuous intravenous (IV) analgesia and sedation for ≥5 days from March 2020-May 2021. Patients were classified as IWS and non-IWS based on receipt of scheduled oral sedative/analgesic regimens after cessation of IV therapy. Risk factors were assessed in univariate analyses and multivariable modeling. Results: A total of 115 patients were included. The final multivariable model showed: (1) each additional day of IV opioid therapy was associated with an 8% increase in odds of IWS (95% CI, 1.02-1.14), (2) among sedatives, receipt of lorazepam was associated with 3 times higher odds of IWS (95% CI 1.12-8.15), and (3) each 1-point increase in Simplified Acute Physiology Score (SAPS) II was associated with a 4% reduction in odds of IWS (95% CI 0.93-0.999). Conclusion: Prolonged and high dose exposures to IV opioids and benzodiazepines should be limited when possible. Additional prospective studies are needed to identify modifiable risk factors to prevent IWS.

A retrospective, cross-sectional analysis of delirium in burn injury compared to other surgical specialities

BACKGROUND

Delirium is an acute cerebral disorder characterised by a disturbance in cognition, attention, and awareness. Often, it's undiagnosed and associated with increased morbidity and mortality. For burn patients, the reported prevalence ranges from 16% to 39%, with a multifactorial aetiology, increasing when intensive care is required. A direct comparison of delirium between surgical specialities has not been made.

AIM

1. To audit the use of the 4AT for those who become delirious during their stay. 2. Assess the proportion of patients diagnosed with delirium during hospitalisation by surgical specialities. 3. Identification of the factors associated with delirium in surgical patients.

METHODS

Investigators at a single centre conducted a two-phase study. An initial retrospective audit of delirious patients under burns, general, and orthopaedic specialities over 16months, as defined by ICD-10 coding, identified compliance screening with the 4 A's Test. This informed the design of a retrospective, observational cohort study to compare factors associated with delirium and statistical comparison between four specialities to identify delirium-associated factor, where an analysis corrects for age.

RESULTS

37% of patients with an ICD-10 code indicating delirium had a 4AT test completed. Speciality, number of operations, LOS, ICU hours, age, and discharge destination were all statistically significant independent variables. When all other variables were equal, burns had the highest predicted probability of delirium diagnosis.

CONCLUSIONS

Further analysis to identify and diagnose across the specialties is required. From a patient viewpoint, their LOS, ICU hours, and operations are increased for patients coded as delirious compared to non-delirious across the specialities. On a hospital level, the mean difference in cost for a delirious compared to a non-delirious patient is AU$9317. Despite the low incidence of delirium amongst the observed specialities, burns patients were most likely to develop delirium when demographic and clinical profiles were the same, and were more likely to develop delirium at a younger age and if in ICU.

Early alteration of peripheral blood lymphocyte subsets as a risk factor for delirium in critically ill patients after cardiac surgery: A prospective observational study

Objective

There is a high incidence of delirium among patients with organ dysfunction undergoing cardiac surgery who need critical care. This study aimed to explore the risk factors for delirium in critically ill patients undergoing cardiac surgery and the predictive value of related risk factors.

Methods

We conducted a prospective observational study on adult critically ill patients who underwent cardiac surgery between January 2019 and August 2021. Patients were consecutively assigned to delirium and non-delirium groups. Univariate analysis and multivariate logistic analysis were used to determine the risk factors for delirium. Receiver operating characteristic curves and a nomogram were used to identify the predictive value of related risk factors.

Results

Delirium developed in 242 of 379 (63.9%) participants. Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores were 14.2 ± 5.6 and 18 ± 8.4, respectively. Patients with delirium had longer cardiopulmonary bypass time (149.6 ± 59.1 vs. 126.7 ± 48.5 min, p < 0.001) and aortic cross-clamp time (98.7 ± 51.5 vs. 86.1 ± 41.6 min, p = 0.010) compared with the non-delirium group. The area under the curve was 0.824 for CD4⁺ T cell count and 0.862 for CD4/CD8 ratio. Multivariate analysis demonstrated that age [odds ratio (OR) 1.030, p = 0.038], duration of physical restraint (OR 1.030, p < 0.001), interleukin-6 (OR 1.001, p = 0.025), CD19⁺ B cell count (OR 0.996, p = 0.016), CD4⁺ T cell count (OR 1.005, p < 0.001) and CD4/CD8 ratio (OR 5.314, p < 0.001) were independent risk factors for delirium. A nomogram revealed that age, cardiopulmonary bypass duration, CD4⁺ T cell count and CD4/CD8 ratio were independent predictors of delirium.

Conclusion

Age, duration of physical restraint, CD4⁺ T cell count and CD4/CD8 ratio were reliable factors for predicting delirium in critically ill patients after cardiac surgery. The receiver operating characteristic curves and nomogram suggested a potential role for CD4⁺ T cells in mediating potential neuroinflammation of delirium.

Nomogram Models for Predicting Delirium of Patients in Emergency Intensive Care Unit: A Retrospective Cohort Study

Background

Intensive care unit (ICU) delirium is one of the most common clinical syndromes that results in many adverse events that affect patients, families, and hospitals. To date, there has been no tool for effectively predicting the occurrence of delirium in emergency intensive care unit (EICU) patients.

Methods

We conducted a retrospective cohort study and constructed a prediction model for 319 patients in EICU, who met our inclusion criteria. We analyzed the relationship between patients’ clinical data within 24 hours of admission and delirium, applied univariate and multivariate logistic regression analyses to select the most relevant variables for construction of nomogram models, then applied bootstrapping for internal validation.

Results

A total of five variables, namely stomach and urinary tubes, as well as sedative, mechanical ventilation and APACHE-II scores, were selected for model construction. We generated a total of five sets of models (three sets of construction models and two sets of internal verification models), with similar predictive value. The optimal model was selected, and together with the 5 variables used to construct a nomogram. The AUC of the MFP model in all patients was 0.76 (0.70, 0.82), whereas that in non-elderly patients (<60 years old) for the full model was 0.83 (0.74, 0.91). In elderly patients (≥60 years old), the AUC of the MFP model was 0.82 (0.73, 0.91).

Conclusion

Overall, the five-marker-based prognostic tool, established herein, can effectively predict the occurrence of delirium in EICU patients.

Hospital Admission to a Window-Side Bed Does Not Prevent Delirium: A Retrospective Cohort Study of Older Medical Inpatients in General Wards

Background: Delirium in older inpatients is a serious problem. The presence of a window in the intensive care unit has been reported to improve delirium. However, no study has investigated whether window-side bed placement is also effective for delirium prevention in a general ward. Objectives: This study aims to clarify the association between admission to a window-side bed and delirium development in older patients in a general ward. Design: This research is designed as a retrospective cohort study of older patients admitted to the internal medicine departments of Shinshu University Hospital, Japan. Participants: The inclusion criteria were the following: (1) admitted to hospital internal medicine departments between April 2009 and December 2018, (2) older than 75 years, (3) admitted to a multi-patient room in a general ward, and (4) unplanned admission. The number of eligible patients was 1,556. Exposure: This study is a comparison of 495 patients assigned to a window-side bed (window group) with 1,061 patients assigned to a non-window-side bed (non-window group). When patients were transferred to the other type bed after admission, observation was censored. Main Measures: The main outcome of interest was "delirium with event" (e.g., the use of medication or physical restraint for delirium) within 14 days after admission as surveyed by medical chart review in a blinded manner. Key Results: The patients had a median age of 80 years and 38.1% were female. The main outcome was recorded in 36 patients in the window group (10.7 per thousand person-days) and 84 in the non-window group (11.7 per thousand person-days). Log-rank testing showed no significant difference between the groups (p = 0.78). Multivariate analysis with Cox regression modeling also revealed no significant association for the window group with main outcome development (adjusted hazard ratio 0.90, 95% confidence interval of 0.61-1.34). Conclusions: Admission to a window-side bed did not prevent delirium development in older patients admitted to a general ward.

Pre-Existing Psychiatric Illness Is Associated With an Increased Risk of Delirium in Patients With Acute Respiratory Distress Syndrome

BACKGROUND

Patients with acute respiratory distress syndrome (ARDS) are highly susceptible to developing delirium for a multitude of reasons. Previous studies have linked pre-existing depression with an increased risk of postoperative delirium in patients undergoing cardiac and non-cardiac surgery. However, the evidence regarding the association between pre-existing psychiatric illnesses and delirium in ARDS patients is unknown. In this study, we aim to determine the relationship between pre-existing psychiatric illness and the risk of development of delirium amongst ARDS patients.

STUDY DESIGN AND METHODS

We performed a retrospective study of a mixed group of patients admitted to the intensive care unit (ICU) between January 2016 and December 2019 with a diagnosis of ARDS per the Berlin definition. The study group was divided into 2 cohorts: subjects with delirium and subjects without delirium. Comparison between the 2 groups was conducted to examine the impact of pre-existing psychiatric illnesses including major depressive disorder (MDD), generalized anxiety disorder (GAD), bipolar disorder, schizophrenia, or post-traumatic stress disorder. Multivariable logistic regression analysis was performed adjusting for benzodiazepine use, sedatives, analgesics, sequential organ failure assessment score, and corticosteroid use to determine the association between pre-existing psychiatric disorders and delirium.

RESULTS

286 patients with ARDS were identified; 124 (43%) of whom were diagnosed with ICU delirium. In patients diagnosed with ICU delirium, 49.2% were found to have preexisting psychiatric illnesses, compared to 34.0% without any preexisting psychiatric illness (OR = 1.94, P = 0.01). In a subgroup analysis of individual psychiatric illnesses, GAD and MDD were associated with the development of delirium (OR = 1.88, P = 0.04 and OR = 1.76, P = 0.05 respectively).

INTERPRETATION

ARDS patients with preexisting psychiatric illnesses, particularly GAD and MDD are associated with an increased risk of developing ICU delirium. Clinicians should be aware of the effect of psychiatric co-morbidities on developing delirium in critically ill patients.

Association Between Early Tracheostomy and Delirium in Older Adults in the United States

OBJECTIVES

Early tracheostomy (fewer than eight days after intubation) is associated with shorter length of stay in the intensive care unit and shorter duration of mechanical ventilation. Studies assessing the association between early tracheostomy and incidence of delirium, however, are lacking. This investigation sought to fill this gap.

DESIGN

Retrospective cross-sectional study.

SETTING

Multi-institutional acute care facilities in the United States.

PARTICIPANTS

Data were derived from the National Inpatient Sample data from 2010 to 2014. Included patients were 65 or older and underwent both intubation and tracheostomy during the hospitalization. The authors excluded patients who underwent multiple intubations or tracheostomy procedures.

INTERVENTIONS

Early tracheostomy versus non-early tracheostomy.

RESULTS

In total, 23,310 patients were included, of whom 24.8% underwent early tracheostomy. From multivariate logistic regression, early tracheostomy was associated with lower odds of having a delirium diagnosis (odds ratio [OR] 0.77, p < 0.00001) across all admission classifications. Upon subgroup analysis, early tracheostomy was associated significantly with lower odds of having delirium for patients admitted with medical (OR 0.74, p < 0.00001) and nonsurgical injury admissions (OR 0.74, p = 0.00116).

CONCLUSIONS

Early tracheostomy was associated significantly with lower odds of delirium among all patients studied. This association held true across medical and nonsurgical subgroups.

Dexmedetomidine Alleviates LPS-Induced Neuronal Dysfunction by Modulating the AKT/GSK-3β/CRMP-2 Pathway in Hippocampal Neurons

OBJECTIVE

Dexmedetomidine, an α2-adrenergic receptor agonist, mitigates cognitive dysfunction in elderly patients after surgery with general anesthesia. However, the underlying mechanism by which dexmedetomidine reduces cognitive dysfunction remains to be fully elucidated. The aim of this study was to investigate the effects of dexmedetomidine on lipopolysaccharide (LPS)-induced neuronal dysfunction in cultured hippocampal neurons.

METHODS

LPS, in the presence and absence of dexmedetomidine, was applied to cultured hippocampal neurons to mimic post-surgical inflammation. Neuronal morphology, including neurite outgrowth and synaptic transmission, was observed, and miniature excitatory postsynaptic currents were recorded by electrophysiological patch-clamp.

RESULTS

LPS significantly impaired neurite outgrowth in hippocampal neurons in a concentration- and time-dependent manner, which was reversed by dexmedetomidine treatment. Electrophysiological patch-clamp results showed that LPS induced synaptic transmission dysfunction, which was restored after dexmedetomidine addition. Furthermore, Western blotting assays showed that LPS suppressed the AKT/GSK-3β/CRMP-2 signaling pathway and dexmedetomidine countered the inhibitory effect of LPS by re-activating this pathway.

CONCLUSION

In general, dexmedetomidine protected against the effects of LPS-induced hippocampal neuron damage, including neurite outgrowth and synaptic transmission. Overall, dexmedetomidine modulated the AKT/GSK-3β/CRMP-2 signaling pathway to alleviate LPS-induced neurological dysfunction.

The effect of perioperative anesthetics for prevention of postoperative delirium on general anesthesia: A network meta-analysis

STUDY OBJECTIVE

Postoperative delirium (POD) is a common neurological system disorder in surgical patients. Anesthesia providers have a wide choice of sedative agents involving different mechanisms in clinical practice, and the incidence of POD varies regarding which sedative agent administered. This network meta-analysis aimed to comprehensively analyze the safety and efficacy of each choice for patients.

DESIGN

A network meta-analysis.

SETTING

Vanderbilt University Medical Center.

MEASUREMENTS

We searched PubMed, EMBASE, Ovid Medline and Cochrane Central Register of Controlled Trials (CENTRAL) through the end of September 2018 with the registration number CRD42018110585. The randomized controlled trials were identified and extracted by two reviewers independently. Commonly used sedative agents such as placebo, sevoflurane, desflurane, isoflurane, dexmedetomidine, propofol, midazolam, and ketamine were assessed in this network meta-analysis and the primary outcome was the incidence of POD. The data were synthesized by network meta-analysis. Pair-wise meta-analyses were conducted using the random-effects model. Each intervention was ranked according to its corresponding surface under the cumulative ranking curve (SUCRA) values. The GRADE framework was undertaken to evaluate the risk of bias.

MAIN RESULTS

We identified 39 RCTs and 5991 patients in this meta-analysis. Dexmedetomidine was found to be the most effective option in reducing POD, compared to midazolam, propofol, desflurane, and sevoflurane. The results revealed that dexmedetomidine was associated with a lower incidence of POD, whereas midazolam was associated with a significantly higher number of patients with delirium. Midazolam and propofol were also associated with a higher incidence of perioperative hypotension and bradycardia.

CONCLUSION

Our study provided meta-analytic evidence and suggested dexmedetomidine could be considered as the most effective sedative agent to reduce POD. However, clinical practitioners still need to weigh the pros and cons before choosing a sedative agent for individual patient.

Serum glial fibrillary acidic protein and ubiquitin C-terminal hydrolase-L1 for diagnosis of sepsis-associated encephalopathy and outcome prognostication

PURPOSE

We investigated the role of serum Glial Fibrillary Acidic Protein (GFAP) and Ubiquitin C-Terminal Hydrolase-L1 (UCH-L1) in diagnosis of sepsis-associated encephalopathy(SAE), predicting prognosis and long-term quality of life with patients of sepsis.

MATERIALS AND METHODS

This is a prospective single center study entailed 105 patients whosuffered from sepsis from Jan 2015 to Aug 2016. Serum concentrations of GFAP and UCH-L1 for diagnosis of SAE and predicting prognosis and long-term quality of life with patients of sepsis were analyzed.

RESULTS

The serum concentrations of GFAP and UCH-L1 were higher in SAE group than in no-SAE group (p < .001). GFAP and UCH-L1 produced an AUC of 0.824 and 0.812 respectively for diagnosis of SAE with optimal cut-off values 0.532 ng/ml and 7.72 ng/ml respectively. The optimal cut-off values of GFAP and UCH-L1 to distinguish patients with survivors from non-survivors were 0.536 ng/ml and 8.06 ng/ml with an area under the curve of 0.773 and 0.746. Patients with a higher GFAP levels had worse long-term usual activities and patients with a higher UCH-L1 levels had more long-term pain (P = .026).

CONCLUSIONS

Serum concentrations GFAP and UCH-L1 early elevated and associated with sepsis-associated encephalopathy, poor prognosis and quality of life.

Pharmacological Prevention of Postoperative Delirium: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

The high prevalence of delirium among postoperative patients has increased morbidity and mortality. The kind of drug that can effectively reduce the incidence of delirium has become the focus of discussion in recent years. However, a consensus in this respect has yet to be reached.

Methods

Randomized controlled trials (RCTs) were retrieved from the PubMed, Cochrane Library, ClinicalTrials.gov, and Embase databases from their inception through October 12, 2018. We included RCTs of pharmacological prevention for postoperative delirium in adults (at least 18 years), and the Cochrane risk of bias tool was used to evaluate the methodological quality of trials. The primary outcomes were the risk ratios (RRs) of incidence of postoperative delirium, and the secondary outcomes were the RRs of mortality and adverse events in the intervention and control groups.

Results

Thirty-eight trials, which comprised 20302 patients and 18 different drugs, were included in the analysis. Of the 38 studies, 17 were rated as low risk with respect to methodological quality. Dexmedetomidine administration (RR 0.58, 95%CI 0.44-0.76, P<0.01) was associated with a significantly lower incidence of postoperative delirium than the control conditions. However, the findings from the studies with a low risk of bias did not show a significant difference in this beneficial effect (RR 0.64, 95%CI 0.39-1.04, P=0.07). The antipsychotic drugs olanzapine (RR 0.44, 95%CI 0.30- 0.65, P<0.01) and risperidone (RR 0.42, 95%CI 0.19-0.92, P=0.03) had promising effects, but there was a lack of sufficient evidence to obtain a definitive conclusion. The beneficial effect of other drugs, including haloperidol, methylprednisolone, dexamethasone, gabapentin, ketamine, cyproheptadine, donepezil, hypertonic saline, melatonin, nimodipine, ondansetron, pregabalin, rivastigmine, TJ-54, and tryptophan, was not proven on the basis of present evidence.

Conclusion

Among the pharmacological prophylactic measures for postoperative delirium, dexmedetomidine, olanzapine, and risperidone showed higher efficacy than other drugs. However, more high-quality evidence is needed to confirm these results.

Risk factors for delirium: are therapeutic interventions part of it?

Background: Delirium is associated with increased morbidity and mortality in critically ill patients. Research on risk factors for delirium allows clinicians to identify high-risk patients, which is the basis for early prevention and diagnosis. Besides the risk factors for delirium that are commonly studied, here we more focused on the less-studied therapeutic interventions for critically ill patients which are potentially modifiable. Materials and methods: A total of 320 non-comatose patients admitted to the ICU for more than 24 hrs during 9 months were eligible for the study. Delirium was screened once daily using the CAM-ICU. Demographics, admission clinical data, and daily interventions were collected. Results: Ninety-two patients (28.75%) experienced delirium at least once. Delirious patients were more likely to have longer duration of mechanical ventilation, ICU stay, and hospital stay. Most of the less-studied therapeutic interventions were linked to delirium in the univariate analysis, including gastric tube, artificial airway, deep intravenous catheter, arterial line, urinary catheter, use of vasoactive drugs, and sedative medication. After adjusting with age and ICU length of stay, mechanical ventilation (OR: 5.123; 95% CI: 2.501-10.494), Acute Physiology and Chronic Health Evaluation (APACHE) II score≥20 at admission (OR: 1.897; 95% CI: 1.045-3.441), and gastric tube (OR: 1.935, 95% CI: 1.012-3.698) were associated with increased risk of delirium in multivariate analysis. Conclusion: Delirium was associated with prolonged mechanical ventilation, ICU stay, and hospital stay. Multivariate risk factors were gastric tube, mechanical ventilation, and APACHE II score. Although being a preliminary study, this study suggests the necessity of earliest removal of tubes and catheters when no longer needed.