Strategies for prevention of postoperative delirium: a systematic review and meta-analysis of randomized trials

Interventions for preventing delirium in hospitalised non-ICU patients

BACKGROUND

Delirium is a common mental disorder, which is distressing and has serious adverse outcomes in hospitalised patients. Prevention of delirium is desirable from the perspective of patients and carers, and healthcare providers. It is currently unclear, however, whether interventions for preventing delirium are effective.

OBJECTIVES

To assess the effectiveness of interventions for preventing delirium in hospitalised non-Intensive Care Unit (ICU) patients.

SEARCH METHODS

We searched ALOIS - the Cochrane Dementia and Cognitive Improvement Group's Specialized Register on 4 December 2015 for all randomised studies on preventing delirium. We also searched MEDLINE (Ovid SP), EMBASE (Ovid SP), PsycINFO (Ovid SP), Central (The Cochrane Library), CINAHL (EBSCOhost), LILACS (BIREME), Web of Science core collection (ISI Web of Science), ClinicalTrials.gov and the WHO meta register of trials, ICTRP.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of single and multi- component non-pharmacological and pharmacological interventions for preventing delirium in hospitalised non-ICU patients.

DATA COLLECTION AND ANALYSIS

Two review authors examined titles and abstracts of citations identified by the search for eligibility and extracted data independently, with any disagreements settled by consensus. The primary outcome was incidence of delirium; secondary outcomes included duration and severity of delirium, institutional care at discharge, quality of life and healthcare costs. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes; and between group mean differences and standard deviations for continuous outcomes.

MAIN RESULTS

We included 39 trials that recruited 16,082 participants, assessing 22 different interventions or comparisons. Fourteen trials were placebo-controlled, 15 evaluated a delirium prevention intervention against usual care, and 10 compared two different interventions. Thirty-two studies were conducted in patients undergoing surgery, the majority in orthopaedic settings. Seven studies were conducted in general medical or geriatric medicine settings.We found multi-component interventions reduced the incidence of delirium compared to usual care (RR 0.69, 95% CI 0.59 to 0.81; seven studies; 1950 participants; moderate-quality evidence). Effect sizes were similar in medical (RR 0.63, 95% CI 0.43 to 0.92; four studies; 1365 participants) and surgical settings (RR 0.71, 95% CI 0.59 to 0.85; three studies; 585 participants). In the subgroup of patients with pre-existing dementia, the effect of multi-component interventions remains uncertain (RR 0.90, 95% CI 0.59 to 1.36; one study, 50 participants; low-quality evidence).There is no clear evidence that cholinesterase inhibitors are effective in preventing delirium compared to placebo (RR 0.68, 95% CI, 0.17 to 2.62; two studies, 113 participants; very low-quality evidence).Three trials provide no clear evidence of an effect of antipsychotic medications as a group on the incidence of delirium (RR 0.73, 95% CI, 0.33 to 1.59; 916 participants; very low-quality evidence). In a pre-planned subgroup analysis there was no evidence for effectiveness of a typical antipsychotic (haloperidol) (RR 1.05, 95% CI 0.69 to 1.60; two studies; 516 participants, low-quality evidence). However, delirium incidence was lower (RR 0.36, 95% CI 0.24 to 0.52; one study; 400 participants, moderate-quality evidence) for patients treated with an atypical antipsychotic (olanzapine) compared to placebo (moderate-quality evidence).There is no clear evidence that melatonin or melatonin agonists reduce delirium incidence compared to placebo (RR 0.41, 95% CI 0.09 to 1.89; three studies, 529 participants; low-quality evidence).There is moderate-quality evidence that Bispectral Index (BIS)-guided anaesthesia reduces the incidence of delirium compared to BIS-blinded anaesthesia or clinical judgement (RR 0.71, 95% CI 0.60 to 0.85; two studies; 2057 participants).It is not possible to generate robust evidence statements for a range of additional pharmacological and anaesthetic interventions due to small numbers of trials, of variable methodological quality.

AUTHORS' CONCLUSIONS

There is strong evidence supporting multi-component interventions to prevent delirium in hospitalised patients. There is no clear evidence that cholinesterase inhibitors, antipsychotic medication or melatonin reduce the incidence of delirium. Using the Bispectral Index to monitor and control depth of anaesthesia reduces the incidence of postoperative delirium. The role of drugs and other anaesthetic techniques to prevent delirium remains uncertain.

Outcomes of dexmedetomidine treatment in pediatric patients undergoing congenital heart disease surgery: a meta-analysis

BACKGROUND

Dexmedetomidine decreases cardiac complications in adults undergoing cardiovascular surgery. This systematic review assessed whether perioperative dexmedetomidine improves congenital heart disease (CHD) surgery outcomes in children.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched for randomized controlled trials (RCTs) or observational studies that were published until 16 April 2015 and compared dexmedetomidine with placebo or an alternative anesthetic agent during pediatric CHD surgery. The assessed outcomes included hemodynamics, ventilation length, intensive care unit (ICU) and hospital stays, blood glucose and serum cortisol levels, postoperative analgesia requirements, and postoperative delirium.

RESULTS

Five RCTs and nine observational studies involving 2229 patients were included. In pooled analyses, dexmedetomidine was associated with shorter length of mechanical ventilation (mean difference: -93.36, 95% CI: -137.45, -49.27), lower postoperative fentanyl (mean difference: -24.11, 95% CI: -36.98, -11.24) and morphine (mean difference: -0.07, 95% CI: -0.14, 0.00) requirements, reduced stress response (i.e., lower blood glucose and serum cortisol levels), and lower risk of delirium (OR: 0.39, 95% CI: 0.21, 0.74). The hemodynamics of dexmedetomidine-treated patients appeared more stable, but there were no significant differences in the ICU or hospital stay durations. Dexmedetomidine may increase the bradycardia and hypotension risk (OR: 3.14, 95% CI: 1.47, 6.69).

CONCLUSIONS

Current evidence indicates that dexmedetomidine improves outcomes in children undergoing CHD surgery. However, this finding largely relies on data from observational studies; high-quality RCTs are warranted because of the potential for subject selection bias.

Incidence and risk factors of postoperative delirium in elderly patients undergoing transurethral resection of prostate: a prospective cohort study

AIM

The aim of the present study was to investigate the occurrence of postoperative delirium (POD) in elderly patients undergoing transurethral resection of prostate (TURP) and to identify those factors associated with delirium.

METHODS

From July 2010 to February 2015, 358 patients, aged ≥65 years and undergoing TURP were prospectively enrolled. Personal, medical and cognitive data, laboratory assessments, pain intensity, preoperative medications, and details of hemodynamic control were collected as predictors of delirium. POD was assessed using the Confusion Assessment Method.

RESULTS

In the present study, POD occurred in 28 out of 358 cases (7.8%) after TURP, with duration of 1-4 days. The multivariate analysis showed that old age and visual analog scale pain scores were associated with POD. Marital status, body mass index, education, alcohol consumption, smoking history, preoperative psychotropic medication usage, activities of daily living scores, preoperative Mini-Mental Status Examination score, anesthesia type, American Society of Anesthesiologists classification, or hypotensive episodes during surgery did not significantly correlate with the occurrence of POD.

CONCLUSION

Old age and pain intensity after surgery were found as the risk factors for the development of delirium in elderly patients undergoing TURP. These findings might help develop preventive strategies to decrease POD through targeted evaluation.

Systematic review and meta-analysis of risk factors for postoperative delirium among older patients undergoing gastrointestinal surgery

BACKGROUND

Postoperative delirium (POD) is common after surgery. As age is a known risk factor, the increased ageing of the population undergoing surgery emphasizes the importance of the subject. Knowledge of other potential risk factors in older patients with surgical gastrointestinal diseases is lacking. The aim here was to collate and synthesize the published literature on risk factors for delirium in this group.

METHODS

Five databases were searched (MEDLINE, Web of Science, Embase, CINAHL(®) and PSYCinfo(®) ) between January 1987 and November 2014. The Newcastle-Ottawa Scale was used to rate study quality. Pooled odds ratios or mean differences for individual risk factors were estimated using the Mantel-Haenszel and inverse-variance methods.

RESULTS

Eleven studies met the inclusion criteria; they provided a total of 1427 patients (318 with delirium and 1109 without), and predominantly included patients undergoing elective colorectal surgery. The incidence of POD ranged from 8·2 to 54·4 per cent. A total of 95 risk factors were investigated, illustrating wide heterogeneity in study design. Seven statistically significant risk factors were identified in pooled analysis: old age, American Society of Anesthesiologists (ASA) physical status grade at least III, body mass index, lower serum level of albumin, intraoperative hypotension, perioperative blood transfusion and history of alcohol excess. Patients with POD had a significantly increased duration of hospital stay and a higher mortality rate compared with those without delirium.

CONCLUSION

Delirium is common in older patients undergoing gastrointestinal surgery. Several risk factors were consistently associated with POD.

Defining the Role of Dexmedetomidine in the Prevention of Delirium in the Intensive Care Unit

Dexmedetomidine is a highly selective α 2 agonist used as a sedative agent. It also provides anxiolysis and sympatholysis without significant respiratory compromise or delirium. We conducted a systematic review to examine whether sedation of patients in the intensive care unit (ICU) with dexmedetomidine was associated with a lower incidence of delirium as compared to other nondexmedetomidine sedation strategies. A search of PUBMED, EMBASE, and the Cochrane Database of Systematic Reviews yielded only three trials from 1966 through April 2015 that met our predefined inclusion criteria and assessed dexmedetomidine and outcomes of delirium as their primary endpoint. The studies varied in regard to population, comparator sedation regimen, delirium outcome measure, and dexmedetomidine dosing. All trials are limited by design issues that limit our ability definitively to conclude that dexmedetomidine prevents delirium. Evidence does suggest that dexmedetomidine may allow for avoidance of deep sedation and use of benzodiazepines, factors both observed to increase the risk for developing delirium. Our assessment of currently published literature highlights the need for ongoing research to better delineate the role of dexmedetomidine for delirium prevention.

Effects of two different anesthesia-analgesia methods on incidence of postoperative delirium in elderly patients undergoing major thoracic and abdominal surgery: study rationale and protocol for a multicenter randomized controlled trial

Background

Delirium is a common complication in elderly patients after surgery and associated with increased morbidity and mortality. Studies suggest that deep anesthesia and intense pain are important precipitating factors of postoperative delirium. Neuraxial block is frequently used in combination with general anesthesia for patients undergoing major thoracic and abdominal surgery. Compared with general anesthesia alone and postoperative intravenous analgesia, combined epidural-general anesthesia and postoperative epidural analgesia decreases the requirement of general anesthetics during surgery and provided better pain relief after surgery. However, whether combined epidural-general anesthesia plus epidural analgesia is superior to general anesthesia plus intravenous analgesia in decreasing the incidence of postoperative delirium remains unknown.

Methods/design

This is a multicenter, open-label, randomized, parallel-controlled clinical trial. One thousand eight hundred elderly patients (age range 60–90 years) who are scheduled to undergo major thoracic or abdominal surgery are randomized to receive either general anesthesia plus postoperative intravenous analgesia or combined epidural-general anesthesia plus postoperative epidural analgesia. The primary outcome is the 7-day incidence of postoperative delirium. Secondary outcomes include the duration of postoperative delirium, the intensity of pain during the first three days after surgery, the 30-day incidences of postoperative non-delirium complications, the length of stay in hospital after surgery and 30-day all-cause mortality.

Discussion

Results of the present study will provide information to guide clinical practice in choosing appropriate anesthesia-analgesia method for elderly patients undergoing major thoracic and abdominal surgery.

Trial registration

The study is registered on ClinicalTrials.gov NCT01661907 and Chinese Clinical Trial Registry ChiCTR-TRC-12002371.

Efficacy of Non-Pharmacological Interventions to Prevent and Treat Delirium in Older Patients: A Systematic Overview. The SENATOR project ONTOP Series

Background

Non-pharmacological intervention (e.g. multidisciplinary interventions, music therapy, bright light therapy, educational interventions etc.) are alternative interventions that can be used in older subjects. There are plenty reviews of non-pharmacological interventions for the prevention and treatment of delirium in older patients and clinicians need a synthesized, methodologically sound document for their decision making.

Methods and Findings

We performed a systematic overview of systematic reviews (SRs) of comparative studies concerning non-pharmacological intervention to treat or prevent delirium in older patients. The PubMed, Cochrane Database of Systematic Reviews, EMBASE, CINHAL, and PsychINFO (April 28th, 2014) were searched for relevant articles. AMSTAR was used to assess the quality of the SRs. The GRADE approach was used to assess the quality of primary studies. The elements of the multicomponent interventions were identified and compared among different studies to explore the possibility of performing a meta-analysis. Risk ratios were estimated using a random-effects model. Twenty-four SRs with 31 primary studies satisfied the inclusion criteria. Based on the AMSTAR criteria twelve reviews resulted of moderate quality and three resulted of high quality. Overall, multicomponent non-pharmacological interventions significantly reduced the incidence of delirium in surgical wards [2 randomized trials (RCTs): relative risk (RR) 0.71, 95% Confidence Interval (CI) 0.59 to 0.86, I²=0%; (GRADE evidence: moderate)] and in medical wards [2 CCTs: RR 0.65, 95%CI 0.49 to 0.86, I²=0%; (GRADE evidence: moderate)]. There is no evidence supporting the efficacy of non-pharmacological interventions to prevent delirium in low risk populations (i.e. low rate of delirium in the control group)[1 RCT: RR 1.75, 95%CI 0.50 to 6.10 (GRADE evidence: very low)]. For patients who have developed delirium, the available evidence does not support the efficacy of multicomponent non-pharmacological interventions to treat delirium. Among single component interventions only staff education, reorientation protocol (GRADE evidence: very low)] and Geriatric Risk Assessment MedGuide software [hazard ratio 0.42, 95%CI 0.35 to 0.52, (GRADE evidence: moderate)] resulted effective in preventing delirium.

Conclusions

In older patients multi-component non-pharmacological interventions as well as some single-components intervention were effective in preventing delirium but not to treat delirium.

Major publications in the critical care pharmacotherapy literature: January-December 2013

PURPOSE

Ten recently published articles with important implications for critical care pharmacotherapy are summarized.

SUMMARY

The Critical Care Pharmacotherapy Literature Update (CCPLU) group is a national assembly of experienced intensive care unit (ICU) pharmacists across the United States. Group members monitor 25 peer-reviewed journals on an ongoing basis to identify literature relevant to pharmacy practice in the critical care setting. After evaluation by CCPLU group members, selected articles are chosen for summarization and distribution to group members nationwide based on (1) applicability to critical care practice, (2) relevance to pharmacy practitioners, and (3) quality of evidence or research methodology. Hundreds of relevant articles were evaluated by the group during the period January-December 2013, of which 98 were summarized and disseminated nationally to CCPLU group members. Among those 98 publications, 10 deemed to be of particularly high utility to critical care practitioners were included in this review. The 10 articles address topics such as rapid lowering of blood pressure in patients with intracranial hemorrhage, adjunctive therapy to prevent renal injury due to acute heart failure, triple-drug therapy to improve neurologic outcomes after cardiac arrest, and continuous versus intermittent infusion of β-lactam antibiotics in severe sepsis.

CONCLUSION

There were many important additions to the critical care pharmacotherapy literature in 2013, including an updated guideline on the management of myocardial infarction and reports on advances in research focused on improving outcomes in patients with stroke or cardiac arrest and preventing the spread of drug-resistant pathogens in the ICU.

Neurokinin-1 receptor antagonists in preventing postoperative nausea and vomiting: a systematic review and meta-analysis

Newly developed neurokinin-1 receptor (NK-1R) antagonists have been recently tried in the prevention of postoperative nausea and vomiting (PONV). This systematic review and meta-analysis was conducted to explore whether NK-1R antagonists were effective in preventing PONV.The PRISMA statement guidelines were followed. Randomized clinical trials (RCTs) that tested the preventive effects of NK-1R antagonists on PONV were identified by searching EMBASE, CINAHL, PubMed, and the Cochrane Library databases followed by screening. Data extraction was performed using a predefined form and trial quality was assessed using a modified Jadad scale. The primary outcome measure was the incidence of PONV. Meta-analysis was performed for studies using similar interventions. Network meta-analysis (NMA) was conducted to compare the anti-vomiting effects of placebo, ondansetron, and aprepitant at different doses.Fourteen RCTs were included. Meta-analysis found that 80 mg of aprepitant could reduce the incidences of nausea (3 RCTs with 224 patients, pooled risk ratio (RR) = 0.60, 95% confidence interval (CI) = 0.47 to 0.75), and vomiting (3 RCTs with 224 patients, pooled RR = 0.13, 95% CI = 0.04 to 0.37) compared with placebo. Neither 40 mg (3 RCTs with 1171 patients, RR = 0.47, 95% CI = 0.37 to 0.60) nor 125 mg (2 RCTs with 1058 patients, RR = 0.32, 95% CI = 0.13 to 0.78) of aprepitant showed superiority over 4 mg of ondansetron in preventing postoperative vomiting. NMA did not find a dose-dependent effect of aprepitant on preventing postoperative vomiting.Limited data suggested that NK-1R antagonists, especially aprepitant were effective in preventing PONV compared with placebo. More large-sampled high-quality RCTs are needed.

Do antipsychotics prevent postoperative delirium? A systematic review and meta-analysis

OBJECTIVE

To summarize the effect of antipsychotics for preventing postoperative delirium.

DESIGN

We conducted a literature search using Medline, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and clinicaltrials.gov. We included randomized controlled trials of adults undergoing surgery who were given antipsychotics to prevent postoperative delirium. Quality was assessed via the Cochrane risk of bias tool. Random-effects meta-analysis and meta-regression were conducted. Q-statistics and I(2) were used for assessment of heterogeneity. The main outcome was delirium incidence using validated definitions.

RESULTS

A total of 1710 subjects were included, with a mean age ranging from 60.7 to 86.4 years. Antipsychotics reduced the incidence of postoperative delirium with the global effect-size estimate (weighted odds ratio) using the random effects model of 0.44 (95% confidence interval: 0.28-0.70; N = 6; Q-value: 16, p-value 0.0005; I(2) = 69%). Significant heterogeneity existed with the pooled global effect of delirium incidence; however, meta-regression allowed us to test both treatment-level and patient-level explanations for significant between-study variance. Baseline risk for delirium was found to be a significant contributor to study heterogeneity, and meta-regression suggested that antipsychotic type and dosage were two of the several treatment-level factors that also may have led to heterogeneity. Our analysis implied the presence of a breakeven baseline level of delirium risk below which preventive treatment with antipsychotics might prove ineffective.

CONCLUSIONS

Within the limits of few randomized controlled trials, antipsychotics appeared to reduce the incidence of postoperative delirium in several surgical settings, predominantly orthopedic and for those at higher risk for delirium.

Melatonin and melatonin agonist for delirium in the elderly patients

The objective of this review is to summarize the available data on the use of melatonin and melatonin agonist for the prevention and management of delirium in the elderly patients from randomized controlled trials (RCTs). A systematic search of 5 major databases PubMed, MEDLINE, PsychINFO, Embase, and Cochrane Library was conducted. This search yielded a total of 2 RCTs for melatonin. One study compared melatonin to midazolam, clonidine, and control groups for the prevention and management of delirium in individuals who were pre- and posthip post-hip arthroplasty. The other study compared melatonin to placebo for the prevention of delirium in older adults admitted to an inpatient internal medicine service. Data from these 2 studies indicate that melatonin may have some benefit in the prevention and management of delirium in older adults. However, there is no evidence that melatonin reduces the severity of delirium or has any effect on behaviors or functions in these individuals. Melatonin was well tolerated in these 2 studies. The search for a melatonin agonist for delirium in the elderly patients yielded 1 study of ramelteon. In this study, ramelteon was found to be beneficial in preventing delirium in medically ill individuals when compared to placebo. Ramelteon was well tolerated in this study.

The protocol of the Oslo Study of Clonidine in Elderly Patients with Delirium; LUCID: a randomised placebo-controlled trial

Background

Delirium affects 15% of hospitalised patients and is linked with poor outcomes, yet few pharmacological treatment options exist. One hypothesis is that delirium may in part result from exaggerated and/or prolonged stress responses. Dexmedetomidine, a parenterally-administered alpha2-adrenergic receptor agonist which attenuates sympathetic nervous system activity, shows promise as treatment in ICU delirium. Clonidine exhibits similar pharmacodynamic properties and can be administered orally. We therefore wish to explore possible effects of clonidine upon the duration and severity of delirium in general medical inpatients.

Methods/Design

The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is a randomised, placebo-controlled, double-blinded, parallel group study with 4-month prospective follow-up. We will recruit 100 older medical inpatients with delirium or subsyndromal delirium in the acute geriatric ward. Participants will be randomised to oral clonidine or placebo until delirium free for 2 days (Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria), or after a maximum of 7 days treatment. Assessment of haemodynamics (blood pressure, heart rate and electrocardiogram) and delirium will be performed daily until discharge or a maximum of 7 days after end of treatment. The primary endpoint is the trajectory of delirium over time (measured by Memorial Delirium Assessment Scale). Secondary endpoints include the duration of delirium, use of rescue medication for delirium, pharmacokinetics and pharmacodynamics of clonidine, cognitive function after 4 months, length of hospital stay and need for institutionalisation.

Discussion

LUCID will explore the efficacy and safety of clonidine for delirium in older medical inpatients.

Trial registration

ClinicalTrials.gov NCT01956604. EudraCT Number: 2013-000815-26

Neurological complications of surgery and anaesthesia

Injury to the central and peripheral nervous systems is often permanent. As such, adverse neurological outcomes of surgery and anaesthesia can be devastating for patients and their families. In this article, we review the incidence, risk factors, outcomes, prevention, and treatment of a number of important neurological complications in the perioperative period.

Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey

Cognitive side-effects such as emergence agitation (EA), postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are not infrequently complicating the postoperative care especially in elderly and fragile patients. The aim of the present survey was to gain insight regarding concern and interest in prevention and treatment strategies for postoperative delirium and dysfunction, and the use of EEG-based depth-of-anaesthesia monitoring possibly reducing the risk for cognitive side effects among anaesthesia personnel.

METHODS

A web-based validated questionnaire was sent to all Swedish anaesthesiologists and nurse anaesthetists during summer 2013. The questionnaire consisted of 3 sections, subjective preferences, routines and practices related to the perioperative handling of EA, POD, POCD.

RESULTS

The response rate was 52%. Cardiovascular/pulmonary risks where assessed as importance by 98, 97% of responders while 69% considered the risk of neurocognitive side-effects important. When asked explicitly around cognitive side-effects 89%, 37% and 44% assessed awareness, POC and POD respectively of importance. EEG-based depth-of-anaesthesia monitors were used in 50% of hospitals. The responders were not convinced about the benefits of such monitors even in at-risk patients. Structured protocols for the management of postoperative cognitive side-effects were available only in few hospitals.

CONCLUSION

Swedish anaesthesia personnel are concerned about the risk of postoperative cognitive side-effects but are more concerned about cardiovascular/pulmonary risks, pain, PONV and the rare event of awareness. Most respondents were not convinced about the use of depth-of-anaesthesia monitors. There is a need to improve knowledge around risk factors, prevention and management of postoperative cognitive side effects.

Intravenous Patient-controlled Analgesia Has a Positive Effect on the Prognosis of Delirium in Patients Undergoing Orthopedic Surgery

BACKGROUND

Postoperative delirium is relatively common. However, the relationship between intravenous patient-controlled analgesia (IV-PCA) and delirium has not been thoroughly investigated. The aim of this study was to evaluate the effects of IV-PCA on the prognosis of postoperative delirium in patients undergoing orthopedic surgery.

METHODS

Medical records of 129 patients with postoperative delirium were reviewed. Patients were divided into two groups according to whether they used IV-PCA with fentanyl and ketorolac. The IV-PCA group consisted of 73 patients who were managed with IV-PCA; the NO-PCA group consisted of 56 patients who were managed without PCA.

RESULTS

Incidences of multiple psychiatric consultations and prolonged delirium were significantly lower in patients using IV-PCA with fentanyl and ketorolac than in those without PCA.

CONCLUSIONS

We recommend the use of IV-PCA for pain control and management of delirium in patients with postoperative delirium.

Delirium: definition, epidemiology, and diagnosis

This article serves to (1) review the relationship of the terms "delirium" and "encephalopathy," (2) describe delirium as defined in current diagnostic systems, (3) summarize the epidemiology and theories of pathogenesis, (4) review clinical diagnostic approaches, and (5) highlight the history using EEG in the study of delirium in the psychiatric literature. Delirium is an important medical syndrome with significant implications; there is continued need for better physiologic measures of the underlying brain dysfunction.

Delirium in trauma

Delirium is a common, severe and acute neuropsychiatric syndrome that affects mainly older patients. Delirium is a well-recognised complication of trauma and is important as it is associated with an increase in mortality as well as cognitive and functional decline, increased length of hospital stay and increased risk of institutionalisation on discharge. Recognition and management is challenging and the psychological impact for patients and relatives devastating. This review discusses the current understanding of delirium with specific reference to trauma patients.

Should general anaesthesia be avoided in the elderly?

Surgery and anaesthesia exert comparatively greater adverse effects on the elderly than on the younger brain, manifest by the higher prevalence of postoperative delirium and cognitive dysfunction. Postoperative delirium and cognitive dysfunction delay rehabilitation, and are associated with increases in morbidity and mortality among elderly surgical patients. We review the aetiology of postoperative delirium and cognitive dysfunction in the elderly with a particular focus on anaesthesia and sedation, discuss methods of diagnosing and monitoring postoperative cognitive decline, and describe the treatment strategies by which such decline may be prevented.

Do stress markers and anesthetic technique predict delirium in the elderly?

BACKGROUND

Postoperative delirium (PD) is a prevalent complication of elderly surgical patients, which predisposes to worsened cognitive recovery and dementia. Risk of PD has been associated with increasing magnitude of the hypothalamic-pituitary-adrenal stress response (serum cortisol, epinephrine and norepinephrine) to surgery. Anesthetics suppress this response; however, some (total intravenous anesthesia, TIVA) more than others (anesthetic gases). Prior comparisons of anesthetics have been equivocal but have not included stress markers. We hypothesized that TIVA would decrease serum stress markers and the incidence of PD.

METHODS

We performed a prospective cohort study of 76 elderly major surgical patients. Patients received TIVA or sevoflurane gas, and blood was drawn for serum markers pre-, intra-, and postoperatively. PD was assessed with the Confusion Assessment Method. We compared stress markers and PD between patients who received TIVA versus sevoflurane, and then modeled PD including stress and anesthetic.

RESULTS

The group that received TIVA during surgery demonstrated lower levels of all stress markers compared to the gas group, but no difference in PD. However, across groups, the postoperative norepinephrine level was much higher in patients who developed PD. Other markers and other times had no effect.

CONCLUSION

The development of PD depends more on postoperative stress than intraoperative stress or anesthetic.

Effects of a screening and treatment protocol with haloperidol on post-cardiotomy delirium: a prospective cohort study

OBJECTIVES

Post-cardiotomy delirium is common and associated with increased morbidity and mortality. No gold standard exists for detecting delirium, and evidence to support the choice of treatment is needed. Haloperidol is widely used for treating delirium, but indication, doses and therapeutic targets vary. Moreover, doubt has been raised regarding overall efficacy. The purpose of this study was to assess the effect of a combination of early detection and standardized treatment with haloperidol on post-cardiotomy delirium, with the hypothesis that the proportion of delirium- and coma-free days could be increased. Length of stay (LOS), complications and 180-day mortality are reported.

METHODS

Prospective interventional cohort study. One hundred and seventeen adult patients undergoing cardiac surgery were included before introduction of a screening and treatment protocol with haloperidol for delirium, and 123 patients were included after. Nurses screened patients using validated tools (the Delirium Observation Screening (DOS) scale and confusion assessment method for the intensive care unit (CAM-ICU)). In case of delirium, a checklist to eliminate precipitating/ inducing factors and a protocol for standardized dosing with haloperidol was applied. Group comparison was done using non-parametric tests and analysis of fractions, and associations between delirium and predefined covariates were analysed with logistic regression.

RESULTS

Incidence of delirium after cardiac surgery was 21 (14-29) and 22 (15-30) %, onset was on postoperative day 1 (1-4) and 1 (1-3), duration was 1 (1-4) day and 3 (1-5) days, respectively, with no significant difference (Period 1 vs 2, all values are given as the median and 95% confidence interval). The proportion of delirium- and coma-free days was 67 (61-73) and 65 (60-70) %, respectively (ns). There was no difference in LOS or complication rate. Delirium was associated to increasing age, increased length of stay and complications.

CONCLUSIONS

We observed no increase in the proportion of delirium- and coma-free days after introduction of a combination of early detection and standardized treatment with haloperidol on post-cardiotomy delirium. Most patients were not severely affected, and the few who were, proved difficult to treat, indicating that a simple treatment protocol with haloperidol was ineffective.

Nurse screening for delirium in older patients attending the emergency department

BACKGROUND

Delirium in older emergency department (ED) patients is common, associated with many adverse outcomes, and costly to manage. Delirium detection in the ED is almost universally poor.

OBJECTIVES

The authors aimed to develop a simple clinical risk screening tool that could be used by ED nurses as part of their initial assessment to identify patients at risk of delirium.

METHODS

A prospective cross-sectional study of patients 65 years and older attending a single ED.

RESULTS

Of 320 enrolled patients, 23 (7.2%) had delirium. Logistic regression analysis revealed 3 risk factors strongly associated with delirium risk: cognitive impairment, depression, and an abnormal heart rate/rhythm. Weighting these variables based on the strength of their association with delirium yielded a risk score from 0-4 inclusive. A cutoff of 2 or more in that score would have given a sensitivity of 87%, specificity of 70%, and NPV of 99%, while avoiding further diagnostic workup for delirium in approximately two-thirds of all patients, when used as an initial screen.

CONCLUSIONS

A simple risk screening tool using factors evident on initial nurse assessment can be used to identify patients at risk of delirium. Further trials are needed to test whether the tool improves patient outcomes.