Delirium in a sub-intensive care unit for the elderly: occurrence and risk factors

BACKGROUND AND AIMS

The objective was to study occurrence and risk factors of delirium in a new model of care, the Sub-Intensive Care Unit for the elderly (SICU), which is a level of care between that offered by ordinary wards and intensive care.

METHODS

A prospective observational study of 401 consecutively admitted patients, 60+ years, in a four-bed SICU in the geriatric ward of a general hospital. Delirium was detected by the Confusion Assessment Method (CAM) at admission (prevalent) and during SICU stay (incident). Impaired function (Barthel Index) and/or IADL two weeks prior to admission identified disability, and additional Mini-Mental State Examination (MMSE) <18 at discharge identified probable dementia.

RESULTS

Delirium was detected in 117 patients (29.2%). Of these 62 (15.5%) had delirium at admission and a further 55 developed delirium during their time in the SICU. Delirium occurred in 19 (11.4%) of the "robust" (no dementia or disability), 28 (24.1%) of the disabled and 70 (58.4%) of the demented patients (p<0.001). Prevalent delirium was found in 8 (4.8%), 11 (9.5%) and 43 (36.1%) (p<0.001) and incident in 11 (6.6%), 17 (14.7%) and 27 (22.7%) (p<0.001) of the robust, disabled, and demented patients respectively. Heavy alcohol use, maximum intake of 7 or more drugs, and the use of a bladder catheter were independently associated with delirium.

CONCLUSIONS

Delirium was common in the SICU, and patients with probable dementia had the highest risk. They tended to have delirium at admission, whereas patients without dementia, although less at risk, were more prone to developing delirium during their stay in the SICU.

Management of the critically ill geriatric patient

OBJECTIVE

To review the effect of an aging society on the utilization of critical care services and the physiology of aging as it applies to critical illness and prognosis and management issues in the intensive care unit (ICU).

DATA SOURCE

MEDLINE, Embase, and citation review of relevant primary and review articles.

DATA SYNTHESIS

Elderly patients (age of >65 yrs) currently account for 42-52% of ICU admissions and for almost 60% of all ICU days. Aging is associated with decreased cardiopulmonary and renal reserve and with a high rate of co-morbidities, increasing the risks of the elderly developing progressive organ failure. Elderly ICU patients are at a particularly high risk of developing delirium, which is associated with significant morbidity. Severity of illness and age are the important factors determining ICU survival. Age and functional status before ICU admission are the major determinants of survival at 6 and 12 months after ICU discharge. Age alone should not be used to triage ICU patients; the decision to admit an elderly patient to an ICU should be based on the patients co-morbidities, acuity of illness, prehospital functional status, and preferences with regard to life-sustaining treatment.

CONCLUSIONS

The management of critically ill elderly patients is a complex issue and involves an understanding of the changing demographics of our society and the physiology of aging. The reality of our aging society dictates that we must focus on how to best care for the elderly who develop critical illness.

Post-operative delirium is associated with poor cognitive outcome and dementia

The objective of the present study is to evaluate the association between the occurrence of delirium and the cognitive outcome in elderly subjects. Hospital files of 572 patients who underwent hip or knee replacement between 1998 and 2004 were examined. A sample of 90 elderly subjects (31 with evidence of post-operative delirium), non-demented at baseline, was screened for cognitive decline and dementia. Diagnosis of dementia was highly associated with the occurrence of delirium. The relative risk for the diagnosis of dementia among subjects with previous history of delirium, according to the IQcode screening, was 10.5 (95% CI: 3.3-33.2). Such patients had a significantly higher mean IQcode score (3.75) as compared to controls (3.1; p < 0.001). Cognitive functions most affected in these patients were memory, orientation and abstract thinking. We conclude that the occurrence of post-operative delirium in cognitively unimpaired elderly subjects is associated with a worse cognitive outcome and an increased risk of dementia.

Delirium: The clinical concept

Delirium is a common syndrome complicating terminal illness. It is underrecognized partly because it is a difficult clinical concept. Consciousness, awareness, alertness, arousal, awakeness, vigilance, and attention are some of the terms used to describe the deficits occurring in delirium. Though interconnected, they are often loosely defined. Alertness is the primary impairment, and attentional deficits are objective clinical indices of the cognitive impairments of delirium. Simple bedside assessments of delirium are considered. The “deliriant” threshold and the symptomatic fluctuations of delirium are important concepts in the understanding of delirium. Jackson's conceptualization of the nervous system is relevant to delirium. Raising the deliriant threshold by multicomponent interventions is the intent of the palliative management of terminal delirium.

Abnormal neurotransmitter metabolite levels in Alzheimer patients with a delirium

BACKGROUND

Delirium is a complex neuropsychiatric syndrome with an acute onset and fluctuating course. Several studies have suggested the presence of disturbed cholinergic, dopaminergic and serotonergic pathways in delirium as well as in Alzheimer's disease. Abnormal concentrations of amino acids and of neurotransmitter metabolites have been found in plasma, platelets and cerebrospinal fluid of AD patients, and in plasma and CSF of patients with a delirium. The aim of this study was to investigate amino acid and neurotransmitter metabolite levels in plasma of AD patients with a concurrent delirium.

METHODS

In a case-control study of patients suffering from Alzheimer's disease (AD) with concurrent delirium, we investigated the contribution of delirium to some biochemical parameters in blood. We compared plasma amino acid and neurotransmitter metabolite levels of 17 delirious AD patients with those of 17 age- and gender-matched non-delirious AD patients and 29 age- and gender-matched controls.

RESULTS

Homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) levels were higher in delirious AD patients than in controls, but only HVA concentrations were higher in delirious AD patients than in non-delirious AD patients.

CONCLUSIONS

Our findings suggest that central dopaminergic and serotonergic turnover are increased in AD patients with delirium and that the high dopaminergic turnover might reflect the consequences of delirium.

Does delirium need immediate medical referral in a frail, homebound elder?

BACKGROUND AND PURPOSE

This case report describes the clinical decision making process of a physical therapist whose examination of a home bound elderly woman led to a referral for hospitalization. We illustrate how the use of a comprehensive systems screen and thorough examination identified a patient with treatable conditions that required medical care.

CASE DESCRIPTION

The patient was a frail 93-year-old woman. She was referred for home-care physical therapy with multiple medical comorbidities and functional decline following a short hospitalization for fall-related injuries. Her function improved after several visits, but upon resuming treatment after a 2- week hiatus, the patient demonstrated major decline in cognitive and physical function.

OUTCOMES

The comprehensive systems screen revealed that the patient had increased pallor, loose and frequent bowel movements, urinary incontinence and increased frequency of micturition, confusion and apathy, and extreme fatigue. Her examination showed large declines in scores for Functional Independence Measures, Mini Mental Status Examination, Berg Balance Test, and Timed Up and Go. These results were consistent with indicators for delirium, dehydration, and anemia. The findings were reported to the patient's physician and family members agreed to have the patient evaluated in the local emergency room.

CONCLUSIONS

This case report illustrates how knowledge of the pathologies associated with delirium and thorough examination can assist the physical therapist in making clinical decisions when homecare patients require prompt medical referral.

Pilot clinical trial of gabapentin to decrease postoperative delirium in older patients

In this randomized pilot clinical trial, the authors tested the hypothesis that using gabapentin as an add-on agent in the treatment of postoperative pain reduces the occurrence of postoperative delirium. Postoperative delirium occurred in 5/12 patients (42%) who received placebo vs 0/9 patients who received gabapentin, p = 0.045. The reduction in delirium appears to be secondary to the opioid-sparing effect of gabapentin.

Delirium within Three Days of Stroke in a Cohort of Elderly Patients

OBJECTIVES

To evaluate the incidence of stroke, risk factors for stroke, and outcomes in elderly stroke patients with delirium.

DESIGN

Cohort study with 12-month follow-up.

SETTING

Bankstown-Lidcombe Hospital, a 450-bed teaching hospital of the University of New South Wales, Sydney, Australia.

PARTICIPANTS

One hundred fifty-six stroke patients aged 65 and older recruited over 1 year.

MEASUREMENTS

Incidence of delirium (defined in accordance with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria) within 3 days poststroke, length of hospital stay, discharge destination, short- and long-term mortality, Functional Independence Measure (FIM) scores, and Mini-Mental State Examination (MMSE) scores.

RESULTS

Thirty-nine (25%) elderly stroke patients had delirium within 3 days after stroke. Logistic regression analysis found that older age (P=.04), hemorrhagic stroke (P=.02), metabolic disorders (P=.003), dementia prestroke (P=.02), Glasgow Coma Scale (GCS) score less than 15 on admission (P<.001), and inability to lift both arms on admission (P=.03) were independent predisposing factors for delirium. Patients who had a cardioembolic stroke (odds ratio (OR)=5.58) or total anterior circulation infarction (OR=3.42) were also more likely to develop delirium. Patients with delirium were associated with higher 6- and 12-month mortality (P<.05), lower 12-month FIM and MMSE scores, and a higher 12-month institutionalization rate.

CONCLUSION

Delirium occurred frequently in acute stroke patients aged 65 and older. Factors independently associated with delirium included old age, intracerebral hemorrhage, metabolic factors, prestroke dementia, initial GCS less than 15, and inability to lift both arms on admission. Patients with delirium had higher long-term mortality and a worse functional outcome.

Osteoporotic fractures in older adults

Osteoporotic fractures are emerging as a major public health problem in the aging population. Fractures result in increased morbidity, mortality and health expenditures. This article reviews current evidence for the management of common issues following osteoporotic fractures in older adults including: (1) thromboembolism prevention; (2) delirium prevention; (3) pain management; (4) rehabilitation; (5) assessing the cause of fracture; and (6) prevention of subsequent fractures. Areas for practice improvement and further research are highlighted.

Preoperative anxiety, postoperative pain, and behavioral recovery in young children undergoing surgery

OBJECTIVE

Findings from published studies suggest that the postoperative recovery process is more painful, slower, and more complicated in adult patients who had high levels of preoperative anxiety. To date, no similar investigation has ever been conducted in young children.

METHODS

We recruited 241 children aged 5 to 12 years scheduled to undergo elective outpatient tonsillectomy and adenoidectomy. Before surgery, we assessed child and parental situational anxiety and temperament. After surgery, all subjects were admitted to a research unit in which postoperative pain and analgesic consumption were assessed every 3 hours. After 24 hours in the hospital, children were discharged and followed up at home for the next 14 days. Pain management at home was standardized.

RESULTS

Parental assessment of pain in their child showed that anxious children experienced significantly more pain both during the hospital stay and over the first 3 days at home. During home recovery, anxious children also consumed, on average, significantly more codeine and acetaminophen compared with the children who were not anxious. Anxious children also had a higher incidence of emergence delirium compared with the children who were not anxious (9.7% vs 1.5%) and had a higher incidence of postoperative anxiety and sleep problems.

CONCLUSIONS

Preoperative anxiety in young children undergoing surgery is associated with a more painful postoperative recovery and a higher incidence of sleep and other problems.

Management of hip fracture: the family physician's role

The incidence of hip fracture is expected to increase as the population ages. One in five persons dies in the first year after sustaining a hip fracture, and those who survive past one year may have significant functional limitation. Although surgery is the main treatment for hip fracture, family physicians play a key role as patients' medical consultants. Surgical repair is recommended for stable patients within 24 to 48 hours of hospitalization. Antibiotic prophylaxis is indicated to prevent infection after surgery. Thromboprophylaxis has become the standard of care for management of hip fracture. Effective agents include unfractionated heparin, low-molecular-weight heparin, fondaparinux, and warfarin. Optimal pain control, usually with narcotic analgesics, is essential to ensure patient comfort and to facilitate rehabilitation. Rehabilitation after hip fracture surgery ideally should start on the first postoperative day with progression to ambulation as tolerated. Indwelling urinary catheters should be removed within 24 hours of surgery. Prevention, early recognition, and treatment of contributing factors for delirium also are crucial. Interventions to help prevent future falls, exercise and balance training in ambulatory patients, and the treatment of osteoporosis are important strategies for the secondary prevention of hip fracture.

Emergence delirium in adults in the post-anaesthesia care unit

BACKGROUND

Emergence delirium in the post-anaesthesia care unit (PACU) is poorly understood. The goal of this prospective study was to determine frequency and risk factors of emergence delirium in adults after general anaesthesia.

METHODS

In this prospective study, 1,359 consecutive patients were included. Contextual risk factors and occurrence of delirium according to the Riker sedation scale were documented. Groups were defined for the analysis according to the occurrence or not of agitation, then after exclusion of patients with preoperative anxiety and neuroleptics, or both, and antidepressants or benzodiazepines treatments.

RESULTS

Sixty-four (4.7%) patients developed delirium in the PACU, which can go from thrashing to violent behaviour and removal of tubes and catheters. Preoperative anxiety was not found to be a risk factor. Preoperative medication by benzodiazepines (OR=1.910, 95% CI=1.101-3.315, P=0.021), breast surgery (OR=5.190, 95% CI=1.422-18.947, P=0.013), abdominal surgery (OR=3.206, 95% CI=1.262-8.143, P=0.014), and long duration of surgery increased the risk of delirium (OR=1.005, 95% CI=1.002-1.008, P=0.001), while a previous history of illness and long-term treatment by antidepressants decreased the risk (respectively, OR=0.544, 95% CI=0.315-0.939, P=0.029 and OR=0.245, 95% CI=0.084-0.710, P=0.010).

CONCLUSIONS

Preoperative benzodiazepines, breast and abdominal surgery and surgery of long duration are risk factors for emergence delirium.

Nitrous oxide does not change the incidence of postoperative delirium or cognitive decline in elderly surgical patients

BACKGROUND

Postoperative delirium and cognitive decline are common in elderly surgical patients after non-cardiac surgery. Despite this prevalence and clinical importance, no specific aetiological factor has been identified for postoperative delirium and cognitive decline. In experimental setting in a rat model, nitrous oxide (N(2)O) produces neurotoxic effect at high concentrations and in an age-dependent manner. Whether this neurotoxic response may be observed clinically has not been previously determined. We hypothesized that in the elderly patients undergoing non-cardiac surgery, exposure to N(2)O resulted in an increased incidence of postoperative delirium than would be expected for patients not receiving N(2)O.

METHODS

Patients who were >or=65 yr of age, undergoing non-cardiac surgery and requiring general anaesthesia were randomized to receive an inhalational agent and either N(2)O with oxygen or oxygen alone. A structured interview was conducted before operation and for the first two postoperative days to determine the presence of delirium using the Confusion Assessment Method.

RESULTS

A total of 228 patients were studied with a mean (range) age of 73.9 (65-95) yr. After operation, 43.8% of patients developed delirium. By multivariate logistic regression, age [odds ratio (OR) 1.07; 95% confidence interval (CI) 1.02-1.26], dependence on performing one or more independent activities of daily living (OR 1.54; 95% CI 1.01-2.35), use of patient-controlled analgesia for postoperative pain control (OR 3.75; 95% CI 1.27-11.01) and postoperative use of benzodiazepine (OR 2.29; 95% CI 1.21-4.36) were independently associated with an increased risk for postoperative delirium. In contrast, the use of N(2)O had no association with postoperative delirium.

CONCLUSIONS

Exposure to N(2)O resulted in an equal incidence of postoperative delirium when compared with no exposure to N(2)O.