Delirium in the hospital: Emphasis on the management of geriatric patients

Psychometrically, a review of Table 4 suggests that validity appeared stable with adequate specificity (64% to 99%) but more variable sensitivity (36% to 100%). These reliability parameters also will be affected by the classification sys­tem (ie, DSM vs ICD) and the cut-off score employed.³² Most measures (eg, Confusion Assessment Method [CAM], CAM-ICU) provide an adequate sample of behavioral (ie, level of alertness), motor (ie, psychomo­tor activity), and cognitive (ie, orientation, attention, memory, and receptive language) function, with the exception of the Global Attentiveness Rating, which is a 2-minute open conversation protocol between physi­cian and patient.

Some measures are stand-alone instru­ments, such as the Memorial Delirium Assessment Scale, whereas the CAM requires administration of separate cogni­tive screens, including the Mini-Mental State Examination (MMSE) and Digit Span.³³ Instruments to detect delirium in critically ill patients are a more recent development. Wong et al³⁴ reported that the most widely studied tool was the CAM. Obtaining collat­eral information from family, caregivers, and hospital staff is essential, particularly given the fluctuating nature of delirium.

Management
Prevention. Identify patients at high risk of delirium so that preventive strategies can be employed. Multi-component, nonphar­macotherapeutic interventions are used in clinical settings but few randomized trials have been conducted. The contributing effectiveness of individual components is not well-studied, but most include staff education to increase awareness of delir­ium. Of 3 multi-component intervention randomized trials, 2 reported a signifi­cantly lower incidence of delirium in the intervention group.^35-37 Implementation of a multi-component protocol in medical/ surgical units was associated with a sig­nificant reduction in use of restraints.³⁸

As in Mr. D’s case, complex drug regimens, particularly for CNS illness, can increase the risk of delirium. Considering the medication profile for patients with complex systemic illness—in particular, minimizing the use anticholinergics and dopamine agonists— may be crucial in preventing delirium.

Prophylactic administration of antipsychotics may reduce the risk of devel­oping postoperative delirium.³⁹ Studies of the use of these agents were characterized by small sample sizes and selected groups of patient populations. Of the 4 random­ized studies evaluating prophylactic anti­psychotics (vs placebo), 3 found a lower incidence of delirium in the intervention groups.^39-41

A study of haloperidol in post-GI sur­gery patients showed a reduced occurrence of delirium,⁴⁰ whereas its prophylactic use in patients undergoing hip surgery⁴² did not reduce the incidence of delirium com­pared with placebo, but did decrease sever­ity when delirium occurred.⁴²

Risperidone³⁹ in post-cardiac sur­gery and olanzapine⁴¹ perioperatively in patients undergoing total knee or hip replacement have been shown to decrease delirium severity and duration. Targeted prophylaxis with risperidone⁴³ in post-cardiac surgery patients who showed disturbed cognition but did not meet cri­teria for delirium reduced the number of patients requiring medication, compared with placebo.⁴³

Dexmedetomidine, an α-2 adrenergic receptor agonist, compared with propofol or midazolam in post-cardiac valve surgery patients, resulted in a decreased incidence of delirium but no difference in delirium duration, hospital length of stay, or use of other medications.⁴⁴ However, other studies have shown that dexmedetomidine reduces ICU length of stay and duration of mechani­cal ventilation.⁴⁵

Treatment. Management of hospitalized medically ill geriatric patients with delirium is challenging and requires a comprehensive approach. The first step in delirium man­agement is prompt identification and man­agement of systemic medical disturbances associated with the delirium episode. First-line, nonpharmacotherapeutic strategies for patients with delirium include:
• reorientation
• behavioral interventions (eg, use of clear instructions and frequent eye con­tact with patients)
• environmental interventions (eg, mini­mal noise, adequate lighting, and lim­ited room and staff changes)
• avoidance of physical restraints.⁴⁶

Consider employing family members or hospital staff sitters to stay with the patient and to reassure, reorient, and watch for agitation and other unsafe behaviors (eg, attempted elopement). Psychoeducation for the patient and family on the phenomenol­ogy of delirium can be helpful.

The use of drug treatment strategies should be integrated into a comprehensive approach that includes the routine use of nondrug measures.⁴⁶ Using medications for treating hypoactive delirium, formerly con­troversial, now has wider acceptance.^47,48 A few high-quality randomized trials have been performed.^25,49,50

Pharmacotherapy, especially in frail patients, should be initiated at the lowest start­ing dosage and titrated cautiously to clinical effect and for the shortest period of time nec­essary. Antipsychotics are preferred agents for treating all subtypes of delirium; haloperidol is widely used.^46,51,52 However, antipsychotics, including haloperidol, can be associated with adverse neurologic effects such as extrapyra­midal symptoms (EPS) and NMS.

Although reported less frequently than with haloperidol, other agents have been implicated in development of EPS and NMS, including atypical antipsychotics and anti­emetic dopamine antagonists, particularly in parkinsonism-prone patients.⁵³ Strategies that can minimize such risks in geriatric inpatients with delirium include oral, rather than par­enteral, use of antipsychotics—preferential use of atypical over typical antipsychotics— and lowest effective dosages.⁵⁴