Delirium: Apply the ‘4 Ps’ for comprehensive treatment (2024)

Four principles of treating delirium can help protect medical/surgical patients at risk for morbidity and functional decline. These principals—which I call the “four Ps”—are prompt identification, protection, pragmatic intervention, and pharmacotherapy.

This article describes an up-to-date, “four-Ps” approach to treating delirium—including use of antipsychotics and supportive care—and offers evidence and case reports to address these clinical questions:

• What causes delirium?
• Does delirium worsen prognosis?
• Can delirium be prevented?

FOUR ‘Ps’ FOR TREATING DELIRIUM

When a patient’s mental status changes dramatically (Box 1),¹ identifying potential delirium causes requires careful medical, psychiatric, and neurologic assessment. Assimilating this information is as essential to positive outcomes as are intensive nursing care and appropriate interventions.

Box 1

Prompt identification. Delirium often goes unrecognized, delaying treatment. Easily administered rating scales—such as the Delirium Rating Scale (DRS)² and the Confusion Assessment Method (CAM)³ —can help detect emerging symptoms.

Patient protection. Provide intensive nursing care—often one-to-one observation and containment—and, where possible, enlist the family in reassuring and calming the patient. Restraints may be needed to safeguard against injury and to prevent the patient from removing or dislocating monitoring equipment and IV access.

Pragmatic intervention. With medical colleagues, begin treating biochemical and physiologic abnormalities that are the most likely and most remediable contributors (Box 2).^2,4-6 Review the patient’s medications and discontinue or replace any that may be causing delirium.

Pharmacotherapy. Based on clinical studies, antipsychotics appear to possess antidelirium properties and may be considered as one part of a patient’s treatment plan. Interpreting these studies is complicated, however, by delirium’s complexity, numerous causes, and presumed mechanisms, as well as the transience of some forms. For ethical reasons, no placebo-controlled studies of delirium treatment have been done.

EVIDENCE ON ANTIPSYCHOTICS

Haloperidol has been the drug of choice for managing delirium because it is less likely to cause hypotension and sedation than other neuroleptics. Optimum haloperidol dosing in delirium has not been established, but the usual range is 2 to 6 mg every 4 to 6 hours, depending on the patient’s age and delirium severity.

Instances of QTc interval prolongation have been reported with high-dose IV haloperidol (> 100 mg). This life-threatening effect—which can induce torsades de pointes dysrhythmia, ventricular tachycardias, and fibrillation—is very rare, quite variable, and unpredictable. It probably is a function of total dose and neuroleptic administration rate.

Atypical antipsychotics share haloperidol’s advantages over first-generation neuroleptics, with lower potential for dystonic reactions, parkinsonian side effects, and tardive dyskinesia. Preliminary evidence suggests that atypicals may be safe and effective in treating delirium, although no randomized controlled trials have been done and accurate dose-response curves have not been established. Low to modest dosages have been used in case series.

Risperidone. Two prospective, open-label trials—each with 10 patients—suggest that low-dose risperidone is effective for treating delirium:

• In one trial, risperidone given at an average dosage of 1.7 mg/d was effective in 80% of patients with delirium, and one patient responded to 0.5 mg/d. Some patients experienced sleepiness or mild drug-induced parkinsonism.⁷
• In the other trial, risperidone was started at 0.5 mg twice daily, with additional doses allowed on day 1 for cognitive and behavioral symptoms. This dosage was maintained until DRS scores declined to ≤12, then was reduced by 50% and continued until day 6. Mean maintenance dosage was 0.75 mg/d. Two patients discontinued risperidone because of sedation or hypotension.⁸

Box 2