‘Targeted’ prophylaxis advised in elderly surgical patients
MedWire News: Giving prophylactic antipsychotics to elderly patients with evidence of subsyndromal delirium after surgery may reduce their risk for developing clinical delirium, research suggests.
Prophylactic treatment with risperidone roughly halved the incidence of delirium in susceptible patients, report Sameh Hakim (Ain Shams University, Cairo, Egypt) and colleagues in Anesthesiology.
The findings suggest that "even within a high-risk population, treatment can be further targeted, thus preventing unnecessary drug administration to approximately 40% of the patients," say editorialists Leif Saager and Daniel Sessler (Cleveland Clinic, Ohio, USA).
But they caution: "Small studies often overestimate true treatment effects; large trials evaluating the important strategy suggested by Hakim et al are thus very much needed."
The study included 101 patients, aged at least 65 years, who developed subsyndromal delirium after undergoing on-pump cardiac surgery. The researchers note that there is no formal definition of subsyndromal delirium; here they used a score of 1-3 on the Intensive Care Delirium Screening Checklist (ICDSC). Patients with a score higher than 3 were assessed with Diagnostic and Statistical Manual of Mental Disorders criteria to confirm the presence of clinical delirium.
On the appearance of subsyndromal delirium, patients were randomly assigned to receive risperidone 0.5 mg or placebo every 12 hours. Thereafter, 34.0% of patients in the placebo group developed delirium, compared with just 13.7% of those given risperidone.
This equated to an 80% reduction in risk for delirium and a number needed to treat of 4.9 to prevent one case of delirium, say Hakim et al.
This effect persisted in competing-risks regression analysis, with placebo treatment independently associated with a 3.85-fold increase in the risk for delirium, relative to risperidone treatment.
Among patients who did develop clinical delirium, treatment allocation had no effect on the duration of delirium, the highest score on the ICDSC, need for and dose of haloperidol, or length of intensive care unit or hospital stay.
The researchers note that a larger benefit of prophylactic medication might be possible if patients were treated before developing any symptoms of delirium.
They add that the targeted approach they adopted "may seem more appealing than dispensation of prophylactic medication to all patients," but add that "a randomized trial ideally would give evidence on whether prophylactic medication would be more effective if given immediately after surgery or during the subsyndromal phase of delirium."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Eleanor McDermid