Existing tools underpowered to assess delirium severity in advanced cancer patients

Delirium appears to be common among advanced cancer patients, and common assessment tools are underpowered to measure the severity of delirium in this population, a new study has found.

The study included 302 patients (mean age, 72.0±10.5 years; 71 percent male) who had severe motor anxiety at baseline. Delirium was assessed using the following tools: the Richmond Agitation-Sedation Scale-Palliative care version (RASS-PAL), the Delirium Rating Scale-Revised-98 (DRS-R-98), and the Nursing Delirium Screening Scale (Nu-DESC).

On day 3, 29 patients (10 percent) fell unconscious and two (1 percent) become non-communicative. Complete response (CR) to treatment, defined as showing no signs of agitation and being fully communicative, was reported in 15 percent of the participants. Thirty-two percent were partially responsive (PR), and another 32 percent showed no changes (NC) after treatment.

RASS-PAL was able to successfully differentiate NC patients from those with CR, and those who were unconscious/non-communicative (UC). However, it failed to discriminate between CR and PR participants. RASS-PAL scores were highest in the NC group, followed by the CR and PR participants, and was lowest in the UC patients.

In comparison, while the DRS-R-98 and Nu-DESC tools were able to differentiate between CR, PR, and NR, they were deemed to be underpowered in assessing delirium severity.

In both tools, UC patients earned the highest scores, suggesting the most severe delirium “even when this might be a result of appropriate symptomatic treatment to relieve agitation just before death,” the researchers said.

“These findings suggest that we need a more suitable tool to quantify the severity of delirium in end-of-life care settings,” they added.