Type of study: Randomized controlled trial

The finding: In the setting of hospitalized patients with advanced cancer who have agitated delirium, a combination of lorazepam and haloperidol intravenously leads to reduction in agitation within 8 hours compared to haloperidol alone.

Strength and weaknesses: This is a double blind, parallel group, placebo-controlled randomized clinical trial including patients diagnosed with delirium. The study was powered for the primary outcome (reduction in RASS) but not the secondary outcomes of delirium severity, delirium-related distress, and communication capacity. These findings might not be generalized to patients in the home setting or with less severe illness. In addition, this only involved a single dose of lorazepam. The delirium recall questionnaire requires validation.

Relevance: Delirium and agitation management in the palliative care setting is underrepresented in the consultation-liaison literature. Using lorazepam along with haloperidol in cases of agitated delirium in the palliative care setting may be justified when the priority is to reduce agitation rather than maintaining alertness.

Type of study: Cohort study

The finding: Benzodiazepine exposure is associated with delirium and longer lengths of stay in the PICU in infants and young children. Younger age and hypoxia are also with longer length of stay and dexmedetomidine exposure was associated with increased likelihood of ICU discharge. Benzodiazepine exposure is predictive of delirium diagnosis the next day and average duration of delirium was 1-2 days.

Strength and weaknesses: This is an analysis of a prospective observational study validating the psCAM-ICU in a population of 300 patients who were 6 months to 5 years old. Multiple risk factors for delirium were examined, however, environmental issues such as sleep deprivation, restraint, and social isolation were not examined. Limits of the study are that the findings might not generalize to older children. Benzodiazepine exposure was measure by dose administration not by blood levels. Since this was a single center study, it is not clear if the population study is representative for all PICUs. Delirium diagnoses may be a reflection of severity of illness and not just benzodiazepine exposure and so the severity of illness could be contributing to the longer length of stay in the PICU. Also presence of delirium might not be considered or identified by the medical team when discharging the patient from the PICU.

Relevance: This is the largest prospective study evaluating delirium and risk factors in a preschool population. This study suggests that just as with adults, benzodiazepine exposure in the critically ill infants and young children is predictive of negative short term outcomes.

Disclosure Note: MG was one of the authors of the publication and also one of the authors of this annotation.

Type of study: Randomized controlled trial

The finding: Gabapentin 900mg before non-cardiac surgery followed by 300mg TID for 72 hours after surgery did not reduce delirium incidence in patients over 65 years old compared to the control group.

Strength and weaknesses: The study used the CAM tool for delirium screening, but did not specify frequency of screening, and appears to have only been conducted once daily, which may have been insufficient for detecting delirium. Patients with significant sedation measured on the Richmond Agitation and Sedation Scale scores were excluded from delirium evaluation. A significant number of subjects (n=102) did not receive CAM screening on at least one of the three post-surgical days. For these reasons, the incidence of delirium may have been inaccurate and underestimated. Documentation on the use of benzodiazepines, antipsychotics, alpha agonists, or other medications apart from opioids were not included in the study, and may have been different in study groups.

Relevance: Perioperative and post-operative gabapentoid use may be of interest to consultation-liaison psychiatrists concerned as to the deliriogenic potential of these sedating medications. This study also showed only a mild opioid-sparing effect that may not be clinically significant, consistent with another recent study that showed only a modest increase in opioid cessation rates weeks after surgery but no major effect on pain cessation. More research is needed on the effect of gabapentoids on reducing pain, opioid use, and delirium in the postoperative setting.