Impact of Early Reinitiation of Neuropsychiatric Medications on Agitation and Delirium in the Intensive Care Unit: A Retrospective Study

BACKGROUND

Approximately 17% of intensive care unit (ICU) patients are prescribed at least 1 home neuropsychiatric medication (NPM). When abruptly discontinued, withdrawal symptoms may occur manifesting as agitation or delirium in the ICU setting.

OBJECTIVE

To evaluate the impact of early reinitiation of NPMs.

METHODS

This was a retrospective, observational cohort of adult ICU patients in a tertiary care hospital. Patients were included if admitted to the ICU and prescribed a NPM prior to arrival. Study groups were based on the timing of reinitiation of at least 50% of NPMs: ≤72 hours (early group) versus >72 hours (late group).

RESULTS

The primary outcome was the proportion of patients with at least 1 agitation or delirium episode in the first 72 hours. Agitation and delirium were defined as at least 1 RASS assessment between +2 to +4 and a positive CAM-ICU assessment, respectively. A total of 300 patients were included, with 187 (62%) and 113 (38%) in the early and late groups, respectively. There was no difference in agitation or delirium (late 54 [48%] vs early 62 [33%]; adjusted odds ratio [aOR] = 1.5; 95% CI = 0.8-2.8; P = 0.193). Independent risk factors found to be associated with the primary outcome were restraints (aOR = 12.9; 95% CI = 6.9-24.0; P < 0.001) and benzodiazepines (BZDs; aOR = 2.0; 95% CI = 1.0-3.7; P = 0.038).

CONCLUSIONS

After adjustment for baseline differences, there was no difference in agitation or delirium. Independent risk factors were restraint use and newly initiated BZDs.

The sodium channel blocker RS100642 reverses down-regulation of the sodium channel alpha-subunit Na(v) 1.1 expression caused by transient ischemic brain injury in rats

In this study we evaluated the expression of five sodium channel (NaCh) Alpha-subunit genes after transient middle cerebral artery occlusion (MCAo) in the rat and the effects of treatment with the NaCh blocker and experimental neuroprotective agent RS100642 as compared to the prototype NaCh blocker mexiletine. The expression of Na(v) 1.1, Na(v) 1.2, Na(v) 1.3, Na(v) 1.7, Na(v) 1.8 and the housekeeping gene beta-actin were studied in vehicle or drug-treated rats at 6, 24 and 48 h post-MCAo using real-time quantitative RT-PCR. RS100642 (1 mg/kg), mexiletine (10 mg/kg), or vehicle (1 ml/kg) was injected (i.v.) at 30 min, 2, 4, and 6 h post-injury. Following MCAo only the Na(v) 1.1 and Na(v) 1.2 genes were significantly down-regulated in the ipsilateral hemisphere of the injured brains. RS100642 treatment significantly reversed the down-regulation of Na(v) 1.1 (but not Na(v) 1.2) at 24-48 h post-injury. Mexiletine treatment, on the other hand, had no significant effect on the down-regulation of either gene. These findings demonstrate that treatment with a neuroprotective dose of RS100642 significantly reverses the down-regulation of Na(v) 1.1 caused by ischemic brain injury and suggests that RS100642 selectively targets the Na(v) 1.1 Alpha-subunit of the NaCh. Furthermore, our findings strengthen the hypothesis that ischemic injury may produce selective depletion of voltage-gated NaChs, and suggest that the Na(v) 1.1 NaCh Alpha-subunit may play a key role in the neuronal injury/recovery process.