Delirium in critically ill patients can be reduced with statins

Continued use of statins may help prevent delirium in critically ill patients who received statins before hospital admission, according to a study published online ahead of print in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

The observational trial included 470 patients admitted to a mixed medical-surgical critical care unit in the United Kingdom. Of those patients included in the study, 151 received statins. Statins were only administered to patients who had received statins prior to admission. After adjustment for age, sex, and illness severity, administration of statins the previous evening was associated with a significantly lower risk of delirium and a concomitant reduction in serum C-reactive protein (CRP), a marker of systemic inflammation, the following day.

This is said to be the first study using a validated delirium-screening tool, the Confusion Assessment Method-ICU (CAM-ICU), to show that the administration of statins reduces delirium in these patients.

“Data on statin use and delirium and time spent in sedation-induced coma were collected along with reasons for statin administration and daily severity of illness,” said lead author Valerie J. Page, MB, ChB, of the Watford General Hospital in Watford, United Kingdom.

Although the pathogenesis of delirium is not fully understood, these data are consistent with a neuro-inflammatory cause and suggest that the anti-inflammatory effects of statins may contribute to the effects of statin treatment on delirium.

The analysis was based on individual days looking at the relationship between daily administration and whether the patient was in delirium or in coma [ie, the short-term impact of statin administration].  The data was adjusted for daily severity of illness and a propensity score, according to Dr Page.

“Patients who took statins during their critical care stay had less chance of developing delirium,” Dr Page said. “It is likely due to the anti-inflammatory properties of statins because there was also a reduction in the anti-inflammatory marker C-reactive protein. When the risk of delirium was adjusted to take into account the decrease in inflammation, the link between statin administration and delirium was no longer significant.”  

Delirium is the most common neuropsychiatric disorder in hospitals-particularly in critically ill patients-but also elderly trauma patients and patients with dementia, according to Dr Page. 

“It is predictive of worse outcomes including death and long-term cognitive impairment equivalent to a moderate traumatic brain injury or mild dementia-regardless of age,” she explained. “The longer the duration of delirium the worse the cognitive outcome.  There is no current treatment for delirium.”

The findings would suggest that if a patient was on statins before admission “they should be continued-currently not always the case,” said Dr Page. “Also, statin therapy may modify delirium in critically ill patients.  Further research is needed and a phase 2 trial is currently under way at Watford General Hospital.”