Although postcardiotomy delirium has been studied widely, there are few
data about the current prevalence, compared to that reported in the late
1960s. There have been few efforts to replicate early observations. The
authors review the literature using meta-analysis to combine the results of
44 studies. They examined the relationships between postcardiotomy delirium
and 28 hypothesized risk variables. The prevalence of postcardiotomy
delirium has remained fairly constant over time at 32%. There was no
difference in the total prevalence of postcardiotomy delirium reported in
studies that used interviews versus chart reviews. Sex, previous
psychiatric illness, intelligence, and time on bypass failed to correlate
with postcardiotomy delirium, and age correlated with it only slightly.
Correlation coefficients of more than 0.30 were found only for
noncongenital heart disease and postoperative EEG abnormality. Preoperative
psychiatric intervention had the highest correlation with postcardiotomy
delirium (r = -0.60).