Level 2: Mid-level evidence
Postoperative delirium is common in elderly patients following surgery for hip-fracture repair. Some clinicians may be reluctant to fully treat the postoperative pain due to concerns that opioid treatment could increase delirium risk. In particular, meperidine (Demerol) has been found to be associated with increased risk of delirium in elderly postoperative patients in a systematic review (Anesth Analg. 2006;102:1255-1266).
A study investigated the effects of the opioid hydromorphone on cognitive impairment in a cohort of 236 consecutive patients (mean age 82 years) having hip fracture surgery ( J Am Geriatr Soc. 2011;59:2256-2262). Patients were assessed at baseline for preexisting dementia and were followed for postoperative pain, hydromorphone use, and incidence of delirium. Patients with preoperative delirium were excluded.
At baseline, 28% of patients had dementia determined by preoperative exam or history. Hydromorphone was given intravenously postoperatively to maintain a pain score <3 on a 0-10 oral rating scale. The drug was given to 93% of patients without dementia and to 83% of patients with dementia.
There was no significant association between hydromorphone use and delirium in either patients without dementia (P=0.33) or patients with dementia (P=0.4). Mean pain scores and opioid use were significantly lower in patients with dementia compared to those without dementia.
The strongest predictor of postoperative delirium was pre-existing dementia: delirium occurred in 51.5% of patients with dementia and in 15.3% of patients without dementia (odds ratio 5.86, P<0.001). Intensive-care-unit admission was also strongly associated with delirium (odd ratio 2.71, P=0.006).
Alan Ehrlich, MD, is a deputy editor for DynaMed, in Ipswich, Mass., and assistant clinical professor in Family Medicine, University of Massachusetts Medical School in Worcester.
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