Pre-operative pain and depressive symptoms in older adults place them at greater risk of delirium following surgery, according to a study published in The Lancet Psychiatry.
Both pain and depression are independent and interactive risk factors for delirium, suggesting a cumulative effect.
“Understanding the impact of preoperative pain and depression on risk of delirium in older surgical patients is important,” said lead author Cyrus Kosar, MD, Harvard Medical School, and Hebrew Senior Life Institute for Aging Research (IFAR), Boston, Massachusetts. “By exploring the interaction between pain, depression, and delirium we may uncover potential targets for intervention.”
The study included 459 patients aged 70 years and older without dementia who were scheduled for orthopaedic surgery between June 2010 and August 2013. Patients self-reported current pain along with the average and worst pain for the previous 7 days. Prior to surgery depressive symptoms were assessed using the geriatric depression scale and chart review. Post-surgical delirium was measured by the confusion assessment method and chart review.
Results showed that 23% of patients showed signs of delirium, which occurred much more frequently in patients with depressive symptoms prior to surgery than in those without depression. Pre-operative pain was also linked to increased risk of delirium across all pain measures.
Further analyses found that patients with depressive symptoms had a 21% increased risk of delirium associated with a 1-point difference in the worst pain score, while patients without depressive symptoms demonstrated only a fraction of the risk (3%), indicating a significant interaction between pain and depressive symptoms.
Higher average pain scores also conferred excess delirium risk in patients with depressive symptoms; however, the risk difference between those without depressive symptoms was not as large.
“Our study demonstrates that the combination of higher symptoms of pain and depression increases delirium risk in older adults,” said Dr. Sharon. “Doctors considering surgery for older patients should be aware of the delirium risk and potential contributions of pain and depressive symptoms in their preoperative evaluations.”