Exploration of Relationships Between Postoperative Pain and Subsyndromal Delirium in Older Adults.

BACKGROUND: Subsyndromal delirium is associated with serious adverse outcomes of longer lengths of stay, increased long-term care admissions, and higher 6-month mortality rates. Postoperative pain is a risk factor for delirium, but the relationship between pain and the severity of subclinical delirium symptoms is unclear. A better understanding will inform nursing interventions to reduce adverse outcomes associated with delirium symptoms.

OBJECTIVES: The purpose of this correlational study was to determine the relationship between pain and subsyndromal delirium in older adults following joint replacement surgery.

METHODS: Delirium assessments were completed on postoperative Days 1, 2, and 3 for 49 adults of ages 65 years or older following joint replacement surgery. Multiple linear regression was used to analyze data for relationships between postoperative pain and subsyndromal delirium and, secondarily, postoperative opioid intake and subsyndromal delirium while accounting for known preoperative risk factors.

RESULTS: Increased age, cognitive impairment, current smoking, and higher levels of self-reported pain were significantly related to subsyndromal delirium (p < .001). After accounting for preoperative risk factors of age, cognitive status, smoking status, and opioid intake, pain was significantly related to subsyndromal delirium (β = .28, p < .05); however, opioid intake did not contribute to subsyndromal delirium.

DISCUSSION: Higher pain levels were significantly related to subsyndromal delirium when age, cognitive status, smoking status, and opioid intake were accounted for (p < .05), although opioid intake was not significantly related to subsyndromal delirium after accounting for age, cognitive status, smoking status, and pain. Nurses caring for older adults who undergo joint replacement surgery are encouraged to ensure effective pain management to reduce onset and severity of delirium symptoms.