Factors Contributing to Memory of Acute Pain in Older Adults Undergoing Planned and Unplanned Hip Surgery.

OBJECTIVES: Previous research on pain memory provides inconsistent evidence about the accuracy of pain recall, and few studies have attempted to examine broad affective and contextual contributions to this phenomenon. The present research aimed to determine the accuracy of postoperative pain recall after 3 months, with respect to the context of the surgery and the congruence of affective states concurrent with the initial experience and its recall. The study also aimed to identify predictors of remembered pain by analyzing a range of sensory, cognitive, and affective factors.

METHODS: Older adults, undergoing planned (N=40) and unplanned hip surgery (N=31), were enrolled in this prospective study to investigate their presurgery, postsurgery, and delayed ratings of expected, experienced, and recalled pain intensity and unpleasantness, state anxiety, and positive and negative affect.

RESULTS: Memory of postoperative pain was found to be accurate, regardless of the context of the surgery. Affective states in the postoperative period were congruent with those during pain recall. The study also revealed that in planned surgery context, remembered pain was predicted by experienced postoperative pain, cognitive functions, positive and negative affect; whereas in unplanned surgery context its significant predictors included age, anxiety, and negative and positive affect.

DISCUSSION: The results of this study suggest that older orthopedic patients remember postoperative pain correctly after 3 months and that mood dependence effect may contribute to memory of pain. Pain recall after planned surgery seems to depend mainly on the actual experience, while following unplanned surgery it depends on affective factors. Present findings contribute to knowledge about pain memory in older adults and have implications for patients' recovery and best practice in perioperative hospital care.