Background and Goal of Study: Cognitive problems early after surgery are often considered transient in nature. The relation of cognitive performance to other recovery parameters has rarely been systematically assessed early after surgery.
Materials and Methods: The PQRS was performed prior to surgery, 15 mins, 40mins, 1 and 3 days after anaesthesia. Recovery was measured in multiple domains: physiological, nociceptive (pain and nausea), emotive (anxiety and depression), cognitive, and activities of daily living (ADL). Recovery was defined as “return to baseline values or better”. Cognitive recovery included a tolerance factor to account for normal performance variability. A sub-analysis of the PQRS feasibility data compared patients who at day 3 were categorised as recovered or not recovered in the cognitive domain. Data are presented as the proportion of patients recovered. Analysis tested the global hypothesis of group differences in recovery over time using the Cochran Mantel Haenzel test.
Results and Discussion: 565 of 701 patients were included; 423 (80.2%) recovered in the cognitive domain at day 3, and 112 (19.8%) did not. The recovery by domains is shown in Figure 1.
Cognitive recovery from 15 minutes to Day 1 was significantly lower in patients who had not recovered at day 3 (P< 0.001). Of these, 48% had recovered on Day 1, but lapsed to non-recovery on Day 3.
Emotional (P=0.019) and ADL (P=0.005) recovery were less likely to occur in the group who had not shown cognitive recovery at Day 3. They were also older, consumed more alcohol, had a longer anesthetic, and were more likely to be inpatients, and have moderate or major surgery.
No difference was found for the physiological and nociceptive domains.
Conclusion(s): Failure of cognitive recovery is common 3 days after surgery, and is associated with poorer recovery in the ADL and emotive domains, but not in nociceptive or physiological domains.
1. Royse CF, Newman S, Chung F et al: Development and feasibility of a scale to assess postoperative recovery: the post-operative quality recovery scale. Anesthesiology 2010; 113: 892-905.
Acknowledgements: Baxter Healthcare funded the study.