Postoperative cognitive dysfunction (POCD) is reported to occur after major surgery in as many as 20% of patients, elderly patients may especially experience problems in the weeks and months after surgery. Recent studies vary greatly in methods of evaluation and diagnosis of POCD, and the pathogenic mechanisms are still unclear. We evaluated a large uniform cohort of elderly patients in a standardized approach, after major joint replacement surgery (total hip and knee replacement). Patients were in an optimized perioperative approach (fast track) with multimodal opioid-sparing analgesia, early mobilization, and short length of stay (LOS ≤3 days) and discharged to home.
In a prospective multicenter study, we included 225 patients aged ≥60 years undergoing well-defined fast-track total hip or total knee replacement. Patients had neuropsychological testing preoperatively and 1 to 2 weeks and 3 months postoperatively. LOS, pain, opioid use, inflammatory response, and sleep quality were recorded. The practice effect of repeated cognitive testing was gauged using data from a healthy community-dwelling control group (n = 161).
Median LOS was 2 days (interquartile range 2–3). The incidence of POCD at 1 to 2 weeks was 9.1% (95% confidence interval [CI], 5.4%–13.1%) and 8.0% (95% CI, 4.5%–12.0%) at 3 months. There was no statistically significant difference between patients with and without early POCD, regarding pain, opioid use, sleep quality, or C-reactive protein response, although the CIs were wide. Patients with early POCD had a higher Mini Mental State Examination score preoperatively (difference in medians 0.5 [95% CI, −1.0% to 0.0%]; P = 0.034). If there was an association between early POCD and late POCD, the sample size was unfortunately too small to verify this (23.6% of patients with early POCD had late onset vs 6.7% in non-POCD group; risk difference 16.9 (95% CI, −2.1% to 41.1%; P = 0.089).
The incidence of POCD early after total hip and knee replacement seems to be lower after a fast-track approach than rates previously reported for these procedures, but late POCD occurred with an incidence similar to that in previous studies of major noncardiac elective surgery. No association between early and late POCD could be verified.
From the *Section of Surgical Pathophysiology and †Department of Anesthesia, Centre of Head and Orthopedics, Rigshospitalet, University of Copenhagen; ‡The Lundbeck Centre for Fast-Track Hip and Knee Arthroplasty, Copenhagen; §Department of Orthopaedic Surgery, Holstebro Hospital, Holstebro; ‖Department of Orthopaedic Surgery, Gentofte Hospital, Gentofte; ¶Department of Orthopaedic Surgery, Århus University Hospital, Århus; and #Department of Anesthesia, Centre of Head and Orthopaedics, University Hospital of Copenhagen, Copenhagen, Denmark.
Accepted for publication February 6, 2014.
The authors declare no conflicts of interest.
Reprints will not be available from the authors.
Address correspondence to Lene Krenk, MD, PhD, Section of Surgical Pathophysiology, 4074 Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Address e-mail to Lene.firstname.lastname@example.org.