Postoperative cognitive dysfunction is rare after fast-track hip- and knee arthroplasty - But potentially related to opioid use

STUDY OBJECTIVE: Postoperative cognitive dysfunction (POCD) remains a frequent postoperative complication in non-fast-track surgeries, with negative implications for return to daily activities and work. In fast-track total hip and -knee arthroplasty (THA/TKA) an 8-9% incidence of POCD after 3 months has been reported, but without details on specific perioperative risk factors. Thus, we re-investigated the incidence and role of suggested factors for POCD in a well-controlled patient cohort, to guide future preventive interventions.

DESIGN: A subanalysis of a prospective study.

SETTING: Hospital ward, patients own home.

PATIENTS: One-hundred-and-four patients undergoing elective THA/TKA.

INTERVENTIONS: A full contextual and validated cognitive test battery pre- and 2-3 weeks postoperatively by interview by research nurse.

MEASUREMENTS: Results from the cognitive test battery were corrected for learning effect by normative data from an age-matched unoperated control group. Potential perioperative risk factors (age, procedure, gender, inflammation, blood-percentage, opioids etc.) associated with POCD was investigated by univariate and multivariate logistic analysis, with a 5% significance level.

MAIN RESULTS: Four patients (3.9%) developed POCD. POCD-positive patients consumed higher dose of opioids in the acute postoperative period (postoperative days 0-3: median 214 mg), vs. POCD-negative patients (postoperative days 0-3: median 98 mg, p = 0.008), and during the 2-3-week study period (POCD-positive vs. POCD-negative patients, median 739 mg vs. 208 mg, respectively). Other pre and postoperative factors were non-significant but associated with the development of POCD.

CONCLUSION: POCD is rare in fast-track THA/TKA patients and may be related to postoperative opioid consumption, supporting the ongoing focus on opioid-sparing analgesia.