Survey criteria for fibromyalgia independently predict increased postoperative opioid consumption after lower-extremity joint arthroplasty: a prospective, observational cohort study.

BACKGROUND: Variance in pain after total knee and hip arthroplasty may be due to a number of procedural and peripheral factors but also, in some individuals, to aberrant central pain processing as is described in conditions like fibromyalgia. To test this hypothesis, the authors conducted a prospective, observational cohort study of patients undergoing lower-extremity joint arthroplasty. METHODS: Five hundred nineteen patients were preoperatively phenotyped using validated self-reported pain questionnaires, psychological measures, and health information. In addition to being assessed for factors previously found to be associated with poor outcomes in arthroplasty, participants also completed the American College of Rheumatology survey criteria for fibromyalgia. Previous studies have suggested that rather than being "present" or "absent," features of fibromyalgia as measured by this instrument, occur over a wide continuum. Postoperative pain control was assessed by total postoperative opioid consumption. RESULTS: Preoperatively, patients with higher fibromyalgia survey scores were younger, more likely to be female, taking more opioids, reported higher pain severity, and had a more negative psychological profile. In the multivariate analysis, the fibromyalgia survey score, younger age, preoperative opioid use, knee (vs. hip), pain severity at baseline, and the anesthetic technique were all predictive of increased postoperative opioid consumption. CONCLUSIONS: The use of the survey criteria for fibromyalgia led to the finding of distinct phenotypic differences, and the measure was independently predictive of opioid consumption. This self-report measure may provide an additional simple means of predicting postoperative pain outcomes and analgesic requirements. Future studies are needed to determine whether tailored therapies can improve postoperative pain control in this population.

Prevention of intraoperative awareness with explicit recall in an unselected surgical population: a randomized comparative effectiveness trial.

BACKGROUND: Intraoperative awareness with explicit recall occurs in approximately 0.15% of all surgical cases. Efficacy trials based on the Bispectral Index® (BIS) monitor (Covidien, Boulder, CO) and anesthetic concentrations have focused on high-risk patients, but there are no effectiveness data applicable to an unselected surgical population. METHODS: We conducted a randomized controlled trial of unselected surgical patients at three hospitals of a tertiary academic medical center. Surgical cases were randomized to alerting algorithms based on either BIS values or anesthetic concentrations. The primary outcome was the incidence of definite intraoperative awareness; prespecified secondary outcomes included postanesthetic recovery variables. RESULTS: The study was terminated because of futility. At interim analysis the incidence of definite awareness was 0.12% (11/9,376) (95% CI: 0.07-0.21%) in the anesthetic concentration group and 0.08% (8/9,460) (95% CI: 0.04-0.16%) in the BIS group (P = 0.48). There was no significant difference between the two groups in terms of meeting criteria for recovery room discharge or incidence of nausea and vomiting. By post hoc secondary analysis, the BIS protocol was associated with a 4.7-fold reduction in definite or possible awareness events compared with a cohort receiving no intervention (P = 0.001; 95% CI: 1.7-13.1). CONCLUSION: This negative trial could not detect a difference in the incidence of definite awareness or recovery variables between monitoring protocols based on either BIS values or anesthetic concentration. By post hoc analysis, a protocol based on BIS monitoring reduced the incidence of definite or possible intraoperative awareness compared with routine care.