Regional Anesthesia and Readmission Rates After Total Knee Arthroplasty

Association of Patient Race and Hospital with Utilization of Regional Anesthesia for Treatment of Postoperative Pain in Total Knee Arthroplasty: A Retrospective Analysis Using Medicare Claims

BACKGROUND

Regional anesthesia for total knee arthroplasty has been deemed high priority by national and international societies, and its use can serve as a measure of healthcare equity. The association between utilization of regional anesthesia for postoperative pain and (1) race and (2) hospital in patients undergoing total knee arthroplasty was estimated. The hypothesis was that Black patients would be less likely than White patients to receive regional anesthesia, and that variability in regional anesthesia would more likely be attributable to the hospital where surgery occurred than race.

METHODS

This study used Medicare fee-for-service claims for patients aged 65 yr or older who underwent primary total knee arthroplasty between January 1, 2011, and December 31, 2016. The primary outcome was administration of regional anesthesia for postoperative pain, defined as any peripheral (femoral, lumbar plexus, or other) or neuraxial (spinal or epidural) block. The primary exposure was self-reported race (Black, White, or Other). Clinical significance was defined as a relative difference of 10% in regional anesthesia administration.

RESULTS

Data from 733,406 cases across 2,507 hospitals were analyzed: 90.7% of patients were identified as White, 4.7% as Black, and 4.6% as Other. Median hospital-level prevalence of use of regional anesthesia was 51% (interquartile range, 18 to 79%). Black patients did not have a statistically different probability of receiving a regional anesthetic compared to White patients (adjusted estimates: Black, 53.3% [95% CI, 52.5 to 54.1%]; White, 52.7% [95% CI, 52.4 to 54.1%]; P = 0.132). Findings were robust to alternate specifications of the exposure and outcome. Analysis of variance revealed that 42.0% of the variation in block administration was attributable to hospital, compared to less than 0.01% to race, after adjusting for other patient-level confounders.

CONCLUSIONS

Race was not associated with administration of regional anesthesia in Medicare patients undergoing primary total knee arthroplasty. Variation in the use of regional anesthesia was primarily associated with the hospital where surgery occurred.

EDITOR’S PERSPECTIVE

Surgeon Variation in Perioperative Opioid Prescribing and Medium- or Long-term Opioid Utilization after Total Knee Arthroplasty: A Cross-sectional Analysis

BACKGROUND

Whether a particular surgeon's opioid prescribing behavior is associated with prolonged postoperative opioid use is unknown. This study tested the hypothesis that the patients of surgeons with a higher propensity to prescribe opioids are more likely to utilize opioids long-term postoperatively.

METHODS

The study identified 612,378 Medicare fee-for-service patients undergoing total knee arthroplasty between January 1, 2011, and December 31, 2016. "High-intensity" surgeons were defined as those whose patients were, on average, in the upper quartile of opioid utilization in the immediate perioperative period (preoperative day 7 to postoperative day 7). The study then estimated whether patients of high-intensity surgeons had higher opioid utilization in the midterm (postoperative days 8 to 90) and long-term (postoperative days 91 to 365), utilizing an instrumental variable approach to minimize confounding from unobservable factors.

RESULTS

In the final sample of 604,093 patients, the average age was 74 yr (SD 5), and there were 413,121 (68.4%) females. A total of 180,926 patients (30%) were treated by high-intensity surgeons. On average, patients receiving treatment from a high-intensity surgeon received 36.1 (SD 35.0) oral morphine equivalent (morphine milligram equivalents) per day during the immediate perioperative period compared to 17.3 morphine milligram equivalents (SD 23.1) per day for all other patients (+18.9 morphine milligram equivalents per day difference; 95% CI, 18.7 to 19.0; P < 0.001). After adjusting for confounders, receiving treatment from a high-intensity surgeon was associated with higher opioid utilization in the midterm opioid postoperative period (+2.4 morphine milligram equivalents per day difference; 95% CI, 1.7 to 3.2; P < 0.001 [11.4 morphine milligram equivalents per day vs. 9.0]) and lower opioid utilization in the long-term postoperative period (-1.0 morphine milligram equivalents per day difference; 95% CI, -1.4 to -0.6; P < 0.001 [2.8 morphine milligram equivalents per day vs. 3.8]). While statistically significant, these differences are clinically small.

CONCLUSIONS

Among Medicare fee-for-service patients undergoing total knee arthroplasty, surgeon-level variation in opioid utilization in the immediate perioperative period was associated with statistically significant but clinically insignificant differences in opioid utilization in the medium- and long-term postoperative periods.

EDITOR’S PERSPECTIVE

Effect of peripheral nerve blocks on postanesthesia care unit length of stay in patients undergoing ambulatory surgery: a retrospective cohort study

BACKGROUND

Peripheral regional anesthesia and analgesia may increase the efficiency of ambulatory surgical centers by reducing pain and preventing nausea and vomiting, which are important modifiable causes of prolonged postanesthesia care unit (PACU) length of stay. We hypothesized that the use of peripheral nerve blocks (PNB) was associated with shorter PACU length of stay in ambulatory surgery.

METHODS

In this retrospective cohort study, we analyzed data from adult ambulatory surgical cases, in which PNB was a viable anesthetic option (ie, was routinely performed for these procedures), at an academic medical center between 2008 and 2018. We assessed the association between the use of PNB and the primary endpoint of PACU length of stay. As key secondary endpoint, we compared intraoperative opioid doses. Analyses were adjusted for patient demographics, comorbidities and intraoperative factors.

RESULTS

A total of 57 040 cases were analyzed, of whom 13 648 (23.9%) received a PNB. The use of PNB was associated with shorter PACU length of stay (a decrease of 7.3 min, 95% CI 6.1 to 8.6, p<0.001). This association was most pronounced in surgeries of long duration (decrease of 11.2 min, 95% CI 9.0 to 13.4) and in patients undergoing leg and ankle procedures (decrease of 15.1 min, 95% CI 5.5 to 24.6). Intraoperative opioid doses were significantly lower in patients receiving a nerve block (decrease of 9.40 mg oral morphine equivalents, 95% CI 8.34 to 10.46, p<0.001).

CONCLUSION

The use of PNB significantly reduced PACU length of stay in ambulatory surgical patients, which may in part be attributed to lower intraoperative opioid requirements.