EREM Reduces Reliance on Parenteral Opioids and Pump Technology after Total Joint Arthroplasty

1. EREM Reduces Reliance on Parenteral Opioids and Pump Technology after Total Joint Arthroplasty Kishor Gandhi MD MPH, Kathleen Colfer MSN, RN-BC, Robert F Olszewski, Jr, BS, Steven Schaefer, BS, and Eugene Viscusi MD

2. Introduction: Ø Pain control is an important source of morbidity in the hospital setting Ø Effective control of postoperative pain reduce1-4: • Incidences of myocardial infarctions • Deep venous thrombosis • Pulmonary embolisms Ø Current treatment of pain control includes: • Epidural analgesia with continuous catheters • PCA’s that supply parenteral opioids upon patient needs 1 Liu et al Anesthesia and Analgesia 1995 82:1474-1506 2 Wu et al Anesthesia and Analgesia 2000 91:1232-1242 3 Beattle et al Anesthesia and Analgesia 2001 93: 853-858 4 Rodgers et al BMJ 2000 321:1493-1496

3. Introduction (Cont’d): • Extended-release Epidural Morphine (EREM) [DepoDurTM]: • microscopic spherical particles with internal aqueous chambers that contain morphine • After a single injection in epidural space before surgery, the chambers degrade at physiologic conditions to release morphine slowly up to 48 hours • The delayed release of morphine provides adequate pain relief for patients until they are transitioned to oral analgesics • The purpose of this analysis: • Retrospectively evaluate post-operative pain and opioid requirements in patients who received EREM compared to controls with traditional modes of therapy

4. Retrospective IRB approved analysis includes random selection of patients who underwent TJA from January-July 2007 Patients were chosen based on different postoperative analgesic modalities: Total Hip Arthroplasty EREM 7.5 mg EREM 10 mg Combined intrathecal Morphine PF with Fentanyl IV-PCA Fentanyl IV-PCA Methods: • Total Knee Arthroplasty • EREM 10 mg • EREM 12.5 mg • Indwelling epidural catheter with 0.2% Ropivacaine and fentanyl IV-PCA • Single Injection femoral nerve block and fentanyl IV-PCA

5. Methods (cont’d): • Patient information was extracted from medical records and gathered in a database • Information included: • post-operative pain measured at multiple times during POD 0, 1, & 2; • need for oral opioids, parenteral opioids, or IV- PCA requirements for postoperative pain control • Primary outcomes measured include average pain score of patients on POD 0, 1, & 2 with different modes of post-operative pain control after TJA • Further analysis includes the proportion of patients who needed oral and parenteral opioids during postoperative day 0, 1, & 2 • All opioids (oral and parenteral) converted to parenteral morphine (IV) equivalence • Statistical analysis was done with ANOVA with alpha=005 with two tailed distribution to compare means Bonferoni adjustments were conducted to allow for multiple comparisons between groups

6. Results:Figure 1: Post-operative opioid requirements in patients after Total Hip Arthroplasty Average Morphine Requirements After Total Hip Arthroplasty (THA) Average Morphine Requirements (mg) Depodur 7.5 Depodur 10 IT Morphine PF - Fentanyl IV-PCA Fentanyl IV-PCA Post-operative Pain Control Modality

7. Figure 2: Post-operative opioid requirements in patients after Total Knee Arthroplasty Average Morphine Requirements After Total Knee Arthroplasty (THA) Average Morphine Requirements (mg) Indwelling Epidural Cathet with 0.2% Ropivicaine + Fentanyl IV-PCA Depodur 10.0 Depodur 10 Single Femoral Nerve Block + Fentanyl IV-PCA Post-operative Pain Control Modality

8. Results:Table 1: Post-operative analgesic requirements of patients after Total Hip Arthroplasty

9. Results:Table 2: Post-operative analgesic requirements of patients after Total Knee Arthroplasty

10. Discussion: Ø Bonferoni adjustments in ANOVA showed the difference in average patient morphine requirements to be significantly less in the EREM groups (p<0.001) [Figure 1 & Table 1] Ø Average pain intensity after total hip arthroplasty was greater with traditional modes of post-operative pain control with intravenous PCA when compared to EREM 7.5mg and EREM 10mg (Table 1) Ø EREM 7.5 mg and EREM 10 mg were comparable for post-operative pain control after THA Ø Percentage of patients who required no opioid rescue after THA was high in EREM groups with minimal usage of pump technology Ø Patients after total knee arthroplasty had improved pain control and decreased supplemental opioid usage in EREM 10.0 mg and EREM 12.5 mg groups when compared to post-operative regimen with epidural and femoral nerve block Ø Bonferoni adjustments in ANOVA showed a significance difference in morphine requirements in EREM groups (p<0.01) on day 0 and day 1 when compared to the control groups (Figure 2 & Table 2) Ø The majority of patients receiving EREM after TKA required little supplemental opioids, usually managed with oral agents alone

11. Conclusion: ØThe majority of patients who received EREM for TJA had adequate pain control with minimal analgesic supplement Few patients required the addition of IV PCA ØThis study demonstrates potential ease-of-care benefits by eliminating analgesic therapies that rely on indwelling catheter and pump delivery ØEREM 7.5 mg and EREM 10 mg was superior in total hip arthroplasty, while EREM 12.5 mg had higher efficacy in total knee arthroplasty

12. Limitations: • Limitations of this study include a small sample size • This was a retrospective analysis with can cause bias in: • Selection • Recording