Observational study on intrathecal and peridural changes after routine spinal and epidural anesthesia in patients undergoing total joint arthroplasty

Intranasal Low-Dose Dexmedetomidine Reduces Postoperative Opioid Requirement in Patients Undergoing Hip Arthroplasty Under General Anesthesia

BACKGROUND

Patients undergoing total hip arthroplasty (THA) need substantial amount of opioids for postoperative pain management, which necessitates opioid-sparing modalities. Dexmedetomidine is a novel alpha-2-adrenoceptor-activating drug for procedural sedation. In addition to its sedative effect, dexmedetomidine has analgesic and antiemetic effects. We evaluated retrospectively the effect of intraoperatively administered intranasal low-dose dexmedetomidine on postoperative opioid requirement in patients undergoing THA.

METHODS

We included 120 patients with American Society of Anesthesiologists status 1-2, age between 35 and 80 years, and scheduled for unilateral primary THA under general anesthesia with total intravenous anesthesia. Half of the patients received 50 μg of intranasal dexmedetomidine after anesthesia induction, while the rest were treated conventionally. Postoperative opioid requirements were calculated as morphine equivalent doses for both groups. The impact of intranasal dexmedetomidine on postoperative hemodynamics and length of stay was evaluated.

RESULTS

The cumulative postoperative opioid requirement was significantly reduced in the dexmedetomidine group compared with the control group (26.3 mg, 95% confidence interval 15.6-36.4, P < .001). The cumulative dose was significantly different between the groups already at 12, 24, and 36 h postoperatively (P = .01; P = .001; P < .001, respectively). Dexmedetomidine group had lower mean arterial pressure in the postanesthesia care unit compared with the control group (P = .01). There was no difference in the postanesthesia care unit stay or postoperative length of stay between the two groups (P = .47; P = .10, respectively).

CONCLUSION

Compared with the control group, intraoperative use of intranasal low-dose dexmedetomidine decreases opioid consumption and sympathetic response during acute postoperative period in patients undergoing THA.

One-Day vs Two-Day Epidural Analgesia for Total Knee Arthroplasty (TKA): A Retrospective Cohort Study

Introduction:

Over 500,000 total knee arthroplasties (TKAs) are performed annually in the US, yet postoperative pain management varies widely. In patients managed with epidural analgesia, the epidural catheter is generally removed on the second postoperative day. We compared in-hospital outcomes associated with removing the epidural catheter on postoperative day 1 (POD1-group) vs on postoperative day 2 (POD2-group) among patients undergoing TKA.

Methods:

We identified 89 patients who had TKA performed by a single surgeon from January through July 2007, and who were managed with epidural analgesia. This study took advantage of a change of policy from removing the epidural on the second postoperative day prior to March 2007 (n = 34) to removing the epidural on the first postoperative day thereafter (n = 55). Data were obtained by medical record review and analyzed with bivariate and multivariate techniques. Outcomes included knee range of motion (ROM), pain (0-10 scale), distance walked, narcotic usage, and length of stay.

Results:

The mean patient age was 68 ± 10 years. We did not identify clinically important differences in preoperative characteristics across groups. Patients in the POD1- group had a shorter length of stay (median of 3 vs 4 days in the POD2-group, p<0.001). The POD1-group also walked a greater distance on the second postoperative day (mean of 38 feet vs 9 feet in the POD2-group, p < 0.002). We did not observe a difference between the two groups with respect to change in passive ROM, pain on the second postoperative day, or narcotic usage. The POD1-group had more restricted continuous passive motion settings on the second postoperative day than the POD2-group (50° vs 65°, p = 0.031), and the POD1-group had somewhat worse passive range of motion at discharge (e.g. passive flexion 82o vs 76o in the POD2- group, p = 0.078).

Conclusion:

The balance between a shorter hospital stay and earlier walking achievement with the POD1-strategy-- vs better ROM at the time of discharge with the POD2-strategy-- should be considered when planning TKA pain management. These results should be confirmed with longer term studies and randomized designs.

Evidence Level III:

Retrospective comparative study.