Factors influencing the choice of anesthetic technique for primary hip and knee arthroplasty

Factors associated with success and failure of patient-controlled oral analgesia after total hip and knee arthroplasty: a historical comparative cohort study

PURPOSE

Patient-controlled oral analgesia (PCOA) is a novel method of oral opioid administration using set doses of short-acting oral opioids self-administered by patients with a "lockout" period as part of a multimodal regimen. Failure of PCOA can result in severe postoperative pain necessitating use of intravenous patient-controlled analgesia (IV-PCA) with its potential complications. This study evaluated factors related to success or failure of PCOA following total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

We conducted a retrospective cohort study of all adults who underwent THA and TKA at our institution by extracting data from the proprietary database of our acute pain service. Patient, anesthetic, and surgical variables associated with PCOA failure defined as inadequate analgesia requiring conversion to IV-PCA within 24 hr following THA and TKA were evaluated. Univariable and multivariable logistic regression analyses were performed to identify predictors of PCOA failure.

RESULTS

Of the 926 patients who underwent THA or TKA (n = 411 and 515, respectively), 147 (15.9%) patients (67 THA and 80 TKA patients) had PCOA failure with moderate-to-severe pain. Multivariable regression analysis showed that PCOA failure occurred in those with younger age (adjusted odds ratio [aOR] per year of age, 0.97; 99% CI, 0.95 to 0.99; P < 0.001), preoperative chronic use of controlled-release opioids (aOR, 3.45; 99% CI, 1.60 to 7.35; P < 0.001), and with the use of general anesthesia vs spinal anesthesia (aOR, 2.86; 99% CI, 1.20 to 6.84; P = 0.002).

CONCLUSION

The use of PCOA provides adequate analgesia to a majority of patients undergoing THA and TKA. Factors predictive for PCOA failure should be considered when choosing the primary breakthrough analgesic modality following THA/TKA.

HTX-011 Reduced Pain and Opioid Use After Primary Total Knee Arthroplasty: Results of a Randomized Phase 2b Trial

BACKGROUND

HTX-011 is an extended-release, dual-acting local anesthetic consisting of bupivacaine and low-dose meloxicam in a novel polymer that is administered by needle-free application during surgery. The active ingredients are released from the polymer by controlled diffusion over 72 hours.

METHODS

This phase 2b, double-blind, placebo-controlled and active-controlled trial enrolled patients undergoing primary unilateral total knee arthroplasty under general anesthesia. Two hundred thirty-two patients were randomized into 4 groups: HTX-011 400 mg bupivacaine/12 mg meloxicam, applied without a needle into the surgical site, the same dose of HTX-011 with a separate 50 mg ropivacaine injection into the posterior capsule, bupivacaine hydrochloride (HCl) 125 mg injection, and saline placebo injection. Only opioids were permitted for postoperative pain rescue. Primary and key secondary endpoints were mean area under the curve of pain intensity scores over 48 hours and 72 hours, respectively, for HTX-011 groups vs placebo.

RESULTS

Both HTX-011 groups had significantly reduced mean pain intensity vs placebo through 48 and 72 hours (both P < .001). Ropivacaine added a small initial benefit in the first 12 hours. Both HTX-011 groups also had decreased mean pain intensity vs bupivacaine HCl alone through 48 and 72 hours (P < .05). The HTX-011 groups had significantly earlier discharge readiness along with lower opioid consumption through 72 hours. HTX-011 alone or with ropivacaine was well-tolerated with a safety profile similar to controls.

CONCLUSION

Needle-free application of HTX-011 400 mg bupivacaine/12 mg meloxicam provided superior pain reduction through 72 hours after total knee arthroplasty compared with placebo and bupivacaine HCl alone.