TOPLINE:

In patients who underwent total knee arthroplasty, adding a continuous adductor canal catheter block did not significantly reduce the use of opioids over 24-48 hours of surgery compared with a single-injection block along with dexamethasone.

METHODOLOGY:

• Researchers in New York City conducted a randomized controlled trial to assess whether a continuous adductor canal block (ACB) reduced the use of opioids after total knee arthroplasty.
• The final analysis included 84 adults undergoing primary unilateral total knee arthroplasty between November 2018 and June 2023. Patients were randomly assigned to receive either continuous infusion (n = 43; mean age, 59.6 years; 46.5% women) or a single injection (n = 41; mean age, 59.9 years; 65.9% women).
• All patients received a 15 mL ACB with 0.25% bupivacaine. The continuous infusion group also had a catheter infusing 0.2% ropivacaine at 8 mL/h for about 50 hours, whereas the single-injection group had 2 mg perineural dexamethasone added to the block and a sham catheter.
• All patients received spinal-epidural anesthesia with an iPACK block and periarticular infiltration, a pain regimen of anti-inflammatory drugs, acetaminophen, and opioids as needed, along with round-the-clock telemedicine follow-up.
• The primary outcome was the consumption of opioids during 24-48 hours after surgery, and the secondary outcome was the consumption of opioids in the postanesthesia care unit. Pain scores were also assessed among other exploratory analyses.

TAKEAWAY:

• The consumption of opioids over 24-48 hours after surgery or in the postanesthesia care unit did not differ significantly between the continuous infusion and single-injection groups.
• Mean scores for pain at rest on day 2 after surgery were lower in the continuous infusion group than in the single-injection group (estimated difference, -1.273; P = .020).
• Catheter-related issues were more common in the continuous infusion group than in the single-injection group, although differences were not statistically significant.
• No cases of local anesthetic systemic toxicity were observed.

IN PRACTICE:

“Continuous adductor canal catheter infusion, initiated at the resolution of spinal anesthesia, did not provide statistically significant advantages over single-injection ACB with perineural dexamethasone in reducing opioid consumption, managing pain, improving patient satisfaction, minimizing adverse effects, or enhancing functional recovery following TKA [total knee arthroplasty] within 24-48 hours. Both pain management strategies exhibited comparable efficacy and safety profiles,” the researchers reported.

SOURCE:

The study was led by David H. Kim, MD, of Hospital for Special Surgery in New York City. It was published online on June 4 in Regional Anesthesia and Pain Medicine.

LIMITATIONS:

The infusion lasted only about 50 hours, which may have missed the outcomes of a longer infusion. The pump was started while the initial nerve block was still active rather than timed to resolution of block. The study enrolled a relatively healthy, English-speaking, low-risk group, limiting broader applicability.

DISCLOSURES:

Arrow catheters, ambulatory pumps, and the Diagnotes telemedicine app were provided at no cost. The study received support from the Hospital for Special Surgery and the National Institutes of Health. Three authors reported being members of the editorial board of Regional Anesthesia and Pain Medicine.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.