Background & Aims

Patient-controlled-analgesia (PCA) is widely used as an effective method for acute postoperative pain relief, allowing individualized administration of analgesics. PCA traditionally relies on opioids, which possess potent analgesia but are associated with various side effects. Consequently, there has been a paradigm shift toward replacing or supplementing opioid with non-opioid analgesia in a multimodal approach. However, non-opioid analgesics also have limitations, including side effects, ceiling effects, and relatively lower potency.
Therefore, this study aims to compare pain scores and complications between opioid-based and non-opioid based background infusion in PCA.

Methods

This prospective, double-blinded, randomized controlled, non-inferiority trial included patients, aged 50-89, who were scheduled for elective total knee arthroplasty. Patients were randomized equally into opioid group and non-opioid group in a 1:1 ratio. The continuous chamber of the PCA device contained fentanyl 1200mcg for opioid group, and ketorolac tromethamine 150mg plus nefopam hydrochloride 100mg for non-opioid group (total volume 50ml, rate: 1cc/hr). The bolus chamber contained fentanyl 300mcg for both groups (total volume 30ml, bolus 1cc/hr, lock-out time 10 minutes). We measured resting, moving pain (0-10 VAS) at 24, 48 hours postoperatively, and possible complications (nausea, vomiting, dizziness, drowsiness, respiratory depression, constipation, urinary retention, kidney or liver dysfunction, and gastrointestinal or surgical site bleeding), and length of hospital stays.

Results

A total of 75 patients were enrolled, with 3 patients dropped out, resulting in 36 patients in each group for analysis. Resting pain at 24 and 48 hours after surgery was significantly lower in the opioid group (5.6±2.7 vs. 7±3, p=0.039, 2.1±1.8 vs. 3.7±4.1, p=0.03), while moving pain was comparable (6±2.9 vs. 6±3.1, p>0.99, 4.9±2 vs. 5.1±1.7, p=0.73). The complication rate was also higher in the opioid group (44.4% vs. 22%, p = 0.046, OR 2.8 [1.1-7.8]). In types of complications, significant differences were observed in nausea and vomiting (27.8% vs. 8.3%, p=0.032, OR 4.2[1.06-17]). Additionally, dizziness (5.6%), drowsiness (5.6%), respiratory depression (2.8%) occurred only in the opioid group, while constipation (8.3% vs. 13.9%, p=0.45) and urinary retention (5.6% vs. 2.8%, p=0.56) showed no statistical difference. There were no cases of renal or hepatic impairment or bleeding in either group. Hospital stay (14.8±5.7 vs. 14.8±5.5, p>0.99) was similar between the two groups.

Conclusions

In patients underwent total knee arthroplasty, PCA with opioid-based background infusion resulted in lower pain scores but higher complication rates than non-opioid infusion.

References

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3.O’Neill A, Lirk P. Multimodal Analgesia. Anesthesiol Clin. 2022 Sep;40(3):455-468. doi: 10.1016/j.anclin.2022.04.002. Epub 2022 Aug 2. PMID: 36049874.
4.Choi E, Karm MH, So E, Choi YJ, Park S, Oh Y, Yun HJ, Kim HJ, Seo KS. Effects on postoperative nausea and vomiting of nefopam versus fentanyl following bimaxillary orthognathic surgery: a prospective double-blind randomized controlled trial. J Dent Anesth Pain Med. 2019 Feb;19(1):55-66. doi: 10.17245/jdapm.2019.19.1.55. Epub 2019 Feb 28.
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Presenting Author

Jiwon Han

Poster Authors

Jiwon Han

MD, PhD

Chung-Ang University/Seoul, Republic of Korea

Lead Author

Seihee Min

Chung-Ang University

Lead Author

Topics

  • Treatment/Management: Pharmacology: Opioid