Effect on pain relief and inflammatory response following addition of tenoxicam to intravenous patient-controlled morphine analgesia: a double-blind, randomized, controlled study in patients undergoing spine fusion surgery

Abstract

Objective: This study tested the hypothesis that adding tenoxicam (T) to intravenous patient-controlled analgesia (IV-PCA) with morphine (M) would improve postoperative pain relief and wound inflammatory responses compared with M alone after spine surgery.

Design: Randomized, prospective, double-blind, controlled study.

Subjects: Ninety-four patients eligible for elective spine surgery.

Setting: Teaching hospital.

Methods: Patients were randomized to one of three groups: the M group (PCA regimen with M), the TM group (PCA regimen with T and M), or the T+TM group (20 mg T administered 30 minutes before wound closure in addition to the TM regimen). The primary end point was the numeric rating scale score for pain intensity, and secondary end points pertaining to postoperative pain management included M consumption, PCA demand/delivery, use of rescue analgesics, adverse events, and levels of inflammatory mediators in wound drainages.

Results: PCA demand was reduced in both the TM and T+TM groups compared with the M group (both P ≤ 0.001). The incidence of skin itching was significantly reduced in the T+TM group compared with the other groups (both P ≤ 0.05). PGE2 and interleukin-6 levels in wound drainages were reduced in the TM and T+TM groups compared with the M group (both P ≤ 0.001).

Conclusions: The combination of T and M for IV-PCA was not more efficacious than IV-PCA with M alone in reducing postoperative pain after spine surgery but reduced PCA demand and suppressed local inflammation at the surgical site. Administration of T before wound closure may ameliorate IV-PCA M-induced skin itching.