Eficácia analgésica e anti-inflamatória da lidocaína administrada em pontos de acupuntura comparativamente à via intravenosa em cadelas com piometra

Abstract

The aim of this study was to evaluate perioperative analgesic and anti-inflammatory efficacy of lidocaine administered at acupuncture points compared to intravenous (IV) route in dogs. Twenty-seven dogs undergoing ovariohysterectomy diagnosed with pyometra were included in the study. After methadone (0.3 mg/kg) administration by intramuscular (IM) route, anesthesia was induced with IV propofol and maintained with isoflurane/O2. The dogs were distributed into three groups: LIV (n = 9): IV lidocaine 1% infusion (loading dose of 2 mg/kg, constant rate infusion of 50 µg/kg/min); LAP (n = 9): subcutaneous lidocaine 1% (1 mg/kg) injected bilaterally at ST36 and SP6 acupoints; SAL (n=9): IV saline infusion (loading dose of 2 mL/kg, constant rate infusion of 2 mL/kg/min). Fentanyl (2.5 µg/kg IV) was given to control cardiovascular responses to surgical stimulation. Sedation and pain were assessed preoperatively and over 24 hours after extubation using sedation scoring, a Numerical Rating Scale (NRS) and the short-form of the Glasgow Composite Pain Scale (CMPS-SF). Methadone (0.3 mg/kg, IM) was administered as rescue analgesia if CMPS-SF ≥ 6/24. Serum concentration of interleukins (IL-6 and IL-10), tumor necrosis factor, and C-reactive protein were recorded at baseline, 6, 12, and 24 hours after surgery. Data were analyzed using the chi-square test, Tukey test, qui-square test, Kruskal–Wallis test, Friedman test, and Spearman correlation (P < 0.05). Intraoperatively, fentanyl was given to 44.4% (4/9), 33.3% (3/9) and 11.1% (1/9) of the dogs in the SAL, LIV and LAP groups, respectively (P = 0.46). Postoperative rescue analgesia was required in 33.3% (3/9), 33.3% (3/9) e 11.1% (1/9) of the dogs in the SAL, LIV and LAP groups, respectively (P = 0.46). The levels of inflammatory biomarkers did not differ among groups and over time. Compared with baseline values, at 24 h post-surgery the concentration of IL-6 was decreased by 56%, 29%, 20,4% in the LAP, LIV and SAL groups, respectively (P = 0.13-0.49). In conclusion, the three treatments were statistically comparable, however the administration of lidocaine at ST36 and SP6 acupoints resulted in a trend toward lower perioperative analgesic supplementation and greater reduction of IL- concentration in dogs in SIRS secondary to pyometra.