Bloqueio do plano transverso abdominal associado à analgesia intraperitoneal com levobupivacaína, comparado ao uso epidural, em cadelas submetidas à ovariohisterectomia, anestesiadas com propofol.

Abstract

Locoregional anesthesia as perioperative analgesia strategy provides a decrease in anesthetic requirements and postoperative analgesia. This study aimed to compare the cardiorespiratory effects, anesthetic consumption, and analgesic efficiency of levobupivacaine in ultrasound guided transversus abdominis plane (TAP) block, associated with intraperitoneal analgesia, in propofol-anesthetized dogs undergoing ovariohysterectomy (OH). Fourteen healthy adult female dogs received pre-medication (PM) with acepromazine maleate (0.03 mg/kg) and pethidine hydrochloride (3 mg/kg) intramuscularly. Induction was carried out with propofol (5 mg/kg) and anesthetic maintenance achieved under spontaneous ventilation (FiO2 = 1.0). Animals were divided into two groups: group AG (n = 7) received bilateral 0.25% levobupivacaine (1 mg/kg) in ultrasound-guided TAP blockade added of intraperitoneal instillation and group BG (n = 7), which was treated with the same drug (2mg/kg at 0.5%) by epidural route (0.1 ml/cm occiput-coccygeal distance). Heart rate (HR), respiratory rate (f), systolic (SAP), diastolic (DAP) and mean arterial blood pressure (MAP), oxyhemoglobin saturation (SpO2), and end-tidal carbon dioxide (ETCO2) were recorded immediately before (MB) and twenty-minutes after PM (M1) - except SpO2 and ETCO2 as well as at supramaximal stimuli moments [end of celiotomy (M2); clamping of the right (M3) and left (M4) ovarian pedicles; uterine cervix clamping (M5); muscles (M6), subcutaneous (M7) and skin (M8) suture]. In the postoperative period, the quality of anesthetic recovery and time between the end of anesthesia and the occurrence of: extubation (EX), head movement (HM), sternal position (EP) and quadrupedal position (QP), was determined. Pain scores were recorded according to the Melbourne University Pain Scale (EDUM) during six hours (M30, M60, M90, M120, M180, M240 and M360). There was no difference in propofol consumption between groups. Higher HR averages were detected in BG (M2, M4, M6, M7 and M8). At M1, lower MAP and DAP values for BG and lower f means for AGwere found. Recovery quality was regular for AG (100%) and regular (6/7; 85.7%) or excellent (1/7; 14.28%) for BG. Longer times for HM (p = 0.008) and EP (p = 0.024) were detected in AG, xi as well as higher pain scores at 90 minutes postoperatively. However, no analgesic rescues were required in both treatments. The use of levobupivacaine in ultrasound-guided bilateral TAP block associated with intraperitoneal instillation of the same drug may be an alternative to epidural anesthesia as part of multimodal anesthetic protocols in intraabdominal surgeries, because they provide similar analgesia. Both techniques provided cardiorespiratory stability and determined similar effects on propofol consumption.