1. Patient features and anesthetic protocol
ANALGESIC EFFECT OF A T6-T11 BILATERAL INTERCOSTAL NERVE BLOCK
IN A DOG UNDERGOING SURGICAL EXCISION OF AN ABDOMINAL WALL TUMOR
Diego F Echeverry,1-2 Jessica T Peláez,1-2 Diego A Ospina,1-2 Edwin F Buriticá,1-2 Fabián Castañeda1-2
1 Department of Animal Health, Faculty of Veterinary Medicine and Zootechny, Universidad del Tolima, Ibagué, Colombia.
2 Small Animal Medicine and Surgery Research Group, Tolima University, Ibagué, Colombia.
Introduction
Abdominal surgery elicits considerable nociceptive input,1 where much of the pain described seems to originate from the incision of the abdominal wall.2 The transverse abdominal plane (TAP) block has been proposed as a suitable alternative to traditional loco-regional techniques to improve analgesia in procedures performed on the abdominal wall;3 nevertheless, the TAP block can be ineffective in providing analgesia in the most cranial part of the abdominal wall.2 and complementary intercostal nerve blocks (INB) have been indicated to cover this deficit.
Objective
To describe the intraoperative analgesic effect of an intercostal nerve block in a dog undergoing surgical excision of a tumor located in the cranial abdominal wall.
Patient features and anesthetic protocol
Patient: an 8 years-old and 33.7 kg Golden retriever dog Diagnostic: Fibrosarcoma located dorso-caudal to the xiphoid process. Surgical procedure: surgical tumor resection.
Premedication: acepromazine (0.01 mg kg-1 IV), tramadol (3 mg kg-1 IV), meloxicam (0.3 mg kg-1 SC) IM. Induction: propofol (5 mg kg-1 IV). Manteinance: Isofluorane in oxygen 100%.
Locoregional block technique: A T6-T11 INB was performed bilaterally at the chondrocostal junction level using a 22 G spinal needle (Fig. 1-2). Local anesthetic: 0.5 mL of bupivacaine (0.5 %) to infiltrate close to each nerve, (0.9 mg kg-1 total dose).
Andrés Bandera Rojas ©
Fig 2. Schematic representation of figure 1 showing the blocked nerves (T6-L11) (red targets) and the tumor location (red circle).
Fig 1. Position of the needle for the intercostal nerve block (INB).
Intraoperative anesthetic monitoring
The heart rate (HR), the mean arterial blood pressure (MAP), and the ETIso% were monitored throughout the procedure. Increases over 20% in the HR and MAP were considered indicative of inadequate analgesic coverage in such a case 3 μg Kg-1 of fentanyl IV would be administered.
RESULTS:
Physiological parameters were stable during the entire surgical procedure: mean HR 90 bpm, MAP 73 mm of Hg, ETIso 2%. Fentanyl was not supplemented.
Conclusion
The intercostal nerve blocks technique employed here was effective to provide an adequate analgesia to perform the surgical resection of this fibrosarcoma, located at the craneal abdomen, in this dog.
References
1. Brunt J, Downing R, Hagedorn JE, et al. AAHA/AAFP pain management guidelines for dogs & cats. J Am Anim Hosp Assoc 2007; 43:
2. Wall PD, Melzack R Pain measurements in persons in pain. In: Wall PD, Melzack R, eds. Textbook of pain. 4th ed. Edinburgh, UK: Churchill Livingstone, p. 409–426.
3. Schroeder CA, Snyder LB, Tearney CC, et al. Ultrasound-guided transversus abdominis plane block in the dog: an anatomical evaluation. Vet Anaesth Analg 2011; 38: