RESUMEN
(1) Background: The diagnostic and therapeutic procedures performed under sedation or general anesthesia in bovines are numerous. The analgesic drugs that can be legally used are few, making perioperative analgesia challenging. (2) Methods: Calves were administered butorphanol 0.1 mg kg-1 alone (SB) or combined with 0.02 mg kg-1 of a detomidine (DB) IV. The antinociceptive effect (trigeminocervical reflex threshold (TCRt)), as well as the behavioral (sedation and excitation) and physiological (heart and respiratory rate) changes were investigated. Five time windows were defined: BL (30 min pre-injection), T1 (0-30 min post-injection (PI)), T2 (31-60 min PI), T3 (61-90 min PI) and T4 (91-120 min PI). (3) Results: Both groups had a significative increase in TCRt at T1-T4 compared to the BL. The TCRt was significatively higher in DB than in SB at T1, T2 and T4. Heart rate decreased significatively in DB compared to that in BL. Calves were significantly more sedated in the DB group, and significantly more excited in the SB group compared to the BL. (4) Conclusions: Butorphanol alone has a statistically significant antinociceptive effect, but it elicits marked excitation, limiting its clinical applicability under this dosing regimen. The co-administration of detomidine eliminated the excitatory effect and induced consistent sedation and a significantly more pronounced antinociceptive effect.
RESUMEN
The transversus thoracis plane (TTP) block desensitizes the intercostal nerves that run through this plane, providing analgesia to the ventral thoracic wall. Two canine cadavers were used to assess the feasibility of the transverse approach for the TTP (t-TTP) under ultrasound guidance to inject a solution at the third and sixth intercostal spaces. Eight cadavers were used to compare the spread and number of intercostal nerves that were stained when a low volume (LV) 0.5 mL kg-1 or a high volume (HV) 1 mL kg-1 of a dye-lidocaine solution was injected into the same hemithorax, injecting the volume equally at these intercostal spaces using the transverse approach. Fisher's exact test and Wilcoxon signed-rank test were used to contrast the spread of the different volume solutions. The injectate spread along the TTP after all injections, dying a median number (range) of 3 (2-5) and 6 (5-6) nerves with LV and HV, respectively (p = 0.011). The two-point injection of HV, using the t-TTP approach, is a feasible technique that provides a consistent staining from T2 to T7 intercostal nerves. The injection of HV instead of LV increases the spread and enhances the number of stained intercostal nerves.
RESUMEN
Perioperative management of cases undergoing phaeochromocytoma removal should aim at normalising blood pressure and heart rate, restoring volume depletion, and preventing catecholamine release induced by surgical manipulation. In this case report, a novel pharmacological approach in a dog undergoing surgical tumour excision is described. A 7-year-old 25-kg spayed female Labrador Retriever presented for repeated episodes of generalised weakness, pale mucous membranes, tachycardia, tremor, panting, vomiting, and hypertension over the last month was referred for surgical treatment of a left-sided adrenal tumour with invasion of the caudal vena cava. Severe hypertensive episodes occurred repeatedly, starting early during the anaesthetic period, while clipping and cleaning the abdominal area, and continued intraoperatively when the tumour was handled. Moderate hypotension occurred once the tumour was isolated and worsened during temporary caudal vena cava flow interruption and cavotomy. The patient was treated preoperatively with phenoxybenzamine to prevent hypertensive crises. Intraoperatively, magnesium sulphate and urapidil were used to control blood pressure. This treatment was effective in reducing the magnitude of blood pressure spikes but not sufficient to prevent hypertensive peaks, especially during tumour manipulation. Hypotension was treated with synthetic colloid and crystalloid boli, and noradrenaline continuous infusion. Blood transfusion was performed in response to acute bleeding during cavotomy. The dog recovered successfully from anaesthesia and its quality of life was deemed excellent by the owner at the last follow up, 22 months after surgery. The histopathology confirmed the diagnosis of phaeochromocytoma with an invasion of the phrenicoabdominal vein. In the present case, we obtained a successful outcome but failed to provide haemodynamic stability throughout the procedure.