Revista de Medicina Veterinária e Saúde

Abstrato

Brief Notes on Canine Anaesthesia and Opioid-Free Analgesia

Teha Elemo

A 4.5-year-old dog was put under anaesthesia for a partial pancreatectomy to remove an insulinoma, a pancreatic tumour that secretes insulin and causes hypoglycemia. Dexmedetomidine (2 g/kg) and maropitant (1 mg/kg) were administered intravenously as premedicators to the patient. Alfaxalone (0.5 mg/kg) and diazepam (0.2 mg/kg) were administered intravenously to produce anaesthesia, and dexmedetomidine (1 g/kg/h) and isoflurane in 70% oxygen were used to maintain it. With ropivacaine (0.3% 1 ml/kg) divided into four locations, a bilateral transversus abdominis plane block was carried out. Ketamine, fentanyl, and methadone were administered intravenously as additional intraoperative analgesics. Lactated Ringer’s solution was given, and the amount of extra glucose was changed according to glycemia.Although the patient had slight hyperglycemia after surgery, they were comfortable and didn’t need any analgesics for the 48-hour hospital stay. In this example, an insulinoma was successfully treated with a dexmedetomidine constantrate infusion and an opioid-free multimodal analgesia.

Background: A functioning insulin-secreting tumour that is malignant and develops from pancreatic cells results in hypoglycemia. It is the most frequent endocrine pancreatic tumour seen in dogs, although being uncommon. The animals typically exhibit neurological symptoms, which might include paralysis, convulsions, coma, or even death. These clinical symptoms are due to an increase in insulin antagonist counterregulatory hormones and neuronal glucose deprivation (neuroglycopenia). Clinical symptoms, laboratory tests, including concurrent hyperinsulinemia and hypoglycemia, and imaging are used to make the diagnosis. However, histology, which needs surgical management following a medical stabilisation, is the basis for a conclusive diagnosis. There are several difficulties in administering anaesthesia to a patient who needs to have an insulinoma surgically removed. The likelihood of rebound hyperglycemia following excision and insulinoma-related hypoglycemia in particular may make it difficult to maintain normoglycemia. Additionally,postoperative pancreatitis, which is documented in 10% of operated cases, is a frequent complication. 3 Anaesthetic considerations might influence the results, even though manipulating the pancreas is the main cause of problems and can, regrettably, never be avoided. This is because mu-opioids, like morphine or fentanyl, have been shown to cause pancreatitis by disrupting the sphincter of Oddi, making opioid-free analgesia an intriguing possibility. 4 Nevertheless,multimodal analgesia must be used with careful attention to pain control. Postoperative analgesia and intraoperative nociception must be routinely diagnosed and treated right away. Additionally, it’s preferable for cardiovascular and respiratory stability during general anaesthesia. Due to its powerful sedative, analgesic, and minimum alveolar concentration (MAC)-sparing properties, dexmedetomidine is a highly selective alpha-2-adrenoreceptor agonist that is frequently employed in veterinary anaesthesia. 5 Alpha-2 agonists have historically been advised against while treating insulinoma patients because they inhibit insulin secretion. This turned out to be contentious, nevertheless, because preventing insulin release from the tumour would allow for the avoidance of harmful hypoglycemia during surgery. In this regard, Guedes and Rude6 demonstrated that premedicating dogs having insulinoma excision with medetomidine,another alpha-2-agonist, decreased insulin concentration, increased plasma glucose concentrations, and decreased intraoperative glucose supplementation. Dexmedetomidine has only been used once, in a brief case report, to treat a canine insulinoma during surgery. This case report details the successful anaesthetic management of a dog undergoing partial pancreatectomy for the removal of an insulinoma, which included the use of an opioid-sparing analgesic strategy with multimodal analgesia, including locoregional analgesia, and dexmedetomidine constant-rate infusion (CRI) for partial intravenous anaesthesia (PIVA).