Treating pancreatitis (Proceedings)
Treatment of the inciting cause
Whenever possible the inciting cause should be removed. However, as indicated above this may be difficult to accomplish as most cases of canine and feline pancreatitis are idiopathic. A serum chemistry profile should be performed to rule out hypertriglyeridemia and/or hypercalcemia. Exposure to unnecessary drugs, especially those implicated in causing pancreatitis in dogs, cats, or other species, should be avoided. Thus, first, a careful, drug history should be taken. Then, the clinician should determine whether treatment is needed. For example, a patient that is treated with an anticonvulsant medication probably should be maintained on some anticonvulsant therapy, but, if being treated with potassium bromide and/or phenobarbital should be changed to another anticonvulsant medication.
Aggressive fluid therapy is the mainstay of supportive therapy. Fluid, electrolyte, and acid-base imbalances need to be assessed, and corrected as early as possible. This is especially important since systemic complications are associated with a worse outcome and many of the systemic complications, once established, are difficult to treat.Supportive care
The traditional recommendation for any patient with pancreatitis is to give nothing per os for three to four days. This recommendation may be justified in patients that vomit relentlessly. However, there is little evidence to justify this strategy in patients that do not. The issue is complicated further in cats by the fact that cats with pancreatitis often develop hepatic lipidosis. Preferred routes of alimentation are a jejunostomy tube or total parenteral nutrition. However, these strategies are impractical in many cases and a gastrostomy tube or a nasogastric tube are acceptable alternatives if a patient does not vomit. There is good evidence in human patients with pancreatitis that alimentation is crucial to counterbalance the catabolic effects of pancreatitis and a nasogastric tube has been shown to be quite effective in humans with pancreatitis. However, regardless of the mode of alimentation, a diet low in fat should be chosen. It is currently believed that this recommendation is far more important in dogs than in cats. In dogs or cats that do vomit relentlessly, the patient should be held NPO for 3-4 days. In cats alternative routes to oral alimentation must be pursued if the cat has been anorectic before presentation or if there is evidence to support concurrent hepatic lipidosis. After holding a patient NPO water is slowly reintroduced, followed by small amounts of a carbohydrate-rich and low-fat diet.
Abdominal pain is the key clinical sign in human patients with pancreatitis and is recognized in excess of 90% of all pancreatitis patients. Abdominal pain is much more commonly recognized in dogs than in cats with pancreatitis, but even in dogs the reported rate of abdominal pain is only approximately 58%. It is unlikely that abdominal pain occurs less frequently in dogs than in cats and it is much more likely that abdominal pain remains unidentified in veterinary species. Thus, the presence of abdominal pain should be assumed and analgesic drugs are indicated in all small animal patients with pancreatitis. Meperidine, butorphanol tartrate, morphine, fentanyl, or combinations of multiple analgesic drugs can be used in hospitalized patients. Outpatients can be treated with oral butorphanol, tramadol, or a fentanyl patch.
Until recently the choices for antiemetic agents for use in dogs and cats with pancreatitis was limited. Metoclopramide, a dopamine inhibitor, was most widely used. However, it's effect on splanchnic perfusion remains in question and the author does not like to use metoclopramide in dogs or cats with pancreatitis. Fortunately, several other antiemetic agents have become available over the last few years. Dolasetron is a 5HT3 antagonist and is a very effective antiemetic agent in both dogs and cats. The injectable formulation of dolasetron can be used for intravenous, subcutaneous, and oral administration and is being used at 0.3-0.6 mg/kg q 12-24 hr in both dogs and cats. Recently, a new drug, maropitant, an NK1 antagonist has become available in both Europe and the US. Initial experiences in dogs are good, but there is little experience in cats and the drug is currently not licensed for use in cats.