Not-so-ordinary ER cases you should know

Walter Brown, BS, RVTg, VTS (ECC) (right) meets Adam Christman, DVM, MBA, dvm360^® chief veterinary officer (left) in an embrace before delivering his keynote address.

On the final day of the Fetch dvm360^® Conference in Charlotte, North Carolina, veterinary technician Walter Brown, BS, RVTg, VTS (ECC), took the stage for a lively keynote address on bizarre cases in the emergency room (ER), because according to him, “you never know what you’re going to get.” He shared real-life anecdotes and paired his expert knowledge with humor for an interactive lecture on triaging, stabilizing, and treating these ER patients.

Here are 2 of the case studies he presented:

Case #1: Hypernatremia

In this clinical case, local college fraternity brothers who were at a pool party with their German shorthaired pointer, arrived at the ER. The dog drank a significant amount of saltwater and ingested beef jerky, and Brown discovered it was experiencing saltwater intoxication, or hypernatremia. This consists of increased values outside the sodium reference range which is 140-150 mEq/L for canines and 146-157 mEq/L for felines. With hypernatremia, “Either you have an excess in salt, meaning you ate a lot of things that are salty, or you can have what we call free water loss,” explained Brown. The clinical signs include seizures, comas, and potential permanent neurological damage.

Brown said that fluid needs must be taken into consideration when treating hypernatremia patients experiencing shock and/or dehydration. Those with chronic hypernatremia (> 48 hours) must be treated slowly to reduce rapid cell volume expansion which can cause swelling. “Depending on how long this hypernatremia has been going on, you don’t want to lower the sodium too fast. When you lower the sodium too fast, you have these neurological damages.” Sodium levels should be corrected slowly at a rate of 0.5 to 1 mEq/L/hr.

The formula to calculate free water deficits = ([current [Na]p ÷ target [Na]p] – 1) x (0.6 x body weight in kg). "This is the amount of water you want to replace to the patient. And this allows you to lower that sodium level to where it needs to be,” said Brown. He added that water may be supplemented intravenously (as D5W) or orally on an hourly basis for alert patients. Free water replacement by itself will not correct dehydration or hypovolemia as free water replacement does not have the sodium required for this. Most patients are supplemented with 0.9% NaCl intravenous fluids.

Case #2: Anticoagulant Rodenticide Toxicity

Three southern ladies came to the ER that suspected their 3 Rat Terriers ingested rat poison. The dogs were involved in a barn hunt game and succeeded at getting into the poisoning, rather than finding the rats, suffering from anticoagulant rodenticide toxicity. This can result in secondary coagulopathies by depleting coagulation factors II, VII, IX and X (Vitamin-K dependent factors). The clinical signs include lung and body cavity bleeding (though bleeding in other areas can be seen), and there also may be areas of petechia and ecchymosis. Brown shared, “A lot of times owners don’t know until 2 or 3 days after when they start seeing these clinical signs.”

To treat anticoagulant rodenticide toxicity, if the ingestion is known with 4 hours and no contraindications, emesis can be induced. “I often don't suggest owners to do hydrogen peroxide, unless they are safe to do it, and I've seen a lot of owners do hydrogen peroxide and [it] causes [the dog] to aspirate and then we have more problems.” At the clinic, these treatments can be used for emesis at the following levels: apomorphine: 0.03mg/kg IV or 0.04mg/kg IM (dogs); 3% hydrogen peroxide: 1 to 2 ml/kg PO (dogs); xylazine: 0.44mg/kg IM or SC (cats).

Additionally, activated charcoal (1-4g/kg PO) should be administered to absorb remaining rodenticide. It is most effective within an hour of ingestion. It can be paired with can foods so patients are inclined to consume it. Sodium sulfate (250mg/kg in dog and cats) or 70% sorbitol solution (1-2ml/kg) can be administered via cathartic.

Forty-eight hours after ingestion, a Prothrombin Time (PT) should be accessed for all patients if no vitamin K has been received. “The PT measures the extrinsic coagulation pathway and includes factor VII which has the shortest half-life, this means the PT will be prolonged before the activated partial thromboplastin time (aPTT) and before the development of clinical signs,” said Brown.

After 48 hours, if the PT is prolonged with no clinical signs of bleeding, the patient should be started on oral vitamin K for a 4-week period and monitored for signs of secondary bleeding. A PT should be rechecked 48 hours following the last dose of vitamin K. If the PT is still prolonged, vitamin K should be supplemented for another 2 weeks with a follow up PT, according to Brown.

Reference

Brown W. Oh hell to the no! Bizarre cases in the ER! Presented at Fetch dvm360^® conference; Charlotte, North Carolina. March 24-26, 2023.