Igor Yankin - VETEMCRIT

Approach to Hypernatremia in Dogs and Cats

Hypernatremia is defined as a serum sodium level above the reference range. It is a relatively infrequently encountered electrolyte disturbance in dogs and cats. In one retrospective study (Ueda et al. 2015), 5.7% dogs and 8.0% cats were diagnosed with hypernatremia. It was associated with increased case fatality rates in this population of patients. Understanding hypernatremia requires a comprehension of body fluid compartments, as well as concepts of the preservation of normal body water balance. The animal body maintains a normal osmolality between 280 and 310 mOsm/kg via Arginine Vasopressin (AVP), thirst, and the renal response to AVP; dysfunction of all three of these factors can cause hypernatremia (Mushin et al. 2016). In this post, I present a step-by-step approach to the hypernatremia in canine and feline patients. Further reading is recommended to deepen understanding of the physiology and pathophysiology of sodium and water balance.

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Approach to Hypokalemia: Diagnosis and Treatment

All causes of hypokalemia can be divided into 3 big groups:

Decreased intake (unlikely to be a sole cause)
Intracellular shift
External loss (GI or renal)

A step-by-step approach to diagnosis of hypokalemia

Step 1: Review current medication history. Drugs that can promote hypokalemia (via intracellular shifting or increased losses/decreased intake):

K-deficient fluids
loop/thiazide diuretics
insulin, dextrose
albuterol, terbutaline and other beta agonists
catecholamines

Approach to Hyperkalemia: Diagnosis and Treatment

This blog post commences a series of articles on diagnostic and therapeutic approaches to potassium and sodium derangements. This is meant to be a quick reference/guideline for emergency veterinarians, students and technicians. All readers are welcome to leave feedback and comments below.

Dysnatremias: The role of urine sodium and osmolality

All living organisms originated in the sea. A constant salt concentration was important to maintain their vital functions. To overcome their dependency on the sea environment, a sophisticated renal system has developed in modern mammals that allows them to maintain a steady concentration of various electrolytes and water balance.

Understanding sodium and water balance is important for clinicians who treat animals with renal disorders, sodium derangements and other critical conditions. Not surprisingly, this topic may appear complex and daunting to the majority of veterinary practitioners.

Why I don’t use artificial colloids…

Currently, veterinary emergency and critical care practitioners (diplomates, residents and emergency veterinarians) are divided into two camps: those that don’t use artificial colloids and those that do. Each camp has its own arguments in favor or against the use of synthetic colloids (hydroxyethyl starches, specifically). The objective of this blog post is NOT to convince the other party that he or she is wrong and I am right, but an attempt to find out what is true and what to do about it. The reader should understand that there will be a lot of personal opinions in this post, and, as always, I recommend to exercise your critical thinking before taking these statements for granted. Ray Dalio, one of the most successful investors of all times, called this process “thoughtful disagreement”, which is “the process of having a quality back-and-forth in an open minded and assertive way so as to see things through each other’s eyes. This is powerful because it helps both parties see things they’ve been blind to. It also helps to remind people that those who change their minds are the biggest winners because they learned something, whereas those who stubbornly refuse to see the truth are losers. With practice, training, and constant reinforcement, anyone can get good at this”.