Page 174 - Basic Monitoring in Canine and Feline Emergency Patients

Table 8.4. Common diseases leading to potassium abnormalities.

VetBooks.ir Hyperkalemia Hypokalemia
Renal diuresis
Renal failure
Decreased urinary excretion
Renal failure
Gastrointestinal losses (vomiting or diarrhea)
● Urethral obstruction Decreased intake (chronic)
● Ureteral obstruction Translocation into cells
● Uroabdomen ● Treatment diabetic ketoacidosis
● Poor renal perfusion/reduced GFR ● Insulin
Hypoadrenocorticism (decreased aldosterone) ● Respiratory alkalosis
Release from damaged/destroyed cells ● Hypothermia
● Rhabdomyolysis Metabolic alkalosis (shifting into cells)
● Tumor lysis syndrome Catecholamines (exogenous or endogenous)
● Hemolysis Drug therapy
Metabolic acidosis (shifting out of cells) ● Loop diuretics (e.g. furosemide)
Insulin deficiency ● Albuterol overdose
Drug therapy ● Thiazide diuretics (e.g. hydrochlorothiazide)
● Beta blockers
● ACE-inhibitors
● Potassium-sparing diuretics (e.g. spironolactone)
● Excessive potassium supplementation
ACE, acetylcholine esterase; GFR, glomerular filtration rate.

for more information on treatment of potassium approaches to treating electrolytes. As with any
disorders (see Further Reading section). clinical situation, ensure that the patient is not
hypovolemic and displaying clinical signs of shock
8.4 Interpretation of the Findings before focusing on treating measured electrolyte
abnormalities. Table 8.5 presents some very broad
The reader is referred to multiple other sources and general approaches to treating abnormalities in
in the Further Reading section regarding detailed the electrolytes discussed in this chapter.

Table 8.5. Generalized approach to treating electrolyte abnormalities. a
Electrolyte Approach when hyper- Approach when hypo-
Sodium Typically ≥160–170 mEq/L Typically when <130 mEq/L
Administer fluid therapy to replace free water As long as a patient is not hypervolemic on
deficit (and dilute the sodium) examination (e.g. liver failure, congestive heart
1. Calculate water deficit failure, oliguric or anuric renal failure), administer
Water deficit = weight (kg) × fluid therapy rich in sodium to increase [Na] c
([Na] current /[Na] normal − 1) Calculated as:
Assume [Na] normal = 140–145 mEq/L maintenance + dehydration replacement +
Some sources will multiply the above number replacement of any ongoing losses
by 0.6 to represent the proportion of the Treat the underlying cause leading to water retention
body’s weight that is water, making the (and dilution of Na).
equation:
Water deficit = Weight (kg) × 0.6 ×
([Na] current /[Na] normal − 1)
2. Select hypotonic fluid (5% dextrose in
water or 0.45% saline)
3. Fluid rate = water deficit to patient over
b
time + maintenance fluids + replacement of
any ongoing losses
Continued

166 E.J. Thomovsky