Hypernatremia and the Kalemias

My new band name for real

loss of water, hypertonic IV solution, rarely excessive oral intake

Hypernatremia (Na+ over 145) is usually due to the

Hypothalamus (leads to ADH release)

What organ senses osmolarity to trigger the thirst reflex?

Oliguric (no pee) vs non-oliguric (pee)

Since all hypernatremic conditions are hypertonic (295+ mOsm/kg) what do we need to determine?

cell death by shrinkage

Acute symptoms of hypernatremia are due to

orthostatic hypotension, lethargy, irritability, weakness, hyperthermia, delirium, seizures, coma, oliguria, osmotic cerebral myelination (RARE)

Symptoms of severe hypernatremia (Na 160+)

reduced water (lack of access, burns), nonrenal losses, water shifts into cells (rare)

Causes of oliguric hypernatremia (300+ mOsm/kg (osmolality))

central and nephrogenic DI (give ADH to determine which one)

Causes of non-oliguric hypernatremia (under 250 mOsm/kg (osmolality))

osmotic diuresis (mannitol, urea)

Causes of non-oliguric hypernatremia (300+ mOsm/kg (osmolality))

if mild Hypotonic fluids (orally or D5W); NS 0.9% followed by D5W (severe)

Treatment plan for hypovolemic hypernatremia

SLAM D5W until Na gets to 145, after that go slower; DDVAP (central DI), Dialysis (extreme cases)

Treatment plan for acute hypovolemic hypernatremia (rare)

D5W based on weight and Na level (goal is 140)

Treatment plan for chronic hypovolemic hypernatremia

12 mEq/L in 24 hours

What is the limit for correcting hypernatremia

INSIDE THE CELL

Where does potassium live?

Sodium/potassium pump (intracellular), dietary intake (extracellular)

How is K+ balanced?

metabolic alkalosis, hyperglycemia/insulin, beta-2 adrenergic agonist, hypothermia

Internal losses of K is due to

Diarrhea (most common), medications (thiazides, loop), adrenal tumors (hella aldosterone), sweat, low Mg (refractory), inadequate intake

External causes of hypokalemia

3.0-3.5 (mild), 2.5-3.0 (moderate), <2.5 (severe)

What are the levels for hypokalemia?

polyuria/polydipsia (short term), tubulointerstitial nephritis (long term), arrhythmias, cardiac arrest, smooth muscle contraction (constipation), skeletal muscle cramps, flaccid paralysis, respiratory depression, fatigue, hallucinations, delirium, psychosis

Signs and Symptoms of hypokalemia

BMP, ABG, Renin, aldosterone, cortisol, TSH, 24 hour urine, spot K/Cr ratio, EKG, imaging (look for adrenal adenoma, pituitary tumor, RAAS)

Work up for hypokalemia

under 25 (not the kidneys), over 40 (kidneys NOT working)

24 hr urine findings for hypokalemia

T wave flattening → ST depression and inverted Ts, prolonged QT → U waves

EKG findings for HYPOkalemia

Treat the underlying (like the metabolic acidosis), Oral K 20-40 mEq/day (mild-moderate), IV K (if under 3 or serious symptoms), Cardiac monitoring, K sparing diuretic PRN, Mg (if refractory)

Treatment plan for hypokalemia

K under 2.5, severe symptoms

When should hypokalemia peeps be referred or admitted

Pseudo (MOST COMMON - tourniquet on too long when drawing blood, small bore needles, clenched fist), tissue breakdown (rhabdo, tumor lysis syndrome, hemolysis), Hyperglycemia, Metabolic acidosis, AKI, CKD, hyporeniemic/hypoaldosteronism, excessive intake with renal disease, ACEi/ARB, beta blockers, K sparing, aldosterone antagonists, NSAIDs

Causes of HYPERkalemia

Asymptomatic (if mild), arrhythmias, palpitations, SOB, hyperventilation, flaccid paralysis, worsens any metabolic acidosis

Signs and symptoms of HYPERkalemia

CBC, CMP, ABG, aldosterone, renin, cortisol, EKG (Occurs at 5.5, deadly at 7.0 normal EKG does not mean normal K)

Diagnostics for HYPERkalemia

Peak Ts → prolonged PR interval and QRS → loss of P waves → sine waves → V.fib/asystole

EKG findings in HYPERkalemia

IV Calcium gluconate, K+ shift (insulin/glucose or beta agonist), loop diurectics, hemodialysis (AKI, CKD, life-threatening, refractory), Sodium polystyrene (kayexalate - only if life threatening and dialysis is not available; RISK OF NECROSIS)

Emergent treatment of HYPERkalemia (6.5+ or EKG changes)

Repeat blood work and ECG, fix underlying issues, remove the source, stop any offending meds, Loop/thiazides, Potassium binders (patiromer, sodium zirconium Cyclosilicate), Dialysis, Sodium polystyrene, SGLT-2 for chronic prevention

Non-emergent/excretory treatment of HYPERkalemia

kidney disease/transplant, Severe or life threatening hyperkalemia

When should HYPERkalemia homies be referred/admitted?