Renal: Electrolytes & Fluids

1500 mL + 20/kg > 20

• Acute weight loss
• Tachycardia
• Orthostasis
• Dry membranes
• Dec. skin turgor
• BUN:SCR >20:1

Acute Weight Gain

Edema

Fluids 1st -> Na

Normal 135-145

• Mild 125-130
• Moderate 115-125
• Severe 110-115

Usu. asymptomatic

Nausea, malaise, HA, lethargy, restlessness, disorientation, seizures, coma, depressed reflexes

• External losses (GI, Skin, Lungs)
• Renal losses
• Diuretics
• Adrenal insufficiency

• Asymptomatic / Na > 120 -> NS
• Symptomatic / Na < 120 -> 3% NaCl

Goal: Na inc. <12mEq/L in 24h

Avoids risk of pontine demyelination (paralysis)

• CHF
• Cirrhosis
• Nephrosis

Treat underlying cause

Fluid ; Na restriction (<1L/d ; 1-2g/day)

• Hypothyroidism
• Hypocortisolism
• Renal failure
• SIADH
• 1^o polydipsia
• Low solute intake

Remove underlying cause

<1L/day fluids

Conivaptan 20 mg IV bolus then 20 mg IV cont. infusion QD x 4d

OR

Tolvaptan 15 mg PO x 1d -> 30 mg QD

OR

Demeclocycline 300 mg PO TID

• Lethargy
• Weakness
• Confusion
• Restlessness
• Irritability

• Renal
• Adrenal
• GI
• Lungs
• Skin

0.45% NaCl or D5W

NS if hypotensive (<90)

Goal Na dec <12/24h

(Avoids cerebral edema)

• Na Overload
• Mineralocorticoid excess

• Loops (Furosemide 20-40 mg q6-12h)
• dec. Na <12/24h

• Diabetes insipidus
• Skin loss
• Iatrogenic
• Osmotic diuresis
• Primary polydipsia

Desmopressin 10 mcg QD intranasal

• remove/treat cause
• <2g Na QD
• Thiazides (HCTZ 25-50 mg PO QD)