Fluid and Electrolyte Fluid and Electrolyte AbnormalitiesAbnormalities

HypovolemiaHypovolemia

Mild: 4% loss TBW or Mild: 4% loss TBW or << 15% blood volume 15% blood volumeModerate: 6% TBW or 15-30% BVModerate: 6% TBW or 15-30% BVSevere: 8% TBW or 30-40% BVSevere: 8% TBW or 30-40% BVShock: >8% TBW or > 40% BVShock: >8% TBW or > 40% BVS/Sx: S/Sx: MS changes, sleepy, apathy, coma MS changes, sleepy, apathy, coma orthostatic, tachy, decreased pulse pressure, low orthostatic, tachy, decreased pulse pressure, low

CVP, low PCWPCVP, low PCWP Poor turgor, hypothermia, dry membranesPoor turgor, hypothermia, dry membranes OliguriaOliguria, ileus, weakness, ileus, weakness

Hypovolemia, continuedHypovolemia, continued

Lab: Lab: BUN:Cr ratio greater than 20BUN:Cr ratio greater than 20 Inc. hematocrit, 3% per liter deficitInc. hematocrit, 3% per liter deficit FFeeNa < 1%, increased urine spec. gravity and Na < 1%, increased urine spec. gravity and

osmolalityosmolality

Hypovolemia, continuedHypovolemia, continued

Treatment:Treatment: Acute: 2L LR via large bore IV then bloodAcute: 2L LR via large bore IV then blood Subacute:Subacute:

Isotonic or hypotonic deficits give isotonic NS or Isotonic or hypotonic deficits give isotonic NS or hypotonic 1/2NS or LR (e.g. vomiting = NS, hypotonic 1/2NS or LR (e.g. vomiting = NS, diarrhea = LR)diarrhea = LR)

Hypertonic deficits (e.g. dehydration with jejunal Hypertonic deficits (e.g. dehydration with jejunal feedings) give D5W. Seen in fever, ventilator, or feedings) give D5W. Seen in fever, ventilator, or diaphoresisdiaphoresis

HypervolemiaHypervolemia

Etiology: Cardiac failure, Renal failure, Etiology: Cardiac failure, Renal failure, mobilization of fluid, iatrogenic, mobilization of fluid, iatrogenic, psychologic or Ecstasypsychologic or EcstasyS/Sx:S/Sx: Wt gain over baseline. (Fasting losses are Wt gain over baseline. (Fasting losses are

0.25-0.5 kg/day)0.25-0.5 kg/day) JVD, rales or wheezing, pedal/sacral edemaJVD, rales or wheezing, pedal/sacral edema elevated CVP or PCWPelevated CVP or PCWP Pulmonary edema on CXRPulmonary edema on CXR

Hypervolemia, continuedHypervolemia, continued

Lab:Lab: Decreased Hct and albuminDecreased Hct and albumin Na may be low, normal or increased but total Na may be low, normal or increased but total

body Na is usually increasedbody Na is usually increased

Treatment:Treatment: Water restrict to 1500 cc/dayWater restrict to 1500 cc/day +/- Diuretics+/- Diuretics Sodium restrict to 0.5 gm/daySodium restrict to 0.5 gm/day (Albumin followed by diuretics)(Albumin followed by diuretics)

HyponatremiaHyponatremia

FormsForms HypotonicHypotonic

Hypovolemic with loss of isotonic fluid and hypotonic Hypovolemic with loss of isotonic fluid and hypotonic replacementreplacementHypervolemic due to retention statesHypervolemic due to retention statesIsovolemic due to free water overload, SIADH, renal dx, Isovolemic due to free water overload, SIADH, renal dx, hypokalemia (ADH sensitization)hypokalemia (ADH sensitization)

Isotonic or “pseudohyponatremia”Isotonic or “pseudohyponatremia”Occurs with hypertriglyceridemia or hyperproteinemiaOccurs with hypertriglyceridemia or hyperproteinemia

HypertonicHypertonicNon sodium osmotics induce redistribution (glucose, Non sodium osmotics induce redistribution (glucose, mannitol) for each 100mg/dl of glucose over 100 Na is mannitol) for each 100mg/dl of glucose over 100 Na is decreased by 3 mEq/Ldecreased by 3 mEq/L

Hyponatremia, continuedHyponatremia, continued

S/Sx: S/Sx: Neurologic: muscle twitching, hyperreflexia, seizures Neurologic: muscle twitching, hyperreflexia, seizures

and HTNand HTN Salivation, lacrimation, diarrheaSalivation, lacrimation, diarrhea Often asymptomatic if slow until below 120 mEq/L. Often asymptomatic if slow until below 120 mEq/L.

(130 mEq/L if acute) (130 mEq/L if acute)

Treatment: correct underlying disorderTreatment: correct underlying disorder Fluid restrict, Fluid restrict, ++ diuretics diuretics Hypertonic saline to increase level 2-3 mEq/L/hr and Hypertonic saline to increase level 2-3 mEq/L/hr and

max rate 100cc of 5% saline/hrmax rate 100cc of 5% saline/hr

HypernatremiaHypernatremia

Free water deficit or water loss greater Free water deficit or water loss greater than salt loss. Always assoc with hyper than salt loss. Always assoc with hyper osmolar state.osmolar state.Forms:Forms: Hypervolemic: loss of hypotonic fluids with Hypervolemic: loss of hypotonic fluids with

inadequate replacement with hypertonic fluidsinadequate replacement with hypertonic fluids Isovolemic is subclinical hypovolemia seen in Isovolemic is subclinical hypovolemia seen in

diabetes insipidusdiabetes insipidus Hypervolemic usually iatrogenic, also Hypervolemic usually iatrogenic, also

Cushing’s, Conn’s, CAHCushing’s, Conn’s, CAH

Hypernatremia, continuedHypernatremia, continued

S/Sx:S/Sx: Neurologic: restless, seizure, coma, delirium and Neurologic: restless, seizure, coma, delirium and

maniamania Sticky mucus membranes, poor Sticky mucus membranes, poor

salivation/lacrimation, hyperpyrexia, Red swollen salivation/lacrimation, hyperpyrexia, Red swollen tonguetongue

THIRST, weaknessTHIRST, weaknessTreatment: correct underlying disorderTreatment: correct underlying disorder Free water replacement: (0.6 * kg BW) * ((Na/140) Free water replacement: (0.6 * kg BW) * ((Na/140)

– 1). Slow infusion of D5W give ½ over first 8 hrs – 1). Slow infusion of D5W give ½ over first 8 hrs then rest over next 16-24 hrs to avoid cerebral then rest over next 16-24 hrs to avoid cerebral edema. edema.

HypokalemiaHypokalemia

Etiology:Etiology: Intracellular uptake with redistribution seen in acute Intracellular uptake with redistribution seen in acute

alkalosis, inmsulin therapy, and anabolismalkalosis, inmsulin therapy, and anabolism Depletion due to GI losses, renal/diuretics, steroids, Depletion due to GI losses, renal/diuretics, steroids,

and renal tubular acidosisand renal tubular acidosis

S/Sx:S/Sx: Clinical: muscle weakness/fatigue, decreased DTR’s, Clinical: muscle weakness/fatigue, decreased DTR’s,

ileus. Insulin resistance in DMileus. Insulin resistance in DM EKG: low, flat T-waves, ST depression, and U wavesEKG: low, flat T-waves, ST depression, and U waves

Hypokalemia, continuedHypokalemia, continued

ECG changes in hypokalemiaECG changes in hypokalemia

Hypokalemia, continuedHypokalemia, continued

Treatment:Treatment: Check renal functionCheck renal function Treat alkalosis, decrease sodium intakeTreat alkalosis, decrease sodium intake PO with 20-40 mEq dosesPO with 20-40 mEq doses IV: peripheral 7.5 mEq/hr, central 20 mEq/hr IV: peripheral 7.5 mEq/hr, central 20 mEq/hr

and increase Kand increase K++ in maintenance fluids. in maintenance fluids.

HyperkalemiaHyperkalemia

Etiology:Etiology: Psuedohyperkalemia in leukocytosis, Psuedohyperkalemia in leukocytosis,

hemolysis and thrombocytosishemolysis and thrombocytosis Redistribution in acidosis, hypoinsulinism, Redistribution in acidosis, hypoinsulinism,

tissue necrosis, digoxin poisoningtissue necrosis, digoxin poisoning Renal insufficiency, mineralocorticoid Renal insufficiency, mineralocorticoid

deficiency, DM, spironolactone usedeficiency, DM, spironolactone use

Hyperkalemia, continuedHyperkalemia, continued

S/Sx: S/Sx: Clinical: nausea/vomiting, colic, weakness Clinical: nausea/vomiting, colic, weakness

diarrheadiarrhea EKG: early – peaked T waves then flat P EKG: early – peaked T waves then flat P

waves, depressed ST segment, widened QRS waves, depressed ST segment, widened QRS progressing to sine wave and V fib.progressing to sine wave and V fib.

Cardiac arrest occurs in diastoleCardiac arrest occurs in diastole

Hyperkalemia – ECG ChangesHyperkalemia – ECG Changes

Hyperkalemia, continuedHyperkalemia, continued

Treatment:Treatment: Remove iatrogenic causesRemove iatrogenic causes Acute: if > 7.5 mEq/L or EKG changesAcute: if > 7.5 mEq/L or EKG changes

Ca-gluconate – 1 gm over 2 min IVCa-gluconate – 1 gm over 2 min IV

Sodium bicarbonate – 1 amp, may repeat in 15minSodium bicarbonate – 1 amp, may repeat in 15min

D50W (1 ampule = 50 gm) and 10U regular insulinD50W (1 ampule = 50 gm) and 10U regular insulin

Emergent dialysisEmergent dialysis Hydration and diuresis, kayexalate 20-50 g, in Hydration and diuresis, kayexalate 20-50 g, in

100-200cc of 20% sorbitol q 4hrs or enema100-200cc of 20% sorbitol q 4hrs or enema

CalciumCalcium

Hypocalcemia:Hypocalcemia: Seen in hypoalbuminemia. Check ionized CaSeen in hypoalbuminemia. Check ionized Ca Often symptomatic below 8 mEq/dLOften symptomatic below 8 mEq/dL Check PTH: Check PTH:

low may be Mg deficiencylow may be Mg deficiencyHigh think pancreatitis, hyperPO4, low Vitamin D, High think pancreatitis, hyperPO4, low Vitamin D, pseudohypoparathyroidism, massive blood transfusion, pseudohypoparathyroidism, massive blood transfusion, drugs (e.g. gentamicin) renal insufficiencydrugs (e.g. gentamicin) renal insufficiency

S/Sx: numbness, tingling, circumoral paresthesia, S/Sx: numbness, tingling, circumoral paresthesia, cramps tetany, increased DTR’s, Chvostek’s sign, cramps tetany, increased DTR’s, Chvostek’s sign, Trousseau’s signTrousseau’s sign

EKG has prolonged QT intervalEKG has prolonged QT interval

ECG Changes in Calcium AbnormalitiesECG Changes in Calcium Abnormalities

Calcium, continuedCalcium, continued

Hypocalcemia cont.Hypocalcemia cont. Treatment:Treatment:

Acute: (IV) CaCl 10 cc of 10% solution = 6.5 Acute: (IV) CaCl 10 cc of 10% solution = 6.5 mmole Ca or CaGluconate 10cc of 10% solution = mmole Ca or CaGluconate 10cc of 10% solution = 2.2 mmole Ca2.2 mmole Ca

Chronic: (PO) 0.5-1.25 gm CaCOChronic: (PO) 0.5-1.25 gm CaCO33 = 200-500 mg = 200-500 mg

Ca. Ca. Phosphate binding antacids improve GI absorption of CaPhosphate binding antacids improve GI absorption of Ca

Vit D (calciferol) must have normal serum PO4. Vit D (calciferol) must have normal serum PO4. Start 50,000 – 200,000 units/dayStart 50,000 – 200,000 units/day

Calcium, continuedCalcium, continued

HypercalcemiaHypercalcemia Usually secondary to hyperparathyroidism or Usually secondary to hyperparathyroidism or

malignancy. Other causes are thiazides, milk-alkali malignancy. Other causes are thiazides, milk-alkali syndrome, granulomatous disease, acute adrenal syndrome, granulomatous disease, acute adrenal insufficiencyinsufficiency

Acute crisis is serum Ca> 12mg/dL. Critical at 16-Acute crisis is serum Ca> 12mg/dL. Critical at 16-20mg/dL20mg/dL

S/Sx: N/V, anorexia, abdominal pain, confusion, S/Sx: N/V, anorexia, abdominal pain, confusion, lethargy MS changes= “Bones, stone, abdominal lethargy MS changes= “Bones, stone, abdominal groans and psychic overtones.”groans and psychic overtones.”

Calcium, continuedCalcium, continued

Treatment: Hydration with NS then loop Treatment: Hydration with NS then loop diuretic. Steroids for lymphoma, multiple diuretic. Steroids for lymphoma, multiple myeloma, adrenal insufficiency, bone mets, myeloma, adrenal insufficiency, bone mets, Vit D intoxication. May need Hemodialysis.Vit D intoxication. May need Hemodialysis.

Mithramycin for malignancy induced hyperCa Mithramycin for malignancy induced hyperCa refractory to other treatment. Give 15-25 mcg/kg refractory to other treatment. Give 15-25 mcg/kg IVPIVP

Calcitonin in malignant PTH syndromesCalcitonin in malignant PTH syndromes

MagnesiumMagnesium

HypomagnesemiaHypomagnesemia Malnutrition, burns, pancreatitis, SIADH, Malnutrition, burns, pancreatitis, SIADH,

parathyroidectomy, primary parathyroidectomy, primary hyperaldosteronismhyperaldosteronism

S/Sx: weakness, fatigue, MS changes, S/Sx: weakness, fatigue, MS changes, hyperreflexia, seizure, arrhythmiahyperreflexia, seizure, arrhythmia

Treatment: IV replacement of 2-4 gm of Treatment: IV replacement of 2-4 gm of MgSO4 per day or oral replacement MgSO4 per day or oral replacement

Magnesium, continuedMagnesium, continued

HypermagnesemiaHypermagnesemia Renal insufficiency, antacid abuse, adrenal Renal insufficiency, antacid abuse, adrenal

insufficiency, hypothyroidism, iatrogenicinsufficiency, hypothyroidism, iatrogenic S/Sx: N/V, weakness, MS changes, S/Sx: N/V, weakness, MS changes,

hyporeflexia, paralysis of voluntary muscles, hyporeflexia, paralysis of voluntary muscles, EKG has AV block and prolonged QT interval.EKG has AV block and prolonged QT interval.

Treatment: Discontinue source, IV Treatment: Discontinue source, IV CaGluconate for acute Rx, DialysisCaGluconate for acute Rx, Dialysis

PhosphatePhosphate

HypophosphatemiaHypophosphatemia Seen in hyperalimentation, after starvation, Seen in hyperalimentation, after starvation,

DKA, malabsorption, phosphate binding DKA, malabsorption, phosphate binding antacids, alkalosis, hemodialysis, antacids, alkalosis, hemodialysis, hyperparathyroidismhyperparathyroidism

S/Sx: myocardial depression due to low ATP, S/Sx: myocardial depression due to low ATP, shift of oxyhemoglobin curve to left due to low shift of oxyhemoglobin curve to left due to low 2,3 DPG, anorexia, bone pain, hemolysis, 2,3 DPG, anorexia, bone pain, hemolysis, cardiac arrestcardiac arrest

PhosphatePhosphate

Treatment: PO replacement (Neutraphos) or Treatment: PO replacement (Neutraphos) or IV KPhos or NaPhos 0.08-0.20 mM/kg over 6 IV KPhos or NaPhos 0.08-0.20 mM/kg over 6 hrshrs

HyperphosphatemiaHyperphosphatemia Renal insufficiency, hypoparathyroidism, may Renal insufficiency, hypoparathyroidism, may

produce metastatic calcificationproduce metastatic calcification Treat with restriction and phosphate-binding Treat with restriction and phosphate-binding

antacid (Amphogel)antacid (Amphogel)

ZincZinc

1-2 gm in body (brain, pancreas, liver, kidney, 1-2 gm in body (brain, pancreas, liver, kidney, prostate and testis)prostate and testis)Enzyme activator and cofactorEnzyme activator and cofactorDeficiency in malabsorption, trauma, IBD, Deficiency in malabsorption, trauma, IBD, refeeding syndrome, cancer or diarrhea refeeding syndrome, cancer or diarrhea Absorbed in terminal ileumAbsorbed in terminal ileumS/Sx: “4 D’s” – diarrhea, depression, dermatitis, S/Sx: “4 D’s” – diarrhea, depression, dermatitis, dementiadementia Also alopecia, nyctalopia, tremor, loss of tasteAlso alopecia, nyctalopia, tremor, loss of taste

Treat with zinc sulfate 3-6mg/day if with (normal Treat with zinc sulfate 3-6mg/day if with (normal number of stools)number of stools)