electrolytes disorders

ELECTROLYTE ELECTROLYTE DISORDERSDISORDERS

EMPA ResidencyUTHSCSA

+ +2+

2+

4

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Composition of body fluidsComposition of body fluids Fluid CompartmentsFluid Compartments Fluid balanceFluid balance Specific ElectrolytesSpecific Electrolytes

– SodiumSodium– PotassiumPotassium– MagnesiumMagnesium– CalciumCalcium– PhosphorusPhosphorus

Key pointsKey points QuestionsQuestions

Outline


Total fluid volume 42 litersECF 33% --- 1) Plasma 7% 2) Interstitial Fluid 26% 3) Lymph <1%ICF 67% mEqui per liter

Cations Plasma ISF Cell

Na+ 142.0 145.1 12

K+ 4.3 4.4 150

Ca2+ 5 2.4 4

Mg2+ 3 1.5 34

Total 154 153.0 200

Anions Plasma ISF Cell

Cl- 104 117.4 4

HCO3- 24 27.1 12

Phosphates 2 2.3 40

Proteins 14 0.0 54

Other 5.9 6.2 90

Total 149.9 153.0 200

Body Fluid Composition


Fluid Compartments


Serum OsmolalitySerum Osmolality– Number of osmoles (osmotically Number of osmoles (osmotically

active particles) in the serumactive particles) in the serum– Normal rangeNormal range

275 to 295 mosm/L275 to 295 mosm/L

Fluid Balance

2[Serum Na+] + ------------ + ------------Glucose BUN

18 2.8


Major extracellular cationMajor extracellular cation Normal rangeNormal range

– 135 to 150 meq/L135 to 150 meq/L

Sodium


Serum NaSerum Na++ < 135 meq/L < 135 meq/L– Primary water gain or NaPrimary water gain or Na++ loss > water loss > water– Altered distribution of body waterAltered distribution of body water– Sx’s related to rate of change > NaSx’s related to rate of change > Na++

valuevalue– Sx at NaSx at Na++ < 120 meq/L < 120 meq/L– Seizures likely at NaSeizures likely at Na++ << 113 113

Hyponatremia


Pathophysiology: CNSPathophysiology: CNS– Water shifts into brain cellsWater shifts into brain cells

– ApathyApathy –– Altered Altered ConsciousnessConsciousness

– AgitationAgitation –– Seizures Seizures– HeadacheHeadache –– Coma Coma

– Risk of brain damage > during Risk of brain damage > during treatmenttreatment

– Central Pontine Myelinolysis (CPM)Central Pontine Myelinolysis (CPM)

Hyponatremia


Pathophysiology: CardiovascularPathophysiology: Cardiovascular– Effect depends on arterial blood Effect depends on arterial blood

volumevolume– Volume depletionVolume depletion

Water shifts from ECF ICFWater shifts from ECF ICF Shock at lesser degrees of TBW depletionShock at lesser degrees of TBW depletion

– ADH Opposes effects of fluid shiftsADH Opposes effects of fluid shifts Increases water reabsorption ?????Increases water reabsorption ????? Potent vasoconstrictorPotent vasoconstrictor

Hyponatremia


Pathophysiology: Musculoskeletal Pathophysiology: Musculoskeletal SystemSystem– Muscle cramps & weakness with Muscle cramps & weakness with

exerciseexercise– Sx if sweat losses replaced with Sx if sweat losses replaced with

waterwater

Hyponatremia


Pathophysiology: Renal SystemPathophysiology: Renal System– Production of dilute urineProduction of dilute urine– Impacted by amount of ADH presentImpacted by amount of ADH present– Urine NaUrine Na++ < 10 renal handling of < 10 renal handling of

NA intactNA intact– Urine NaUrine Na++ > 20 intrinsic renal > 20 intrinsic renal

tubular damagetubular damage

Hyponatremia


DiagnosisDiagnosis

Hyponatremia

Plasma Osmolality

Normal (275-295)Isotonichyponatremia

Low (< 275)Hypotonichyponatremia

High (> 295)Hypertonichyponatremia

Hypovolemic Hypervolemic Euvolemic


HypertonicHypertonic Hyponatremia (P Hyponatremia (Posmosm > > 295)295)– Large quantities of solute in ECFLarge quantities of solute in ECF– Water moves from ICF ECFWater moves from ICF ECF– Hyperglycemia most common causeHyperglycemia most common cause

Each 100 mg/dl plasma glucose will Each 100 mg/dl plasma glucose will serum Naserum Na++ by 1.6 meq/L by 1.6 meq/L

– TreatmentTreatment Volume replacementVolume replacement

Hyponatremia


IsotonicIsotonic Hyponatremia (P Hyponatremia (Posmosm 275 - 275 - 295)295)– ““Pseudohyponatremia”Pseudohyponatremia”– Artifact in serum NaArtifact in serum Na++ measurement measurement

22° High levels of plasma proteins and ° High levels of plasma proteins and lipidslipids

– Etiology:Etiology: HyperlipidemiaHyperlipidemia HyperproteinemiaHyperproteinemia

Hyponatremia


HypotonicHypotonic Hyponatremia (P Hyponatremia (Posmosm < < 275)275)

Hyponatremia

Plasma Osmolality

Normal (275-295)Isotonichyponatremia

Low (< 275)Hypotonichyponatremia

High (> 295)Hypertonichyponatremia

Hypovolemic Hypervolemic Euvolemic


HypotonicHypotonic Hyponatremia Hyponatremia– Hypovolemic vs Hypervolemic vs Hypovolemic vs Hypervolemic vs

EuvolemicEuvolemic Plasma electrolytes and osmolalityPlasma electrolytes and osmolality Urine electrolytes and osmolalityUrine electrolytes and osmolality

Hyponatremia


HypovolemicHypovolemic Hyponatremia Hyponatremia– Loss of NaLoss of Na++ and water and water– Replacement with hypotonic fluidsReplacement with hypotonic fluids– Sodium loss “renal” vs “extrarenal”Sodium loss “renal” vs “extrarenal”

Hyponatremia


HypovolemicHypovolemic Hyponatremia Hyponatremia– Renal NaRenal Na++ loss loss

Urine NaUrine Na++ > 20 meq/L > 20 meq/L Etiology:Etiology:

– Diuretic useDiuretic use– Salt-wasting nephropathy (renal tubular acidosis, Salt-wasting nephropathy (renal tubular acidosis,

chronic renal failure, interstitial nephritis)chronic renal failure, interstitial nephritis)– Osmotic diuresis (glucose, urea, mannitol, Osmotic diuresis (glucose, urea, mannitol,

hyperproteinemiahyperproteinemia– Mineralocorticoid (aldosterone) deficiencyMineralocorticoid (aldosterone) deficiency

Hyponatremia


HypovolemicHypovolemic Hyponatremia Hyponatremia– Extrarenal NaExtrarenal Na++ loss loss

Urine NaUrine Na++ < 20 meq/L < 20 meq/L Etiology:Etiology:

– Volume replacement with hypotonic fluidsVolume replacement with hypotonic fluids– GI loss (vomiting, diarrhea, fistula, tube suction)GI loss (vomiting, diarrhea, fistula, tube suction)– Third-space loss (burns, hemorrhagic pancreatitis, Third-space loss (burns, hemorrhagic pancreatitis,

peritonitis)peritonitis)– Sweating (cystic fibrosis)Sweating (cystic fibrosis)

Hyponatremia


HypovolemicHypovolemic Hyponatremia Hyponatremia– TreatmentTreatment

Re-expansion of ECF with isotonic salineRe-expansion of ECF with isotonic saline Correction of underlying disorderCorrection of underlying disorder

Hyponatremia


EuvolemicEuvolemic Hyponatremia Hyponatremia– Normal volume status and Normal volume status and

hyponatremiahyponatremia– Sx usually 2Sx usually 2° CNS hypotonicity° CNS hypotonicity– Urine NaUrine Na++ > 20 meq/L > 20 meq/L– SIADH most notable causeSIADH most notable cause

Hyponatremia


EuvolemicEuvolemic Hyponatremia Hyponatremia– SIADHSIADH

Hypotonic hyponatremiaHypotonic hyponatremia Inappropriately elevated urine osmolality (usually > Inappropriately elevated urine osmolality (usually >

200 mosm/kg)200 mosm/kg) Elevated urine NaElevated urine Na++ (> 20 meq/L) (> 20 meq/L) Clinical euvolemiaClinical euvolemia Normal adrenal, renal, cardiac, hepatic, and thyroid Normal adrenal, renal, cardiac, hepatic, and thyroid

functionfunction Correctable with water restrictionCorrectable with water restriction

Hyponatremia


EuvolemicEuvolemic Hyponatremia Hyponatremia– Etiology:Etiology:

HypothyroidismHypothyroidism Pain, stress, nausea, psychosis (stimulates Pain, stress, nausea, psychosis (stimulates

ADH)ADH) Drugs: ADH, nicotine, sulfonylureas, Drugs: ADH, nicotine, sulfonylureas,

morphine, barbs, NSAIDS, APAP, morphine, barbs, NSAIDS, APAP, Carbamazepine, Phenothiazines, TCAs, Carbamazepine, Phenothiazines, TCAs, Colchicine, Clofibrate, Cyclophosphamide, Colchicine, Clofibrate, Cyclophosphamide, Isoproterenol, Tolbutamide, MAOIsIsoproterenol, Tolbutamide, MAOIs

Hyponatremia


EuvolemicEuvolemic Hyponatremia Hyponatremia– Etiology (Cont):Etiology (Cont):

Water intoxication (psychogenic polydipsia)Water intoxication (psychogenic polydipsia) Glucocorticoid deficiencyGlucocorticoid deficiency Positive pressure ventilationPositive pressure ventilation PorphyriaPorphyria Essential (reset osmostat or sick cell Essential (reset osmostat or sick cell

syndrome)syndrome)

Hyponatremia


EuvolemicEuvolemic Hyponatremia Hyponatremia– TreatmentTreatment

Fluid restrictionFluid restriction Work-up and management of underlying Work-up and management of underlying

disorderdisorder Hospital admission usually warrantedHospital admission usually warranted

Hyponatremia


HypervolemicHypervolemic Hyponatremia Hyponatremia– Total body water in great excessTotal body water in great excess– Sx of volume overloadSx of volume overload

Peripheral/pulmonary edemaPeripheral/pulmonary edema

– Impaired water excretionImpaired water excretion– Water retention in excess of NaWater retention in excess of Na++

retentionretention

Hyponatremia


HypervolemicHypervolemic Hyponatremia Hyponatremia– Without advanced renal insufficiencyWithout advanced renal insufficiency

Urine NaUrine Na++ < 20 meq/L < 20 meq/L Cirrhosis, ascites, CHF, Nephrotic syndromeCirrhosis, ascites, CHF, Nephrotic syndrome

– Advanced acute or chronic renal Advanced acute or chronic renal insufficiencyinsufficiency Urine NaUrine Na++ > 20 meq/L > 20 meq/L Renal failure (inability to excrete free Renal failure (inability to excrete free

water)water)

Hyponatremia


HypervolemicHypervolemic Hyponatremia Hyponatremia– TreatmentTreatment

Optimize treatment for underlying disorderOptimize treatment for underlying disorder Judicious salt and water restrictionJudicious salt and water restriction ++ Diuretics Diuretics ++ Dialysis Dialysis

Hyponatremia


Treatment of Severe HyponatremiaTreatment of Severe Hyponatremia– Indications:Indications:

Serum NaSerum Na++ < 120 meq/L < 120 meq/L Rapid development ( NaRapid development ( Na++ > 0.5 meq/L/hr) > 0.5 meq/L/hr) Patient in extremis (coma, seizures)Patient in extremis (coma, seizures)

– 3% Saline Solution (513 meq/L) @ 25 - 3% Saline Solution (513 meq/L) @ 25 - 100 ml/hr100 ml/hr NaNa++ should not exceed 0.5 – 1.0 meq/L/hr should not exceed 0.5 – 1.0 meq/L/hr

Hyponatremia


Complications of TherapyComplications of Therapy– Central Pontine Myelinolysis (CPM)Central Pontine Myelinolysis (CPM)

22° excessively rapid correction of ° excessively rapid correction of hyponatremiahyponatremia

Fluctuating level of consciousnessFluctuating level of consciousness Behavioral disturbancesBehavioral disturbances DysarthriaDysarthria DysphagiaDysphagia ConvulsionsConvulsions Pseudobulbar palsyPseudobulbar palsy QuadriparesisQuadriparesis

Hyponatremia


Serum NaSerum Na++ > 150 meq/L > 150 meq/L– DDecrease in total body waterecrease in total body water

Reduced intakeReduced intake Excessive lossExcessive loss

– Thirst is body’s defensive mechanismThirst is body’s defensive mechanism

Hypernatremia


PathophysiologyPathophysiology– 2 Primary Mechanisms2 Primary Mechanisms

Renal response to ADHRenal response to ADH– Conservation of free waterConservation of free water– Urine output with osmolality > 1000 mosm/kgUrine output with osmolality > 1000 mosm/kg

Failure of ADH responseFailure of ADH response– Inability to excrete NaInability to excrete Na++ properly properly– Urine osmolality 200-300 mosm/kgUrine osmolality 200-300 mosm/kg– Urinary NaUrinary Na++ 60-100 meq/kg 60-100 meq/kg

Hypernatremia


PathophysiologyPathophysiology– Rapid hypertonicity or short durationRapid hypertonicity or short duration

Loss of 10% of body wt 2° dehydrationLoss of 10% of body wt 2° dehydration– Skin turgor, “doughy” skinSkin turgor, “doughy” skin

CNS cellular dehydrationCNS cellular dehydration– HemorrhageHemorrhage– Tearing of cerebral blood vessels 2° brain shrinkageTearing of cerebral blood vessels 2° brain shrinkage

– Gradual hypertonicityGradual hypertonicity Idiogenic osmoles prevent brain shrinkageIdiogenic osmoles prevent brain shrinkage

Hypernatremia


EtiologyEtiology– Excessive sodium intakeExcessive sodium intake

Iatrogenic NaIatrogenic Na++ administration administration Seawater ingestionSeawater ingestion Mineralocorticoid or glucocorticoid excessMineralocorticoid or glucocorticoid excess

– Pure water lossPure water loss Inability to swallow, bedridden, comatoseInability to swallow, bedridden, comatose

Hypernatremia


Etiology (Cont):Etiology (Cont):– Loss of water in excess of NaLoss of water in excess of Na++

GastrointestinalGastrointestinal– Vomiting, diarrheaVomiting, diarrhea

RenalRenal– Central Diabetes InsipidusCentral Diabetes Insipidus– Impaired renal concentrating abilityImpaired renal concentrating ability

DrugsDrugs– Alcohol, Lithium, Phenytoin, Propoxyphene, Alcohol, Lithium, Phenytoin, Propoxyphene,

SulfonylureasSulfonylureas

Hypernatremia


Etiology (Cont):Etiology (Cont):– Loss of water in excess of NaLoss of water in excess of Na++

Skin lossSkin loss– Burns, sweatingBurns, sweating

Peritoneal dialysisPeritoneal dialysis

Hypernatremia


Clinical Features:Clinical Features:– Acute sx at NaAcute sx at Na++ > 158 meq/L > 158 meq/L

OsmolOsmol– Restless, irritabilityRestless, irritability 350-375350-375– Tremulousness, ataxiaTremulousness, ataxia 375-375-

400400– Hyperreflexia, twitching, spasticityHyperreflexia, twitching, spasticity 400-400-

430430– Seizures and deathSeizures and death > 430> 430

Hypernatremia


TreatmentTreatment– **Volume replacement****Volume replacement**

NS/LR until tissue perfusion restoredNS/LR until tissue perfusion restored 0.45% Saline until urine output 0.45% Saline until urine output >>

0.5mL/kg/hr0.5mL/kg/hr

– in Nain Na++ should not exceed 10-15 should not exceed 10-15 meq/L/daymeq/L/day Monitor serum electrolytes frequentlyMonitor serum electrolytes frequently

– Manage underlying disorderManage underlying disorder

Hypernatremia


Complications of therapyComplications of therapy– Excessively rapid correctionExcessively rapid correction

Cerebral edemaCerebral edema SeizuresSeizures Permanent neuro sequelaePermanent neuro sequelae DeathDeath

Hypernatremia


Major intracellular cationMajor intracellular cation Normal rangeNormal range

– 3.5 to 5.5 meq/L3.5 to 5.5 meq/L Serum level does not reflect total Serum level does not reflect total

body Kbody K++

Potassium


Serum KSerum K++ < 3.5 meq/L < 3.5 meq/L PathophysiologyPathophysiology

– KK++ shifts into cells as ECF pH rises shifts into cells as ECF pH rises 0.10 in pH causes 0.5 meq/l in serum K0.10 in pH causes 0.5 meq/l in serum K++

– KK++ losses usually via GI tract or kidneys losses usually via GI tract or kidneys– Aldosterone 2Aldosterone 2° volume loss° volume loss

NaNa++ & HCO & HCO33-- retention in exchange for K retention in exchange for K++

Hypokalemia


EtiologyEtiology– ECF ICF shiftsECF ICF shifts

Metabolic alkalosisMetabolic alkalosis Trtm of DKA (increased insulin)Trtm of DKA (increased insulin)

– Decreased intakeDecreased intake– GI lossGI loss

Vomiting, diarrhea, malabsorptionVomiting, diarrhea, malabsorption

Hypokalemia


Etiology (Cont)Etiology (Cont)– Renal lossRenal loss

Diuretics, AldosteronismDiuretics, Aldosteronism Osmotic diuresisOsmotic diuresis Licorice, chewing tobaccoLicorice, chewing tobacco

– Drugs/ToxinsDrugs/Toxins PCN, Amphotericin B, Lithium, Thalium, PCN, Amphotericin B, Lithium, Thalium,

DopamineDopamine

– Sweat lossSweat loss

Hypokalemia


Clinical FeaturesClinical Features– Sx onset at serum KSx onset at serum K++ << 2.5 meq/L 2.5 meq/L– CardiovascularCardiovascular

Increased HTNIncreased HTN Orthostatic hypotensionOrthostatic hypotension DysrhythmiasDysrhythmias EKG abnormalitiesEKG abnormalities

– Flat T-waves, prominent U-waves, ST-segment Flat T-waves, prominent U-waves, ST-segment depressiondepression

Hypokalemia


Clinical Features (Cont):Clinical Features (Cont):– NeuromuscularNeuromuscular

Malaise, weakness, fatigueMalaise, weakness, fatigue Hyporeflexia, cramps, paresthesiasHyporeflexia, cramps, paresthesias

– RenalRenal Increased ammonia production Increased ammonia production

encephalopathyencephalopathy Decreased GFRDecreased GFR

– GastrointestinalGastrointestinal IleusIleus

Hypokalemia


TreatmentTreatment– Replace KReplace K++

OralOral IntravenousIntravenous

– 10-20 meq/L in 100 mL NS10-20 meq/L in 100 mL NS– Not > 40 meq in a single liter IV fluidNot > 40 meq in a single liter IV fluid– Not > 40 meq in 1 hourNot > 40 meq in 1 hour– Concentrations > 20 meq/L require a central lineConcentrations > 20 meq/L require a central line

20 meq will serum K20 meq will serum K++ ≈ 0.25 meq/L ≈ 0.25 meq/L

– Cardiac monitor during replacement Cardiac monitor during replacement therapytherapy

Hypokalemia


Serum KSerum K++ > 5.5 meq/L > 5.5 meq/L– Oliguric renal failureOliguric renal failure– Severe hemolysisSevere hemolysis– Excessive tissue breakdownExcessive tissue breakdown

PseudohyperkalemiaPseudohyperkalemia– Hemolysis during blood drawHemolysis during blood draw– Cell breakdown after 30 minutesCell breakdown after 30 minutes

Hyperkalemia


EtiologyEtiology– ICF ECF shiftsICF ECF shifts

AcidosisAcidosis Beta blockadeBeta blockade Insulin deficiencyInsulin deficiency Digitalis intoxicationDigitalis intoxication

– KK++ load load Supplements, foods, KSupplements, foods, K++ containing drugs containing drugs Blood transfusionBlood transfusion RhabdomyolysisRhabdomyolysis

Hyperkalemia


Etiology (Cont)Etiology (Cont)– Decreased excretionDecreased excretion

Renal failureRenal failure DrugsDrugs

– KK++ sparing diuretics, B-Blockers, NSAIDs, ACE sparing diuretics, B-Blockers, NSAIDs, ACE InhibitorsInhibitors

Aldosterone deficiencyAldosterone deficiency

Hyperkalemia


Clinical FeaturesClinical Features– CardiovascularCardiovascular

V-Fib, complete heart block, asystoleV-Fib, complete heart block, asystole EKG abnormalitiesEKG abnormalities

– Tall, peaked T-waves, short QT, prolonged PRTall, peaked T-waves, short QT, prolonged PR– QRS widening, flattening of P-waveQRS widening, flattening of P-wave– QRS complex degrades into sine wave patternQRS complex degrades into sine wave pattern

Hyperkalemia


EKGEKG

Hyperkalemia


Clinical Features (Cont)Clinical Features (Cont)– NeuromuscularNeuromuscular

Weakness, paresthesiasWeakness, paresthesias Areflexia, ascending paralysisAreflexia, ascending paralysis

– GastrointestinalGastrointestinal N/V, intestinal colicN/V, intestinal colic DiarrheaDiarrhea

Hyperkalemia


TreatmentTreatment– Membrane stabilizationMembrane stabilization

Cardiac irritability or KCardiac irritability or K++ > 7.5 meq/L > 7.5 meq/L 10% Calcium Gluconate or Calcium Chloride10% Calcium Gluconate or Calcium Chloride

– Redistribution (Shift KRedistribution (Shift K++ to the ICF) to the ICF) Glucose/Insulin (bolus, infusion)Glucose/Insulin (bolus, infusion) NaHCONaHCO33 - 50 to 100 meq IV over 2 min - 50 to 100 meq IV over 2 min B-Agonists (Albuterol neb)B-Agonists (Albuterol neb)

Hyperkalemia


TreatmentTreatment– Remove KRemove K++ from the body from the body

DiureticsDiuretics– Lasix 40 mg IVLasix 40 mg IV

Kaexalate PO/PRKaexalate PO/PR– Each gram eliminates 1 meq KEach gram eliminates 1 meq K++

DialysisDialysis– Severely ill or already on dialysis Severely ill or already on dialysis

Hyperkalemia


Normal rangeNormal range– 8.5 to 10.5 mg/dL8.5 to 10.5 mg/dL– Ionized fraction is physiologically Ionized fraction is physiologically

activeactive

Calcium


HypocalcemiaHypocalcemia– Serum CaSerum Ca2+2+ < 8.5 mg/dL < 8.5 mg/dL– Ionized level < 2.0 meq/LIonized level < 2.0 meq/L– Common CausesCommon Causes

ShockShock SepsisSepsis Renal failureRenal failure PancreatitisPancreatitis

Hypocalcemia


EtiologyEtiology– HypoalbuminemiaHypoalbuminemia– Vitamin D deficiencyVitamin D deficiency

HypoparathyroidismHypoparathyroidism HyperphosphatemiaHyperphosphatemia MalignancyMalignancy

– DrugsDrugs Cimetidine, Phosphates, Dilantin, Phenobarbital,

Glucagon, Aminoglycosides, Cisplatin, Heparin, Theophylline, Protamine, Norepinephrine, Loop diuretics, Glucocorticoids, Magnesium Sulfate, Nitroprusside

Hypocalcemia


Clinical FeaturesClinical Features– NeurologicalNeurological

Circumoral & digital paresthesiasCircumoral & digital paresthesias TetanyTetany Chvostek signChvostek sign Trousseau signTrousseau sign Impaired memory, confusionImpaired memory, confusion Hallucinations, dementia, seizuresHallucinations, dementia, seizures

Hypocalcemia


Clinical Features (Cont)Clinical Features (Cont)– MuscularMuscular

Spasms, cramps, weaknessSpasms, cramps, weakness

– DermatologicDermatologic HyperpigmentationHyperpigmentation Coarse, brittle hairCoarse, brittle hair Dry, scaly skinDry, scaly skin

Hypocalcemia


Clinical Features (Cont)Clinical Features (Cont)– CardiovascularCardiovascular

Heart failureHeart failure VasoconstrictionVasoconstriction EKG abnormalitiesEKG abnormalities

– Prolonged QTProlonged QT

– SkeletalSkeletal OsteodystrophyOsteodystrophy RicketsRickets OsteomalaciaOsteomalacia

Hypocalcemia


Clinical Features (Cont)Clinical Features (Cont)– Skeletal (Cont)Skeletal (Cont)

X-Ray abnormalitiesX-Ray abnormalities– CraniotabesCraniotabes– Frontal skull bossingFrontal skull bossing– Rachitic rosary ribsRachitic rosary ribs– Widened rib cageWidened rib cage– Bowed legsBowed legs– Bone demineralizationBone demineralization

Hypocalcemia


TreatmentTreatment– AsymptomaticAsymptomatic

Oral replacementOral replacement

– Symptomatic or SevereSymptomatic or Severe 10% Calcium Gluconate IV, 10-30 ml10% Calcium Gluconate IV, 10-30 ml 10% Calcium Chloride IV, 10 ml10% Calcium Chloride IV, 10 ml

Hypocalcemia


Total CaTotal Ca2+2+ > 10.5 mg/dL > 10.5 mg/dL Ionized CaIonized Ca2+2+ > 2.7 meq/L > 2.7 meq/L

Hypercalcemia


EtiologyEtiology– MalignancyMalignancy– EndocrinopathiesEndocrinopathies

HyperparathyroidismHyperparathyroidism PheochromocytomaPheochromocytoma Adrenal insufficiencyAdrenal insufficiency

– DrugsDrugs Hypervitaminosis D/AHypervitaminosis D/A Thiazides, LithiumThiazides, Lithium

– ImmobilizationImmobilization

Hypercalcemia

90%


Clinical FeaturesClinical Features– GeneralGeneral

Malaise, weakness, dehydration, polydipsiaMalaise, weakness, dehydration, polydipsia

– NeurologicNeurologic Confusion, apathy, decreased memory, irritabilityConfusion, apathy, decreased memory, irritability Hallucinations, headache, ataxiaHallucinations, headache, ataxia Hyporeflexia, hypotoniaHyporeflexia, hypotonia

– CardiovascularCardiovascular HTN, dysrhythmiasHTN, dysrhythmias EKG abnormalitiesEKG abnormalities

– Short QT & ST, Wide T-waveShort QT & ST, Wide T-wave

Hypercalcemia


Clinical Features (Cont)Clinical Features (Cont)– GastrointestinalGastrointestinal

N/V, anorexia, wt lossN/V, anorexia, wt loss Constipation, abdominal painConstipation, abdominal pain PUD, PancreatitisPUD, Pancreatitis

– SkeletalSkeletal Fractures, bone pain, deformitiesFractures, bone pain, deformities

– UrologicUrologic Polyuria, polydipsiaPolyuria, polydipsia Renal insufficiencyRenal insufficiency NephrolithiasisNephrolithiasis

Hypercalcemia


Memory AidMemory Aid– StonesStones ---- ---- Renal CalculiRenal Calculi– BonesBones ---- ---- OsteolysisOsteolysis– MoansMoans ---- ---- Psychiatric disordersPsychiatric disorders– Groans ----Groans ---- Abdominal (PUD, Abdominal (PUD,

Pancreatitis)Pancreatitis)

Hypercalcemia


TreatmentTreatment– Treat dehydrationTreat dehydration

IV NS until ECF volume restoredIV NS until ECF volume restored Lasix 40 to 100 mg IV q 2-4 hrsLasix 40 to 100 mg IV q 2-4 hrs

– Decrease bone absorptionDecrease bone absorption CalcitoninCalcitonin MithramycinMithramycin HydrocortisoneHydrocortisone IndomethacinIndomethacin

– Monitor for hypokalemia, hypomagnesemiaMonitor for hypokalemia, hypomagnesemia

Hypercalcemia


Intracellular cationIntracellular cation Normal rangeNormal range

– 1.5 to 2.5 meq/L1.5 to 2.5 meq/L

Magnesium


Serum MgSerum Mg2+2+ < 1.5 meq/L < 1.5 meq/L Coexistent disordersCoexistent disorders

– HypokalemiaHypokalemia– HypocalcemiaHypocalcemia

Hypomagnesemia


EtiologyEtiology– RedistributionRedistribution

Trtm of DKATrtm of DKA

– Decreased intakeDecreased intake Alcoholism, malnutritionAlcoholism, malnutrition Bowel resection, malabsorptionBowel resection, malabsorption

– Extrarenal lossExtrarenal loss Lactation, sweatingLactation, sweating Burns, sepsisBurns, sepsis DiarrheaDiarrhea

Hypomagnesemia


Etiology (Cont)Etiology (Cont)– Renal lossRenal loss

DrugsDrugs– Loop diuretics, Aminoglycosides, Amphotericin Loop diuretics, Aminoglycosides, Amphotericin

B, Vitamin D intoxication, Alcohol, CisplatinB, Vitamin D intoxication, Alcohol, Cisplatin SIADHSIADH Hyperthyroidism, HyperparathyroidismHyperthyroidism, Hyperparathyroidism

Hypomagnesemia


Clinical FeaturesClinical Features– NeuromuscularNeuromuscular

TetanyTetany Muscle weaknessMuscle weakness Cerebellar (ataxia, nystagmus, vertigo)Cerebellar (ataxia, nystagmus, vertigo) Confusion, obtundation, comaConfusion, obtundation, coma SeizuresSeizures Apathy, depressionApathy, depression IrritabilityIrritability ParesthesiasParesthesias

Hypomagnesemia


Clinical FeaturesClinical Features– GastrointestinalGastrointestinal

Dysphagia, anorexia, nauseaDysphagia, anorexia, nausea

– CardiovascularCardiovascular Heart failureHeart failure DysrhythmiasDysrhythmias HypotenstionHypotenstion EKG abnormalitiesEKG abnormalities

– Prolonged PR & QT, wide QRSProlonged PR & QT, wide QRS– Depressed ST segment, inverted T-wavesDepressed ST segment, inverted T-waves

Hypomagnesemia


TreatmentTreatment– OralOral– IV replacementIV replacement

Severe proven hypomagnesemiaSevere proven hypomagnesemia Alcoholics with DTsAlcoholics with DTs Up to 8-12 g MgSOUp to 8-12 g MgSO44 day 1, then 4-6 g/day day 1, then 4-6 g/day

– Monitor for hypokalemia, Monitor for hypokalemia, hypocalcemia, & hypophosphatemiahypocalcemia, & hypophosphatemia

Hypomagnesemia


Serum MgSerum Mg2+2+ > 2.5 meq/L > 2.5 meq/L Coexistent disordersCoexistent disorders

– HyperkalemiaHyperkalemia– HypercalcemiaHypercalcemia

Hypermagnesemia


EtiologyEtiology– Renal failure (most common)Renal failure (most common)– Increased MgIncreased Mg2+2+ load load

Laxatives, antacids, enemasLaxatives, antacids, enemas Untreated DKAUntreated DKA RhabdomyolysisRhabdomyolysis

– Increased renal absorptionIncreased renal absorption HyperparathyroidismHyperparathyroidism HypothyroidismHypothyroidism Mineralocorticoid/adrenal insufficiencyMineralocorticoid/adrenal insufficiency

Hypermagnesemia


Clinical FeaturesClinical Features– NauseaNausea > 2.0 meq/L > 2.0 meq/L– SomnolenceSomnolence > 3.0 meq/L > 3.0 meq/L– Decreased/absent DTRsDecreased/absent DTRs > 4.0 meq/L > 4.0 meq/L– Resp compromise, apneaResp compromise, apnea > 8.0 meq/L > 8.0 meq/L– Hypotension, heart block Hypotension, heart block ≈ 15.0 meq/L≈ 15.0 meq/L

– EKG abnormalitiesEKG abnormalities >> 5.0 meq/L 5.0 meq/L Prolonged PR & QTProlonged PR & QT Prolonged QRS durationProlonged QRS duration

Hypermagnesemia


TreatmentTreatment– D/C MgD/C Mg2+2+ administration administration– Dilution using IV NSDilution using IV NS– Lasix 40-80 mg IVLasix 40-80 mg IV– DialysisDialysis

Hypermagnesemia


Intracellular anionIntracellular anion Normal rangeNormal range

– 2.5 to 4.5 mg/dL2.5 to 4.5 mg/dL

Phosphate


Serum POSerum PO44 < 2.5 mg/dL < 2.5 mg/dL

Sx onset at POSx onset at PO44 < 1.0 mg/dL < 1.0 mg/dL

Hypophosphatemia


EtiologyEtiology– Decreased oral intakeDecreased oral intake

Malnutrition (Alcoholics)Malnutrition (Alcoholics)

– Excessive lossExcessive loss– Shift from ECF ICFShift from ECF ICF

Respiratory/Metabolic AlkalosisRespiratory/Metabolic Alkalosis

– HyperalimentationHyperalimentation– HyperparathyroidismHyperparathyroidism– DKA, AKADKA, AKA

Hypophosphatemia


Clinical FeaturesClinical Features– Progressive weakness and tremorsProgressive weakness and tremors– Circumoral & fingertip paresthesiasCircumoral & fingertip paresthesias– Absent DTRsAbsent DTRs– Mental obtundationMental obtundation– HyperventilationHyperventilation– AnorexiaAnorexia

Hypophosphatemia


TreatmentTreatment– Serum POSerum PO44 level < 1.0 mg/dL level < 1.0 mg/dL

IV replacementIV replacement 2.5 mg/kg IV over 6 hours 2.5 mg/kg IV over 6 hours Check serum POCheck serum PO44 after each dose after each dose

Hypophosphatemia


Complications of therapyComplications of therapy– HypocalcemiaHypocalcemia– Metastatic calcificationMetastatic calcification– HypotensionHypotension– HyperkalemiaHyperkalemia

Hypophosphatemia


Serum POSerum PO44 > 4.5 mg/dL > 4.5 mg/dL EtiologyEtiology

– Decreased renal excretionDecreased renal excretion– Shift from ICF ECFShift from ICF ECF– Increased intakeIncreased intake– Most common with renal dysfunctionMost common with renal dysfunction– HypoparathyroidismHypoparathyroidism

Hyperphosphatemia


Clinical FeaturesClinical Features– Sx related to renal failureSx related to renal failure– Sx of hypocalcemiaSx of hypocalcemia– Sx of hypomagnesemiaSx of hypomagnesemia

Hyperphosphatemia


TreatmentTreatment– Treat underlying causeTreat underlying cause– Restrict Calcium Phosphate intakeRestrict Calcium Phosphate intake– Dilution using IV NSDilution using IV NS– Acetazolamide 500 mg q 6 hrsAcetazolamide 500 mg q 6 hrs– Aluminum Carbonate/HydroxideAluminum Carbonate/Hydroxide

Absorbs phosphate secreted into gutAbsorbs phosphate secreted into gut

– HemodialysisHemodialysis

Hyperphosphatemia


Things to rememberThings to remember– Treat the patient, not the lab valueTreat the patient, not the lab value– Rate of correction should mirror rate of Rate of correction should mirror rate of

changechange– Correct in orderly fashionCorrect in orderly fashion

1. Volume1. Volume 2. pH2. pH 3. Potassium, Calcium, Magnesium3. Potassium, Calcium, Magnesium 4. Sodium and Chloride4. Sodium and Chloride

– Consider impact of interventions overallConsider impact of interventions overall

Key Points


Questions

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electrolytes disorders

Health & Medicine