SIADHSIADHMontonMonton

1 1 กคกค 4848

HyponatremiaHyponatremia

excludeexclude pseudohyponatremiapseudohyponatremia

volume statusvolume status

Hypovolemia Euvolemia Hypervolemia Hypovolemia Euvolemia Hypervolemia

HypervolemiaHypervolemia

Congestive heart failureCongestive heart failure

CirrhosisCirrhosis

Nephrotic syndromeNephrotic syndrome

Renal failureRenal failure

HypovolemiaHypovolemia

Renal lossRenal loss

Extrarenal lossExtrarenal loss

gastrointestinal lossgastrointestinal loss

skin lossskin loss

third space lossthird space loss

EuvolemiaEuvolemia

SIADHSIADH

Adrenal insufficiencyAdrenal insufficiency

HypothyroidismHypothyroidism

Primary polydipsiaPrimary polydipsia

SIADHSIADH

Nonphysiologic release of ADH Nonphysiologic release of ADH

Not due to usual stimuli or hypoosmolarity Not due to usual stimuli or hypoosmolarity or hypovolemiaor hypovolemia

Inappropriate urinary concentrationInappropriate urinary concentration

Hyponatremia ,hypoosmolarityHyponatremia ,hypoosmolarity

High urine osmolarityHigh urine osmolarity

PathophysiologyPathophysiology

Persistent ADH activityPersistent ADH activity

Water retentionWater retention

Volume expansionVolume expansion

Stimulate volume receptorsStimulate volume receptors Carotid sinus, aortic arch Carotid sinus, aortic arch SNS SNS Left atrium Left atrium ANP ANP Juxtaglomerular apparatus Juxtaglomerular apparatus RAAS RAAS

Sodium & water excretion (secondary)Sodium & water excretion (secondary)

PathophysiologyPathophysiology

Water retention Na,H2O excreteWater retention Na,H2O excrete

hypoosmolarityhypoosmolarity

hyponatremiahyponatremia

EtiologyEtiology

Neuropsychiatric disorderNeuropsychiatric disorder

Pulmonary diseasePulmonary disease

DrugDrug

Postoperative patientPostoperative patient

CarcinomaCarcinoma

Neuropsychiatric disorderNeuropsychiatric disorder

InfectionInfection

VascularVascular

NeoplasmNeoplasm

PsychosisPsychosis

OthersOthers HIV infectionHIV infection

Pulmonary diseasePulmonary disease

PneumoniaPneumonia

TBTB

Acute respiratory failureAcute respiratory failure

OthersOthers AsthmaAsthma AtelectasisAtelectasis PneumothoraxPneumothorax

DrugsDrugs

Cyclophosphamide – IV formCyclophosphamide – IV form

CarbamazepineCarbamazepine

HaloperidolHaloperidol

AmitriptylineAmitriptyline

FluoxetineFluoxetine

CarcinomaCarcinoma

Small cell lung cancerSmall cell lung cancer

DuodenumDuodenum

PancreasPancreas

etc.etc.

DiagnosisDiagnosis

Hyponatremia,HypoosmolarityHyponatremia,HypoosmolarityEuvolemia , mild hypervolemiaEuvolemia , mild hypervolemiaUrine osmolarity > 100 mOsm/kgUrine osmolarity > 100 mOsm/kgUrine Na > 40 mEq/l or < 10 mEq/lUrine Na > 40 mEq/l or < 10 mEq/lHypouricemiaHypouricemiaClinical settingClinical settingExclude adrenal insufficiency, Exclude adrenal insufficiency, hypothyroidism & other hyponatremiahypothyroidism & other hyponatremia

TreatmentTreatment

Water restrictionWater restriction

Salt administrationSalt administration

Loop diureticLoop diuretic

Demeclocycline or lithiumDemeclocycline or lithium

Vasopressin receptor antagonistVasopressin receptor antagonist

Water restrictionWater restrictionaim to aim to negative water balancenegative water balance

SaltSalt administrationadministrationprinciple : principle : effective osmolarity of the effective osmolarity of the

fluid given must be greater fluid given must be greater than that of the urinethan that of the urine

eg. If Uosm = 700 mOsm/kgeg. If Uosm = 700 mOsm/kg

NSS is inappropriateNSS is inappropriate

3%NaCl is appropriate 3%NaCl is appropriate

Loop diureticLoop diuretic

Na

K

2Cl

H2O

ADH

mTALH

Collecting tubule

ADH antagonizing effectADH antagonizing effect

DemeclocyclineDemeclocycline

LithiumLithium

Incompletely understandIncompletely understand

Vasopressin receptor antagonistVasopressin receptor antagonistSelective water diuresisSelective water diuresis