Hyponatremia/HypernatremiaBy Surijdei Amanda DeCruiz

Sodium Overview

Na+ regulation is associated with H2O homeostasis (Independent Mechanisms)

Change in Na+ conc. = H2O homeostasis

Change in Na+ content = Na+ homeostasis Na+ is actively pumped out of cells ECF An increase in Na+ intake increase ECF volume

increase GFR; increase Na+ excretion A decrease in Na+ intake decrease ECF volume

decrease GFR; decrease Na+ excretion

Sodium Homeostasis

Water Homeostasis

Sodium

Decrease in Renal Perfusion Pressure Stimulates RAAS Aldosterone Na+ reabsorption/K+ excretion (Late DT)

Decrease Plasma tone ADH suppression

Steady State Preservation H2O intake = H2O output (Renal, GI, Resp, Skin)

No Steady State = Hypo/Hypernatremia

Hyponatremia

Too much H2O in relation to serum Na+ (Plasma Na+ conc. <135 mmol/L)

Clinical symptoms Na+ < 120 mEq/L; Exception increase in ICP i.e. after head trauma (decrease ECF H2O shifts into the brain increase ICP thus critical to keep Na+ Normal/Slightly increase) Neuro: H2O intoxication increases ICF volume cerebral

edema, headache, delirium, irritability, muscle twitching, weakness, hyperactive DTR, increase ICP, seizures, coma.

GI: Nausea, vomiting, ileus, watery diarrhea, salivation Cardiovascular: HTN Renal:Oliguria progressing to Anuria if delayed therapy

Hyponatremia

Hyponatremia

Hyponatremia

Hyponatremia Diagnosis

Dx: Osmolality:

Low Plasma “True Hyponatremia” Low Urine “Diluting Urine” Primary Polydipsia High Urine (Incr. ADH) SIADH, Hypothyroidism, CHF

Urine Na+ Conc: >20mmol/L Salt Wasting, Hypoaldosteronism,

Diuretics <40mmol/L SIADH

Hyponatremia Treatment

Hypernatremia

Too much serum Na+ in relation to H2O (Plasma Na+ conc. >145 mmol/L) Neuro: AMS, weakness, restlessness, focal neuro deficit,

confusion, seizure, coma GI: dry mucosa/ tissue membrane, decrease salivation

Hypernatremia

Hypernatremia Diagnosis

Dx: Osmolality >800mosm/kg: Urine Volume decreased:

Kidneys respond appropriately Give Desmopressin

Increase = Central DI Decrease= Nephrogenic DI

Hypernatremia Treatment