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Fluid volume deficit, excess and water intoxication. Fluid Volume Disturbances. Fluid Volume Deficit (Hypovolemia). Fluid Volume Deficit. Mild – 2% of body weight loss Moderate – 5% of body weight loss Severe – 8% or more of body weight loss. THREE TYPES OF deficit.
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Fluid Volume Disturbances • Fluid Volume Deficit (Hypovolemia)
Fluid Volume Deficit • Mild – 2% of body weight loss • Moderate – 5% of body weight loss • Severe – 8% or more of body weight loss
THREE TYPES OF deficit • Hyperosmolar fluid volume deficit- water loss is greater than the electrolyte loss • Isosmolar fluid volume deficit – equal proportion of fluid and electrolyte loss
Fluid Volume Deficit • Pathophysiology – results from loss of body fluids and occurs more rapidly when coupled with decreased fluid intake
Fluid Volume Deficit • Clinical manifestations • Acute weight loss • Decreased skin turgor
Fluid Volume Deficit - Oliguria - Concentrated urine - Postural hypotension - Weak, rapid, heart rate - Flattened neck veins - Increased temperature - Decreased central venous pressure
Severe vomiting Traumatic injuries Ileostomy Burns Use of diuretics ETIOLOGY AND RISK FACTORS
LABORATORY FINDINGS • Increased osmolality(> 295 mOsm/ kg) • Increase BU (>25 mg / L ) • Elevated hematocrit (> 55%) • Increased specific gravity of urine ( > 1.030)
MANAGEMENT Management of fluid in patient with fluid deficit should aim at Replacing deficit Correcting ongoing losses Maintenance
Management of mild deficit • Mild fluid volume loss can be corrected with oral fluid replacement
Management of moderate/severe volume deficit • IV fluids needed
Fluid Volume Excess • Pathophysiology – may be related to fluid overload or diminished function of the homeostatic mechinisms responsible for regulating fluid balance
ETIOLOGY AND RISK FACTORS • Heart failure • Renal disorders • Cirrhosis of liver • Increased ingestion of high sodium foods • Excessive amount of IV fluids containing sodium • Electrolyte free IV fluids • SIADH,Sepsis • decreased colloid osmotic pressure • lymphatic and venous obstruction • Cushing’s syndrome & glucocorticoids
Why does heart failure leads to oedema • Reduced renal perfusion--- activates renin angiotensin aldosterone mechanism---- results in fluid retention
Why does renal failure cause oedema? • Why does liver failure cause oedema
CLINICAL MANIFESTATION • Dyspnea & crackles in lungs • pleural effusion • Neck veins prominant • Bounding pulse &elevated BP • Pitting & sacral edema • Weight gain • Increased CVP • Change in level of consciousness
LAB INVESTIGATION • serum osmolality <275mOsm/ kg • Decreased hematocrit [ < 45%]
MANAGEMENT • Diuretics • Restrict fluids • In people with HF, ACE inhibitors • A low sodium diet
Water intoxication • At the onset of this condition fluid outside the cells has an excessively low amount of solutes in comparison to inside the cells, the fluid shifts through osmosis into the cells in order to balance its concentration. • This causes the cells to swell. In the brain, this swelling increases ICP
features • headache • personality changes • changes in behavior, confusion, irritability • difficulty breathing during exertion • cramping, nausea, vomiting, • seizures, brain damage, coma or death due to cerebral oedema
Risk factors • Psychiatric conditions-polydipsia • Over replacement of IV fluids • Heat stress
management • Restriction of fluids is sufficient in mild cases • If severe diuretics needed