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
• 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
ETIOLOGY AND RISK FACTORS
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Severe vomiting
Traumatic injuries
Ileostomy
Burns
• Use of diuretics
LABORATORY FINDINGS
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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 (Hypervolemia)
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
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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
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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
Fluid Volume Excess
LAB INVESTIGATION
• serum osmolality <275mOsm/ kg
• Decreased hematocrit [ < 45%]
MANAGEMENT
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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
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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
Thank you!!