Critical Care Lab Values

Water

• 60% of total body weight
• Varies w/ age, gender, body type
• Obese people have less body water
• Needed to deliver nutrients/electrolytes

1 kg = 2.2 lbs

Extracellular

• 40% of total body water
• Plasma
• Interstitial fluid (between cells)
• Transcellular: CSF, peritoneal
• ALSO: pleural, synovial, pericardial

Intracellular

• 60% of total body water
• Most abundant K & HPO4

Regulation of Fluid Movement

ALDOSTERONE prevents:
Na+ & H2O loss
K+ getting too high

NATRIURETIC PEPTIDES

• Atrial (ANP)
• Ventricle (BNP)
• Response to blood volume
• Increase urine output

Fluid Volume Excess

• Acute Renal Failure
• Chronic Kidney Disease
• Excessive Na+ intake
• Over-infusion IV fluids

Fluid Volume Excess

• Response to surgical trauma
• SIADH
• Excessive water retention
• Protein deficit, pregnancy, thyroid
• Medications

Fluid Volume Deficit

• Vomiting/diarrhea
• Burns
• Heatstroke
• Alcohol
• Diabetes insipidus

Fluid Volume Deficits

• Hypertonic solutions
• Adrenalectomy
• Thiazide diuretics
• NPO status

Vital Signs Assessments

• Blood pressure
• Respiratory rate
• Temperature
• Weight

Signs/Symptoms

• Cardiovascular
• Respiratory
• Integumentary
• Neurological

Signs/Symptoms

• Musculoskeletal
• Renal
• Gastrointestinal

Review Lab Values

• Hematocrit
• Serum Osmolality
• Blood Urea Nitrogen (BUN)
• Urine specific gravity