CHAPTER 1 Cardiovascular System^39
moving in the body from vessels into tissue (third spacing), or dehydration.
External hemorrhage is loss of blood, plasma, fluids and electrolytes, due to
trauma, GI bleed, vomiting, or diarrhea. Third spacing can result from ascites or
pancreatitis.
PROGNOSIS
Prognosis depends on the etiology of the low volume; there may occasionally be
more than one reason.
HALLMARK SIGNS AND SYMPTOMS
- Hypotension because blood volume in the body is decreased
- Urine output less than 25 ml/hour because less blood is perfusing the kid-
neys, causing decreased urinary output - Heart rate >100 (tachycardia), because the heart attempts to compensate for
the decreased volume - Cold skin, because of peripheral vasoconstriction due to decreased volume
- Restlessness, agitation; may be seen due to poor perfusion of the brain
INTERPRETING TEST RESULTS
- Blood tests.
- CBC anemia.
- Chemistry to look at volume as depicted by the creatinine and BUN.
- Coagulation studies.
- Type and cross-match for blood transfusion.
- Arterial Blood Gas (ABG)
- Decrease pH—if not perfusing well, acidosis will occur.
- Metabolic acidosis—byproducts of metabolism will accumulate.
- Increase partial pressure of arterial carbon dioxide and decrease partial
pressure of arterial oxygen due to poor perfusion.