Acid base I Flashcards
what are the clinical decision making steps to assessing acid base disorders?
- history
- pH: acidemic or alkalemic?
- metabolic or respiratory?
- anion gap?
- appropriate compensation?
- if metabolic acidosis, is it a mixed disorder?
- diagnosis?
- treatment?
what is the pH range compatible with life?
6.80 - 7.80
can a respiratory acid base disorder be both alkalosis and acidosis?
no
what is the range of normal blood pH?
7.35 - 7.45
what is the conceptual cause of metabolic alkalosis?
increased serum HCO3-
what maintains metabolic alkalosis?
condition resulting in inability to secrete HCO3- by the kidneys
what value indicates a primary metabolic alkalosis?
over 40 mmol / L [HCO3-]
what is the compensatory mechanism for metabolic alkalosis?
respiratory acidosis - hypoventilation, increased pCO2
what are the etiologies of metabolic alkalosis?
- GI proton loss
- renal proton loss
- intracellular shift of hydrogen
- alkali administration
- contraction alkalosis
what should be considered the normal value for bicarb?
25 mmol / L
although contraction alkalosis can be caused by diuretics, it is maintained by ___________
hyperaldosteronism
what is the mechanism for contraction alkalosis?
- diuretics trigger secretion of H+ and K+ with loss of volume
- to counteract this hypovolemia, aldosterone is released which promotes Na+/H2O/HCO3- and secretion of K+/H+
what are two major reasons why metabolic alkalosis can be maintained?
- chloride depletion (also decreases bicarb secretion)
- hypokalemia
which two drugs can cause renal hydrogen loss leading to metabolic alkalosis?
- loop diuretics
- thiazide diuretics
what are the treatment options for metabolic alkalosis?
- correct underlying cause and maintainers
- correct electrolyte abnormalities (NaCl or KCl resuscitation)