Acid-Base Balance Flashcards
normal pH
7.35-7.45
>7.45=alkalosis
<7.35=acidosis
buffer systems
pH balance
-20:1 ratio
compensatory buffers
-respiratory system
kidneys
-renal system
-normal bicarb=22-26
chemical buffer system
combine with excess acids or bases to stop pH changes
-HCO3 buffer system
-proteins
-H+/K+ exchange system
20:1 bicarb to carbonic acid in plasma
renal buffer system
eliminate H+, reabsorb/make HCO3-
-tubular buffer systems (phosphate buffer)
-chloride bicarb exchange
respiratory buffer system
lungs excrete CO2+H20 (H2CO3)
-adjusted by rate+depth of breathing for pH changes
bicarb buffer system equation
CO2+H2O↔H2CO3↔(HCO3–)+(H+)
respiratory acidosis
high carbonic acid, low pH
-inverse relationship with CO2 and pH
respiratory alkalosis
low carbonic acid, high pH
-inverse relationship with CO2 and pH
metabolic acidosis
low bicarbonate, low pH
metabolic alkalosis
high bicarbonate, high pH
metabolic acidosis causes
excess acids (H+) in blood:
-diabetic ketoacidosis
-lactic acidosis
-hyperthyroidism
-burns/infection
decreased HCO3-:
-diarrhea
-tubular acidosis (can’t absorb HCO3-)
-GI fistula (opening/rupturing)
-intestinal decompression
metabolic acidosis process
excess H+ binds to chemical buffers>decreased pH increases breathing out CO2>kidneys secrete H+>Na+, HCO3- return to blood>excess H+ diffuses into cells>changes K+, Na+, Ca2+ ions and muscle excitability
respiratory acidosis causes
decreased breathing from
-chronic lung disease
-pain medications
-infections
-burns
-weak respiratory muscles
headaches, blurred vision, irritability, tetanus, psychological disturbance
respiratory acidosis process
carbonic acid made when breathing decreases>2-3 DPG in RBC makes Hb release O2>CO2 build-up in tissues, fluids, CSF>CO2, H+ dilates cerebral BV, increased BF to brain>increased CO2 makes kidneys keep HCO3- and Na+ but excrete H+, NH4>excess H+ pushes K+ out of cells>hyperkalemia, lactic acid buildup decreases neurologic, cardiac function
metabolic alkalosis causes
excessive HCO3-:
-HCO3 reabsorption
-high aldosterone
-loop diuretics (fluid loss, not HCO3-)
-excessive antacids
decreased H+:
-NG suctioning
-vomiting
-hypokalemia