April 6 Lecture

Danielson

pH 7.0 is neutral (i.e., pH = pOH) at  room temperature (20 C).

pH 7.4 is neutral at body temperature (37 C)

pH is determined by ratio of HCO3 / PCO2 or pH is determined by kidneys/lungs

pH = 6.1 + 1.3 = 7.4   1.3 = log 20    20 = [HCO3]/(PCO2 x 0.03) = 24/(40 x 0.03) = 24/1.2 =20 

If ratio is 20, pH will be normal.   COPD PaCO2 may be twice normal = 80 mm Hg.  Renal compensation will increase [HCO3} over time to twice normal = 48 mM.   Ratio will be 48/(80 x 0.03) = 48/2.4 = 20.

acid base practice questions
https://spreadsheets.google.com/viewform?formkey=dFV2U2lDbTJxZGFGLWtva3M4Sng1b2c6MQ