The partial pressure of ammonia in arterial blood can be estimated from the total blood ammonia concentration.
Parameters:
(1) hydrogen ion concentration from pH
(2) Ka = 9.8 * 10^(-10)
(3) KH = 1.75 * 10^(-5)
(4) total blood ammonia in µmol/L
pH =
= (-1) * LOG10(hydrogen ion concentration)
hydrogen ion concentration in moles/L =
= 10^((-1)*pH)
partial pressure of ammonia =
= KH * (ammonia concentration) / (1 + ((hydrogen ion concentration) / Ka))
where:
• The calculation appears to match the values given in Bhatia et al. The blood ammonia value is not converted to moles/L.
