Dependence of lung uptake of lidocaine in vivo on blood pH.

Lung uptake of lidocaine was studied in anaesthetized Swedish landrace pigs using the double indicator dilution method with indocyanine green dye as intravascular marker. The pigs were given infusions of sodium bicarbonate or hydrochloric acid to arterial blood pH in the range 7 to 8. Lung uptake of lidocaine was found to correlate statistically significant (P less than 0.05) with pH. Lung uptake in the first injection before the infusion of acid or base, was 42 +/- 4 (mean +/- S.E.M.)%. The uptake was not found to correlate to cardiac output. The conclusion from this work is therefore that lung uptake of xenobiotic amines in part is dependent on blood pH.