Extracorporeal bicarbonate space after bicarbonate or a bicarbonate-carbonate mixture in acidotic dogs.
The effects of sodium bicarbonate and a bicarbonate-carbonate mixture on expired CO2 and the volume of distribution of bicarbonate were studied in eight anesthetized, paralyzed, and ventilated dogs made acidotic with HCl (5 mmol/kg) infused over 90 min. Both sodium bicarbonate and Carbicarb resulted in systemic alkalinization and comparable increases in the serum bicarbonate at 50 min (7.07 +/- 0.91 vs. 7.99 +/- 0.77, respectively; P = NS). Sodium bicarbonate infusion resulted in an increase in CO2 excretion that accounted for a fractional CO2 excretion of 0.20 +/- 0.09, whereas infusion of a bicarbonate-carbonate mixture resulted in a fractional CO2 excretion of -0.06 +/- 0.09 (P less than 0.01). The uncorrected volume of distribution of bicarbonate after sodium bicarbonate infusion was higher than that seen with the bicarbonate-carbonate mixture (0.60 +/- 0.07 vs. 0.34 +/- 0.03 l/kg; P less than 0.01). However, when the volume of bicarbonate distribution was corrected for expired CO2, there was no difference between treatment with sodium bicarbonate and the bicarbonate-carbonate mixture (0.44 +/- 0.07 vs. 0.38 +/- 0.04 l/kg; P = NS). These data demonstrate that, in this animal model of acidosis, sodium bicarbonate treatment of systemic acidosis is accompanied by a generation of a considerable amount of CO2, whereas treatment with a bicarbonate-carbonate mixture is not. This suggests that in states of impaired ventilation, a bicarbonate-carbonate mixture may offer more efficient systemic alkalinization and may be associated with less CO2 generation than sodium bicarbonate.
Kindig
N B
NB
Department of Electrical Engineering, University of Colorado, Denver.
Sherrill
D S
DS
Shapiro
J I
JI
Filley
G F
GF
D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000138:Acidosis / Q000378:metabolism*; D000818:Animals; D001639:Bicarbonates / Q000378:metabolism* / Q000494:pharmacology*; D002245:Carbon Dioxide / Q000378:metabolism*; D002254:Carbonates / Q000494:pharmacology*; D004285:Dogs; D004338:Drug Combinations / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology*; D017693:Sodium Bicarbonate
D001639:Bicarbonates; D002254:Carbonates; D004338:Drug Combinations; C046283:sodium bicarbonate, sodium carbonate drug combination; D002245:Carbon Dioxide; D017693:Sodium Bicarbonate; D012964:Sodium