Enhanced Extracorporeal CO2 Removal by Regional Blood Acidification: Effect of Infusion of Three Metabolizable Acids.
Acidification of blood entering a membrane lung (ML) with lactic acid enhances CO2 removal (VCO2ML). We compared the effects of infusion of acetic, citric, and lactic acids on VCO2ML. Three sheep were connected to a custom-made circuit, consisting of a Hemolung device (Alung Technologies, Pittsburgh, PA), a hemofilter (NxStage, NxStage Medical, Lawrence, MA), and a peristaltic pump recirculating ultrafiltrate before the ML. Blood flow was set at 250 ml/min, gas flow (GF) at 10 L/min, and recirculating ultrafiltrate flow at 100 ml/min. Acetic (4.4 M), citric (0.4 M), or lactic (4.4 M) acids were infused in the ultrafiltrate at 1.5 mEq/min, for 2 hours each, in randomized fashion. VCO2ML was measured by the Hemolung built-in capnometer. Circuit and arterial blood gas samples were collected at baseline and during acid infusion. Hemodynamics and ventilation were monitored. Acetic, citric, or lactic acids similarly enhanced VCO2ML (+35%), from 37.4 ± 3.6 to 50.6 ± 7.4, 49.8 ± 5.6, and 52.0 ± 8.2 ml/min, respectively. Acids similarly decreased pH, increased pCO2, and reduced HCO3 of the post-acid extracorporeal blood sample. No significant effects on arterial gas values, ventilation, or hemodynamics were observed. In conclusion, it is possible to increase VCO2ML by more than one-third using any one of the three metabolizable acids.
From the *U.S. Army Institute of Surgical Research, Fort Sam Houston, San Antonio Texas; †Dipartimento di Scienze della Salute, Università degli Studi di Milano Bicocca, Monza (MB), Italy; ‡Department of Anesthesiology and Intensive Care Medicine, §Pediatric Department, University Hospital Bonn, Bonn, Germany; and ¶Dipartimento di Anestesia e Rianimazione, Ospedale San Gerardo, Monza (MB), Italy.
Vittorio
V
Scaravilli
Stefan
S
Kreyer
Katharina
K
Linden
Slava
S
Belenkiy
Antonio
A
Pesenti
Alberto
A
Zanella
Leopoldo C
LC
Cancio
Andriy I
AI
Batchinsky
D019342:Acetic Acid / Q000378:metabolism / Q000494:pharmacology; D000142:Acidosis, Respiratory / Q000097:blood* / Q000188:drug therapy / Q000601:surgery; D000818:Animals; D001784:Blood Gas Analysis; D002118:Calcium / Q000097:blood* / Q000378:metabolism; D002245:Carbon Dioxide / Q000097:blood* / Q000378:metabolism; D002264:Carboxylic Acids / Q000494:pharmacology*; D019343:Citric Acid / Q000378:metabolism / Q000494:pharmacology; D005112:Extracorporeal Circulation / Q000379:methods*; D005260:Female; D006439:Hemodynamics; D019344:Lactic Acid / Q000378:metabolism / Q000494:pharmacology; D012121:Respiration, Artificial / Q000379:methods*; D012756:Sheep
D002264:Carboxylic Acids; D002245:Carbon Dioxide; D019343:Citric Acid; D019344:Lactic Acid; D019342:Acetic Acid; D002118:Calcium