Epinephrine-induced lactic acidosis following cardiopulmonary bypass.
OBJECTIVE
To determine if lactic acidosis occurring after cardiopulmonary bypass could be attributed to the metabolic or other effects of epinephrine administration.


METHODS
Prospective, randomized study.


METHODS
Postsurgical cardiothoracic intensive therapy unit.


METHODS
Thirty-six adult patients, without acidosis, requiring vasoconstrictors for the management of hypotension after cardiopulmonary bypass.


METHODS
Randomized administration of either epinephrine or norepinephrine by infusion.


RESULTS
Hemodynamic and metabolic data were collected before commencement of vasoconstrictor therapy (time 0) and then 1 hr (time 1), 6 to 10 hrs (time 2), and 22 to 30 hrs (time 3) later. Six of the 19 patients who received epinephrine developed lactic acidosis. None of the 17 patients receiving norepinephrine developed lactic acidosis. In the epinephrine group, but not in the norepinephrine group, lactate concentration increased significantly at times 1 and 2 (p = .01), while pH and base excess decreased (p < or = .01). Blood glucose concentration was higher in the epinephrine group at time 2 (p = .02), while the cardiac index (p < .03) and the mixed venous Po2 (p = .04) were higher at time 1. compared with the norepinephrine group, the patients receiving epinephrine had higher femoral venous lactate concentrations (p = .03), increased lower limb blood flow (p = .05), and increased femoral venous oxygen saturations (p = .04).


CONCLUSIONS
The use of epinephrine after cardiopulmonary bypass precipitates the development of lactic acidosis in some patients. This phenomenon is presumably a beta-mediated effect, and is associated with an increase in whole-body and lower limb blood flow and a decrease in whole-body and transfemoral oxygen extraction. The phenomenon does not appear to be related to reduced tissue perfusion and does not have the poor outlook of lactic acidosis associated with shock.
Totaro
R J
RJ
Department of Intensive Care, Royal North Shore Hospital, St. Leonards, NSW, Australia.
Raper
R F
RF
D000140:Acidosis, Lactic / Q000097:blood / Q000139:chemically induced* / Q000503:physiopathology; D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000009:adverse effects; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000009:adverse effects*; D000368:Aged; D000704:Analysis of Variance; D002315:Cardiopulmonary Bypass; D004837:Epinephrine / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000008:administration & dosage / Q000009:adverse effects; D011183:Postoperative Complications / Q000097:blood / Q000139:chemically induced* / Q000503:physiopathology; D011446:Prospective Studies; D013997:Time Factors; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000009:adverse effects*
D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D014662:Vasoconstrictor Agents; D009638:Norepinephrine; D004837:Epinephrine