Random and controlled study.
SETTING: Animal research facility and laboratory.
SUBJECTS: Yorkshire swine (n = 18).
INTERVENTIONS: Blood samples were taken at baseline, 15 mins after reaching pH of 7.1, and 15 mins after THAM pH neutralization. Coagulation function was assessed by
thrombin generation, prothrombin time, activated partial thromboplastin time, activated clotting time, and thromboelastography (maximum clot formation time [R+K], clotting rapidity [alpha], and clot strength [maximum amplitude]). An additional six pigs (
sham group) were infused with THAM, and an equal volume of fluid as the 12 coagulopathic pigs was given to assess effects of THAM and
hemodilution. Comparisons were made using a mixed model analysis of variance. No change in any indexes of coagulation was observed in
sham pigs. Compared with baseline,
acidosis of pH 7.1 decreased base excess from 6.6 +/- 0.5 mM to -12.4 +/- 0.5 mM; reduced
fibrinogen levels to 72% +/- 2%, platelet counts to 53% +/- 3%,
thrombin generation to 58% +/- 4%, alpha to 84% +/- 2%, and maximum amplitude to 75% +/- 3%; and prolonged prothrombin time to 113% +/- 2%, partial thromboplastin time to 122% +/- 4%, activated clotting time to 124% +/- 3%, and R + K to 119% +/- 3% (all p < .05). THAM infusion corrected pH to 7.40 +/- 0.02 and base excess to 2.6 +/- 0.9 mM (p < .05). However, there were no differences in
thrombin generation, prothrombin time, partial thromboplastin time, activated clotting time, R+K, alpha, or maximum amplitude between the groups with or without pH correction.
CONCLUSIONS:
Acidosis impaired coagulation by depleting
clotting factors, inhibiting
thrombin generation, and affecting clot strength and stability. THAM corrected
acid-base deficit but did not acutely reverse the coagulation abnormalities in the model.