Acidosis impairs the coagulation: A thromboelastographic study.
BACKGROUND
Coagulopathy is a contributor to and predictor of death in bleeding patients. Acidosis is known to be a predictor of worse outcome in trauma patients and to be a coexisting factor in coagulopathic patients, but it has not been studied if it is a causal factor in the development of coagulopathy.


METHODS
We have adjusted the pH level in blood samples from healthy volunteers to different levels between 7.4 and 6.8 by the use of hydrochloric acid. Thereafter we have studied the coagulation at the different pH levels by the use of thromboelastography.


RESULTS
We found a strong correlation between pH levels and impairment of the coagulation, where the clot strength is increased much slower at pH levels below 7.4 even though the initiation of the clotting seems to be normal. The clot formation time was increased by 168% at pH 6.8 as compared with pH 7.4 (p < 0.00001, r = 0.89) whereas the clotting time was left unaffected.


CONCLUSIONS
Acidosis causes a strong impairment of the coagulation as measured with thromboelastography. The impairment found when lowering pH from 7.4 to 7.15 was almost identical to the impairment seen in another study by Kettner et al. when the temperature was lowered from 36 degrees C to 32 degrees C.
Engström
Martin
M
Department of Anaesthesia and Intensive Care, Lund University Hospital, Lund, Sweden. martin.engstrom@med.lu.se
Schött
Ulf
U
Romner
Bertil
B
Reinstrup
Peter
P
D000138:Acidosis / Q000150:complications* / Q000503:physiopathology; D001777:Blood Coagulation / Q000502:physiology*; D001778:Blood Coagulation Disorders / Q000209:etiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013916:Thrombelastography