Effects of acidosis, alkalosis, hyperthermia and hypothermia on haemostasis: results of point of care testing with the thromboelastography analyser

In this study we assessed the effects of changes in pH, temperature, and their combination in whole blood on thromboelastographic variables. Blood was collected from six healthy volunteers. Thromboelastograph (TEG series 5000; Haemoscope Corporation, Illinois, USA) channels were set at temperatures of 32, 37, and 39 degrees C and each was filled with artificially acidified, alkalified, and neutral blood, respectively. Acidification (pH 6.95) significantly impairs thromboelastographic variables reaction time r (from 23.3 to 33.7 min; P = 0.0280), kinetic time k (from 8.7 to 16.1 min; P = 0.028), angle a (from 24.3 degrees to 13.8 degrees; P = 0.028), prothrombin time (from 11.4 to 12.1 s; P = 0.044), and activated partial thromboplastin time (from 29.3 to 45.0 s; P = 0.028). A temperature drop from 37 to 32 degrees C in blood of neutral pH significantly impaired k (from 8.7 to 10.2 min; P = 0.028) and alpha (from 24.3 degrees to 21.0 degrees; P = 0.027), whereas maximum amplitude ma significantly increased (from 46.5 to 52.5 mm; P = 0.027). A temperature rise from 37 to 39 degrees C at pH 7.37 did not affect any of the TEG variables. Artificial alkalization (pH 7.68) at a temperature of 37 degrees C had no effect on any of the measured variables. Acidosis causes a significant impairment of clot formation and clot strength. Hypothermia had the same effects, but to a lesser extent. These findings emphasize the need for correction of acidosis and hypothermia to normalize haemostasis. Blood Coagul Fibrinolysis 20:436-439 (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.