TY - JOUR
T1 - Coagulation competence and fluid recruitment after moderate blood loss in young men
AU - Zaar, Morten
AU - Mørkeberg, Jakob
AU - Pott, Frank C
AU - Johansson, Pär I
AU - Secher, Niels H
PY - 2014/9
Y1 - 2014/9
N2 - The coagulation system is activated by a reduction of the central blood volume during orthostatic stress and lower body negative pressure suggesting that also a blood loss enhances coagulation. During bleeding, however, the central blood volume is supported by fluid recruitment to the circulation and redistribution of the blood volume. In eight supine male volunteers (24 ± 3 years, blood volume of 6.9 ± 0.7 l; mean ± SD), 2 × 450 ml blood was withdrawn over ∼ 30 min while cardiovascular variables were monitored. Coagulation was evaluated by thrombelastography, and fluid recruitment was estimated by red blood cell count. Withdrawing 900 ml blood increased heart rate (62 ± 7 to 69 ± 13 bpm, P < 0.05; mean ± SD) and reduced stroke volume (113 ± 12 to 96 ± 14 ml, P < 0.05) leaving cardiac output, mean arterial pressure, and total peripheral resistance unchanged and, furthermore, reduced red blood cell count (4.80 ± 0.33 to 4.64 ± 0.37 × 10(12) cells l(-1), P < 0.05) indicating that 218 ± 173 ml fluid was recruited to the circulation. Withdrawing 450 ml blood reduced the time until initial fibrin formation (R: 6.5 ± 0.9 to 5.1 ± 1.0 min, P < 0.01), whereas the rate of clot formation increased after withdrawal of 900 ml blood (α-Angle: 66 ± 4 to 70 ± 3 deg, P < 0.01). Clot strength (maximal amplitude: 57 ± 4 mm), clot lysis 30 min after maximal amplitude (LY30: 0.8% [0-3.5%] (median [range])), and platelet count (218 ± 25 × 10(9) l(-1)) were unaffected. For supine males, ∼ 25% of a moderate blood loss is compensated by fluid recruitment to the circulation, which may explain the minor cardiovascular response. Yet, a blood loss of 450 ml accelerates coagulation, and this is further accentuated when blood loss is 900 ml.
AB - The coagulation system is activated by a reduction of the central blood volume during orthostatic stress and lower body negative pressure suggesting that also a blood loss enhances coagulation. During bleeding, however, the central blood volume is supported by fluid recruitment to the circulation and redistribution of the blood volume. In eight supine male volunteers (24 ± 3 years, blood volume of 6.9 ± 0.7 l; mean ± SD), 2 × 450 ml blood was withdrawn over ∼ 30 min while cardiovascular variables were monitored. Coagulation was evaluated by thrombelastography, and fluid recruitment was estimated by red blood cell count. Withdrawing 900 ml blood increased heart rate (62 ± 7 to 69 ± 13 bpm, P < 0.05; mean ± SD) and reduced stroke volume (113 ± 12 to 96 ± 14 ml, P < 0.05) leaving cardiac output, mean arterial pressure, and total peripheral resistance unchanged and, furthermore, reduced red blood cell count (4.80 ± 0.33 to 4.64 ± 0.37 × 10(12) cells l(-1), P < 0.05) indicating that 218 ± 173 ml fluid was recruited to the circulation. Withdrawing 450 ml blood reduced the time until initial fibrin formation (R: 6.5 ± 0.9 to 5.1 ± 1.0 min, P < 0.01), whereas the rate of clot formation increased after withdrawal of 900 ml blood (α-Angle: 66 ± 4 to 70 ± 3 deg, P < 0.01). Clot strength (maximal amplitude: 57 ± 4 mm), clot lysis 30 min after maximal amplitude (LY30: 0.8% [0-3.5%] (median [range])), and platelet count (218 ± 25 × 10(9) l(-1)) were unaffected. For supine males, ∼ 25% of a moderate blood loss is compensated by fluid recruitment to the circulation, which may explain the minor cardiovascular response. Yet, a blood loss of 450 ml accelerates coagulation, and this is further accentuated when blood loss is 900 ml.
KW - Adaptation, Physiological
KW - Adult
KW - Blood Coagulation
KW - Blood Coagulation Tests
KW - Blood Volume
KW - Cardiac Output
KW - Heart Rate
KW - Hemorrhage
KW - Humans
KW - Male
KW - Phlebotomy
KW - Time Factors
KW - Vascular Resistance
U2 - 10.1097/mbc.0000000000000114
DO - 10.1097/mbc.0000000000000114
M3 - Journal article
C2 - 24732173
SN - 0957-5235
VL - 25
SP - 592
EP - 596
JO - Blood Coagulation and Fibrinolysis
JF - Blood Coagulation and Fibrinolysis
IS - 6
ER -