Changes in the haemostatic system after thermoneutral and hyperthermic water immersion.
Warm water bathing is a popular recreational activity and is frequently used in rehabilitation medicine. Although well tolerated in most cases, there are reports indicating an increased risk of thrombotic events after hot tub bathing. The effects of a 45 min thermoneutral bath followed by a 50 min bath with increasing water temperature (maximum 41 degrees C) until reaching a body core temperature of 39 degrees C on factors of blood coagulation and fibrinolysis were studied in eight healthy male volunteers. Blood was obtained after a 45-min resting period as control and after the thermoneutral and hyperthermic bath as well as after another 45 min recovery period at the end of the study. Hyperthermic immersion (HI) lead to a shortening of activated partial thromboplastin time (aPTT) (P < 0.05). Fibrinogen concentration decreased immediately after HI (P < 0.05) but increased during recovery (P < 0.05). Plasminogen activator inhibitor (PAI) activity decreased during HI (P < 0.05), D-dimer concentration was not found to change. Thrombocyte count increased (P < 0.05) during HI. The increases in tissue-type plasminogen activator concentration as well as leucocyte count during HI were due to haemoconcentration. Prothrombin time, PAI-activity and granulocyte count decreased during thermoneutral immersion (P < 0.05). Warm water bathing leads to haemoconcentration and minimal activation of coagulation. The PAI-1 activity is decreased. A marked risk for thrombotic or bleeding complications during warm water bathing in healthy males could not be ascertained.
Department of Physiology, Center for Space Medicine Berlin, Charité, University Medicine Berlin, Campus Benjamin Franklin, Arnimallee 22, 14195, Berlin, Germany. leif-hendrik.boldt@charite.de
Leif-Hendrik
LH
Boldt
Waltraud
W
Fraszl
Lothar
L
Röcker
Jörg Christian
JC
Schefold
Mathias
M
Steinach
Thilo
T
Noack
Hanns-Christian
HC
Gunga
D000328:Adult; D001772:Blood Cell Count; D001777:Blood Coagulation / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology*; D003124:Colorimetry; D004797:Enzyme-Linked Immunosorbent Assay; D005334:Fever / Q000503:physiopathology*; D005340:Fibrinogen / Q000378:metabolism; D006339:Heart Rate / Q000502:physiology; D006487:Hemostasis / Q000502:physiology*; D006801:Humans; D007101:Immersion / Q000503:physiopathology*; D007958:Leukocyte Count; D008297:Male; D010314:Partial Thromboplastin Time; D011517:Prothrombin Time; D013696:Temperature; D010959:Tissue Plasminogen Activator / Q000097:blood
D005340:Fibrinogen; D010959:Tissue Plasminogen Activator