Analysis of thromboelastography, PT, APTT and fibrinogen in intraosseous and venous samples-an experimental study.
BACKGROUND
Laboratory analysis of coagulation is often important in emergencies. If vascular access is challenging, intraosseous catheterization may be necessary for treatment. We studied the analysis of coagulation parameters in intraosseous aspirate during stable conditions and after major haemorrhage in a porcine model.


METHODS
Ten anesthetized pigs received central venous and intraosseous catheters and samples were taken for analysis of thromboelastography (TEG), prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen concentration. Analyses were repeated after removal of 50 % of the calculated blood volume and resuscitation with crystalloid. Intraosseous and venous values were compared.


RESULTS
Bleeding and resuscitation resulted in haemodilution and hypotension. Median TEG reaction time was shorter in intraosseous than in venous samples before (1.6 vs 4.6 min) and after (1.6 vs 4.7 min) haemodilution. Median maximal amplitude was smaller in intraosseous samples at baseline (68.3 vs 76.4 mm). No major differences were demonstrated for the other TEG parameters. The intraosseous samples often coagulated in vitro, making analysis of PT, APTT and fibrinogen difficult. After haemodilution, TEG maximal amplitude and α-angle, and fibrinogen concentration, were decreased and PT increased.


CONCLUSIONS
The intraosseous samples were clinically hypercoagulable and the TEG demonstrated a shortened reaction time. The reason for this may hypothetically be found in the composition of the IO aspirate or in the sampling technique. After 50 % haemorrhage and haemodilution, a clinically relevant decrease in fibrinogen concentration and a lower TEG maximal amplitude were observed.


CONCLUSIONS
Although the sample is small, these data indicate that intraosseous samples are hypercoagulable, which may limit their usefulness for coagulation studies. Major haemodilution only moderately affected the studied parameters.
Anaesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden. gunnar.strandberg@surgsci.uu.se.|Department of Surgical Sciences, Uppsala University, Uppsala University Hospital, 751 85, Uppsala, Sweden. gunnar.strandberg@surgsci.uu.se.
Gunnar
http://orcid.org/0000-0003-4959-6389
G
Strandberg
Hedenstierna laboratory, Anaesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
Miklós
M
Lipcsey
Anaesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
Mats
M
Eriksson
Immunology and Transfusion medicine, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
Norbert
N
Lubenow
Clinical Chemistry, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
Anders
A
Larsson
D000818:Animals; D001777:Blood Coagulation / Q000502:physiology*; D001853:Bone Marrow / Q000378:metabolism*; D004195:Disease Models, Animal; D004630:Emergencies; D005340:Fibrinogen / Q000032:analysis*; D006470:Hemorrhage / Q000175:diagnosis* / Q000378:metabolism; D010314:Partial Thromboplastin Time / Q000379:methods*; D011517:Prothrombin Time / Q000379:methods*; D013552:Swine; D013916:Thrombelastography / Q000379:methods*
D005340:Fibrinogen
Blood coagulation; Haemorrhage; Infusions; Intraosseous; Thrombelastography