Low Cerebral Oxygenation Levels during Resuscitation in Out-of-hospital Cardiac Arrest Are Associated with Hyperfibrinolysis.
BACKGROUND
The authors investigated whether patients with out-of-hospital cardiac arrest with an initial low cerebral oxygen level during cardiopulmonary resuscitation are more prone to develop hyperfibrinolysis than patients with normal cerebral oxygenation levels and which part of the fibrinolytic system is involved in this response.


METHODS
In 46 patients, hyperfibrinolysis was diagnosed immediately upon emergency department admission using rotational thromboelastometry and defined as a lysis more than 15%. Simultaneously, initial cerebral tissue oxygenation was measured using near-infrared spectroscopy, and oxygen desaturation was defined as a tissue oxygenation index (TOI) of 50% or less. Blood sample analysis included markers for hypoperfusion and fibrinolysis.


RESULTS
There was no difference in prehospital cardiopulmonary resuscitation duration between patients with or without hyperfibrinolysis. An initial TOI of 50% or less was associated with more clot lysis (91% [17 to 100%; n = 16]) compared with patients with a normal TOI (6% [4 to 11%]; n = 30; P < 0.001), with lower levels of plasminogen (151.6 ± 61.0 vs. 225.3 ± 47.0 μg/ml; P < 0.001) and higher levels of tissue plasminogen activator (t-PA; 18.3 ± 7.4 vs. 7.9 ± 4.7 ng/ml; P < 0.001) and plasminogen activator inhibitor-1 (19.3 ± 8.9 vs. 12.1 ± 6.1 ng/ml; P = 0.013). There were no differences in (activated) protein C levels among groups. The initial TOI was negatively correlated with t-PA (r = -0.69; P < 0001). Mortality rates were highest in patients with hyperfibrinolysis.


CONCLUSIONS
Activation of the fibrinolytic system is more common in out-of-hospital cardiac arrest patients with an initial cerebral tissue oxygenation value of 50% or less during resuscitation and is linked to increased levels of t-PA rather than involvement of protein C.
From the Departments of Anesthesiology (A.D., V.A.V., S.E.D., L.A.S., C.E.v.d.B., S.A.L., C.B.), Surgery (L.M.G.G.), Emergency Medicine (L.M.G.G.), and Intensive Care Medicine (A.M.E.S.-M., M.C.d.W.), Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands; and Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands (P.M.v.d.V.).
Anne
A
Duvekot
Victor A
VA
Viersen
Simone E
SE
Dekker
Leo M G
LM
Geeraedts
Lothar A
LA
Schwarte
Angelique M E
AM
Spoelstra-Man
Peter M
PM
van de Ven
Charissa E
CE
van den Brom
Monique C
MC
de Waard
Stephan A
SA
Loer
Christa
C
Boer
D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000378:metabolism*; D005260:Female; D005342:Fibrinolysis / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000150:complications / Q000378:metabolism* / Q000628:therapy*; D010101:Oxygen Consumption / Q000502:physiology*; D011446:Prospective Studies; D012151:Resuscitation / Q000639:trends*