Changes in cerebral blood flow and oxygen extraction during post-resuscitation syndrome.
BACKGROUND
Most survivors of out-of-hospital cardiac arrest (OHCA) will die subsequently from post-anoxic encephalopathy. In animals, the severity of brain damage is mainly influenced by the duration of cardiac arrest and also by the cerebral blood flow (CBF) and oxygen extraction (CEO2) abnormalities observed during the post-resuscitation period. The aim of our study was to describe CBF and CEO2 modifications during the first 72 h in OHCA patients treated by induced mild hypothermia.


METHODS
Consecutive OHCA patients were studied every 12 h over 72 h. Diastolic flow velocities (dFV), mean flow velocities (mFV) and pulsatility index (PI) were assessed by transcranial doppler (TCD) as an estimate of CBF changes. Simultaneous measurements of CEO2 were obtained using retrograde jugular catheterisation.


RESULTS
Eighteen patients (61 [47-74] years) were studied (12 non-survivors and 6 survivors). At admission, mFV values were low (27.3 [21.5-33.6]cm/s) but reached normal values after 72 h (50.5 [36.7-58.1]cm/s). Initial PI values were high (1.6 [1.3-1.9]) but reached normal values after 72 h (1.04 [0.82-1.2]). No differences were found between survivors and non-survivors regarding these CBF estimates. CEO2 values were quite normal at admission (20.4 [11-27%]) but decreased over time in non-survivors until H72 (25.8% [19.3-31.1] versus 5.7% [5.1-11.5], p=0.02).


CONCLUSIONS
Cerebral haemodynamic and oxygenation values are altered considerably but evolve during the first 72 h following resuscitation after cardiac arrest. In particular, these changes may lead to a mismatch between CBF and CEO2 leading to a "luxurous perfusion" in non-survivors.
Lemiale
Virginie
V
Medical Intensive Care Unit, Cochin Hospital, 27 rue du Faubourg Saint-Jacques, 75679 Paris Cedex 14, France.
Huet
Olivier
O
Vigué
Bernard
B
Mathonnet
Armelle
A
Spaulding
Christian
C
Mira
Jean-Paul
JP
Carli
Pierre
P
Duranteau
Jacques
J
Cariou
Alain
A
D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006323:Heart Arrest / Q000503:physiopathology* / Q000628:therapy*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011673:Pulsatile Flow; D018709:Statistics, Nonparametric; D013577:Syndrome; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial
D010100:Oxygen