Organ blood flow following cardiac arrest in a swine low-flow cardiopulmonary bypass model.
OBJECTIVE
To determine organ blood flow changes, relative to baseline, following cardiac arrest and resuscitation in a closed-chest cardiac arrest swine model using cardiopulmonary bypass to achieve reproducible return of spontaneous circulation (ROSC).


METHODS
Following 10 min of ventricular fibrillation (VF), animals (n = 10) received low-flow cardiopulmonary bypass at 10 ml/kg/min from 10-15 min. At 15 min of VF, norepinephrine (0.12 mg/kg) was given and bypass flow increased to 50 ml/kg/min, followed by countershocks at 16 min. Following ROSC, cardiopulmonary bypass was immediately weaned off with norepinephrine support. Organ blood flows were determined during normal sinus rhythm, during reperfusion of VF and during the early post-ROSC period while off cardiopulmonary bypass support. Organ blood flows during the early ROSC period were compared with organ blood flow at baseline and during VF.


RESULTS
During early reperfusion of VF prior to any drug therapy, myocardial, cerebral and abdominal organ blood flows were all low. All animals achieved ROSC at 16.9 +/- 0.7 min and were weaned from bypass in < 5 min following ROSC. During the early post-ROSC period, blood flow to the myocardial, cerebral and adrenal vascular beds was significantly elevated relative to baseline. Simultaneously, blood flow to the kidneys, liver, spleen and lungs was reduced relative to baseline.


CONCLUSIONS
This low-flow bypass model produces reproducible high resuscitation rates and ROSC times. Early post-resuscitation organ blood flow is characterized by a selective hyperemia involving the cerebral, myocardial and adrenal vascular beds, in contrast to hypoperfusion of the pulmonary and mesenteric vascular beds.
Angelos
M G
MG
Department of Emergency Medicine, Ohio State University, Columbus 43210.
Ward
K R
KR
Hobson
J
J
Beckley
P D
PD
D000818:Animals; D002315:Cardiopulmonary Bypass; D004554:Electric Countershock; D006323:Heart Arrest / Q000503:physiopathology / Q000628:therapy*; D006940:Hyperemia / Q000209:etiology* / Q000503:physiopathology; D009638:Norepinephrine / Q000627:therapeutic use; D012039:Regional Blood Flow / Q000502:physiology*; D012151:Resuscitation / Q000379:methods*; D013552:Swine; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000628:therapy*
D009638:Norepinephrine