Measurement of blood flow index during antegrade selective cerebral perfusion with near-infrared spectroscopy in newborn piglets.
BACKGROUND
Neonates with complex congenital heart defects have traditionally undergone surgery during deep hypothermic cardiac arrest (HCA). Selective cerebral perfusion (SCP) is thought to minimize ischemic brain injury by providing adequate cerebral blood flow. We investigated SCP with different flow rates compared with HCA with respect to cerebral perfusion and tissue oxygenation as assessed by near-infrared spectroscopy.


METHODS
Twenty-one piglets were placed on cardiopulmonary bypass at 18 degrees C, then underwent either HCA or SCP at 25 or 50 mL x kg(-1) x min(-1) for 90 min. The blood flow index (BFI) derived by indocyanine green and tissue oxygen index (TOI) were determined by near-infrared spectroscopy. Mean cerebral blood flow velocity (FV(mean)) was recorded by transcranial Doppler ultrasound.


RESULTS
Both BFI and FV(mean) increased significantly (126 +/- 27% of baseline; 19 +/- 2 cm/s) in the SCP 50 group compared with HCA (no flow) and SCP 25 (65 +/- 24%; 10 +/- 1 cm/s), respectively. TOI increased in the SCP 50 group compared with baseline (74 +/- 4% vs 65 +/- 4%), and was higher compared with HCA (52 +/- 2%) and SCP 25 (59 +/- 2%). Intracranial pressure increased nonsignificantly compared with baseline in the SCP 50 group.


CONCLUSIONS
Both BFI and FV(mean) suggested increased cerebral perfusion in the SCP 50 group compared with the HCA and SCP 25 groups. TOI was significantly higher in both the SCP 25 and SCP 50 groups compared with HCA. SCP at 25 mL x kg(-1) x min(-1) may be most appropriate for cerebral protection.
Meybohm
Patrick
P
Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Schwanenweg 21, 24105 Kiel, Germany. meybohm@anaesthesie.uni-kiel.de
Hoffmann
Grischa
G
Renner
Jochen
J
Boening
Andreas
A
Cavus
Erol
E
Steinfath
Markus
M
Scholz
Jens
J
Bein
Berthold
B
D000818:Animals; D000831:Animals, Newborn; D001783:Blood Flow Velocity; D001831:Body Temperature; D001921:Brain / Q000098:blood supply* / Q000378:metabolism / Q000503:physiopathology; D002545:Brain Ischemia / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D002245:Carbon Dioxide / Q000097:blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D002560:Cerebrovascular Circulation; D050792:Circulatory Arrest, Deep Hypothermia Induced / Q000009:adverse effects*; D007427:Intracranial Pressure; D016343:Monitoring, Intraoperative / Q000379:methods*; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D010477:Perfusion / Q000379:methods*; D012039:Regional Blood Flow; D019265:Spectroscopy, Near-Infrared; D013552:Swine; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial
D002245:Carbon Dioxide; D010100:Oxygen