Mean arterial pressure about 40 mmHg during CPB is associated with cerebral ischemia in piglets

• Published in: Scandinavian cardiovascular journal : SCJ Vol. 40; no. 1; pp. 54 - 61
• Main Authors: Haugen, Oddbjorn, Farstad, Marit, Lise Kvalheim, Venny, Rynning, Stein-Erik, Hammersborg, Stig, Mongstad, Arve, Husby, Paul
• Format: Journal Article
• Language: English
• Published: England Informa UK Ltd 01.02.2006; Taylor & Francis
• Subjects: Animals; Blood Pressure - drug effects; Brain - blood supply; Brain - metabolism; Brain Ischemia - etiology; Brain Ischemia - metabolism; Brain Ischemia - physiopathology; Cardiopulmonary Bypass; Cerebrovascular Circulation; Glucose - metabolism; Hypotension - complications; Lactic Acid - metabolism; Microdialysis; Nitroprusside - pharmacology; Norepinephrine - pharmacology; Pyruvic Acid - metabolism; Swine; Vasoconstrictor Agents - pharmacology; Vasodilator Agents - pharmacology
• ISSN: 1401-7431; 1651-2006
• DOI: 10.1080/14017430500365185

Objective. To investigate if a mean arterial pressure below 50 mmHg during CPB may lead to cerebral ischemia. Material and methods. Piglets with low mean arterial pressure by nitroprusside (LP-group) (n = 6) were compared with piglets given norepinephrine to obtain high pressure (HP-group) (n = 6) during normothermic and hypothermic CPB. Intracranial pressure, flow and markers of cerebral energy metabolism (microdialysis) were recorded. Results. Mean arterial pressure differed significantly between the groups and stabilized about 40-45 mmHg in the LP-group. Cerebral perfusion pressure decreased to 21.3 (7.7) mmHg in the LP-group and increased to 51.8 (11.2) mmHg in the HP-group at 150 min of CPB (P < 0.001, between groups). During bypass the intracerebral glucose concentration decreased significantly in the LP-group. In this group the lactate/pyruvate ratio increased from 15.5 (5.3) to 64.5 (87.6) at 90 min and 45.0 (36.5) at 150 min (P < 0.05) with no such changes in the HP-group. Similarly the cerebral glycerol concentration increased significantly in the LP-group, whereas glycerol remained stable in the HP-group. Conclusion. Mean arterial pressure about 40 mmHg during CPB is associated with cerebral ischemia.