Premium
PRESSURE PASSIVE CEREBRAL BLOOD FLOW AND BREAKDOWN OF THE BLOOD‐BRAIN BARRIER IN EXPERIMENTAL FETAL ASPHYXIA
Author(s) -
LOU H. C.,
LASSEN N. A.,
TWEED W. A.,
JOHNSON G.,
JONES M.,
PALAHNIUK R. J.
Publication year - 1979
Publication title -
acta pædiatrica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 115
eISSN - 1651-2227
pISSN - 0803-5253
DOI - 10.1111/j.1651-2227.1979.tb04430.x
Subject(s) - medicine , asphyxia , cerebral blood flow , fetus , blood flow , perinatal asphyxia , anesthesia , cardiology , pregnancy , biology , genetics
. Lou, H. C., Lassen, N. A., Tweed, W. A., Johnson, G., Jones, M. and Palahniuk, R. J. (Departments of Anaesthesia, Health Sciences Centre, Winnipeg, Canada). Pressure passive cerebral blood flow and breakdown of the blood‐brain barrier in experimental fetal asphyxia. Acta Paediatr Scand, 68: 57, 1979.—Cerebral blood flow (CBF) was studied in non‐exteriorized near‐term sheep fetuses using the radioactive microsphere technique. By partially occluding the umbilical vessels for a period of 1–1 1/2 hours a progressive and severe asphyxia with a final arterial pH of 6.90 was achieved. Varying the mean arterial blood pressure in the fetuses by blood withdrawal or infusion in this state, CBF was measured at different perfusion pressures (mean arterial blood pressure (MABP) minus central venous pressure (CVP)). A passive flow/pressure relationship—loss of autoregulation—was found, with hyperemia reaching CBF values up to 6 times normal at normal MABP of about 60 to 70 mmHg, and severe ischemia reaching CBF values close to zero in large cortical areas at MABP of 30 mmHg. CVP remained essentially unchanged at 10–15 mmHg. The severe and prolonged asphyxia rendered the blood‐brain barrier leaky to the albumin tracer Evans blue. In four other fetuses umbilical cord clamping was omitted. However, only in one of these cases was acidosis completely avoided, and CBF autoregulation maintained. The three other fetuses were acidotic at the end of the surgical procedure and had impaired autoregulation.