Cerebral blood flow decreases with time whereas cerebral oxygen consumption remains stable during hypothermic cardiopulmonary bypass in humans

Journal Article · Fri Feb 01 00:00:00 EST 1991 · Anesthesia and Analgesia (Cleveland) (Current Researches); (USA)

DOI:https://doi.org/10.1213/00000539-199102000-00004· OSTI ID:5986950

Prough, D S; Rogers, A T; Stump, D A; Roy, R C; Cordell, A R; Phipps, J; Taylor, C L ^[1]

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1. Wake Forest Univ., Winston-Salem, NC (USA)

Recent investigations demonstrate that cerebral blood flow (CBF) progressively declines during hypothermic, nonpulsatile cardiopulmonary bypass (CPB). If CBF declines because of brain cooling, the cerebral metabolic rate for oxygen (CMRO2) should decline in parallel with the reduction in CBF. Therefore we studied the response of CBF, the cerebral arteriovenous oxygen content difference (A-VDcereO2) and CMRO2 as a function of the duration of CPB in humans. To do this, we compared the cerebrovascular response to changes in the PaCO2. Because sequential CBF measurements using xenon 133 (133Xe) clearance must be separated by 15-25 min, we hypothesized that a time-dependent decline in CBF would accentuate the CBF reduction caused by a decrease in PaCO2, but would blunt the CBF increase associated with a rise in PaCO2. We measured CBF in 25 patients and calculated the cerebral arteriovenous oxygen content difference using radial arterial and jugular venous bulb blood samples. Patients were randomly assigned to management within either a lower (32-48 mm Hg) or higher (50-71 mm Hg) range of PaCO2 uncorrected for temperature. Each patient underwent two randomly ordered sets of measurements, one at a lower PaCO2 and the other at a higher PaCO2 within the respective ranges. Cerebrovascular responsiveness to changes in PaCO2 was calculated as specific reactivity (SR), the change in CBF divided by the change in PaCO2, expressed in mL.100 g-1.min-1.mm Hg-1.

• OSTI ID: 5986950
• Journal Information: Anesthesia and Analgesia (Cleveland) (Current Researches); (USA), Vol. 72:2; ISSN 0003-2999
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CEREBRAL CORTEX
BLOOD FLOW
OXYGEN
METABOLISM
CARBON DIOXIDE
HYPOTHERMIA
MAN
PATIENTS
SURGERY
TIME DEPENDENCE
XENON 133
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
BODY TEMPERATURE
BRAIN
CARBON COMPOUNDS
CARBON OXIDES
CENTRAL NERVOUS SYSTEM
CEREBRUM
CHALCOGENIDES
DAYS LIVING RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
MEDICINE
NERVOUS SYSTEM
NONMETALS
NUCLEI
ORGANS
OXIDES
OXYGEN COMPOUNDS
PRIMATES
RADIOISOTOPES
VERTEBRATES
XENON ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics
550600 - Medicine