Diabetic patients have abnormal cerebral autoregulation during cardiopulmonary bypass
- Duke Univ. Medical Center, Durham, NC (USA)
We tested the hypothesis that insulin-dependent diabetic patients with coronary artery bypass graft surgery experience altered coupling of cerebral blood flow and oxygen consumption. In a study of 23 patients (11 diabetics and 12 age-matched controls), cerebral blood flow was measured using 133Xe clearance during nonpulsatile, alpha-stat blood gas managed cardiopulmonary bypass at the conditions of hypothermia and normothermia. In diabetic patients, the cerebral blood flow at 26.6 +/- 2.42 degrees C was 25.3 +/- 14.34 ml/100 g/min and at 36.9 +/- 0.58 degrees C it was 27.3 +/- 7.40 ml/100 g/min (p = NS). The control patients increased cerebral blood flow from 20.7 +/- 6.78 ml/100 g/min at 28.4 +/- 2.81 degrees C to 37.6 +/- 8.81 ml/100 g/min at 36.5 +/- 0.45 degrees C (p less than or equal to 0.005). The oxygen consumption was calculated from jugular bulb effluent and increased from hypothermic values of 0.52 +/- 0.20 ml/100 g/min in diabetics to 1.26 +/- 0.28 ml/100 g/min (p = 0.001) at normothermia and rose from 0.60 +/- 0.27 to 1.49 +/- 0.35 ml/100 g/min (p = 0.0005) in the controls. Thus, despite temperature-mediated changes in oxygen consumption, diabetic patients did not increase cerebral blood flow as metabolism increased. Arteriovenous oxygen saturation gradients and oxygen extraction across the brain were calculated from arterial and jugular bulb blood samples. The increase in arteriovenous oxygen difference between temperature conditions in diabetic patients and controls was significantly different (p = 0.01). These data reveal that diabetic patients lose cerebral autoregulation during cardiopulmonary bypass and compensate for an imbalance in adequate oxygen delivery by increasing oxygen extraction.
- OSTI ID:
- 6273202
- Journal Information:
- Circulation; (USA), Journal Name: Circulation; (USA) Vol. 82:5 Suppl; ISSN 0009-7322; ISSN CIRCA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ARTERIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD FLOW
BLOOD VESSELS
BODY
BRAIN
CARDIOVASCULAR SYSTEM
CENTRAL NERVOUS SYSTEM
CEREBRAL CORTEX
CEREBRUM
CORONARIES
DAYS LIVING RADIOISOTOPES
DIABETES MELLITUS
DISEASES
ELEMENTS
ENDOCRINE DISEASES
EVEN-ODD NUCLEI
GRAFTS
HORMONES
INSULIN
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MEDICINE
METABOLIC DISEASES
NERVOUS SYSTEM
NONMETALS
NUCLEI
ORGANS
OXYGEN
PATHOGENESIS
PATIENTS
PEPTIDE HORMONES
RADIOISOTOPES
SURGERY
TRANSPLANTS
XENON 133
XENON ISOTOPES