CARDIOVASCULAR
ENGINEERING
Journal for Extracorporeal Circulation, Assist Devices,Transplantation and Artificial Organs
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CARDIOVASCULAR
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Volume 3, 1998, No 1 |
Abstract:
Near-infrared spectroscopy was used to monitor cerebral oxygen
metabolism in 15 patients undergoing elective aortocoronary
bypass surgery (CPB). Additionally cerebral blood flow using a
pulsed 2-MHz transcranial Doppler (TCD) device was estimated.
Nasopharyngeal and rectal temperature and mean arterial pressure
were continuously registered. As a result we found the onset of
CPB and the period of rewarming to be a potential risk of
cerebral ischaemia. During the early period of initiating CPB no
changes in the rSO2 time course was seen. 10 minutes after the
onset of CPB the regional cerebral oxygen saturation (rSO2) data
decreased significantly (p <0.05) from baseline 66,8 ± 4,0 to 63,8 ± 5,3%. the mean arterial blood pressure (map) decreased significantly from 81,1 ± 7,3 to 44,5 ± 5,3 mmhg (p < 0.05) immediately after the onset of cpb and was accompanied by a significant increase (p < 0.05) of mean blood flow velocity measured in the middle cerebral artery (vmmca) from 25,5 ± 6,1 to 34,9 ± 8,9 cm/s. changes of rso2 data were not significantly accompanied by changes in cerebral blood flow and mean arterial pressure within the range of 45-90 mmhg. during the termination from cpb no significant changes in rso2 time course were observed. the absolute values of rso2 in our study ranged from 78 to 57%. in conclusion we found nirs to be a useful tool to determine phases of cerebral desaturation in the perioperative period. although significant changes were observed, no exact prediction regarding the potential neurological deficits can be made because there are no investigations yet, which have defined a "critical" rso2 value.
Keywords:
near-infrared spectroscopy, cerebral oxygenation, oxygen
metabolism
Reference:
(CVE. 1998; 3 (1): 57-60)
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