TY - JOUR
T1 - Near-infrared spectroscopy assessed cerebral oxygenation during open abdominal aortic aneurysm repair
T2 - relation to end-tidal CO2 tension
AU - Sørensen, H.
AU - Nielsen, Henning Morris Bay
AU - Secher, N H
PY - 2016/8/1
Y1 - 2016/8/1
N2 - During open abdominal aortic aneurism (AAA) repair cerebral blood flow is challenged. Clamping of the aorta may lead to unintended hyperventilation as metabolism is reduced by perfusion of a smaller part of the body and reperfusion of the aorta releases vasodilatory substances including CO2. We intend to adjust ventilation according end-tidal CO2 tension (EtCO2) and here evaluated to what extent that strategy maintains frontal lobe oxygenation (ScO2) as determined by near infrared spectroscopy. For 44 patients [5 women, aged 70 (48–83) years] ScO2, mean arterial pressure (MAP), EtCO2, and ventilation were obtained retrospectively from the anesthetic charts. By clamping the aorta, ScO2 and EtCO2 were kept stable by reducing ventilation (median, −0.8 l min−1; interquartile range, −1.1 to −0.4; P < 0.001). During reperfusion of the aorta a reduction in MAP by 8 mmHg (−15 to −1; P < 0.001) did not prevent an increase in ScO2 by 2 % (−1 to 4; P < 0.001) as EtCO2 increased 0.5 kPa (0.1–1.0; P < 0.001) despite an increase in ventilation by 1.8 l min−1 (0.9–2.7; P < 0.001). Changes in ScO2 related to those in EtCO2 (r = 0.41; P = 0.0001) and cerebral deoxygenation (−15 %) was noted in three patients while cerebral hyperoxygenation (+15 %) manifests in one patient. Thus changes in ScO2 were kept within acceptable limits (±15 %) in 91 % of the patients. For the majority of the patients undergoing AAA repair ScO2 was kept within reasonable limits by reducing ventilation by approximately 1 l min−1 upon clamping of the aorta and increasing ventilation by approximately 2 l min−1 when the lower body is reperfused.
AB - During open abdominal aortic aneurism (AAA) repair cerebral blood flow is challenged. Clamping of the aorta may lead to unintended hyperventilation as metabolism is reduced by perfusion of a smaller part of the body and reperfusion of the aorta releases vasodilatory substances including CO2. We intend to adjust ventilation according end-tidal CO2 tension (EtCO2) and here evaluated to what extent that strategy maintains frontal lobe oxygenation (ScO2) as determined by near infrared spectroscopy. For 44 patients [5 women, aged 70 (48–83) years] ScO2, mean arterial pressure (MAP), EtCO2, and ventilation were obtained retrospectively from the anesthetic charts. By clamping the aorta, ScO2 and EtCO2 were kept stable by reducing ventilation (median, −0.8 l min−1; interquartile range, −1.1 to −0.4; P < 0.001). During reperfusion of the aorta a reduction in MAP by 8 mmHg (−15 to −1; P < 0.001) did not prevent an increase in ScO2 by 2 % (−1 to 4; P < 0.001) as EtCO2 increased 0.5 kPa (0.1–1.0; P < 0.001) despite an increase in ventilation by 1.8 l min−1 (0.9–2.7; P < 0.001). Changes in ScO2 related to those in EtCO2 (r = 0.41; P = 0.0001) and cerebral deoxygenation (−15 %) was noted in three patients while cerebral hyperoxygenation (+15 %) manifests in one patient. Thus changes in ScO2 were kept within acceptable limits (±15 %) in 91 % of the patients. For the majority of the patients undergoing AAA repair ScO2 was kept within reasonable limits by reducing ventilation by approximately 1 l min−1 upon clamping of the aorta and increasing ventilation by approximately 2 l min−1 when the lower body is reperfused.
KW - Journal Article
U2 - 10.1007/s10877-015-9732-5
DO - 10.1007/s10877-015-9732-5
M3 - Journal article
C2 - 26141676
SN - 1387-1307
VL - 30
SP - 409
EP - 415
JO - Journal of Clinical Monitoring and Computing
JF - Journal of Clinical Monitoring and Computing
IS - 4
ER -