title: Cardiac displacement during off-pump coronary artery bypass grafting surgery: effect on sublingual microcirculation and cerebral oxygenation.
abstract: Cardiac displacement during off-pump coronary artery bypass (OPCAB) surgery causes a fall in cardiac output. Here, we investigate how this drop in systemic perfusion is transferred to the oxygenation of sublingual and cerebral tissue. Sublingual microcirculatory perfusion or microcirculatory hemoglobin oxygen saturation (μHbSO(2)) measurements were performed using sidestream dark-field imaging and reflectance spectrophotometry, respectively (both n = 12). The cerebral tissue oxygenation index was measured by near-infrared spectrophotometry (n = 12). Cardiac output was calculated by pulse contour analysis of arterial pressure. Cardiac displacement reduced the cardiac output from 4.3 ± 0.8 to 1.2 ± 0.3 l/min (P < 0.05), paralleled by a decrease in μHbSO(2) from 64.2 ± 9.1 to 48.6 ± 8.7% (P < 0.01). Cardiac displacement did not change functional capillary density, while red blood cell velocity decreased from 895 ± 209 to 396 ± 178 μm/s (P<0.01). Cerebral tissue oxygenation index decreased from 69.5 ± 4.0 to 57.4 ± 8.5% (P<0.01) during cardiac displacement. After repositioning of the heart, all the values returned to baseline. Our data suggest that systemic hemodynamic alterations during cardiac displacement in OPCAB surgery reduce sublingual and cerebral tissue oxygenation. These findings are particularly important for patients at risk for the consequences of cerebral ischemia.
authors: Department of Translational Physiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam,  The Netherlands.
authors: Bektas
authors: B
authors: Atasever
authors: Christa
authors: C
authors: Boer
authors: Ron
authors: R
authors: Speekenbrink
authors: Jan
authors: J
authors: Seyffert
authors: Peter
authors: P
authors: Goedhart
authors: Bas
authors: B
authors: de Mol
authors: Can
authors: C
authors: Ince
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply*; D002302:Cardiac Output; D002560:Cerebrovascular Circulation; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009060:Mouth Floor / Q000098:blood supply*; D009426:Netherlands; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D010108:Oxyhemoglobins / Q000378:metabolism; D011446:Prospective Studies; D012039:Regional Blood Flow; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors
chemical_list: D015415:Biomarkers; D010108:Oxyhemoglobins; D010100:Oxygen