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Table 3 Crude hemodynamic measurements during different time periods and adjusted change in estimate with hyperoxic ventilation

From: Hemodynamic effects of short-term hyperoxia after coronary artery bypass grafting

Hemodynamic variables T1 T2 T3 Hyperoxia vs. normoxia P value
Pre Hyperoxia Post Adjusted change in estimate (95% CI)
Central circulatory variablesa
 MAP (mmHg) 77 (11) 85 (11)*** 78 (11) 6.76 (3.88; 9.63) <0.0001
 CVP (mmHg) 9.1 (1.7) 9.6 (1.7) 9.3 (1.6) 0.35 (0.11; 0.60) 0.01
 HR (beats min−1) 84 (14) 82 (14) 83 (15) −0.55 (−3.05; 2.06) 0.68
Calculated variables
 CO Modelflow (L min−1)b 5.12 (1.04) 4.97 (1.13) 4.98 (1.18) −0.08 (−0.27; 0.11) 0.41
 SVV (%)b 13.6 (9.3) 13.2 (6.9) 15.3 (7.4) −1.76 (−3.38; −0.03) 0.05
 PPV (%)b 15.6 (10.3) 15.1 (7.6) 16.6 (4.9) −1.30 (−2.99; 0.49) 0.16
 CO LiDCOplus (L min−1)c 4.80 (1.10) 4.62 (1.10) 4.79 (1.27) −0.12 (−0.40; 0.08) 0.21
Derived parametersd
 R sys (mmHg min L−1) 13.4 (4.9) 15.3 (5.9)*** 13.6 (5.1) 1.82 (0.96; 2.67) <0.001
 P vr (mmHg) 11.7 (3.3) 13.5 (3.5)* 12.1 (2.8) 1.47 (0.61; 2.37) <0.01
 R vr (mmHg min L−1) 2.4 (0.8) 2.8 (1.0)** 2.5 (0.8) 0.39 (0.21; 0.58) <0.001
 Slopevrc (L min−1 mmHg−1) −0.46 (0.16) −0.38 (0.13)** −0.44 (0.15) 0.07 (0.03; 0.10) <0.001
 P msf (mmHg) 20.8 (3.5) 23.1 (4.0)* 21.4 (2.9) 1.90 (0.95; 2.93) <0.001
 R vo (mmHg min L−1) 7.9 (3.2) 7.9 (4.3) 7.7 (1.9) −0.09 (−1.17; 1.03) 0.87
 Slopevoc (L min−1 mmHg−1) 0.13 (0.05) 0.15 (0.11) 0.14 (0.04) 0.01 (−0.03; 0.05) 0.62
 P cc (mmHg) 38.8 (9.8) 47.9 (15.1)* 40.9 (8.9) 8.55 (4.13; 12.68) <0.001
Cerebral blood flowe
 BFVmca (cm s−1) 34.6 (10.6) 32.3 (10.3) 33.6 (11.5) −1.42 (−3.80; 1.01) 0.26
 Pulsatility index 0.95 0.96 1.0 −0.03 (−0.07; 0.01) 0.17
 Resistance index 0.57 0.57 0.58 0 (−0.01; 0.01) 0.66
Microcirculationf
 RBC filling (%) 72.3 (4.4) 71.1 (5.0) 72.9 (5.1) −1.87 (−3.29; −0.34) 0.02
 PBR (µm) 2.1 (0.2) 2.2 (0.2) 2.1 (0.2) 0.05 (−0.03; 0.12) 0.21
 TVD (mm/mm2) 12.2 (3.5) 12.7 (3.5) 12.0 (3.4) 0.35 (−0.96; 2.08) 0.66
 PVD (mm/mm2) 12.0 (3.7) 12.1 (2.9) 12.0 (3.1) −0.03 (−1.50; 1.70) 0.97
 VVD (µm/mm2) 712 (117) 672 (130) 699 (93) −37.29 (−80.97; 8.01) 0.11
 De Backer Score (n/mm) 14.2 (1.2) 15.1 (1.6) 14.4 (1.6) 0.86 (0.23; 1.51) 0.01
 PV (%) 99.6 (1.3) 93.2 (8.3)* 97.4 (6.1) −4.72 (−7.64; −2.00) <0.01
  100 (IQR 99–100) 98 (IQR 85–100) 100 (IQR 99–100)
 Heterogeneity index (%) 13 [9–14] 22 [21–23]*** 21 [15–21]***
  1. Change in estimate (95% CI) with intervention (hyperoxia) in reference to normoxia periods from linear mixed model adjusted for age, temperature, Hb, PaCO2, norepinephrine dose and propofol dose. P value calculated using t tests with Satterthwaite approximations to degrees of freedom
  2. Data are means (SD). For PV (%), medians (interquartile range) are provided
  3. MAP mean arterial pressure, CVP central venous pressure, HR heart rate, CO cardiac output, SVV stroke volume variation, PPV pulse pressure variation, R sys resistance of the systemic circulation, P vr pressure difference between P msf and P cv, R vr resistance for venous return, Slope vrc slope of venous return curve, P msf mean systemic filling pressure, R vo resistance for ventricular output, Slope voc slope of ventricular output curve, P cc critical closing pressure, BFV mca blood flow velocity in middle cerebral artery, RBC red blood cell, PBR perfused boundary region, TVD total vascular density, PVD perfused vascular density, VVD valid vascular density, PV perfused vessels
  4. P < 0.01; ** P < 0.001; *** P < 0.0001 for paired comparison between indicated outcome and baseline (T1)
  5. aDirectly measured from radial artery and central venous catheters
  6. bCalculated beat-to-beat by pulse contour analysis from Modelflow and averaged over indicated time period
  7. cCalculated by pulse contour analysis from LiDCOplus 15 min after starting the exposure at indicated time period
  8. dSecondarily derived from Modelflow calculated variables
  9. eDirectly measured using transcranial Doppler on middle cerebral artery
  10. fCalculated from sublingual sidestream dark field imaging analyses