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Table 3 Postoperative continuous variables

From: A comparative analysis of predictive models of morbidity in intensive care unit after cardiac surgery – Part II: an illustrative example

Acronym Description (units) Training set Testing set Cut-off
   Mean SD Mean SD  
SAP Systolic arterial pressure (mmHg) 132 23 130 24 n.s.
DAP Diastolic arterial pressure (mmHg) 70.2 14 69.8 13 n.s.
MAP Mean arterial pressure (mmHg) 90.9 16 90.2 16 n.s.
CVP Central venous pressure (mmHg) 8.59 3.4 8.57 3.3 n.s.
FiO2 Fraction of inspired O2 0.533 0.072 0.530 0.075 n.s.
pH Potential of hydrogen 7.45 0.06 7.45 0.06 n.s.
PaCO2 Partial pressure of arterial CO2 (mmHg) 35.3 5.4 35.5 5.3 n.s.
HCO3 HCO3 arterial level (mmol/l) 24.9 2.3 25.0 2.3 n.s.
AaO2 Alveolar-arterial O2 gradient (mmHg) 187 65 188 69 n.s.
Post-HCT Hematocrit (%) 29.7 4.6 29.9 4.2 n.s.
K Potassium (mEq/l) 4.05 0.49 4.06 0.50 5↑
Gly Glycaemia (mmol/l) 170 54 172 54 n.s.
Temp Body temperature (°C) 35.4 0.89 35.3 0.92 n.s.
WBC White blood cells (nl-1) 12.2 4.5 12.6 4.3 n.s.
Hb Hemoglobin (g/dl) 9.85 1.5 9.90 1.4 n.s.
PaO2 Partial pressure of arterial O2 (mmHg) 149 39 145 40 n.s.
SaO2 Arterial oxygen saturation (%) 98.5 1.6 98.4 1.7 n.s.
PvO2 Partial pressure of venous O2 (mmHg) 32.7 4.6 33.1 4.7 32↓
SvO2 Venous O2 saturation (%) 63.5 6.9 64.1 7.0 62.5↓
CaO2 Arterial O2 content (ml/dl) 13.0 1.9 13.0 1.8 n.s.
CvO2 Venous O2 content (ml/dl) 8.41 1.7 8.54 1.7 8↓
AVO2 Artero-venous O2 difference (ml/dl) 4.60 1.0 4.52 1.0 5↑
Post-CI Cardiac index at ICU (l/min/m2) 2.63 0.65 2.61 0.66 2.5↓
SVI Stroke volume index (ml/m2) 29.4 8.2 29.0 8.2 28↓
DO2I O2 delivery index (ml/min/m2) 344 93 344 97 320↓
O2ER O2 extraction ratio (%) 35.3 7.0 34.6 7.2 40↑
RI Respiratory Index (AaO2/PaO2) 1.46 0.93 1.52 1.01 n.s.
P/F PaO2/FiO2 ratio (mmHg) 283 81 280 85 n.s.
VCO2 CO2 production (ml/min) 191 50 187 50 200↓
VO2 O2 consumption (ml/min) 224 59 219 59 220↓
SVRI Systemic vascular resistance index (MPa·s/m) 265 83 265 85 280↑
  1. ↑ or ↓:increased morbidity risk for values greater or less than cut-off, respectively (n.s.: not statistically significant); SD, standard deviation; ICU, intensive care unit.