Development of an Open-Heart Intraoperative Risk Scoring Model for Predicting a Prolonged Intensive Care Unit Stay
Table 2
Univariate risk factors of a prolonged length of ICU stay.
Variable outcomes
AUC for ROC
95% CI
Crude OR
95% CI
Sensitivity (%)
Specificity (%)
Age (years)
<60
1.0
≥60
0.629
0.543–0.716
2.881**
1.518–5.467
62.1
63.7
NYHA classification
I-II
1.0
III-IV
0.589
0.499–0.678
2.496*
1.231–5.063
36.4
81.4
Ejection fraction (%)
>40
1.0
≤40
0.562
0.472–0.653
2.400*
1.052–5.474
42.4
79.4
Hematocrit (%)
>33
1.0
≤33
0.570
0.483–0.657
3.355*
1.202–9.366
90.9
19.6
PaO2/FiO2 ratio (mmHg)
>200
1.0
≤200
0.607
0.517–0.696
2.838**
1.420–5.674
40.9
80.4
Platelet count (/mm3)
>120,000
1.0
≤120,000
0.607
0.517–0.696
2.838**
1.420–5.674
40.9
80.4
Inotropic drugs (items)
1
1.0
≥2
0.672
0.586–0.758
4.932***
2.463–9.876
53.0
81.4
Creatinine (mg%)
<1.2
1.0
≥1.2
0.581
0.491–0.671
2.508*
1.192–5.277
31.8
84.3
Potassium level (mEq/L)
>3.2
1.0
≤3.2
0.578
0.487–0.668
2.812*
1.251–6.323
27.3
88.2
Atrial fibrillation grading#
<2
1.0
≥2
0.634
0.547–0.721
3.020**
1.588–5.742
59.1
67.6
ICU: intensive care unit; AUC for ROC: area under receiver operating characteristic curve; CI: confidence interval; OR: odds ratio; NYHA: New York Heart Association; PaO2: partial pressure of arterial oxygen; FiO2: fraction of inspired oxygen in a gas mixture. Atrial fibrillation (AF) grading: 0: no AF; 1: AF without tachyarrhythmia and needs no treatment; 2: AF with tachyarrhythmia and needs antiarrhythmic therapy; 3: AF with tachyarrhythmia and hemodynamic instability and needs antiarrhythmic therapy. , , .