Research Article

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 outcomesAUC for ROC95% CICrude OR95% CISensitivity (%)Specificity (%)

Age (years)
 <601.0
 ≥600.6290.543–0.7162.881**1.518–5.46762.163.7
NYHA classification
 I-II1.0
 III-IV0.5890.499–0.6782.496*1.231–5.06336.481.4
Ejection fraction (%)
 >401.0
 ≤400.5620.472–0.6532.400*1.052–5.47442.479.4
Hematocrit (%)
 >331.0
 ≤330.5700.483–0.6573.355*1.202–9.36690.919.6
PaO2/FiO2 ratio (mmHg)
 >2001.0
 ≤2000.6070.517–0.6962.838**1.420–5.67440.980.4
Platelet count (/mm3)
 >120,0001.0
 ≤120,0000.6070.517–0.6962.838**1.420–5.67440.980.4
Inotropic drugs (items)
 11.0
 ≥20.6720.586–0.7584.932***2.463–9.87653.081.4
Creatinine (mg%)
 <1.21.0
 ≥1.20.5810.491–0.6712.508*1.192–5.27731.884.3
Potassium level (mEq/L)
 >3.21.0
 ≤3.20.5780.487–0.6682.812*1.251–6.32327.388.2
Atrial fibrillation grading#
 <21.0
 ≥20.6340.547–0.7213.020**1.588–5.74259.167.6

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.
, , .