Table 2.
Model Parameters Predicting Intensive Care Unit Length of Stay and Acute Care Unit Length of Stay
| Parameters | ICU LOS IRR [95% CI] | ACU LOS IRR [95% CI] |
|---|---|---|
|
| ||
| Age | ||
| 0–30 d (preterma) | 2.0 [1.9–2.2] | 1.5 [1.3–1.6] |
| 0–30 d (term) | 1.8 [1.7–1.9] | 1.3 [1.3–1.4] |
| 31–365 d | 1.4 [1.4–1.5] | 1.1 [1.0–1.1] |
| 1–17 y | Reference | Reference |
| ≥18 y | 0.9 [0.9–1.0] | 0.9 [0.9–1.0] |
| Chromosomal anomaly or syndrome | 1.2 [1.1–1.2] | 1.1 [1.1–1.1] |
| Extracardiac anomaly | 1.2 [1.1–1.2] | 1.2 [1.1–1.2] |
| Underweight statusb | 1.1 [1.1–1.1] | 1.1 [1.0–1.1] |
| Previous cardiothoracic surgery | 1.2 [1.2–1.3] | 1.2 [1.2–1.2] |
| 1–2 operations | ||
| ≥3 operations | 1.4 [1.4–1.5] | 1.4 [1.4–1.5] |
| Preoperative length of stayc (d) | 1.0 [1.0–1.0] | 1.0 [1.0–1.0] |
| Preoperative mechanical ventilation | 1.2 [1.1–1.2] | . |
| Preoperative mechanical circulatory support | 1.1 [0.9–1.2] | … |
| Vasoactive support at the time of surgery | 1.2 [1.1–1.2] | 1.1 [1.0–1.1] |
| High risk standard STS risk factor | 1.2 [1.2–1.3] | 1.1 [1.1–1.2] |
| Low risk standard STS risk factor | 1.1 [1.1–1.2] | … |
| STAT score | 1.3 [1.2–1.3] | 1.1 [1.1–1.2] |
| Factors present within 2 hours of ICU admission | ||
| Maximum VasoactiveInotropic Score | ||
| <5 | Reference | Reference |
| 5–15 | 1.3 [1.3–1.4] | 1.1 [1.1–1.2] |
| >15 | 1.8 [1.7–1.9] | 1.1 [1.1–1.2] |
| Mechanical ventilation | 1.4 [1.4–1.5] | … |
| Extracorporeal membrane oxygenation | 2.0 [1.8–2.3] | … |
| Open sternum | 1.4 [1.3–1.4] | … |
| High chest tube output (>5 mL/kg/h) | 1.2 [1.1–1.2] | 1.1 [1.0–1.1] |
| ICU complications and duration of intensive care therapies | ||
| Stroke | … | 1.3 [1.1–1.4] |
| Unplanned reoperation | … | 1.1 [1.1–1.2] |
| Extracorporeal membrane oxygenation | … | 1.3 [1.2–1.4] |
| Hospital acquired infection | … | 1.3 [1.2–1.4] |
| Vasoactive infusion >48 h | … | 1.1 [1.1–1.2] |
| Mechanical ventilation >48 h | … | 1.2 [1.1–1.2] |
| Noninvasive positive pressure ventilation >48 h | … | 1.2 [1.2–1.2] |
a
<37 weeks’ gestation;
b
Weight-for-age z score ≤−2 (age ≤20 years) or body mass index <18.5 kg/m2 (age >20 years);
c
Preoperative length of stay capped at 30 days.
ACU, acute care unit; CI, confidence interval; ICU, intensive care unit; IRR, incidence rate ratio; LOS, length of stay; STAT, The Society of Thoracic Surgeons–European Association for Cardiothoracic Surgery; STS, The Society of Thoracic Surgeons.