Table 3.
Multivariable Model on ICU Mortality
| Variable | Odds Ratio (95% CI) | P Value |
|---|---|---|
| PEEP lower than ARDSNet (vs. on-protocol/high PEEP) | 2.05 (1.32–3.17) | 0.001 |
| PRISM III* | 1.08 (1.06–1.11) | <0.001 |
| Immunodeficiency (vs. no immunodeficiency) | 2.00 (1.27–3.13) | 0.003 |
| Stem cell transplant, no inotropes | 4.64 (2.29–9.39) | <0.001 |
| Stem cell transplant, yes inotropes | 12.4 (5.12–30.1) | 0.013 |
| No stem cell transplant, yes inotropes | 2.67 (1.66–4.30) | <0.001 |
| CHOP dataset (vs. all other datasets) | 0.46 (0.28–0.77) | 0.001 |
| Nitric oxide not at CHOP | 3.28 (1.70–6.35) | 0.001 |
| Nitric oxide at CHOP | 1.29 (0.52–3.23) | NS |
| Driving pressure* | 1.05 (1.009–1.087) | 0.015 |
| PF ratio (Day 1)* | 1.0 (0.998–1.002) | 0.91 |
Definition of abbreviations: ARDSNet = ARDS Network; CHOP = Children’s Hospital of Philadelphia; CI = confidence interval; NS = not significant; PEEP = positive end-expiratory pressure; PF = PaO2/FiO2; PRISM = Pediatric Risk of Mortality.
There was an independent association between PEEP lower than recommended by the ARDSNet protocol for a given FiO2 and higher mortality, after controlling for PRISM III score, immunodeficiency, stem cell transplant, inotrope use, nitric oxide, driving pressure, PF ratio, and dataset. There were multiplicative interactions between inotrope use and stem cell transplant, and CHOP and nitric oxide use. PF ratio was retained in model because it had an important confounding effect on the relationship between PEEP lower than the protocol and mortality.
Variables treated as continuous in the multivariable model.