Table 2. Unadjusted variables for risk of NIV failure.
| Vital sign | Unadjusted hazard ratio (95% confidence interval) | p -Value |
|---|---|---|
| Heart rate (HR) | ||
| Tachycardia at initiation a | 0.93 (0.41, 2.14) | 0.863 |
| Worsening HR at 1 hour | 1.00 (0.42, 2.37) | 0.991 |
| Worsening HR at 6 hours | 2.32 (0.78, 6.71) | 0.130 |
| Respiratory rate (RR) | ||
| At initiation | 0.83 (0.37, 1.84) | 0.644 |
| Worsening RR at 1 hour | 2.91 (1.21, 7.00) | 0.017 |
| Worsening RR at 6 hours | 4.55 (1.44, 14.34) | 0.010 |
| Saturation from pulse oximetry (SpO 2 ) | ||
| At initiation | 0.93 (0.84, 1.02) | 0.102 |
| Worsening SpO 2 at 1 hour | 1.43 (0.53, 3.91) | 0.484 |
| Worsening SpO 2 at 6 hours | 0.60 (0.21, 1.73) | 0.343 |
| Fraction of inspired oxygen (FiO 2 ) ≥ 45% | ||
| At initiation | 3.77 (1.43, 9.95) | 0.007 |
| At 1 hour | 1.74 (0.74, 4.11) | 0.205 |
| At 6 hours | 2.67 (0.90, 7.98) | 0.078 |
| SpO 2 :FiO 2 b | ||
| At initiation | 0.99 (0.98, 1.00) | 0.075 |
| Worsening SpO 2 :FiO 2 at 1 hour | 2.26 (0.46, 11.19) | 0.319 |
| Worsening SpO 2 :FiO 2 at 6 hours | 9.45 (0.85, 105.12) | 0.068 |
| Acuity scores | ||
| PELOD | 1.04 (0.98, 1.10) | 0.197 |
| PRISM | 1.06 (0.97, 1.61) | 0.175 |
Abbreviations: NIV, noninvasive ventilation; PRISM, pediatric risk of mortality; PELOD, pediatric logistic organ dysfunction.
a
Tachycardia defined by being above age-specific norms.
b
Only 46 patients with valid data available.