Variables at 4 hours associated with failure of treatment
| Variable | Univariate analysis p value | Multivariate analysis | |||
|---|---|---|---|---|---|
| Odds ratio | p value | ||||
| At enrolment | |||||
| H+ | <0.001 | 1.23 (1.05 to 1.43) per nmol/l | <0.01 | ||
| Pao2 | 0.035 | ||||
| Paco 2 | <0.001 | 1.77 (1.28 to 2.45) per kPa | <0.01 | ||
| Allocation to NIV | 0.038 | ||||
| At 1 hour | |||||
| Fall in H+ | 0.119 | ||||
| Change in Pao 2 | 0.193 | ||||
| Change in Paco 2 | 0.276 | ||||
| Change in respiratory rate | 0.209 | ||||
| At 4 hours | |||||
| Fall in H+ | 0.035 | 0.89 (0.82 to 0.97) per nmol/l | <0.01 | ||
| Change in Pao 2 | 0.896 | ||||
| Change in Paco 2 | 0.104 | ||||
| Change in respiratory rate | 0.009 | 0.92 (0.84 to 0.99) per breath/min | 0.04 | ||
Paco2 , Pao 2 = arterial carbon dioxide and oxygen tensions; NIV = non-invasive ventilation.