Univariate comparison of survivors and non-survivors
| Hospital survival (readmissions to ICU excluded) | p Value | ||
|---|---|---|---|
| Yes (n = 1768) | No (n = 58) | ||
| ICU, intensive care unit; ABG, arterial blood gas; Pao2, Paco2, arterial oxygen and carbon dioxide tensions; Fio2, fraction of inspired oxygen. | |||
| All values reported as mean (SD) except length of stay reported as median (IQR). | |||
| All values recorded are the worst within the first 24 h. | |||
| *Chronic respiratory disease is defined as chronic restrictive, obstructive or vascular respiratory disease resulting in severe exercise restriction, ie, unable to climb stairs or perform household duties; or documented chronic hypoxia, hypercapnia, secondary polycythaemia, severe pulmonary hypertension (>40 mm Hg) or respiratory dependency. | |||
| 32 patients had no outcome recorded, 41 patients had readmissions to ICU. | |||
| Outcomes | |||
| Duration of ICU stay (days) | 1.6 (0.7–2.9) | 4.6 (1.4–9.2) | <0.001 |
| Proportion ventilated in first 24 h | 34.9% (617/1768) | 74.1% (43/58) | <0.001 |
| Demographic data | |||
| Age (years) | 38.9 (18.1) | 57.2 (19.3) | <0.001 |
| Proportion ⩽16 years | 8.4% (148/1768) | 1.7% (1/58) | 0.251 |
| Proportion > 45 years | 34.2% (605/1768) | 72.4% (42/58) | <0.001 |
| Proportion with chronic respiratory disease* | 16.0% (283/1768) | 32.7% (19/58) | <0.001 |
| Proportion female | 64.5% (628/1768) | 65% (37/58) | 0.887 |
| Physiology | |||
| Pulse | 132 (23) | 132 (27) | 0.956 |
| Mean arterial blood pressure (mm Hg) | 87 (0.6) | 79 (3.7) | <0.001 |
| pH from ABG with lowest Pao2 | 7.28 (0.15) | 7.17 (0.14) | <0.001 |
| Paco2 from ABG with lowest pH (kPa) | 7.24 (3.87) | 9.88 (0.02) | <0.001 |
| Bicarbonate (mmol) | 22.9 (6.0) | 25.1 (8.2) | 0.009 |
| Pao2 (kPa) | 17.33 (12.67) | 19.60 (16.00) | 0.412 |
| Pao2/Fio2 ratio | 277 (159) | 241 (161) | 0.099 |
| Glasgow coma score | 13.9 (2.9) | 10.5 (5.1) | <0.001 |
| Urea (mmol/l) | 6.2 (0.18) | 10.46 (1.3) | <0.001 |
| Creatinine (μmol/l) | 83.3 (1.1) | 126.1 (11.9) | <0.001 |