Table 2. Candidate variables for inclusion in model.
| Characteristic | VAE-VAC | VAE-IVAC | P value |
|---|---|---|---|
| n available for each day | |||
| n with data 4 d before VAE | 108 | 21 | |
| n with data 3 d before VAE | 120 | 28 | |
| n with data 2 d before VAE | 139 | 46 | |
| n with data 1 d before VAE | 139 | 46 | |
| n with data day of VAE | 142 | 46 | |
| n with data 1 d after VAE | 140 | 45 | |
| n with data 2 d after VAE | 125 | 44 | |
| n with data 3 d after VAE | 118 | 43 | |
| WBC count cells × 109/L | |||
| 4 d before VAE | 12.9 (0.7) | 13.8 (1.6) | .60 |
| 3 d before VAE | 13.1 (0.7) | 12.8 (1.5) | .85 |
| 2 d before VAE | 14.6 (0.9) | 13.2 (1.6) | .42 |
| 1 d before VAE | 13.5 (0.6) | 13.2 (1.1) | .81 |
| Day of VAE | 13.7 (0.7) | 13.5 (1.2) | .87 |
| 1 d after VAE | 13.5 (0.7) | 12.9 (1.2) | .67 |
| 2 d after VAE | 12.6 (0.6) | 13.6 (1.1) | .56 |
| 3 d after VAE | 12.6 (0.7) | 13.6 (1.1) | .47 |
| Maximum temperature °C | |||
| 4 d before VAE | 37.7 (0.1) | 37.4 (0.2) | .14 |
| 3 d before VAE | 37.6 (0.1) | 37.8 (0.2) | .31 |
| 2 d before VAE | 37.6 (0.1) | 38.2 (0.1) | <.01 |
| 1 d before VAE | 37.7 (0.1) | 38.2 (0.1) | <.01 |
| Day of VAE | 37.6 (0.1) | 38.1 (0.1) | .002 |
| 1 d after VAE | 37.6 (0.1) | 38.2 (0.1) | <.01 |
| 2 d after VAE | 37.5 (0.1) | 38.0 (0.1) | .01 |
| 3 d after VAE | 37.5 (0.1) | 38.0 (0.1) | <.01 |
| Tracheal secretions | |||
| 4 d before VAE | .73 | ||
| No secretions | 67.5% | 65.1% | |
| Nonpurulent secretions | 21.6% | 27.0% | |
| Purulent secretions | 10.8% | 7.94% | |
| 3 d before VAE | <.01 | ||
| No secretions | 64.6% | 74.4% | |
| Nonpurulent secretions | 32.3% | 10.9% | |
| Purulent secretions | 3.2% | 12.8% | |
| 2 d before VAE | .07 | ||
| No secretions | 98.0% | 90.0% | |
| Nonpurulent secretions | 2.0% | 6.7% | |
| Purulent secretions | 0% | 3.3% | |
| 1 d before VAE | .14 | ||
| No secretions | 61.0% | 45.5% | |
| Nonpurulent secretions | 29.1% | 36.4% | |
| Purulent secretions | 9.9% | 18.2% | |
| Day of VAE | <.01 | ||
| No secretions | 58.2% | 35.6% | |
| Nonpurulent secretions | 32.0% | 40.0% | |
| Purulent secretions | 9.9% | 24.4% | |
| 1 d after VAE | .15 | ||
| No secretions | 61.7% | 46.7% | |
| Nonpurulent secretions | 25.5% | 40.0% | |
| Purulent secretions | 12.8% | 13.3% | |
| 2 d after VAE | .10 | ||
| No secretions | 63.9% | 44.4% | |
| Nonpurulent secretions | 28.6% | 37.8% | |
| Purulent secretions | 7.5% | 17.8% | |
| 3 d after VAE | .11 | ||
| No secretions | 65.9% | 53.5% | |
| Nonpurulent secretions | 24.8% | 25.6% | |
| Purulent secretions | 9.3% | 20.9% | |
| Worst PaO2/FiO2 ratio | |||
| 4 d before VAE | 201 (9.7) | 162 (22) | .10 |
| 3 d before VAE | 206 (9.7) | 186 (20.0) | .38 |
| 2 d before VAE | 184 (8.1) | 145 (13.5) | .02 |
| 1 d before VAE | 177 (7.5) | 152 (12.9) | .09 |
| Day of VAE | 207 (8.9) | 170 (14.6) | .03 |
| 1 d after VAE | 214 (10.0) | 203 (15.9) | .54 |
| 2 d after VAE | 229 (13.4) | 208 (18.6) | .36 |
| 3 d after VAE | 227 (12.9) | 186 (17.3) | .07 |
| Antecedent noninvasive use | 48% (68) | 36% (16) | .17 |
| Culture methodology | .008 | ||
| BAL | 9.9% (14) | 0% (0) | |
| Bronchial washing | 7.0% (10) | 21.8% (10) | |
| Tracheal aspirate | 36.0% (51) | 54.4% (25) | |
| WBCs insputum | .013 | ||
| None | 0% | 4.3% | |
| Present | 7.8% | 4.3% | |
| Few | 20.4% | 15.2% | |
| Many | 18.3% | 41.3% | |
NOTE. Results are n, % or mean SD.
BAL, broncheoalveloar lavage; IVAC, infection-related ventilator-associated complication; VAC, ventilator-associated complication; VAE, ventilator-associated event; WBC, white blood cell.