Table 3:
AUC for invasive mechanical ventilation variables were evaluated with regards to PNMD development in invasively ventilated patients
| a) Determination of AUC and threshold values | ||||||
|---|---|---|---|---|---|---|
| Variables | AUC | 95% CI | Cut-offa | Sensitivity | Specificity | P-value |
| PEEP | 0.718 | 0.668–0.764 | >9 | 77.2 | 62.3 | <0.001 |
| PIP | 0.780 | 0.734–0.822 | >29 | 68.1 | 73.4 | <0.001 |
| PaO2/FiO2 ratio | 0.815 | 0.771–0.854 | ≤120 | 77.2 | 79.2 | <0.001 |
| Compliance | 0.735 | 0.677–0.774 | ≤29 | 81.2 | 67.7 | <0.001 |
| TV | 0.535 | 0.482–0.588 | ≤300 | 13.6 | 96.3 | 0.681 |
| TSS | 0.578 | 0.529–0.625 | >13 | 29.1 | 91.5 | 0.271 |
| b) Comparison of PNMD incidence in subgroupsb | ||||||
| Variables | PNMD incidence, n/% | OR | 95% CI | |||
| PaO2/FiO2 | ||||||
| High PaO2/FiO2 (n = 268) | 5 (1.9) | 1 | ||||
| Low PaO2/FiO2 (n = 86) | 17 (19.8) | 12.959 | 4.618–36.364 | |||
| PIP | ||||||
| Low PIP (n = 259) | 7 (2.7) | 1 | ||||
| High PIP (n = 95) | 15 (15.8) | 6.750 | 2.659–17.138 | |||
| Compliance | ||||||
| High compliance (n = 229) | 4 (1.7) | 1 | ||||
| Low compliance (n = 125) | 18 (14.4) | 9.463 | 3.126–28.644 | |||
| PEEP | ||||||
| Low PEEP (n = 212) | 5 (2.4) | 1 | ||||
| High PEEP (n = 142) | 17 (12.0) | 5.630 | 2.027–15.638 | |||
a
Numerical values with the best sensitivity and specificities were accepted as cut-offs.
b
Using the determined cut-offs, patients were divided into subgroups according to their data above or below the threshold values.
AUC: area under the curve; CI: confidence interval; OR: odds ratio; PEEP: positive end-expiratory pressure; PIP: peak inspiratory pressure; PNMD: pneumomediastinum; TSS: overall lung total severity score; TV: tidal volume. Boldface indicates statistical significance.