Table 2.
Ability of pulse pressure variations to predict an increase of more than 15% in cardiac output after volume expansion according to tidal volume, driving pressure, respiratory compliance, heart rate/respiratory rate ratio and vasopressor use
| AUC ROC 95% CI | Optimal threshold (%) | Gray zone | |
|---|---|---|---|
| V T /IBW (ml/kg) | |||
| <8 (n = 280) | 0.69 (0.64-0.73) | 9 | 2-17 |
| ≥8 (n = 276) | 0.77 (0.73-0.81)a | 12 | 8-19 |
| Driving pressure (cm H 2 0) | |||
| ≤ 20 (n = 356) | 0.67 (0.63-0.72) | 7 | 3-17 |
| >20 (n = 51) | 0.78 (0.74-0.82)b | 14 | 12-21 |
| C st,rs (mL/cm H 2 0) | |||
| ≤ 30 (n = 145) | 0.60 (0.51-0.70) | 12 | 2-21 |
| >30 (n = 262) | 0.73 (0.67-0.79) | 7 | 3-17 |
| HR/RR | |||
| ≤ 3.6 (n = 114) | 0.65 (0.54-0.76) | 7 | 1-12 |
| >3.6 (n = 384) | 0.73 (0.68-0.78) | 10 | 5-17 |
| Vasopressor | |||
| Yes (n = 249) | 0.70 (0.66-0.75) | 14 | 3-16 |
| No (n = 307) | 0.72 (0.69-0.77) | 10 | 6-18 |
Data are presented as medians (95% confidence intervals). a: P <0.001 vs <8 ml.kg−1; b: P <0.001 vs ≤20 cm H20). AUC, area under the receiver operating characteristics curves, Cst,rs, static compliance of the respiratory system; HR/RR, heart rate/respiratory rate ratio; VT /IBW, tidal volume/ideal body weight ratio.