Table 3.
Summary of studies of pulmonary mechanics after thoracentesis in mechanically ventilated patients
| Study | Proportion Mechanically Ventilated | N | Time of Outcome Measurement | Variable | Outcome a | ||
|---|---|---|---|---|---|---|---|
| Before | After | P-value | |||||
| Ahmed 2004 | 100% | 22 | <1 hour before and after thoracentesis | Peak inspiratory pressure (cm H2O) | 34.9 ± 8.4 | 35.9 ± 12.5 | 0.64b |
| Respiratory rate | 19.4 ± 6.5 | 15.5 ± 6.3 | 0.03 | ||||
| Doelken 2006 | 100% | 9 | Immediately before and after procedure | Peak inspiratory pressure (cm H2O) | 43.8 ± 13.7 | 40.8 ± 10.6 | 0.08 |
| Plateau pressure (cm H2O) | 20.0 ± 9.0 | 17.8 ± 5.6 | 0.19 | ||||
| Dynamic compliance (L/cm H2O) | 14.5 ± 5.3 | 15.2 ± 5.0 | 0.12 | ||||
| Ventilator work per cycle (Joules) | 3.42 ± 1.05 | 2.99 ± 0.81 | 0.01 | ||||
| Talmor 1998 | 100% | 19 | Immediately before and after procedure | Peak inspiratory pressure (cm H2O) | 44.3 ± 13.9 | 42.9 ± 18.7 | 0.74b |
| Dynamic compliance (L/cm H2O) | 27.1 ± 15.3 | 35.7 ± 30.5 | < 0.05 | ||||
a Values are reported as mean ± standard deviation.
b P-value not provided in the original paper; we calculated the P-value based on the data provided, assuming a correlation between the before and after measurements of 0.4.