Take home message
Background
Diagnosis of pleural effusion
Diagnostic imaging
Assessment of fluid volume
Authors | Patients | Position | Derived formula | Results | Mean prediction errora/mean biasb
| Limits of agreementsc/standard errord
|
---|---|---|---|---|---|---|
Vignon et al. [29] | Mechanically ventilated and not ventilated patients | Supine | NA | Pleural effusion > 800 mL predicted when the distance is: > 45 mm (right; sensitivity 94%, specificity 76%); > 50 mm (left; sensitivity 100%, specificity 67%) Positive linear correlation between distance and volume: r = 088; r2 = 0.72; p < 0.0001 | 28 ± 146 mLb
| −286 mL and +343mLc
|
Roch et al. [30] | Mechanicall ventilated patients | Supine with arm abducted | NA | A distance between lung and posterior chest wall at the lung base > 5 cm predicted a drained volume > 500 mL (sensitivity 83%, specificity 90%, positive predictive value 91%, negative predictive value 82%) | NA | NA |
Balik et al. [31] | Mechanically ventilated patients | Supine with mild trunk elevation at 15° | V(ml) = 20 × Sep (mm) | Positive linear correlation between distance (Sep) and volume: r = 0.72; r2 = 0.52; p < 0.001 | 158.4 ± 160.6a
| NA |
Usta et al. [32] | Spontaneous breathing patients after cardiac surgery | Sitting | V (ml) = 16 × D (mm) | Positive linear correlation between D and V: r = 0.89, r2 = 0.79; p < 0.001 | −21.1 ± 97.78a
| 97.42d
|
Remérand et al. [33] | Critically ill patients | Supine | V (ml) = LUS × AUS
| Positive linear correlation between ultrasound V and drained V (r = 0.84, p < 0.001) and with CT V (r = 0.90, p < 0.001). | −33b
| −292 to + 227 mLc
|
Authors | Probe position | How to measure (end-expiration) |
---|---|---|
Vignon et al. [29] | Along the dorsolateral part of the chest wall, as posteriorly as possible between the mattress and the patient’s back without lifting the hemithorax, in all IC from the base to the apex | Choose the maximal perpendicular interpleural distance from the leading edge of the dependent surface of the lung to the trailing edge of posterior chest wall, at the apex and at the base |
Roch et al. [30] | Along the posterior axillary line between the ninth and eleventh ribs to identify the liver on the right side, the spleen on the left side, and the diaphragm To visualize the effusion, the transducer was advanced cranially and a longitudinal view was chosen | Use the mean of three measurements obtained by distance between: - Lung and diaphragm - Lung and posterior chest wall at base - Lung and posterior chest wall at fifth IC |
Balik et al. [31] | Along the posterior axillary line moving the probe cranially, obtaining transverse sections perpendicular to the body axis | Choose the maximal distance between parietal and visceral pleura at lung base (minimum requirement: distance ≥ 10 mm) |
Usta et al. [32] | Along mid-scapular line moving cranially (dorsal scanning) | Choose the maximal distance between mid-height of the diaphragm and visceral pleura (minimum requirement: distance ≥ 30 mm) |
Remérand et al. [33] | Along each paravertebral intercostal space, slipping the probe between the patient’s back and mattress | The lower and upper intercostal spaces where PLEFF is detected should be drawn on the patient’s skin to establish PLEFF paravertebral length (LUS) At the half point of LUS the PLEFF area should be manually delineated |
Technical aspects
Ultrasound scanning to define the nature of pleural effusion
Exudate | Transudate | Hemothorax | Empyema | Malignant effusion | |
---|---|---|---|---|---|
Internal echogenicity: Anechoic Complex non-septated Complex septated | Septation, non -septated or anaechoic | Anechoic | Hyperechogenic | Often septated | Complex septation, non-septated |
Echogenicity: Homogeneity or not | Homogeneity or not | Not | Homogeneity | Homogeneity | Homogeneity |
Pleural thickness | Thickened | Normal | Thickness | Thickness | Irregular pleural thickness |
Other findings | Based on the etiologies | General bilaterally, echocardiography findings | Pneumothorax, atelectasis, consolidation | Pulmonary consolidation and air bronchograms | Liver metastasis; presence of pleural or diaphragmatic nodules |