Intensive Care Medicine

, 32:318

Ultrasound estimation of volume of pleural fluid in mechanically ventilated patients

  • M Balik
  • P Plasil
  • P Waldauf
  • J Pazout
  • M Fric
  • M Otahal
  • J Pachl
Brief Report

DOI: 10.1007/s00134-005-0024-2

Cite this article as:
Balik, M., Plasil, P., Waldauf, P. et al. Intensive Care Med (2006) 32: 318. doi:10.1007/s00134-005-0024-2

Abstract

Objective

The aim was to develop a practical method for estimation of the volume of pleural effusion using ultrasonography in mechanically ventilated patients.

Design

Prospective observational study.

Setting

20-bed general intensive care unit in the university hospital.

Patients and participants

81 patients were included after initial suspicion of pleural fluid on chest supine X-ray and pre-puncture ultrasound confirming effusion. Patients with thoracic deformities, post-lung surgery, with diaphragm pathology, haemothorax, empyema and with incomplete aspiration of pleural fluid on post-puncture ultrasound were excluded.

Interventions

Patients were supine with mild trunk elevation at 15°. Probe was moved upwards in posterior axillary line, and transverse section perpendicular to the body axis was obtained with pleural separation visible at lung base. The maximal distance between parietal and visceral pleura (Sep) in end-expiration was recorded. Thoracentesis was performed at previous probe position and volume of pleural fluid (V) recorded.

Measurements and results

92 effusions were evaluated and drained; 11 (12%) were excluded for incomplete aspiration. Success rate of obtaining fluid under ultrasound guidance was 100%; the incidence of pneumothorax or bleeding was zero. Mean Sep was 35 ± 13 mm. Mean V was 658 ± 320 ml. Significant positive correlation between both Sep and V was found: r = 0.72; r2 = 0.52; p < 0.001. The amount of pleural fluid volume can be estimated with the simplified formula: V (ml) = 20 × Sep (mm). Mean prediction error of V using Sep was 158.4 ± 160.6 ml.

Conclusions

Easy quantification of pleural fluid may help to decide about performing thoracentesis in high-risk patients, although thoracentesis under ultrasound guidance appears to be a safe procedure.

Keywords

Intensive carePleural effusionThoracentesisUltrasound diagnosis

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • M Balik
    • 1
    • 2
  • P Plasil
    • 1
  • P Waldauf
    • 1
  • J Pazout
    • 1
  • M Fric
    • 1
  • M Otahal
    • 1
  • J Pachl
    • 1
  1. 1.Department of Anaesthesiology and Intensive CareUniversity Hospital Kralovske VinohradyPrague 10Czech Republic
  2. 2.Department of Intensive CareWestmead HospitalWestmeadAustralia