Does bedside chest ultrasound in the ICU improve early diagnosis and quick resolution of pleural effusion?

Introduction

A bedside chest ultrasound (bCUS) programme performed by intensivists after 18 months of training was introduced on a regular basis in a 10-bed emergency ICU from April to November 2008, in order to check its effectiveness in the early diagnosis and treatment of pleural effusion (PE). The results have been compared with those of a control group, when bCUS was not part of the ICU procedures.

Methods

The procedure was performed within the first 24 hours after admittance. All of the 92 patients were examined supine, with the probe perpendicular to the chest wall, using all of the intercostal spaces as the acoustic window. With this technique, once we identified the lung's base, we looked for signs of PE according to the following criteria: (a) space between the two pleural layers; (b) variation in the interpleural distance of this space during breathing. For each patient the following data were collected: age, sex, weight, height, SAPS II, number of chest drains, number of ultrasound scans performed, number of significant PE (at least 2 cm of width between the two pleurae), amount of ultrasound-guided drainage actually performed within the first 24 hours, timing of resolution of PE. Data were compared with those of a group of patients admitted to the ICU from January to March 2008, when bCUS was not part of the daily procedures and only chest CT and X-ray scans were used as evidence of PE. We considered P < 0.05 statistically significant.

Results

A total of 103 bCUS were performed on the first day in the control group, against the 12 bCUS performed in the study group. A total of 59 PEs for which drainage proved to be useful were found. An amount of 27 pleural drainages were performed within the first 24 hours. We have no evidence of complications. All of the positive cases for PE have been successfully treated. All drainage was performed within the first 24 hours or at least within the first 48 hours.

Conclusion

Compared with the control group (25.9%), in the study group 45% of drainage performed was done within the first 24 hours thanks to the skill of intensivists. As far as PE is concerned, the introduction of bCUS performed by intensivists in the ICU daily routine determines an increase of early diagnosis and treatment. However, the increase in the number of the first-day treatments was not significant since this procedure is now turning from a purely diagnostic approach into an operative one. This will necessarily need time.