Bedside chest ultrasound reduces the rate of chest X-ray and CT examinations

Introduction

A bedside chest ultrasound (bCUS) programme performed by intensivists after 18 months of ultrasound training was introduced in the ICU routine between April and November 2008 in order to evaluate its effects on the number of chest X-ray (CXR) and CT scans. The setting was a 10-bed emergency ICU.

Methods

From April to November 2008 every patient has undergone a bCUS within the first 48 hours since admittance, then between the fourth and the sixth days of their stay. All of the 92 patients were examined supine, with a convex probe perpendicular to the chest wall, using all the intercostal spaces as the acoustic window. From the lung base, every intercostal space has been examined, looking for a pleural effusion, attaining to the following criteria: a space between the visceral and parietal pleura, movement of that space in agreement with the respiratory pattern. As for the volume esteem of the effusion, the distance (mm) between the posterior part of the lung and the posterior chest wall was measured. For each patient the following data were collected: age, sex, weight, height, SAPS II, number of CXR and CT scans done. 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. P < 0.05 was considered statistically significant.

Results

The two groups of patients were statistically homogeneous. Comparing the control group with the study group, CXRs were reduced by 22.63% (from 433 to 335; P = not significant) and CT scans were reduced by 42.36% (from 144 to 83; P < 0.05).

Conclusion

The use of daily routine bCUS is useful to reduce the traditional radiology requests. The decrease of CT scans is statistically relevant. As far as CXR requests are concerned, the decrease does not appear significant since the CXR is relatively easy to perform and it is mandatory after radiopaque device positioning. These amount to 34% of the total CXRs performed.