Could chest ultrasonography replace routine chest X-rays in mechanically ventilated patients?

Impact of routine bedside lung ultrasound implementation on chest x-ray requests for mechanically ventilated children: a before-after uncontrolled quality improvement project

Lung imaging techniques are crucial for managing ventilated patients in pediatric intensive care units (PICUs). Bedside chest x-ray has limitations such as low sensitivity and radiation exposure risks. Recently, lung ultrasound has emerged as a promising technology offering advantages such as real-time monitoring and radiation-free imaging. However, the integration of lung ultrasound into clinical practice raises questions about its impact on chest x-ray prescriptions. This study aims to assess whether implementing lung ultrasound reduces reliance on chest x-rays for ventilated pediatric patients in the PICU. This before-and-after uncontrolled quality improvement project was conducted from January 2022 to December 2023 in a referral PICU. The study included three phases: retrospective evaluation, learning phase, and prospective evaluation. Patients aged under 14 years, intubated, and ventilated for ≤ 30 days were included. Lung ultrasound was performed using a standardized protocol, and chest x-rays were conducted as per clinical indications. During the study period, 430 patients were admitted to the PICU, with 142 requiring mechanical ventilation. Implementation of routine bedside lung ultrasound led to a 39% reduction in chest x-ray requests (p < 0.001). Additionally, there was a significant decrease in irradiation exposure and a 27% reduction in costs associated with chest x-rays.Conclusion: Routine bedside lung ultrasound is a valuable tool in the modern PICU, it reduces the number of chest x-rays, with reduced radiation exposure and a potential cost savings. What is known: • Bedside chest x-ray is the main imaging study in ventilated pediatric patients • Chest x-ray is a valuable tool in pediatric critical care but it is associated with irradiation exposure What is new: • Implementation of bedside lung ultrasound in pediatric critical care unites reduces the chest x-rays requests and therefore patient-irradiation.

Diagnostic Performance of Point of Care Ultrasound Compared to Chest X-Ray in Patients with Hypoxia at a Teaching Hospital Emergency Department in Uganda

Background

Hypoxia is a common presentation in the Emergency Department (ED) worldwide. It affects 9-12% of hospitalized adults in Sub-Saharan Africa. Timely diagnosis of the multiple causes such as pneumonia, heart failure among others is challenging. Chest X-Ray (CXR), one of the most utilized imaging modalities has many limitations, and the gold standard (Computed Tomography scan) is inaccessible. Point of care ultrasound (PoCUS) is more available and increasingly being used, however little is known of its performance in resource limited EDs. The study aimed to assess the diagnostic performance of PoCUS compared with CXR in identifying the causes of hypoxia in the medical ED.

Methods

49 adults presenting with hypoxia (SP02 ≤ 88%) in the medical ED were evaluated. Ultrasound of the lungs and heart (PoCUS) was done, then CXR obtained. Lung ultrasound (LUS) was compared with CXR (first reference standard). Chest X-Ray and PoCUS were each compared to the physician diagnosis (second reference standard) to determine agreement using an acceptable disagreement cut-off of 15%.

Results

31% more abnormalities were identified by LUS than CXR. Lung ultrasound findings agreed with CXR in 86% of the participants with moderate reliability (ĸ=0.75). There was no significant difference between the actual findings of the two tests (X²= 2, p 0.1). Using the second reference, 82% of the CXRs were similar with weak reliability (ĸ=0.5) compared to 98% of PoCUS findings with strong reliability (ĸ=0.9). Compared to PoCUS, CXRs significantly differed from the physician diagnosis (X²= 0.85, p 0.38 vs X²= 8.5, p 0.004 respectively).

Conclusion

Overall, PoCUS was not inferior to CXR when compared to final physician diagnosis in identifying causes of hypoxia, and LUS and CXR had comparable performance. Significantly more abnormalities were identified on PoCUS and it demonstrated better agreement and strong reliability with the physician diagnosis than CXR. We recommend PoCUS use in patients with hypoxia attending resource limited in- and pre-hospital settings.

Excess Radiation to Newborns Hospitalized in the Intensive Care Unit

Newborns in intensive care units are generally subjected to a great number of X-rays procedures and to the risk of radiation-induced damage. This study evaluated a possible excess radiation by excess of radiographs, excess of dose per radiograph or under-collimation of the X-ray beam. The mean of X-rays per newborn was 12 (1-65) during a mean hospitalization of 29 d (1-226 d). The mean frequency was 0.8 X-ray exposures per newborn. About 13% of X-rays were performed without a well-defined clinical motivation. The mean entrance surface dose of 72 μGy was higher than in most of comparative studies. Under-collimation caused non-thoracic structures to appear frequently on chest radiographs. This study indicates a possible reduction in X-rays exposures by applying the justification principle for each X-ray procedure, recommends a multiprofessional work in the attempt to dose optimization, and shows need of correctly use of collimation system to avoid irradiation of non-thoracic structures.