In Reply:

We thank Dr Blanco and Dr Bello for their interest and comments on our manuscript.¹ Bedside lung ultrasound has become a primary tool in daily ICU management. Indeed, it is our concern that, despite its diagnostic success and accuracy, lung ultrasound does not have the same remarkable impact when it comes to patient-centered outcomes. Laursen et al² elegantly showed that point-of-care ultrasonography was superior to standard diagnostic tests alone to establish the correct diagnosis in individuals presenting to the emergency department with respiratory impairment. However, no effects on mortality or length of hospital stay were observed, and there was a significant increase in downstream testing in the point-of-care ultrasonography group.

Certainly we do not rule out the usefulness of echocardiography and lung, diaphragm, and vein ultrasound in many critical and emergency scenarios. Nevertheless, withholding a safe test such as a spontaneous breathing trial up to vanishing of B-lines may be harmful or, at least, pointless. It must be highlighted that simple weaning, which is the most common scenario for an ordinary medical-surgical ICU, comprised 75.6% of our study population.¹

Regarding pleural ultrasound, a systematic review and meta-analysis was unable to identify any evidence to support or refute the use of pleural drainage to promote liberation from mechanical ventilation.³ Llamas-Álvarez et al⁴ raised applicability concerns of diaphragm ultrasound for weaning management after a large number of studies performed it in populations with higher likelihood of weaning failure.

Because de-aeration found in lower lung regions implies gravitational changes after a few days on mechanical ventilation,⁵ our simplified 4-zone approach seemed plausible for the purposes of our study. We did recognize that, based on our data, no inference could be made regarding either entire lung assessment or its integration with echocardiography. We cannot completely agree, however, with the argument that an intensivist could perform this approach accurately without consuming a great deal of time.

We fully agree with the compelling need to explore the full potential of lung ultrasound. We do, however, question whether additional diagnostic testing will truly improve the patient's prognosis, given their current presentation of signs and symptoms.

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