Lung pulse visualized through pleural effusion as a diagnostic sign of complete obstructive atelectasis of the left lung in a critical patient with respiratory failure. / Pulso pulmonar visualizado a través de derrame pleural como signo diagnóstico de atelectasia obstructiva completa del pulmón izquierdo en paciente crítico con insuficiencia respiratoria.

Complete obstructive atelectasis occurs when mucous or a foreign body obstruct one of the main bronchi. Several lung ultrasound signs have been associated with this entity. We describe the case of a patient admitted to the surgical critical care unit in whom lung ultrasound led to a diagnosis of complete obstructive atelectasis, and the presence of pleural effusion provided direct visualization of lung pulse, a sign that has only previously been described by interpreting ultrasound artifacts.