Validity of lung ultrasound FALLS-protocol in differentiating types of shock in critically ill patients

Abstract

Background Acute circulatory collapse is one of the most familiar challenges in ICUs. It is considered that artefacts generated by lung ultrasound (LUS) can help in diagnosis and management. FALLS-protocol using LUS is a tool proposed for the management of unexplained shock. Objectives To investigate the role of LUS FALLS-protocol in differentiating types of shock in critically ill patients. Patients and methods A total of 50 patients presented with undiagnosed shock. Fast bedside echocardiography and LUS FALLS-protocol were applied along with inferior vena cava diameter and collapsibility measurement. Results A total of 19 patients with septic shock on presentation had A profile in all of them and AB profile in three of them, and after resuscitation, they were transformed to B profile with 100% sensitivity, 90.5% specificity, 90.5% positive predictive value (PPV), and 100% negative predictive value (NPV). Overall, 16 patients with hypovolemic shock had A profile in all of them on presentation and after resuscitation, with 100% sensitivity, 94.1% specificity, 88.9% PPV, and 100% NPV. Moreover, eight patients with cardiogenic shock had B profile in all of them on presentation with 100% sensitivity, 95.2% specificity, 80% PPV, and 100% NPV; three patients with obstructive shock had A profile in all of them on presentation, with 100% sensitivity, 25.5% specificity, 7.9% PPV, and 100% NPV; and two patients with anaphylactic shock had A profile in all of them on presentation and transformed to B profile after resuscitation with 100% sensitivity, 50% specificity, 9.5% PPV, and 100% NPV. Our findings showed preference of FALLS-protocol than inferior vena cava diameter and collapsibility in directing fluid therapy. Conclusion Bedside chest ultrasound FALLS-protocol should be considered in the resuscitation pathways with a possible significant effect on patient management.