Summary: Ultrasound imaging of the lung and associated tissues may play an important role in the management of patients with COVID ‐19–associated lung injury. Compared with other monitoring modalities, such as auscultation or radiographic imaging, we argue lung ultrasound has high diagnostic accuracy, is ergonomically favourable and has fewer infection control implications. By informing the initiation, escalation, titration and weaning of respiratory support, lung ultrasound can be integrated into COVID ‐19 care pathways for patients with respiratory failure. Given the unprecedented pressure on healthcare services currently, supporting and educating clinicians is a key enabler of the wider implementation of lung ultrasound. This narrative review provides a summary of evidence and clinical guidance for the use and interpretation of lung ultrasound for patients with moderate, severe and critical COVID ‐19–associated lung injury. Mechanisms by which the potential lung ultrasound workforce can be deployed are explored, including a pragmatic approach to training, governance, imaging, interpretation of images and implementation of lung ultrasound into routine clinical practice.

Echocardiography is ideally suited to guide fluid resuscitation in critically ill patients. It can be used to assess fluid responsiveness by looking at the left ventricle, aortic outflow, inferior vena cava and right ventricle. Static measurements and dynamic variables based on heart–lung interactions all combine to predict and measure fluid responsiveness and assess response to intravenous fluid resuscitation. Thorough knowledge of these variables, the physiology behind them and the pitfalls in their use allows the echocardiographer to confidently assess these patients and in combination with clinical judgement manage them appropriately.

Critically ill patients need rapid access to accurate and reproducible imaging techniques to diagnose pathology, implement, and monitor treatment. Point-of-care ultrasound (US) has become firmly established in acute and critical care settings (FAST, vascular access, echocardiography) and is now emerging as an important tool in the assessment of the lungs.

The resuscitation of a patient in shock is a highly complex endeavor that should go beyond normalizing mean arterial pressure and protocolized fluid loading. We propose a holistic, four-interface conceptual model of shock that we believe can benefit both clinicians at the bedside and researchers. The four circulatory interfaces whose uncoupling results in shock are as follows: the left ventricle to arterial, the arterial to capillary, the capillary to venular, and finally the right ventricle to pulmonary artery. We review the pathophysiology and clinical consequences behind the uncoupling of these interfaces, as well as how to assess them, and propose a strategy for approaching a patient in shock. Bedside assessment of shock may include these critical interfaces in order to avoid hemodynamic incoherence and to focus on microcirculatory restoration rather than simply mean arterial pressure. The purpose of this model is to serve as a mental model for learners as well as a framework for further resuscitation research that incorporates these concepts.

FUSIC haemodynamics (HD) – the latest Focused Ultrasound in Intensive Care (FUSIC) module created by the Intensive Care Society (ICS) – describes a complete haemodynamic assessment with ultrasound based on ten key clinical questions: 1. Is stroke volume abnormal? 2. Is stroke volume responsive to fluid, vasopressors or inotropes? 3. Is the aorta abnormal? 4. Is the aortic valve, mitral valve or tricuspid valve severely abnormal? 5. Is there systolic anterior motion of the mitral valve? 6. Is there a regional wall motion abnormality? 7. Are there features of raised left atrial pressure? 8. Are there features of right ventricular impairment or raised pulmonary artery pressure? 9. Are there features of tamponade? 10. Is there venous congestion? FUSIC HD is the first system of its kind to interrogate major cardiac, arterial and venous structures to direct time-critical interventions in acutely unwell patients. This article explains the rationale for this accreditation, outlines the training pathway and summarises the ten clinical questions. Further details are included in an online supplementary appendix.

The resuscitation of the patient in shock is a highly complex endeavor which should go beyond normalizing mean arterial pressure and protocolized fluid loading. We propose a holistic, four interface conceptual model of shock which we feel can benefit both clinicians at the bedside and researchers. The four circulatory interfaces whose uncoupling result in shock are the left ventricle to arterial, the arterial to capillary, the capillary to venular and finally the right ventricle to pulmonary artery. We review the pathophysiology and clinical consequences behind the uncoupling of these interfaces as well as how to assess them and propose a strategy on how to approach the patient in shock. Bedside assessment of shock may include these critical interfaces in order to avoid hemodynamic incoherence and focus on microcirculatory restoration rather than simply mean arterial pressure. Further research may incorporate these concepts.