Role of Point-of-Care Ultrasound in the Management of Mechanical Ventilation

Ultrasound (US) became an essential tool in the hands of the intensivist and is now recommended both for procedural guidance and diagnostic purposes. Point-of-care ultrasound (POCUS) is an immediately available and repeatable, non-irradiating bedside tool integrating the clinical examination. Recent years were characterized by a growing interest in the fields of lung ultrasound (LUS) and diaphragm ultrasound (DUS). The combination of these two ultrasound techniques with critical care echocardiography (CCE) may integrate the classical approach to mechanically ventilated patients, both for monitoring and diagnostic purposes, finally contributing to the titration of mechanical ventilation and to the management of respiratory disease. Lung, diaphragm, and cardiac US provide significant information to improve the management of the critical patient under mechanical ventilation, from the initial assessment, through the ventilation setting (like PEEP) and its complication diagnosis (like pneumothorax, atelectasis), until the weaning process. LUS is of particular help in COVID-19 patients. It is potentially able to distinguish between the two phenotypes (type H and type L) of COVID-19, based on the different signs and patterns and also the assessment of prone positioning effects and lung recruitment maneuvers in these patients. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

Lung Ultrasound in Critical Care and Emergency Medicine: Clinical Review.

Lung ultrasound has become a part of the daily examination of physicians working in intensive, sub-intensive, and general medical wards. The easy access to hand-held ultrasound machines in wards where they were not available in the past facilitated the widespread use of ultrasound, both for clinical examination and as a guide to procedures; among point-of-care ultrasound techniques, the lung ultrasound saw the greatest spread in the last decade. The COVID-19 pandemic has given a boost to the use of ultrasound since it allows to obtain a wide range of clinical information with a bedside, not harmful, repeatable examination that is reliable. This led to the remarkable growth of publications on lung ultrasounds. The first part of this narrative review aims to discuss basic aspects of lung ultrasounds, from the machine setting, probe choice, and standard examination to signs and semiotics for qualitative and quantitative lung ultrasound interpretation. The second part focuses on how to use lung ultrasound to answer specific clinical questions in critical care units and in emergency departments.

Distribution of Aeration and Pulmonary Blood Volume in Healthy, ARDS and COVID-19 Lungs: A Dual-Energy Computed Tomography Retrospective Cohort Study.

RATIONALE AND OBJECTIVES: Few reports have studied lung aeration and perfusion in normal lungs, COVID-19, and ARDS from other causes (NC-ARDS) using dual-energy computed tomography pulmonary angiograms (DE-CTPA). To describe lung aeration and blood-volume distribution using DE-CTPAs of patients with NC-ARDS, COVID-19, and controls with a normal DE-CTPA ("healthy lungs"). We hypothesized that each of these conditions has unique ranges of aeration and pulmonary blood volumes. MATERIALS AND METHODS: This retrospective, single-center study of DE-CTPAs included patients with COVID-19, NC-ARDS (Berlin criteria), and controls. Patients with macroscopic pulmonary embolisms were excluded. The outcomes studied were the (1) lung blood-volume in areas with different aeration levels (normal, ground glass opacities [GGO], consolidated lung) and (2) aeration/blood-volume ratios. RESULTS: Included were 20 patients with COVID-19 (10 milds, 10 moderate-severe), six with NC-ARDS, and 12 healthy-controls. Lung aeration was lowest in patients with severe COVID-19 24% (IQR13%-31%) followed by those with NC-ARDS 40%(IQR21%-46%). Blood-volume in GGO was lowest in patients with COVID-19 [moderate-severe:-28.6 (IQR-33.1-23.2); mild: -30.1 (IQR-33.3-23.4)] and highest in normally aerated areas in NC-ARDS -37.4 (IQR-52.5-30.2-) and moderate-severe COVID-19 -33.5(IQR-44.2-28.5). The median aeration/blood-volume ratio was lowest in severe COVID-19 but some values overlapped with those observed among patients with NC-ARDS. CONCLUSION: Severe COVID-19 disease is associated with low total aerated lung volume and blood-volume in areas with GGO and overall aeration/blood volume ratios, and with high blood volume in normal lung areas. In this hypothesis-generating study, these findings were most pronounced in severe COVID disease. Larger studies are needed to confirm these preliminary findings.