Lung ultrasound training: how short is too short? observational study on the effects of a focused theoretical training for novice learners.

BACKGROUND: Lung ultrasound has been increasingly used in the last years for the assessment of patients with respiratory diseases; it is considered a simple technique, now spreading from physicians to other healthcare professionals as nurses and physiotherapists, as well as to medical students. These providers may require a different training to acquire lung ultrasound skills, since they are expected to have no previous experience with ultrasound. The aim of the study was to assess the impact of a short theoretical training focused on lung ultrasound pattern recognition in a population of novice nurse learners with no previous experience with ultrasound. METHODS: We included the nurses attending a critical care advanced course for nurses performed at the University of Pavia. Images' interpretation skills were tested on two slide sets (a 25-clip set focused on B-pattern recognition and a 25-clip set focused on identification of pleural movement as lung sliding, lung pulse, lung point, no movement) before and after three 30-minute teaching modules dedicated to general ultrasound principles, B-lines assessment and lung sliding assessment. A cut off of 80% was considered acceptable for correctly interpreted images after this basic course. RESULTS: 22 nurses were enrolled (age 26.0 [24.0-28.0] years; men 4 (18%)); one nurse had previous experience with other ultrasound techniques, none of them had previous experience with lung ultrasound. After the training, the number of correctly interpreted clips improved from 3.5 [0.0-13.0] to 22.0 [19.0-23.0] (p < 0.0001) for B-pattern and from 0.5 [0.0-2.0] to 8.5 [6.0-12.0] (p < 0.0001) for lung sliding assessment. The number of correct answers for B-pattern recognition was significantly higher than for lung sliding assessment, both before (3.5 [0.0-13.0] vs. 0.5 [0.0-2.0]; p = 0.0036) and after (22.0 [19.0-23.0] vs. 8.5 [6.0-12.0]; p < 0.0001) the training. After the training, nurses were able to correctly recognize the presence or the absence of a B-pattern in 84.2 ± 10.3% of cases; lung sliding was correctly assessed in 37.1 ± 15.3% of cases. CONCLUSIONS: Lung ultrasound is considered a simple technique; while a short, focused training significantly improves B-pattern recognition, lung sliding assessment may require a longer training for novice learners. TRIAL REGISTRATION: Not applicable.

Echocardiographic assessment of right ventricular performance in COVID-19 related acute respiratory distress syndrome: the importance of systo-diastolic interaction.

BACKGROUND: The cardiac manifestations of COVID-19 have been described in patients with acute respiratory distress syndrome (ARDS) admitted to intensive care unit (ICU). The presence and impact of right ventricular (RV) diastolic function and performance has not been studied in this population yet. We describe the prevalence of RV diastolic dysfunction, assessed by the pulmonary valve pre-ejection A wave (PV A wave), and the RV systo-diastolic interaction, using the RV total isovolumic time (t-IVT), in COVID-19 ARDS. RESULTS: Prospective observational study enrolling patients with moderate to severe COVID-19 ARDS admitted to ICU who underwent a transthoracic echocardiogram within 24 h of ICU admission and at least a second one during the ICU stay. Respiratory, hemodynamic and biochemistry parameters were collected. 163 patients (age 61.0 ± 9.3 years, 72% males) were enrolled. 36 patients (22.1%) had RV dysfunction, 45 (27.1%) LV systolic dysfunction. 73 patients (44.7%) had PV A wave. The RV t-IVT correlated with TAPSE at ICU admission (p < 0.002; r - 0.61), presence of PV A wave (p < 0.001; r 0.78), peak inspiratory pressure (PIP) (p < 0.001; r 0.42), PEEP (p < 0.001; r 0.68), dynamic driving pressure (DDP) (p < 0.001; r 0.58), and PaO2/FiO2 ratio (p < 0.01; r - 0.35). The presence of PV A wave was associated with higher PIP (p < 0.001; r 0.45), higher PEEP (p < 0.001; r 0.56), higher DDP (p < 0.01, r 0.51), and lower PaO2/FiO2 ratio (p < 0.001; r - 0.49). CONCLUSIONS: RV t-IVT and the presence of PV A wave are non-invasive means to describe a significant RV diastolic dysfunction and may be consider descriptive signs of RV performance in COVID-19 ARDS.