Robert Simon

The rapid spread of SARS-CoV-2 (COVID-19) since December 2019 forced Intensive Care Units to face high numbers of patients admitted simultaneously with limited resources. COVID-19 critically ill patients, especially those on mechanical ventilators, demand special attention as they can develop potential complications with critical hemodynamic and respiratory consequences. Point of Care Ultrasound (POCUS) might have important roles in assessing the critically ill SARS-CoV-2 patient. Mostly, lung ultrasound has been presented as having a role in diagnosis and monitoring, but airway examination and hemodynamic evaluation are of interest also. We propose an A.B.C. POCUS approach focusing on A-airway (orotracheal intubation), B-breathing (interstitial syn-dromes, pneumothorax, atelectasis, pneumonia), and C-circulation (cardiac function, pulmonary embolism, volume status, deep veins thrombosis). This A.B.C. approach has emerged during ICU care for 22 adult COVID-19 critically ill patients, along with the analysis of recent papers describing ultrasound in COVID-19 patients including the use of ultrasound that is currently applied in the management of the general critically ill population. This A.B.C- POCUS algorithm parallels the well-established clinical A.B.C. algorithms. There are few extensive ultrasonographic studies in COVID-19 critically ill patients up to now, but techniques extrapolated from non-COVID studies seem reasonable even though comparative studies are not available yet.

Purpose: To describe the correlation between clinically measured hyomental distance ratio (HMDR_clin) and the ultrasound measurement (HMDR_echo) in patients with and without morbid obesity and to compare their diagnostic accuracy for difficult airway prediction. Methods: HMDR_clin and HMDR_echo were recorded the day before surgery in 160 consecutive consenting patients. Laryngoscopy was performed by a skilled anesthesiologist, with grades III and IV Cormack–Lehane being considered difficult views of the glottis. Linear regression was used to assess the correlation between HMDR_clin and HDMR_echo and receiver operating curve analysis was used to compare the performance of the two for predicting difficult airway. Results: The linear correlation between HMDR_clin and HDMR_echo in patients without morbid obesity had a Pearson coefficient of 0.494, while for patients with morbid obesity this was 0.14. A slightly higher area under the curve for HMDR_echo was oberved: 0.64 (5%CI 0.56–0.71) versus 0.52 (95%CI, 0.44–0.60) (p = 0.34). Conclusion: The association between HMDR_clin and HDMR_echo is moderate in patients without morbid obesity, but negligible in morbidly obese patients. These might be explained by difficulties in palpating anatomical structures of the airway.