ABSTRACT
PURPOSE: To examine whether lung ultrasound prior to prone positioning can predict the resulting gas-exchange response. MATERIALS AND METHODS: This is a prospective observational study on critically-ill COVID-19 patients with a pilot and confirmation cohort. Lung ultrasound examinations were performed before prone positioning and gas-exchange parameters were recorded before and after position change. RESULTS: A total of 79 patients, 36 in the pilot cohort and 43 in the confirmation cohort, were included. In the pilot cohort, a moderate correlation between pre-turn lung ultrasound score index (LUSI) and change in PaO2/FiO2 after prone positioning was found. These findings were corroborated and extended upon in the confirmation cohort. The confirmation cohort found that anterior LUSI had the strongest correlation with follow-up time-points 1, 6, 12, and 24 h after prone positioning, with strength of correlation gradually increasing up to 24 h. In a multivariate model anterior aeration loss (odds ratio 0.035; 95%CI 0.003-0.319 for anterior LUSI >50%) and higher pre-turn PaCO2 (odds ratio 0.479 95% CI 0.235-0.979) were negatively predictive of a PaO2/FiO2 increase ≥20 mmHg. CONCLUSIONS: Anterior LUSI, in addition to other clinical parameters, may be used to aid COVID-19 respiratory strategy and a clinician's decision to prone.
ABSTRACT
High flow nasal oxygen (HFNO) is proven to be effective in non-COVID-19 hypoxemic respiratory failure. In the beginning of the COVID-19 pandemic, HFNO was quickly introduced into daily clinical practice, although the evidence of its effectiveness in COVID-19 was limited. Randomized controlled trials suggest that HFNO has no effect on survival. However, HFNO may lead to less intubations in comparison with conventional oxygen therapy. The evidence of HFNO use in patients with do-not-intubate orders remains very limited. However, in these patients, improvement in comfort could be an important argument to start treatment with HFNO. Additional research is needed to make an evidence based consideration about the clinical use of HFNO in COVID-19 care.
ABSTRACT
Introduction: Beneficial effects of prone position on outcome in ARDS may be related to decreased anterior chest wall compliance, which facilitates lung recruitment. The effects of anterior external chest wall compression (AEC) in supine position on respiratory mechanics and gas exchange are less well known [1]. We aimed to evaluate the effects of AEC in invasively ventilated COVID-19 patients. Methods: In 10 sedated and paralyzed COVID-19 patients ventilated in volume control mode, airway and esophageal pressures, driving pressure (DP) and lung compliance (Clung) were recorded before (baseline) and during (5 kg, 10 kg) AEC (10-min epochs). AEC was performed by placing one or two 5 l fluid bags on anterior chest. Repeated arterial blood gas analysis was available in 6 patients. Results: Patients' (9/1 M/F, age 65 [range 53-74] yrs, BMI 29.2 [range 23.2-50.5] kg/m2, PEEP median 11.8 (IQR 9.7-13.9) cmH2O), Clung at baseline (median 21.3;IQR 15.0-32.6 ml/cmH2O) increased > 10% with 5 kg AEC (mean 20.7 ± 7.3%, max. increase 30.9%) and additionally increased with 5.9% (range -2.9-19.3%) with 10 kg AEC (Fig. 1a, p < 0.001). Better response was related to an anteriorly located baby lung on CT imaging. At baseline, median transpulmonary DP (Pl DP) was 17.46 (IQR 11.50-25.07) cmH2O and decreased with 16.2 ± 4.9% and 20.6 ± 8.2% during 5 kg and 10 kg AEC, respectively (Fig. 1b, p < 0.001). pCO2 decreased in 4 patients and remained equal in 2 patients (Fig. 1c). The latter group also had minimal change in Pl DP and Clung. In all patients PO2 decreased with need for increasing FiO2. Median P/F ratio of 124 (IQR 104-143) mmHg at baseline decreased to 105 (IQR 92-124) mmHg and 86 (IQR 78-114) mmHg during 5 kg and 10 kg AEC respectively. Conclusions: This preliminary data demonstrates improved compliance of the aeriated lung by decreasing hyperinflation. No evidence for recruitment was found in contrast to existing literature showing improved oxygenation [2]. (Table Presented).