Case Report: Lung Ultrasound for the Guidance of Adjunctive Therapies in Two Invasively Ventilated Patients with COVID-19.

Two patients with respiratory failure due to confirmed COVID-19 were examined using bedside lung ultrasound (LUS) shortly after intubation and start of invasive ventilation. In the first patient, LUS revealed extensive atelectatic areas. A recruitment maneuver was applied, resulting in some reaeration of areas that showed atelectasis, and some improvement in oxygenation was observed. Oxygenation improved further with the use of prone positioning. In the second patient, LUS showed diffuse abnormalities without atelectatic areas, and ventilation proceeded without a recruitment maneuver but with prone positioning. These two cases illustrate how LUS could be useful in identifying different lung morphologies early after the start of invasive ventilation and help decide on adjunctive therapies. This has possible implications for ventilator management in resource-limited settings, with limited availability of chest computed tomography and blood gas analyzers. Tailoring invasive ventilation based on LUS findings early after the start of invasive ventilation is feasible, but this should be further evaluated in future studies.

Low hemoglobin and venous saturation levels are associated with poor neurological outcomes after cardiac arrest.

INTRODUCTION: Hemoglobin (Hb) is a main determinant of tissue oxygen delivery and anemia could be particularly harmful in post-anoxic brain injury. The aim of this study was to evaluate the association of Hb and venous Hb oxygen saturation (SvO2/ScvO2) with long-term neurological outcome in patients admitted after cardiac arrest (CA). METHODS: Analysis of adult CA patients admitted to the Department of Intensive Care of the Erasme University Hospital (Brussels, Belgium) over 9 years. We retrieved all data concerning CA characteristics as well as Hb during the first 48 h since injury as well as the need for red blood cells transfusions (RBCT). Minimum Hb and Hb oxygen saturation values were recorded. Neurological outcome was evaluated 3 months after CA. Unfavorable neurological outcome (UO) was defined as a Cerebral Performance Categories (CPC) score of 3-5. RESULTS: We treated 414 patients patients with CA, including 231 (56%) out-of-hospital cardiac arrest (OHCA) and 158 (38%) with an initial shockable rhythm. Median Hb concentration on admission was 12.0 [9.9-13.7] g/dL and the lowest Hb concentration was 10.0 [8.1-11.0] g/dL; 127 patients (31%) received at least one RBCT. Hb oxygen saturation on admission was 67 [59-74]%, while the lowest value was 60 [53-68]%. Low Hb and Hb oxygen saturation values were independently associated with UO; the optimal cut-off to predict UO was <9.9 g/dL and <60%, respectively. CONCLUSIONS: Low hemoglobin values and low values of oxygen venous saturation are significantly associated with unfavorable neurological outcome in adult patients resuscitated from cardiac arrest.

Relationship between Microcirculatory Perfusion and Arterial Elastance: A Pilot Study.

BACKGROUND: Arterial elastance (Ea) represents the total afterload imposed on the left ventricle, and it is largely influenced by systemic vascular resistance (SVR). Although one can expect that Ea is influenced by peripheral endothelial function, no data are available to support it in patients. The aim of this study was to investigate the relationship between Ea, SVR, and microvascular perfusion in critically ill patients undergoing the fluid challenge (FC). METHODS: A prospective study in patients receiving a fluid challenge. A pulse wave analysis system (MostCare, Vygon, France) was used to estimate Ea and an incident dark field (IDF) handheld device (Braedius Medical BV, The Netherlands) to evaluate the sublingual microcirculation. Microvascular perfusion was assessed using the proportion of small-perfused vessels (PPV). Relative changes in each variable were calculated before and after FC; fluid responsiveness was defined as an increase in the cardiac index by at least 10% from baseline. RESULTS: We studied 20 patients requiring a fluid challenge (n=10 for hypotension; n=5 for oliguria; n=3 for lactate values greater than 2 mmol/l; n=2 for tachycardia), including 12 fluid responders. There was a strong correlation between Ea and SVR (r 2 = 0.75; p < 0.001) and only a weak correlation between Ea and PPV at baseline (r 2 = 0.22; p=0.04). Ea decreased from 1.4 [1.2-1.6] to 1.2 [1.1-1.4] mmHg/mL (p=0.01), SVR from 1207 [1006-1373] to 1073 [997-1202] dyn ∗ s/cm5 (p=0.06), and PPV from 56 [51-64] % to 59 [47-73] % (p=0.25) after fluid challenge. Changes in Ea were significantly correlated with changes in SVR, but not with changes in PPV. CONCLUSIONS: The correlation between Ea and indexes of microvascular perfusion in the sublingual region is weak. The impact of microcirculatory perfusion on the arterial load is probably limited.

Acute liver dysfunction after cardiac arrest.

Few data are available regarding hypoxic hepatitis (HH) and acute liver failure (ALF) in patients resuscitated from cardiac arrest (CA). The aim of this study was to describe the occurrence of these complications and their association with outcome. All adult patients admitted to the Department of Intensive Care following CA were considered for inclusion in this retrospective study. Exclusion criteria were early death (<24 hours) or missing biological data. We retrieved data concerning CA characteristics and markers of liver function. ALF was defined as a bilirubin >1.2 mg/dL and an international normalized ratio ≥1.5. HH was defined as an aminotransferase level >1000 IU/L. Neurological outcome was assessed at 3 months and an unfavourable neurological outcome was defined as a Cerebral Performance Categories (CPC) score of 3-5. A total of 374 patients (age 62 [52-74] years; 242 male) were included. ALF developed in 208 patients (56%) and HH in 27 (7%); 24 patients developed both conditions. Patients with HH had higher mortality (89% vs. 51% vs. 45%, respectively) and greater rates of unfavourable neurological outcome (93% vs. 60% vs. 59%, respectively) compared to those with ALF without HH (n = 184) and those without ALF or HH (n = 163; p = 0.03). Unwitnessed arrest, non-shockable initial rhythm, lack of bystander cardiopulmonary resuscitation, high adrenaline doses and the development of acute kidney injury were independent predictors of unfavourable neurological outcome; HH (OR: 16.276 [95% CIs: 2.625-81.345; p = 0.003), but not ALF, was also a significant risk-factor for unfavourable outcome. Although ALF occurs frequently after CA, HH is a rare complication. Only HH is significantly associated with poor neurological outcome in this setting.