Impact of prone position in non-intubated spontaneously breathing patients admitted to the ICU for severe acute respiratory failure due to COVID-19.

PURPOSE: Studies performed in spontaneously breathing patients with mild to moderate respiratory failure suggested that prone position (PP) in COVID-19 could be beneficial. MATERIALS AND METHODS: Consecutive critically ill patients with COVID-19 were enrolled in four ICUs. PP sessions lasted at least 3 h each and were performed twice daily. A Cox proportional hazard model identified factors associated with the need of intubation. A propensity score overlap weighting analysis was performed to assess the association between spontaneous breathing PP (SBPP) and intubation. RESULTS: Among 379 patients, 40 underwent SBPP. Oxygenation was achieved by high flow nasal canula in all but three patients. Duration of proning was 2.5 [1.6;3.4] days. SBPP was well tolerated hemodynamically, increased PaO2/FiO2 (78 [68;96] versus 63 [53;77] mm Hg, p = 0.004) and PaCO2 (38 [34;43] versus 35 [32;38] mm Hg, p = 0.005). Neither day-28 survival (HR 0.51, 95% CI 0.16-1.16] nor risk of invasive ventilation [sHR 0.96; 95% CI 0.49;1.88] differed between patients who underwent PP and others. CONCLUSIONS: SBPP in COVID-19 is feasible and well tolerated in severely hypoxemic patients. It did not induce any effect on risk of intubation and day-28 mortality.

Cerebrospinal fluid metabolomics highlights dysregulation of energy metabolism in overt hepatic encephalopathy.

BACKGROUND & AIMS: Hepatic encephalopathy (HE) is a neurological complication observed in patients with liver disease and/or porto-systemic shunt. The proportion of cirrhotic patients developing overt HE is about 20%, and 60-80% of cirrhotic patients exhibit mild cognitive impairment potentially related to minimal HE. However, the pathophysiological mechanisms of HE remain poorly understood. In this context, metabolomics was used to highlight dysfunction of metabolic pathways in cerebrospinal fluid (CSF) samples of patients suffering from HE. METHODS: CSF samples were collected in 27 control patients without any proven neurological disease and 14 patients with symptoms of HE. Plasma samples were obtained from control patients, and from cirrhotic patients with and without HE. Metabolomic analysis was performed using liquid chromatography coupled to high-resolution mass spectrometry. RESULTS: Concentrations of 73 CSF metabolites, including amino acids, acylcarnitines, bile acids and nucleosides, were altered in HE patients. Accumulation of acetylated compounds, which could be due to a defect of the Krebs cycle in HE patients, is reported for the first time. Furthermore, analysis of plasma samples showed that concentrations of metabolites involved in ammonia, amino-acid and energy metabolism are specifically and significantly increased in CSF samples of HE patients. Lastly, several drugs were detected in CSF samples and could partially explain worsening of neurological symptoms for some patients. CONCLUSION: By enabling the simultaneous monitoring of a large set of metabolites in HE patients, CSF metabolomics highlighted alterations of metabolic pathways linked to energy metabolism that were not observed in plasma samples. LAY SUMMARY: CSF metabolomics provides a global picture of altered metabolic pathways in CSF samples of HE patients and highlights alterations of metabolic pathways linked to energy metabolism that are not observed in plasma samples.