Endogenous Catecholamine Release in COVID-19 Related Acute Respiratory Distress Syndrome: Link between Enhanced Sympathetic Stimulation, Cardiac Dysfunction and Outcome.

The aim of this study was to measure the serum levels of catecholamines in patients admitted to intensive care unit (ICU) with COVID-19-related acute respiratory distress syndrome (ARDS) and describe their relation with clinical, inflammatory and echocardiographic parameters. Serum levels of endogenous catecholamines (norepinephrine, epinephrine and dopamine) were measured at ICU admission. We enrolled 71 patients consecutively admitted to ICU due to moderate to severe ARDS. 11 patients (15.5%) died during the admission in ICU. Serum levels of endogenous catecholamines were significantly elevated. Norepinephrine levels were higher in those with RV and LV systolic dysfunction, higher CRP, and higher IL-6. Patients with higher mortality rate were those with norepinephrine values ≥ 3124 ng/mL, CRP ≥ 17.2 mg/dL and IL-6 ≥ 102 pg/mL. Univariable analysis by Cox proportional hazards regression modelling showed that norepinephrine, IL-6 and CRP had the highest risk of acute mortality. Multivariable analysis showed that only norepinephrine and IL-6 retained in the model. Marked increase of serum catecholamine levels is present during acute phase of critically ill COVID-19 and it is associated with inflammatory and clinical parameters.

[D-Ala2,D-Leu5]-enkephalin (DADLE) and morphine-induced postconditioning by inhibition of mitochondrial permeability transition pore, in human myocardium.

The aim of the study was to examine the cardioprotective effect of morphine and Delta 2 opioid D-Ala2-Leu5 enkephalin(DADLE) administered, at early reoxygenation, in isolated human myocardium exposed to hypoxia­reoxygenation. Then,we tested the involvement of mitochondrial permeability transition pore in morphine and DADLE-induced postconditioning.Human right atrial trabeculae were obtained during cardiac surgery (coronary artery bypass and aortic valve replacement).Isometrically contracting isolated human right atrial trabeculae were exposed to 30-min hypoxia and 60-min reoxygenation(control group). In treatment groups, morphine 0.5 mmol, DADLE 10 nmol, DADLE 50 nmol and DADLE 100 nmol were administered during the first 15 min of reoxygenation. In two additional groups, morphine and DADLE 100 nmol were administered in the presence of atractyloside 50 mmol, the mitochondrial permeability transition pore opener. The force of contraction at the end of 60-min reoxygenation period (FoC60 expressed as % of baseline) was compared (mean+standard deviation) between the groups by an analysis of variance. Morphine (FoC60: 81+9% of baseline), DADLE50 nmol (FoC60: 76+11% of baseline) and DADLE 100 nmol (FoC60: 81+4% of baseline) increased significantly (P,0.001) the FoC60 as compared with the control group (FoC60: 53+3% of baseline). DADLE 10 nmol did not modify the FoC60 (50+9% of baseline; P » 0.60 versus control group). The enhanced recovery of FoC60 induced by morphine and DADLE 100 nmol were abolished in the presence of atractyloside (FoC60: respectively 57+6% and 44+7% of baseline;P, 0.001). In conclusion, the administration of morphine and DADLE, in early reoxygenation period, protected human myocardium, in vitro, against hypoxia­reoxygenation injury, at least in part, by the inhibition of mitochondrial permeability transition pore opening.