The conventional view in severe sepsis or septic shock is that most of the lactate that accumulates in the circulation is due to cellular hypoxia and the onset of anaerobic glycolysis. A number of papers have suggested that lactate formation during sepsis is not due to hypoxia. I discuss this hypothesis and outline the recent advances in the understanding of lactate metabolism in shock. Numerous experimental data have demonstrated that stimulation of aerobic glycolysis – that is, glycolysis not attributable to oxygen deficiency – and glycogenolysis occurs not only in resting, well-oxygenated skeletal muscles but also during experimental haemorrhagic shock and experimental sepsis, and is closely linked to stimulation of sarcolemmal Na+/K+-ATPase under epinephrine stimulation. A human study of hyperkinetic septic shock demonstrated that skeletal muscle is a leading source of lactate production by exaggerated aerobic glycolysis through Na+/K+-ATPase stimulation. There is increasing evidence that sepsis is accompanied by a hypermetabolic state, with enhanced glycolysis and hyperlactataemia. This should not be rigorously interpreted as an indication of hypoxia. It now appears, at least in the hyperkinetic state, that increased lactate production and concentration as a result of hypoxia are often the exception rather than the rule.

There is no study that has compared, in a randomized manner, which vasopressor is most suitable in optimizing both systemic and regional hemodynamics in cardiogenic shock patients. Hence, the present study was designed to compare epinephrine and norepinephrine-dobutamine in dopamine-resistant cardiogenic shock. Open, randomized interventional human study. Medical intensive care unit in a university hospital. Thirty patients with a cardiac index of <2.2 L/min−1/m−2 and a mean arterial pressure of <60 mm Hg resistant to combined dopamine-dobutamine treatment and signs of shock. Patients were not included in cases of cardiogenic shock secondary to acute ischemic events such as myocardial infarction. Noninclusion criteria also included immediate indication of mechanical assistance. Patients were randomized to receive an infusion of either norepinephrine-dobutamine or epinephrine titrated to obtain a mean arterial pressure of between 65 and 70 mm Hg with a stable or increased cardiac index. Both regimens increased cardiac index and oxygen-derived parameters in a similar manner. Patients in the norepinephrine-dobutamine group demonstrated heart rates lower (p < .05) than those in the epinephrine group. Epinephrine infusion was associated with new arrhythmias in three patients. When compared to baseline values, after 6 hrs, epinephrine infusion was associated with an increase in lactate level (p < .01), whereas this level decreased in the norepinephrine-dobutamine group. Tonometered PCO2 gap, a surrogate for splanchnic perfusion adequacy, increased in the epinephrine-treated group (p < .01) while decreasing in the norepinephrine group (p < .01). Diuresis increased in both groups but significantly more so in the norepinephrine-dobutamine group, whereas plasma creatinine decreased in both groups. When considering global hemodynamic effects, epinephrine is as effective as norepinephrine-dobutamine. Nevertheless, epinephrine is associated with a transient lactic acidosis, higher heart rate and arrhythmia, and inadequate gastric mucosa perfusion. Thus, the combination norepinephrine-dobutamine appears to be a more reliable and safer strategy.

For the first 3 months of COVID-19 pandemic, COVID-19 was expected to be an immunizing non-relapsing disease. We report a national case series of 11 virologically-confirmed COVID-19 patients having experienced a second clinically- and virologically-confirmed acute COVID-19 episode. According to the clinical history, we discuss either re-infection or reactivation hypothesis. Larger studies including further virological, immunological and epidemiologic data are needed to understand the mechanisms of these recurrences.