Sepsis is one of the most common causes of death in critical patients. Severe generalized inflammation, infections, and severe physiological imbalances significantly decrease the survival rate with more than 50%. Moreover, monitoring, evaluation, and therapy management often become extremely difficult for the clinician in this type of patients. Current methods of diagnosing sepsis vary based especially on the determination of biochemical-humoral markers, such as cytokines, components of the complement, and proinflammatory and anti-inflammatory compounds. Recent studies highlight the use of new biomarkers for sepsis, namely, miRNAs. miRNAs belong to a class of small, noncoding RNAs with an approximate content of 19–23 nucleotides. Following biochemical and physiological imbalances, the expression of miRNAs in blood or other body fluids changes significantly. Moreover, its stability, specificity, and selectivity make miRNAs ideal candidates for sepsis biomarkers. In conclusion, we can affirm that stable species of circulating miRNAs represent potential biomarkers for monitoring the evolution of sepsis.

The critically ill polytrauma patient presents with a series of associated pathophysiologies secondary to the traumatic injuries. The most important include systemic inflammatory response syndrome (SIRS), sepsis, oxidative stress (OS), metabolic disorders, and finally multiple organ dysfunction syndrome (MODS) and death. The poor outcome of these patients is related to the association of the aforementioned pathologies. The nutrition of the critically ill polytrauma patient is a distinct challenge because of the rapid changes in terms of energetic needs associated with hypermetabolism, sepsis, SIRS, and OS. Moreover, it has been proven that inadequate nutrition can prolong the time spent on a mechanical ventilator and the length of stay in an intensive care unit (ICU). A series of mathematical equations can predict the energy expenditure (EE), but they have disadvantages, such as the fact that they cannot predict the EE accurately in the case of patients with hypermetabolism. Indirect calorimetry (IC) is another method used for evaluating and monitoring the energy status of critically ill patients. In this update paper, we present a series of pathophysiological aspects associated with the metabolic disaster affecting the critically ill polytrauma patient. Furthermore, we present different non-invasive monitoring methods that could help the intensive care physician in the adequate management of this type of patient.

Critically ill polytrauma patients have increased production of free radicals (FRs) and consequent alterations in biochemical pathways, as well as disruption of cellular integrity, due to increased lipid peroxidation. The aim of this study was to investigate several biomarkers associated with increased oxidative stress in critically ill polytrauma patients, and to evaluate the effect of antioxidant treatment on the clinical outcome in these patients. A total of 67 polytrauma patients from an intensive care unit met the selection criteria. Antiox group included 35/67 patients who received antioxidant therapy, while 32/67 patients without antioxidant treatment were considered as control group. Antioxidant therapy consisted of simultaneous administration of Vitamin C (sodium ascorbate) and N-acetylcysteine, through continuous intravenous infusion. Clinical and paraclinical evaluation of the patients was performed daily until discharge or death. At admission, laboratory parameters did not differ significantly between two groups. At discharge/upon death, statistically significant differences in favor of Antiox group were observed in the following parameters: thrombocytes, activated partial thromboplastin time, prothrombin time, total bilirubin, total cholesterol, high-density lipoproteins, low-density lipoproteins, erythrocyte sedimentation rate, interleukin 6 (all p = 0.0001), total protein (p = 0.0005), serum albumin (p = 0.0004), lactate dehydrogenase (p = 0.0006), and C-reactive protein (p = 0.0014). Starting from day 5, the APACHE II score was significantly decreased in Antiox versus control group (p < 0.05). Finally, the sepsis incidence and mortality rate were significantly lower in Antiox group (p < 0.05). Decreasing the level of oxidative stress by antioxidant substances significantly correlated with a better prognosis and outcome in our patients. Further studies should elucidate more clearly the mechanism of action of antioxidants in critically ill polytrauma patients.

The first line of defence against oxidative stress (OS) are the endogenous antioxidants, such as the Se containing compounds. During pregnancy, OS is caused by the intense growth activity of the fetus; therefore, the placenta is a key place for the activity of many seleno-compounds such as glutathione-peroxidase and thioredoxinreductase. This review aims to establish the link between the type of selenium compounds, their concentration, their metabolic pathways, and their role in both physiologic and pathologic processes during pregnancy. A review of current literature establishes that Se containing compounds have a strong antioxidant effect. The limits that define deviations from the normal concentration range of selenium are very close. Both selenium deficiency and excess have an effect on human health. It is well known that oxidative stress, namely the increase in the concentration of reactive species of oxygen and nitrogen (ROS and RNS) and the disruption of cellular redox homeostasis, are responsible for a number of inflammatory, degenerative, autoimmune, and neoplastic diseases. Selenium deficiency in the pregnant woman's body is considered a risk factor for immune deficiency, PIH, spontaneous abortions, and premature birth. In regard to the fetus, while there seems to be a certain protection against selenium-induced toxicity, studies have shown that selenium defficiency leads to IUGR and SGA newborns. Also, combined deficiency of selenium and iodine has been linked to endemic cretinism in newborns. The antioxidant role that selenium performs through selenoproteins is major. Selenium-containing proteins, especially glutathione peroxidase, as antioxidant enzymes, are involved in regulating the ROS and RNS levels and redox balancing in almost all tissues. Among the multiple benefits of selenium in optimal concentrations in the body are stimulation and support of female fertility, as well as good development of the fetus. Hypertensive pathologies that occur in one of ten pregnant women, especially during the second part of the gestation period, are largely due to selenium deficiency.

Critically ill patients with sepsis require a multidisciplinary approach, as this situation implies multiorgan distress, with most of the bodily biochemical and cellular systems being affected by the condition. Moreover, sepsis is characterized by a multitude of biochemical interactions and by dynamic changes of the immune system. At the moment, there is a gap in our understanding of the cellular, genetic, and molecular mechanisms involved in sepsis. One of the systems intensely studied in recent years is the endocannabinoid signaling pathway, as light was shed over a series of important interactions of cannabinoid receptors with biochemical pathways, specifically for sepsis. Furthermore, a series of important implications on inflammation and the immune system that are induced by the activity of cannabinoid receptors stimulated by the delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) have been noticed. One of the most important is their ability to reduce the biosynthesis of pro-inflammatory mediators and the modulation of immune mechanisms. Different studies have reported that cannabinoids can reduce oxidative stress at mitochondrial and cellular levels. The aim of this review paper was to present, in detail, the important mechanisms modulated by the endocannabinoid signaling pathway, as well as of the molecular and cellular links it has with sepsis. At the same time, we wish to present the possible implications of cannabinoids in the most important biological pathways involved in sepsis, such as inflammation, redox activity, immune system, and epigenetic expression.