Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. The brain is one of the organs involved in sepsis, and sepsis-induced brain injury manifests as sepsis-associated encephalopathy (SAE). SAE may be present in up to 70% of septic patients. SAE has a very wide spectrum of clinical symptoms, ranging from mild behavioral changes through cognitive disorders to disorders of consciousness and coma. The presence of SAE increases mortality in the population of septic patients and may lead to chronic cognitive dysfunction in sepsis survivors. Therefore, therapeutic interventions with neuroprotective effects in sepsis are needed. Melatonin, a neurohormone responsible for the control of circadian rhythms, exerts many beneficial physiological effects. Its anti-inflammatory and antioxidant properties are well described. It is considered a potential therapeutic factor in sepsis, with positive results from studies on animal models and with encouraging results from the first human clinical trials. With its antioxidant and anti-inflammatory potential, it may also exert a neuroprotective effect in sepsis-associated encephalopathy. The review presents data on melatonin as a potential drug in SAE in the wider context of the pathophysiology of SAE and the specific actions of the pineal neurohormone.

Background. Though out-of-hospital CA (OHCA) is widely reported, data on in-hospital CA (IHCA), and especially cardiac arrest (CA) in the emergency department (CAED), are scarce. This study aimed to determine the frequency, prevalence, and clinical features of unexpected CA in the ED and compare the data with those of expected CA in the ED. Methods. We defined unexpected CA in the ED as CA occurring in patients in non-critical ED-care areas, classified as not requiring strict monitoring. A retrospective analysis of cases from 2016–2018 was performed, in comparison to other patients experiencing CA in the ED. Results. The 38 cases of unexpected CA in this study constituted 34.5% of CA diagnosed in the ED and 8.4% of all CA treated in the ED. This population did not differ significantly from other CA in the ED regarding demographics, comorbidities, and survival rates. The commonest symptoms were dyspnoea, disorders of consciousness, generalised weakness, and chest pain. The commonest causes of death were acute myocardial infarction, malignant neoplasms with metastases, septic shock, pulmonary embolism, and heart failure. Conclusions. Unexpected CA in the ED represents a group of potentially avoidable CA and deaths. These patients should be analysed, and ED management should include measures aimed at reducing their incidence. Trial registration. The study protocol was approved by the local ethical committee of the author’s institute (Approval number NKBBN/140/2021). As the study was based upon a retrospective analysis of anonymised medical charts, no written consent was obtained from the patients.