RESUMO
Clinically, it is highly challenging to promote recovery in patients with acute liver failure (ALF) and acute-on-chronic liver failure (ACLF). Despite recent advances in understanding the underlying mechanisms of ALF and ACLF, standard medical therapy remains the primary therapeutic approach. Liver transplantation (LT) is considered the last option, and in several cases, it is the only intervention that can be lifesaving. Unfortunately, this intervention is limited by organ donation shortage or exclusion criteria such that not all patients in need can receive a transplant. Another option is to restore impaired liver function with artificial extracorporeal blood purification systems. The first such systems were developed at the end of the 20th century, providing solutions as bridging therapy, either for liver recovery or LT. They enhance the elimination of metabolites and substances that accumulate due to compromised liver function. In addition, they aid in clearance of molecules released during acute liver decompensation, which can initiate an excessive inflammatory response in these patients causing hepatic encephalopathy, multiple-organ failure, and other complications of liver failure. As compared to renal replacement therapies, we have been unsuccessful in using artificial extracorporeal blood purification systems to completely replace liver function despite the outstanding technological evolution of these systems. Extracting middle to high-molecular-weight and hydrophobic/protein-bound molecules remains extremely challenging. The majority of the currently available systems include a combination of methods that cleanse different ranges and types of molecules and toxins. Furthermore, conventional methods such as plasma exchange are being re-evaluated, and novel adsorption filters are increasingly being used for liver indications. These strategies are very promising for the treatment of liver failure. Nevertheless, the best method, system, or device has not been developed yet, and its probability of getting developed in the near future is also low. Furthermore, little is known about the effects of liver support systems on the overall and transplant-free survival of these patients, and further investigation using randomized controlled trials and meta-analyses is needed. This review presents the most popular extracorporeal blood purification techniques for liver replacement therapy. It focuses on general principles of their function, and on evidence regarding their effectiveness in detoxification and in supporting patients with ALF and ACLF. In addition, we have outlined the basic advantages and disadvantages of each system.
RESUMO
RATIONALE: Septic patients admitted to the intensive care unit (ICU) suffer from immune dysregulation, potentially leading to a secondary sepsis episode. This study aims to (i) assess the secondary sepsis rate, (ii) compare the second with the first episodes in terms of demographics, clinical and laboratory characteristics, and outcomes, and iii) evaluate the outcome of secondary sepsis. METHODS: A single-center, retrospective study (2014-2017) was conducted in a Greek ICU, including consecutive cases of adult patients admitted to the ICU for at least 48 h with a principal admission diagnosis of sepsis and stayed for at least 48 h. We searched for a secondary episode of sepsis following the primary-one. We performed survival analyses with Cox proportional hazard, Fine-Gray, and multistate models. RESULTS: In this study, 121 patients that fulfilled the eligibility criteria were included. The secondary sepsis group included 28 (23.1 %) patients, with episode onset, median (interquartile range), 9.5 (7.7-16.2) days after ICU admission, who had less frequently had a medical admission diagnosis, a microbiologically confirmed first episode, and the C-reactive protein was lower. The overall ICU mortality of the cohort was 44.6 %. The group that developed secondary sepsis had higher mortality, but significance was lost in Cox regression [Hazard ratio (95 % CI) 0.59(0.31-1.16)]. However, after multistate modeling adjustment, the attributable mortality was estimated at 43.9 % (95 %CI ± 14.8 %). CONCLUSION: Secondary sepsis was evident in a quarter of the study participants and may be associated with an increased risk of death.