Extracorporeal organ support for critically ill patients:Overcoming the past,achieving the maximum at present,and redefining the future

Extracorporeal organ support(ECOS)has made remarkable progress over the last few years.Renal replacement therapy,introduced a few decades ago,was the first available application of ECOS.The subsequent evolution of ECOS enabled the enhanced support to many other organs,including the heart[veno-arterial extracorporeal membrane oxygenation(ECMO),slow continuous ultrafiltration],the lungs(veno-venous ECMO,extracorporeal carbon dioxide removal),and the liver(blood purification techniques for the detoxification of liver toxins).Moreover,additional indications of these methods,including the suppression of excessive inflammatory response occurring in severe disorders such as sepsis,coronavirus disease 2019,pancreatitis,and trauma(blood purification techniques for the removal of exotoxins,endotoxins,or cytokines),have arisen.Multiple organ support therapy is crucial since a vast majority of critically ill patients present not with a single but with multiple organ failure(MOF),whereas,traditional therapeutic approaches(mechanical ventilation for acute respiratory failure,antibiotics for sepsis,and inotropes for cardiac dysfunction)have reached the maximum efficacy and cannot be improved further.However,several issues remain to be clarified,such as the complexity and cost of ECOS systems,standardization of indications,therapeutic protocols and initiation time,choice of the patients who will benefit most from these interventions,while evidence from randomized controlled trials supporting their use is still limited.Nevertheless,these methods are currently a part of routine clinical practice in intensive care units.This editorial presents the past,present,and future considerations,as well as perspectives regarding these therapies.Our better understanding of these methods,the pathophysiology of MOF,the crosstalk between native organs resulting in MOF,and the crosstalk between native organs and artificial organ support systems when applied sequentially or simultaneously,will lead to the multiplication of their effects and the minimization of complications arising from their use.

Liver replacement therapy with extracorporeal blood purification techniques current knowledge and future directions

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.

Prevention,diagnostic evaluation,management and prognostic implications of liver disease in critically ill patients with COVID-19

Coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2,broke out in December 2019 in Wuhan city of China and spread rapidly worldwide.Therefore,by March 2020,the World Health Organization declared the disease a global pandemic.Apart from the respiratory system,various other organs of the human body are also seriously affected by the virus.Liver injury in patients with a severe form of COVID-19 is estimated to be 14.8%-53.0%.Elevated levels of total bilirubin,aspartate aminotransferase and alanine aminotransferase and low levels of serum albumin and prealbumin are the main laboratory findings.Patients with pre-existing chronic liver disease and cirrhosis are much more prone to develop severe liver injury.This literature review presented the recent scientific findings regarding the pathophysiological mechanisms responsible for liver injury in critically ill patients with COVID-19,the various interactions between drugs used to treat the disease and the function of the liver and the specific tests providing the possibility of early diagnosis of severe liver injury in these patients.Moreover,it highlighted the burden that COVID-19 put on health systems worldwide and its effect on transplant programs and the care provided to critically ill patients in general and particularly to those with chronic liver disease.

Gastroenterology and liver disease during COVID-19 and in anticipation of post-COVID-19 era: Current practice and future directions

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has emerged as a major threat to global public health.The virus causes the clinical syndrome known as coronavirus disease 2019(COVID-19),in which multiple organs can get affected.Apart from manifestations of the respiratory system,which predominate,its clinical presentation is frequently accompanied by symptoms of the gastrointestinal(GI)tract and liver abnormalities.The correlation of symptoms and abnormalities with disease severity is discussed,leading to ambiguous results from international literature.Moreover,the disease infects patients with coexisting liver and GI disorders affecting both their health status and the availability of healthcare services provided to them.The risk of transmission of the disease during aerosol-generating procedures has changed the diagnostic approach and follow-up algorithms for liver and GI diseases.For the safety of both doctors and patients,telemedicine and distant evaluation have become everyday practice,whereas several routines and emergency visits at outpatient and emergency departments have been postponed or delayed.Vaccination against SARS-CoV-2 is underway,providing hope to humanity and the expectation that the post-COVID-19 era is near.This review aims to update knowledge about the manifestations of COVID-19 related to liver and GI diseases and the effect of the pandemic on the diagnostic and therapeutic procedures for these diseases with a special focus on how current practices have changed and what changes will possibly remain in the future.