SARS-CoV-2 infection causes pulmonary shunt by vasodilatation.

Patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may present a significant hypoxemia. The exactly mechanism of such hypoxemia in patients with coronavirus disease 2019 (COVID-19) is not well described. It has been suggested that microthrombosis contributes to this mechanism, increasing pulmonary dead space. However, dead spaces would not be sensible to oxygen supplementation, and also, enlargement of pulmonary vessels it has been evidenced. Shunt mechanism by vasodilatation, instead, could explain decubitus dependence in oxygenation by blood redistribution as observed in these patients, and moreover, would be more sensible to oxygen supplementation than dead spaces. We hypothesized that SARS-CoV-2 causes an intrapulmonary vascular dilatation (IPVD), determining a shunt mechanism by vasodilatation. We performed contrast-enhanced transthoracic echocardiography to search IPVD shunt in patients with confirmed COVID-19, hospitalized in an intensive care unit. Ten patients were recruited; one patient was excluded due to low quality of echocardiographic image, and nine patients were included. IPVD was found in seven (78%) patients, with different grades, including patient with normal compliance and the one without invasive ventilation. We demonstrated that shunt by IPVD is present among patients with COVID-19, and this mechanism is probably implicated in significant hypoxemia observed.

Life-Threatening Electrical Storm Following Liver Transplantation: A Case Report.

BACKGROUND Electrical storm is a rare but potentially life-threatening syndrome characterized by recurrent ventricular arrhythmias. Liver transplant recipients are at increased risk of developing electrical storms due to conditions that prolong QT intervals, such as cirrhotic cardiomyopathy. However, limited information exists on electrical storms in this specific population. This case report presents a patient who experienced 13 cardiac arrests during ventricular fibrillation following liver transplantation. CASE REPORT A 61-year-old woman with a medical history of diabetes, obesity, and cirrhosis due to non-alcoholic fatty liver disease underwent liver transplantation using a deceased donor's liver. Following the procedure, she developed a deterioration in her respiratory function, necessitating orotracheal intubation. Approximately 21 hours post-surgery, she experienced cardiac arrest during ventricular fibrillation, which was rapidly reversed with electrical defibrillation. However, the patient entered a state of electrical storm. Management involved antiarrhythmic medications and temporary transvenous cardiac pacing. She remained stable for 40 hours, but a dislodgment of the device triggered another episode of ventricular fibrillation, leading to her death. CONCLUSIONS This case report highlights the clinical presentation and challenges in managing electrical storms in liver transplant recipients. We hypothesize that cirrhotic cardiomyopathy could be the cause of her recurrent ventricular arrhythmias. Further studies are needed to better understand the underlying mechanisms and risk factors of this life-threatening syndrome in this population, which may enhance risk stratification and enable earlier intervention.

Prolonged Anhepatic State as a Bridge to Retransplantation: A Challenging Case of a 35-Year-Old Male Liver Transplant Patient with a Temporary Portacaval Shunt.

BACKGROUND Liver transplantation is a life-saving intervention for patients with a diagnosis of acute liver failure or end-stage liver disease. Despite advances in surgical techniques and immunosuppressive therapies, primary nonfunction remains a concern, often necessitating retransplantation. In these scenarios, the anhepatic state, achieved through total hepatectomy with a temporary portacaval shunt, serves as a bridge to retransplantation. However, the challenge lies in the uncertain survival period and several potential complications associated with this procedure. CASE REPORT We present a case of a 35-year-old male patient with autoimmune hepatitis who underwent liver transplantation from a deceased donor. Seven days later, he experienced acute liver failure, leading to an urgent listing for retransplantation. To prevent the intense systemic inflammatory response, the patient underwent a total hepatectomy with a temporary portacaval shunt while awaiting another graft and endured a 57-h anhepatic state. On day 17 following retransplantation, he had cerebral death due to a hemorrhagic stroke. CONCLUSIONS This case underscores one of the most prolonged periods of anhepatic state as a bridge to retransplantation, highlighting the complexities associated with this technique. The challenges include sepsis, hypotension, coagulopathy, metabolic acidosis, renal failure, electrolyte disturbances, hypoglycemia, and hypothermia. Vigilant monitoring and careful management are crucial to improve patient outcomes. Further research is needed to optimize the duration of the anhepatic state and minimize complications for liver transplantation recipients.

Diuretic window hypothesis in cirrhosis: Changing the point of view.

Since the 1970s, non-selective beta-blockers (NSBB) have been used to prevent variceal upper bleeding in advanced cirrhotic patients. However, several recent studies have raised the doubt about the benefit of NSBB in end-stage cirrhotic patients. In fact, they suggested a detrimental effect in these patients that even reduced survival. All of these studies have been assembled to compose the "window therapy hypothesis", in which NSBB would have traditional indication to be initiated to prevent variceal upper bleeding; however, treatment should be stopped (or not be initiated) in patients with end-stage cirrhosis. NSBB would reduce the cardiac reserve of these patients, worsening systemic perfusion and prognosis. However, it should be emphasized that these studies present important bias issues, and their results also suggested that diuretic treatment may also be behind the effects observed. In this opinion review, we changed the point of view from NSBB to diuretic treatment, based on a physiopathogenic approach of circulatory parameters of cirrhotic patients studied, and based on diuretic effect in blood pressure lowering and in other hypervolemic disease, as heart failure. We suggest a "diuretic window hypothesis", composed by an open window in hypervolemic phase, an attention window when patient present in a normal plasma volume phase, and a closed window during the plasma hypovolemic phase.

Organ dysfunction in cirrhosis: a mechanism involving the microcirculation.

INTRODUCTION: Microcirculation is essential for adequate tissue perfusion and organ function. Microcirculatory changes may occur in cirrhosis, inducing loss of multiorgan function. The aim was to evaluate preliver transplantation and postliver transplantation aspects of multiorgan function, microcirculation, inflammatory, and endothelial biomarkers and survival in a controlled study including cirrhotic outpatients. PATIENTS AND METHODS: We accessed functional capillary density (FCD) and red blood cell acceleration (RBCA) by nailfold videocapillaroscopy. Inflammatory and endothelial biomarkers [interleukin-6 (IL-6), soluble intercellular adhesion molecule-1, endothelin-1, and tumor necrosis factor-α] were analyzed. Cerebral and renal functions were assessed to represent organ dysfunction and regression analyses were carried out. Receiver operating characteristic curves were constructed and survival Kaplan-Meier analysis was carried out. RESULTS: Fifty-four patients and 18 controls were included. Inflammatory and endothelial markers increased in advanced disease. FCD was reduced and RBCA was progressively lower according to disease severity. RBCA correlated inversely with inflammatory and endothelial biomarkers, and directly with renal function. The presence of hepatic encephalopathy correlated inversely with RBCA and directly with IL-6 and endothelin-1. In multivariate analysis, RBCA was an independent factor for organ dysfunction. The area under the receiver operating chartacteristic curve for IL-6 for survival was 0.74 (0.59-0.89), P=0.05. Transplant-free survival was 97.5% for values under 5.78 ng/ml (IL-6 best cutoff) and 83.9% above 5.78 ng/ml, log-rank=0.018. Eleven patients underwent transplantation, with an overall improvement in microcirculatory function. CONCLUSION: Our results suggest a mechanism of organ damage in cirrhosis, where microcirculatory dysfunction could be correlated to inflammatory and endothelial biomarkers, and loss of multiorgan function. IL-6 seems to be an important survival marker of inflammation. Liver transplantation improved microcirculatory dysfunction, corroborating this hypothesis.

Living Donor Liver Transplant as Rescue Surgery for a Patient with Hepatocellular Carcinoma Who Underwent Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS).

BACKGROUND The associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is an important tool to induce fast liver hypertrophy. The degree of hepatic fibrosis/cirrhosis in patients with HCC negatively impacts their health, and the risk of liver failure is always present. In these cases, liver transplantation may be necessary as a rescue procedure. We present the case of a patient with HCC who underwent ALPPS and developed liver failure. A living donor liver transplant was performed as a rescue procedure. CASE REPORT A 49-year-old man with chronic hepatitis B without cirrhosis underwent computed tomography, which revealed an expansive lesion in the right lobe of his liver that was diagnosed as hepatocellular carcinoma. Liver resection was indicated and liver cirrhosis was observed with high portal pressure after transection. The treatment strategy was switched from right hepatectomy to ALPPS. The patient developed severe liver dysfunction and liver transplantation was indicated. His postoperative course was uneventful and 3 months after the procedure the patient was without complications. CONCLUSIONS Living donor liver transplantation may be necessary as a rescue procedure for patients who underwent ALPPS and develop liver dysfunction.