Perioperative Evolution of Sodium Levels in Cirrhotic Patients Undergoing Liver Transplantation: An Observational Cohort and Literature Review.

BACKGROUND & AIMS: Hyponatremia is an important predictor of early death among cirrhotic patients in the orthotopic liver transplantation (OLT) waiting list. Evidence exists that prioritizing OLT waiting list according to the MELD score combined with plasma sodium concentration might prevent pre transplantation death. However, the evolution of plasma sodium concentrations during the perioperative period of OLT is not well known. We aimed to describe the evolution of perioperative sodium concentration during OLT and its relation to perioperative neurohormonal responses. METHODS: Twenty-seven consecutive cirrhotic patients who underwent OLT were prospectively included in the study over a period of 27 months. We studied the evolution of plasma sodium levels, the hemodynamics, the neurohormonal response and other biological markers during the perioperative period of OLT. RESULTS: Among study's population, four patients had hyponatremia before OLT, all with Child cirrhosis. In patients with hyponatremia, plasmatic sodium reached normal levels during surgery, and sodium levels remained within normal ranges 1 day, 7 days, as well as 6 months after surgery for all patients. Creatinine clearance was decreased significantly during the perioperative period, while creatinine and cystatin C levels increased significantly. Neutrophil gelatinase-associated lipocalin (NGAL) and vasopressin levels did not change significantly in this period. Plasma renin activity, concentrations of norepinephrine and brain natriuretic peptide varied significantly during the perioperative period. CONCLUSION: In our study, plasmatic sodium concentrations among hyponatremic cirrhotic patients undergoing OLT seem to reach normal levels after OLT and remain stable six months after surgery providing more evidence for the importance of sodium levels in prioritization of liver transplant candidates. Further investigation of rapid correction and stabilization of sodium levels after OLT, as observed in our study, would be of interest in order to fully understand the mechanisms involved in cirrhosis-related hyponatremia, its prognostic value and clinical implications.

Early Experience with Intraoperative Leak Test Using a Blend of Methylene Blue and Indocyanine Green During Robotic Gastric Bypass Surgery.

INTRODUCTION: Leak tests using air or methylene blue (MB) for gastrojejunal anastomoses are often performed during gastric bypass surgeries to avoid leaks due to technical errors. Still, early leaks have been reported in the literature. Indocyanine green (ICG) fluorescence with laser excitement makes this dye easily visible even in small amounts, and, thus, may be an excellent agent for leak testing. METHODS: During robotic gastric bypass surgery, a leak test of a gastrojejunal anastomosis was performed with air through a nasogastric tube under manual occlusion of the jejunum. Afterward, 50 ml of a mix of 100 ml sterile water, 2 mg of MB, and 5 mg ICG was injected through the same tube. The entire anastomosis was inspected for integrity under both fluorescent and normal light modes. RESULTS: Leak tests with air and the blend of MB and ICG have been performed in 95 patients from January 2017 to April 2018. No intraoperative leak test-related adverse events occurred. Zero (0%) patients had a positive leak test with air, 0 patients showed MB excretion, and an ICG leak was observed in four (4.2%) patients. No anastomotic complications, including leaks and/or strictures, were found 30 days postoperatively. CONCLUSIONS: Leak tests using a blend of MB and ICG appear to be more sensitive for small defect detection of gastrojejunal anastomoses during robotic gastric bypass surgery. Larger datasets and research that is more stringent are needed to determine the exact clinical value of this new method.

Portopulmonary hypertension and hepatopulmonary syndrome.

Portopulmonary hypertension (POPH) and hepatopulmonary syndrome (HPS) are two frequent complications of liver disease, with prevalence among liver transplant candidates of 6% and 10%, respectively. Both conditions result from a lack of hepatic clearance of vasoactive substances produced in the splanchnic territory. Subsequently, these substances cause mainly pulmonary vascular remodeling and some degree of vasoconstriction in POPH with resulting elevated pulmonary pressure and right ventricular dysfunction. In HPS the vasoactive mediators cause intrapulmonary shunts with hypoxemia. Medical treatment is disappointing overall. Whereas liver transplantation (LT) results in the disappearance of HPS within six to twelve months, its effect on POPH is highly unpredictable. Modern strategies in managing HPS and POPH rely on a thorough screening and grading of the disease's severity, in order to tailor the appropriate therapy and select only the patients who will benefit from LT. The anesthesiologist plays a central role in managing these high-risk patients. Indeed, the important hemodynamic and respiratory modifications of the perioperative period must be avoided through continuation of the preoperatively initiated drugs, appropriate intraoperative monitoring and proper hemodynamic and respiratory therapies.