Adaptive support ventilation versus synchronized intermittent mandatory ventilation with pressure support in weaning patients after orthotopic liver transplantation.

BACKGROUND: The extubation phase is an extremely critical moment in patients who have undergone orthotopic liver transplantation, who do not always have the advantage of long-lasting positive-pressure ventilation and positive expiratory end pressure; these factors can lead to splanchnic venous congestion, and this is why a rapid extubation can represent a great benefit for the graft. METHODS: The aim of this study was to compare the adaptive support ventilation (ASV) mode with the standard mode of weaning in our intensive care unit, synchronized intermittent mandatory ventilation with pressure support (P-SIMV), in patients who received orthotopic liver transplantation. ASV is a positive-pressure mode, in which pressure level and respiratory rate are automatically adjusted according to measured lung dynamics at each breath. Eligible patients were assigned to either ASV or P-SIMV group. The weaning protocol was based on the individual respiratory activity and structured in 4 different phases. RESULTS: The average length of intubation was significantly shorter in the ASV group than in the P-SIMV group (90±13 vs 153±22 minutes, P=.05). The total modifications to the ventilator settings were significantly larger in the P-SIMV group (1.5±1 vs 6±2; P=.003). CONCLUSIONS: Our results suggest that although both procedures are safe and easy to apply, ASV is superior in terms of weaning times, and it simplifies respiratory management. The better patient-machine interaction in ASV has been highlighted by other authors for different clusters of patients.

Exposure assessment to mycotoxins in gluten-free diet for celiac patients.

Mycotoxins are low molecular weight secondary metabolites produced by certain strains of filamentous fungi such as Aspergillus, Penicillium and Fusarium, which attack crops in the field, and grow on foods also during storage under favorable conditions of temperature and humidity. Foods mainly contributing to the intake of mycotoxins with diet are cereals, maize being the most risky commodity due to the potential co-occurrence of more than one mycotoxin, this can be of particular concern especially for vulnerable group of population such as celiac patients that show increased maize-based products consumption. In this study the exposure of celiac patients to fumonisins (FBs) and zearalenone (ZON) has been assessed. The higher exposures, for all the matrices and for both the selected mycotoxins, were for children age group. The lower and upper bound exposure ranged between 348-582 ng/kg bw/day for FBs and 22-83 ng/kg bw/day for ZON; these values result well below the TDI for the selected mycotoxins, representing the 17-29% and 9-33% of the TDI set for FBs and ZON, respectively. Even considering the worst scenario the exposure values reported for children were lower, namely 1385 ng/kg bw/day for FBs and 237 ng/kg bw/day for ZON, than the corresponding toxicological thresholds.

Polymyxin-B endotoxin removal device: making the point on mechanisms of action, clinical effectiveness and possible future applications: review.

In this review, we focus on current information on the apheresis procedures for endotoxins removal with Polymyxin B cartridges (PMX). This device has been designed in 2003 in Japan in order to take advantage of the antibiotic effects of Polymyxins on Gram negative bacteria and endotoxins, by-passing the toxicity shown by the intravenous administration. Although its mechanisms of action are nowadays well-known, we felt the need to sum up all the someway scattered information giving an overall sight on the entire process that brings Polymyxins molecules to function as powerful detergents of the endotoxins from the blood flow. Since the first experiences on humans, over one hundred studies have been published about the clinical use of this device. Even if some of them were limited in number of patients and compliance to international standards, they all converged in showing a highly positive impact of PMX on the improvement of clinic condition and outcome. Recently, more significant and large experiences confirmed the benefits of this treatment on hemodynamic, PaO2/FiO2 ratio, APACHE and SOFA scores and outcome at 28 days even on different typologies of sepsis cases, such as in transplanted patients. Summarizing, this relatively new procedure has proven to be a promising tool against Gram negative and endotoxin sepsis, combining clinical and outcome improvements with a fair cost/effectiveness ratio. Given that, there's still need of wider and more structured clinical studies that could steady the use of this device and widen its fields of applications.

Stages of early acute renal dysfunction in liver transplantation: the influence of graft function.

The development of early acute renal dysfunction (eARD) occurring in the first week after orthotopic liver transplantation (OLT) is mainly influenced by more severe degrees of pre-OLT hepatic insufficiency and liver graft dysfunction. The aim of our study was to evaluate the incidence of eARD post-OLT as well as its association with pre- and post-OLT hepatic dysfunction. We selected 54 end-stage liver disease patients who underwent OLT from 2008 to 2011. The prevalence of eARD was 53.7% (29/54) classified according to AKIN criteria in ARD-Risk (55.2%), ARD-Injury (27.6%) and ARD-Failure (17.2%). The worst stage of post-OLT eARD (eARD-Failure) seems to be influenced by the poor pre-OLT hepatic function as well as by early suboptimal recovery of graft function.

Management of sepsis during MARS treatment in acute on chronic liver failure.

INTRODUCTION: The aim of our study was a 30-day follow-up of the use of early detection of endotoxin by the endotoxin activity assay (EAA) for patients with acute liver failure superimposed on chronic liver disease (AoCLF) and treated with polymyxin-B hemoperfusion-based (PMX-DHP) treatment and albumin dialysis in the molecular adsorbent recirculating system (MARS). MATERIALS AND METHODS: From February 2008 to July 2010, we evaluated 10 AoCLF patients experiencing systemic inflammatory response syndrome (SIRS) in association with suspected infection and an EAA-positive test (>0.60). These patients awaiting liver transplantation (OLT) showed similar Model End-Stage Liver Disease (MELD) scores (range, 19-25) and encephalopathy grade ≤ 2. Five patients received therapy to remove endotoxins with PMX-DHP with MARS treatment for liver failure (group A); the other 5 patients received MARS treatment only (group B). RESULTS: Two PMX-DHP treatments were performed in 4 group A patients (average EA=0.66 [range, 0.61-0.70]) and 3 treatments for 1 patient (EA=0.92). All 5 subjects underwent an average of 4 MARS treatments (range, 3-5). At the end of therapy, the median EA level was 0.42 (range, 0.37-0.48). As reported in the literature, we achieved a significant improvement in liver and kidney functions using MARS. Measurements of lactate, interleukin (IL)-6, and tumor necrosis factor (TNF)-α were significantly improved among patients treated with the extracorporeal therapies. At 30 days of observation, all 5 patients treated with MARS plus PMX-DHP are alive. In group B, a mean of 7.5 MRAS treatments were performed. We observed an improvement in hemodynamic and liver functions with reduced levels of proinflammatory cytokines and lactates in 4 patients. One patient showed no improvement in clinical status with the development of sepsis and subsequent multiorgan failure after 24 days. CONCLUSION: The possibility of an early diagnosis using the EAA in AoCLF patients could prevent the progression of the sepsis cascade. The use of PMX-DHP and MARS in these patients, could lead to resolution of clinical status in a short time.

Model for end-stage liver disease score versus simplified acute physiology score criteria in acute renal failure after liver transplantation.

Hepatic function and renal failure are closely related among patients with end-stage liver disease (ESLD) due to splanchnic hemodynamic mechanisms that characterize advanced decompensated cirrhosis. Acute renal failure (ARF) is a frequent complication that occurs immediately post-orthotopic liver transplantation (OLT). The Model for End-stage Liver Disease (MELD) score describes the survival of patients with ESLD awaiting OLT related to the severity of liver disease. The Simplified Acute Physiology Score (SAPS II) is a mortality prediction model that scores the severity of illness among intensive care unit patients. In a previous study we observed an association between ARF post-OLT and a higher MELD score, but it was not clear whether this association depends on the grade of ESLD or on the critical condition of liver transplant patients. The aim of this study was to evaluate the association of ARF with MELD score and/or SAPS II criteria among liver transplant patients. We analyzed 46 patients with ESLD who underwent deceased donor OLT. All patients were evaluated at baseline and in the first 7 days post-OLT. According to the RIFLE classification, the incidence of the worst grade of ARF post-OLT was 19.2%. These patients showed significantly higher MELD scores, while there was no association with systemic parameters related to the critical patient's condition or with the mortality score as evaluated by SAPS II criteria. We confirmed the association between renal failure and hepatic function among liver transplant patients. A more severe degree of hepatic dysfunction before OLT was associated with a greater incidence of ARF that can adversely affect patient survival.

Extracorporeal removal CO2 using a venovenous, low-flow system (Decapsmart) in a lung transplanted patient: a case report.

BACKGROUND: Primary graft dysfunction (PGD) is a syndrome that may occur after lung transplantation. In some cases of severe PGD, conventional therapies like ventilatory support, administration of inhaled nitric oxide (iNO), and surfactant and intravenous prostacyclins are inadequate to achieve adequate gas exchange. The only lifesaving option is to use an extracorporeal membrane oxygenator. The Decapsmart is a new venovenous, low-flow extracorporeal device to removal carbon dioxide (CO(2)). It does not need a specialized staff. Herein we have presented a case report of a patient who underwent single lung transplantation and experienced respiratory failure. METHODS: On November 2007, a 52-year-old woman underwent a single right lung transplantation, and developed severe PGD in the postoperative period. After institution of conventional treatments, including ventilatory and hemodynamic support, iNO, and prostaglandine E1, we started treatment with Decapsmart to remove CO(2). Hemodynamic and respiratory parameters were assessed at baseline and after 3, 12, 24, and 48 hours. RESULTS: No adverse events occurred. From baseline to 48 hours, pH values increased and partial pressure of CO(2) reduced. At the same time ventilatory support was reduced, thereby mitigating barotrauma and risk of overdistension. CONCLUSION: The use of Decapsmart may be an important aid for patients with severe respiratory acidosis in association with conventional therapy during the perioperative period after lung transplantation.