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.

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.