Impact of graft preservation solutions for liver transplantation on early cytokine release and postoperative organ dysfunctions. A pilot study.

INTRODUCTION: During liver transplantation, graft ischemia-reperfusion injury leads to a systemic inflammatory response producing postoperative organ dysfunctions. The aim of this observational and prospective study was to compare the impact of Solution de conservation des organes et tissus (SCOT) 15 and University of Wisconsin (UW) preservation solutions on early cytokine release, postreperfusion syndrome and postoperative organ dysfunctions. METHODS: Thirty-seven liver transplantations were included: 21 in UW Group and 16 in SCOT 15 group. Five cytokines were measured in systemic blood after anesthetic induction, 30minutes after unclamping portal vein and on postoperative day 1. RESULTS: Following unclamping portal vein, cytokines were released in systemic circulation. Systemic cytokine concentrations were higher in UW than in SCOT 15 group: Interleukin-10, Interleukine-6. In SCOT 15 group, significant reduction of postreperfusion syndrome incidence and acute kidney injury were observed. Alanine and aspartate aminotransferase peak concentrations were higher in SCOT 15 group than in UW group. However, from postoperative day 1 to day 10, aminotransferase returned to normal values and did not differ between groups. CONCLUSIONS: Compared to UW, SCOT 15 decreases systemic cytokine release resulting from graft ischemia-reperfusion injury and reduces incidence of postreperfusion syndrome and postoperative renal failure.

Ultrasound assessment of lung consolidation and reaeration after pleural effusion drainage in patients with Acute Respiratory Distress Syndrome: a pilot study.

PURPOSE: The aim of the pilot study was to assess by ultrasound changes in dimensions of lung consolidation and reaeration after drainage of large pleural effusion in patients with acute respiratory distress syndrome (ARDS). METHODS: Lung ultrasound and blood gas were performed before, 2 hours (H2) and 24 hours (H24) after drainage of pleural effusion. Lung ultrasound aeration score was calculated. Cephalocaudal dimension and diaphragmatic transversal area of lung consolidation were measured. RESULTS: Ten patients were studied. Median volume of drained effusion was 675 ml at H2 and 895 at H24. Two hours after drainage, dimension of cephalocaudal consolidation and diaphragmatic transversal area decreased significantly. Lung reaeration after drainage occurred mainly in latero-inferior and postero-superior regions. PaO2/FiO2 increased significantly at H24. CONCLUSIONS: Ultrasound is a useful method to assess lung consolidation after pleural effusion drainage. Drainage of pleural effusion may lead to a decrease of lung consolidation and improvement of lung reaeration.

Regulatory T cell therapy: An option to induce operational tolerance in liver transplantation.

Regulatory T cells (Treg) may play an important role in operational (clinical) tolerance (OT), a stable graft function without immunosuppression in an otherwise immunocompetent host, that is spontaneously observed in some patients many years after transplantation. Several ongoing clinical trials are currently testing the effects of donor-specific or non-specific Treg infusion with the goal to induce this state of OT a few months after liver transplantation (LT). The preliminary results of two of these trials have been recently published, and raise a number of comments and issues: (1) These two papers demonstrate that a 100 to 1000-fold ex-vivo expansion of Treg is possible in humans after 2 weeks of culture. The optimal human Treg dose is however not clearly established, and might be higher than the dose that would be expected from translating murine data. (2) A lot of concerns are remaining regarding the Treg purity before expansion, the Treg stability during in vitro culture and the in vivo fate of infused cells. A strict monitoring of Treg should thus be done at each step. (3) Since Treg may play a detrimental role in some conditions, such as viral diseases and cancer, potential LT recipients with such diseases should probably be excluded from the initial trials of Treg infusion. (4) The follow-up of tolerant liver recipients should include repeated liver biopsies and detection of autoantibodies and humoral response, in addition to conventional liver graft assessment, in order to prevent the development of immune complications related to immunosuppression withdrawal. (5) The final issue raised by Treg therapy in LT is the choice of the immunosuppressive regimen used before tapering or withdrawal, appropriate to preserve OT establishment.

Relationship between tracheotomy and ventilator-associated pneumonia: a case control study.

The aim of the present study was to determine the relationship between tracheotomy and ventilator-associated pneumonia (VAP). The study used a retrospective case-control study design based on prospective data. All nontrauma immunocompetent patients, intubated and ventilated for >7 days, were eligible for inclusion in the study. A diagnosis of VAP was based on clinical, radiographical and microbiological criteria. Four matching criteria were used, including duration of mechanical ventilation (MV). The indication and timing of tracheotomy were at the discretion of attending physicians. Univariate and multivariate analyses were performed to determine risk factors for VAP in cases (patients with tracheotomy) and controls (patients without tracheotomy). In total, 1,402 patients were eligible for inclusion. Surgical tracheotomy was performed in 226 (16%) patients and matching was successful for 177 (78%). The rate of VAP (22 versus 14 VAP episodes.1,000 MV-days(-1)) was significantly higher in controls than in cases. The rate of VAP after tracheotomy in cases, or after the corresponding day of MV in controls, was also significantly higher in control than in case patients (9.2 versus 4.8 VAP episodes.1,000 MV-days(-1)). In multivariate analysis, neurological failure (odds ratio (95% confidence interval) 2.7 (1.3-5)), antibiotic treatment (2.1 (1.1-3.2)) and tracheotomy (0.18 (0.1-0.3)) were associated with VAP. In summary, the present study demonstrates that tracheotomy is independently associated with decreased risk for ventilator-associated pneumonia.