Guy Freys

Bio: Guy Freys is an academic researcher. The author has contributed to research in topics: Liver transplantation & Inferior vena cava. The author has an hindex of 5, co-authored 6 publications receiving 418 citations.

Factors Associated with Overall and Attributable Mortality in Invasive Aspergillosis

Abstract: 7 Laboratoire d'Epidemiologie et de SantePublique, Faculted e Medecine, UniversiteLouis Pasteur, Strasbourg, France (See the editorial commentary by Kohno on pages XXX-XX) Background. Invasive aspergillosis is associated with high death rates. Factors associated with increased mor- tality have not yet been identified in a large population of patients with various underlying conditions. Methods. We retrospectively reviewed 385 cases of suspected or documented aspergillosis that occurred during a 9-year period. We identified 289 episodes that fulfilled the criteria for possible, probable, or proven invasive aspergillosis according to the international definition criteria and that was treated with an anti-Aspergillus active antifungal drug. Clinical and microbiological variables were analyzed for their effects on overall and attributable mortality. Significant variables in univariate analysis were introduced into a multivariate Cox model. Results. Twelve-week overall and disease-specific survival rates were 52.2% (95% confidence interval, 46.5%- 57.9%) and 59.8% (95% confidence interval, 54.0%-65.4%), respectively. Receipt of allogeneic hematopoietic stem cell or solid-organ transplant, progression of underlying malignancy, prior respiratory disease, receipt of corti- costeroid therapy, renal impairment, low monocyte counts, disseminated aspergillosis, diffuse pulmonary lesions, pleural effusion, and proven or probable (as opposed to possible) aspergillosis are predictors of increased overall mortality. Similar factors are also predictors of increased attributable mortality, with the following exceptions: pleural effusion and low monocyte counts have no impact, whereas neutropenia is associated with a higher attributable mortality. Conclusions. Identification of predictors of death helps in the identification of patients who could benefit from more-aggressive therapeutic strategies. Initiation of therapy at the stage of possible infection improves out- come, and this finding calls for the development of efficient preemptive strategies to fill the gap between empirical and directed therapy.

Tissue oxygenation during liver transplantation.

Abstract: Objectives a) To assess perioperative changes in tissue oxygenation parameters during liver transplantation; b) to evaluate the need for venovenous bypass as hemodynamic support; and c) to assess the efficacy of mixed venous oxygen saturation monitoring and the importance of lactate determinations in the management of patients following liver transplantation. Design Prospective case series. Setting Liver transplant unit in a university hospital. Patients A total of 68 consecutive patients undergoing liver transplantation. The entire population was analyzed before and after transplantation, dividing the patients into two groups, based on whether their initial cardiac index was higher (n = 37) or lower (n = 31) than 4.5 L/min/m2. Measurements Hemodynamic measurements and blood gas analyses were made before incision, before vascular clamping (including hepatic artery, portal vein and inferior vena cava), during the anhepatic phase, and at 5, 30, 60, and 120 mins following unclamping. Oxygen transport and oxygen consumption values were calculated. Serum lactate concentrations were measured by enzymatic technique. Main results Mixed venous oxygen saturation was correlated with oxygen transport (Do2) in the whole population in which an abnormal oxygen consumption (Vo2)-Do2-dependent relationship occurred from the beginning of operation until 30 mins following unclamping. The comparison between hyperdynamic patients (initial cardiac index greater than 4.5 L/min/m2) with impaired tissue oxygenation and normodynamic patients showed that mixed venous oxygen saturation failed to correlate with Do2 when the cardiac index was greater than 4.5 L/min/m2 and that the Vo2-Do2 dependency was only noted in these patients. The serum lactate concentrations were similar in both groups. Conclusions The Vo2-Do2-dependent relationship and mixed venous oxygen saturation-Do2 correlation noted in the 68 studied patients suggest the need for venovenous bypass and the reliability of mixed venous oxygen saturation monitoring in all patients scheduled for liver transplantation. However, a sharper comparison between hyperdynamic and normodynamic patients demonstrated the lack of efficacy of mixed venous oxygen saturation monitoring in predicting adequate tissue oxygenation in the first group and the mandatory need for venous shunting to limit tissue hypoxia which occurred despite its use only in these patients. Lactic acidosis appeared similarly in both groups and could not be linked to tissue hypoxia.

Early discovery of a traumatic carotid-cavernous sinus fistula by jugular venous oxygen saturation monitoring. Case report.

Abstract: ✓ This report describes the early diagnosis, due to an acute increase of jugular venous oxygen saturation occurring 20 hours after trauma, of a traumatic carotid-cavernous sinus fistula after severe head injury. Hyperemia in severe head injury should be treated only after an intracerebral arteriovenous communication has been excluded.

A Clinical Algorithm to Diagnose Invasive Pulmonary Aspergillosis in Critically Ill Patients

Abstract: Rationale: The clinical relevance of Aspergillus-positive endotracheal aspirates in critically ill patients is difficult to assess. Objectives: We externally validate a clinical algorithm to discriminate Aspergillus colonization from putative invasive pulmonary aspergillosis in this patient group. Methods: We performed a multicenter (n = 30) observational study including critically ill patients with one or more Aspergillus-positive endotracheal aspirate cultures (n = 524). The diagnostic accuracy of this algorithm was evaluated using 115 patients with histopathologic data, considered the gold standard. Subsequently, the diagnostic workout of the algorithm was compared on the total cohort (n=524), with the categorization based on the diagnostic criteria of the European Organization for the Research and Treatment of Cancer/Mycoses Study Group. Measurements and Main Results: Among 115 histopathology-controlled patients, 79 had proven aspergillosis. The algorithm judged 86 of 115 cases to haveputative aspergillosis. This diagnosis was confirmed in 72 and rejected in 14 patients. The algorithm judged 29 patients to have Aspergillus colonization. This was confirmed in 22 and rejected in 7 patients. The algorithm had a specificity of 61% and a sensitivity of 92%. The positive and negative predictive values were 61 and 92%, respectively. In the total cohort (n = 524), 79 patients had proven invasive pulmonary aspergillosis (15.1%). According to the European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria, 32 patients had probable aspergillosis (6.1%) and 413 patients were not classifiable (78.8%). The algorithm judged 199 patients to have putative aspergillosis (38.0%) and 246 to have Aspergillus colonization (46.9%). Conclusions: The algorithm demonstrated favorable operating characteristics to discriminate Aspergillus respiratory tract colonization from invasive pulmonary aspergillosis in critically ill patients. Copyright © 2012 by the American Thoracic Society.