Impact of cirrhosis on outcomes in trauma

BACKGROUND: Cirrhosis as an independent predictor of poor outcomes in trauma patients was identified in 1990. We hypothesized that the degree of preinjury hepatic dysfunction is, by itself, an independent predictor of mortality. STUDY DESIGN: The trauma registry at our Level I trauma center was queried for all ICD-9 codes for liver disease from 1999 to 2003, and patients were categorized as having Child-Turcotte-Pugh (CTP) class A, B, or C cirrhosis. Data analyzed included age, mechanism of injury, Abbreviated Injury Score (AIS), Injury Severity Score (ISS), Glasgow Coma Score (GCS), hospital length of stay, ventilator days, procedures performed, transfusion of blood products, admission lactate, base deficit, and mortality. Trauma Related Injury Severity Score (TRISS) methodology was used to calculate the probability of survival. Outcomes data were analyzed, and statistical comparison was performed using group t-test. RESULTS: Of the 50 patients meeting study criteria, 31 had alcohol-related cirrhosis, 18 had a history of hepatitis C, and 1 had cryptogenic cirrhosis. Twenty (40%) met CTP A classification, 16 (32%) met CTP B criteria, and 14 (28%) had CTP class C cirrhosis. One death occurred in the CTP A and B groups. Comparison between the five survivors and nine nonsurvivors from CTP class C showed no statistical significance in terms of age, ISS, TRISS, or GCS. CONCLUSIONS: The mortality rate for class C cirrhotic patients posttrauma continues to be higher than that predicted by TRISS, although patients with less severe hepatic dysfunction do not appear to have significantly lower than predicted survival. The degree of hepatic dysfunction remains an independent predictor of mortality and CTP C criteria must be considered when determining outcomes for patients posttrauma.     

Numerical simulation of the fluid dynamics in vitreous cavity due to saccadic eye movement

In this study, the flow dynamics of vitreous due to saccadic movements following vitreous liquefaction or in post-vitrectomy eyes is investigated. Using a dynamic mesh technique, the eye motion was modeled and unsteady three-dimensional forms of continuity and Navier-Stokes equations were solved numerically. Firstly, the numerical model was validated for a sphere as a model of vitreous chamber and agrees well with the results based on available analytic solutions and experimental data. Then, numerical simulation was performed based on a deformed sphere with an indentation representing the lens. This consists of a vitreous cavity filled with a liquid having the viscosity of liquefied vitreous and balanced salt solution. The wall shear stress on the retina was computed and compared for various saccade amplitudes. Also, the effect of variation in vitreous viscosity and the size of lens indentation are investigated. The results show that the secondary flow in the vertical direction in the vitreous cavity is much higher for the liquefied vitreous and balanced salt solution compared with that for silicone oil. The possible effect of shear stress on the retinal detachment for all studied cases is discussed. A semi-analytic correlation is also developed for maximum wall shear stress of the spherical domain that is subjected to sinusoidal rotations.     

A fatal case of Degos' disease which presented with recurrent intestinal perforation

Degos’ disease,otherwise known as "malignant atrophic papulosis" is a rare vasculopathy with an unknown etiology characterized by typical cutaneous lesions.Involvement of the gastrointestinal(GI) tract is observed in approximately half of patients and small infarctions in the mucosa can cause perforation and resulting peritonitis,the leading cause of death.We present a fatal case of Degos’ disease with skin and GI involvement,manifesting as recurrent intestinal perforations and peritonitis,in a 15-year-old Iranian boy.     

Placement of intraventricular catheters using flexible electromagnetic navigation and a dynamic reference frame: a new technique

BACKGROUND: Catheterization of narrow ventricles may prove difficult resulting in misplacement or inefficient trials with potential damage to brain tissue. MATERIAL AND METHODS: The application of a new module for navigated ventricular catheterization using flexible electromagnetic navigation and a dynamic reference frame is presented. RESULTS: Navigated catheter placement was successful and accurate in a pilot study. Electromagnetic interferences had to be taken into consideration. CONCLUSION: Flexible electromagnetic navigation with a dynamic reference frame is a useful tool for catheter placement as it reduces the risk of misplacement or repeated catheterization trials.