Eduard Kralj

Frequency and number of resuscitation related rib and sternum fractures are higher than generally considered

AIM OF THE STUDY This study aimed to establish the incidence, number and location of CPR-related skeletal chest injuries (SCI) and to investigate the influence of age, gender, changes in resuscitation guidelines and technique of resuscitation. METHODS We analysed SCI in 2148 patients who had undergone resuscitation for non-traumatic cardiac arrest, as shown by autopsies performed at the Institute of Forensic Medicine in Ljubljana in the period 2004-2013. RESULTS External cardiac massage caused SCI in 86% of males and in 91% of females; sternum fractures occurred in 59% of males and 79% of females, rib fractures in 77% of males and 85% of females and sternocostal separations in 33% of males and 12% of females. The average number of all SCI per person was thus almost the same in males and females: 10.95 vs. 10.96. The percentage of patients injured and the number of SCI increased with age. Changes in resuscitation guidelines were also identified as a factor contributing to the incidence and number of SCI. No adverse effect of the use of LUCAS was found. CONCLUSION It is generally considered that at least 1/3 of resuscitated patients sustain rib fractures and at least 1/5 sustains sternum fractures. However, our study showed that these injuries are much more frequent and that increased compression rate and depth cause more SCI. Since in the period 2011-2013 accompanying severe injuries occurred in only 1.85% of cases, the resuscitation technique has not yet jeopardised patients safety, but further close monitoring is needed.

Impact of altered venous hemodynamic conditions on the formation of platelet layers in thromboemboli

Although it is generally believed that the structure of venous thromboemboli is a homogeneous red blood cell-fibrin clot, their structure may be heterogeneous, with non-uniformly distributed platelet layers, known as the lines of Zahn. We tested (a) whether venous thromboemboli ex vivo contained platelet layers, i.e. the lines of Zahn, and (b) whether, according to mathematical modeling, eddies can arise in the venous system, possibly contributing to platelet aggregation. The structure of venous thromboemboli ex vivo was determined by high-resolution magnetic resonance imaging (MRI) and by immunohistochemistry (IHC). High-resolution ultrasound (US) imaging was employed to determine the popliteal vein geometry and hemodynamics in healthy subjects and in subjects with previous venous thrombosis. The US data were then used as input for numerical simulations of venous hemodynamics. MRI and IHC confirmed that 42 of 49 ex vivo venous thromboemboli were structurally heterogeneous with platelet layers. The peak venous flow velocity was higher in patients with partly recanalized deep vein thrombosis than in healthy subjects in the prone position (46±4cm/s vs. 16±3cm/s). Our numerical simulation showed that partial venous obstruction with stenosis or malfunctioning venous valves creates the conditions for eddy blood flow. Our experimental results and computer simulation confirmed that the heterogeneous structure of venous thromboemboli with twisted platelet layers may be associated with eddy flow at the sites of their formation.

Multiparametric MRI in characterizing venous thrombi and pulmonary thromboemboli acquired from patients with pulmonary embolism

The structure of thrombi plays an important role in delaying reperfusion and re‐occlusion after intravenous thrombolysis and could influence the performance of mechanical thrombectomy devices. This study aims to distinguish various thrombi groups based on their T2 and apparent diffusion coefficient (ADC) properties.

An MRI study of the differences in the rate of thrombolysis between red blood cell-rich and platelet-rich components of venous thrombi ex vivo.

To test whether T1‐weighted MRI can detect the differences in the rate of thrombolysis induced by recombinant tissue plasminogen activator (rt‐PA) between platelet‐rich regions and red blood cell (RBC)‐rich regions of venous thrombi ex vivo.