The effect of shock duration on trauma-induced coagulopathy in a murine model

Background Trauma-induced coagulopathy (TIC) is a life-threatening condition associated with high morbidity and mortality. TIC can present with different coagulation defects. In this study, the aim was to determine the effect of shock duration on TIC characteristics. We hypothesized that longer duration of shock leads to a more hypocoagulable rotational thromboelastometry (ROTEM) profile compared to a shorter duration of shock. Methods Male B57BL/6J(c) mice (n = 5–10 per group) were sedated and mechanically ventilated. Trauma was induced by bilateral lower limb fractures and crush injuries to the liver and small intestine. Shock was induced by blood withdrawals until a mean arterial pressure of 25–30 mmHg was achieved. Groups reflected trauma and shock for 30 min (TS30) and trauma and shock for 90 min (TS90). Control groups included ventilation only (V90) and trauma only (T90). Results Mice in the TS90 group had significantly increased base deficit compared to the V90 group. Mortality was 10% in the TS30 group and 30% in the TS90 group. ROTEM profile was more hypocoagulable, as shown by significantly lower maximum clot firmness (MCF) in the TS30 group (43.5 [37.5–46.8] mm) compared to the TS90 group (52.0 [47.0–53.0] mm, p = 0.04). ROTEM clotting time and parameters of clot build-up did not significantly differ between groups. Conclusions TIC characteristics change with shock duration. Contrary to the hypothesis, a shorter duration of shock was associated with decreased maximum clotting amplitudes compared to a longer duration of shock. The effect of shock duration on TIC should be further assessed in trauma patients.

Azithromycin and Septic Shock Outcomes

Introduction: Although there is evidence describing the immunomodulatory effects of macrolide antibiotics, there is little literature exploring the clinical effects these properties may have and their impact on measurable outcomes. Objective: The purpose of this study was to determine if empiric antimicrobial regimens containing azithromycin shorten time to shock resolution. Methods: A retrospective study was performed in adults with septic shock admitted to intensive care units (ICUs) of 3 university-affiliated, urban teaching hospitals between June 2012 and June 2016. Eligible patients with septic shock required treatment with norepinephrine as the first-line vasopressor for a minimum of 4 hours and received at least 48 hours of antimicrobial treatment from the time of shock onset. Propensity scores were utilized to match patients who received azithromycin to those who did not. Results: A total of 3116 patients met initial inclusion criteria. After propensity score matching, 258 patients were included, with 124 and 134 patients in the azithromycin and control groups, respectively. Median shock duration was similar in patients treated with or without azithromycin (45.6 hr vs 59.7 hr, P = .44). In-hospital mortality was also similar (37.9% vs 38.1%, P = .979). There were no significant differences in mechanical ventilation duration, ICU length of stay (LOS), or hospital LOS. Conclusions: In patients admitted to the ICU with septic shock, empiric azithromycin did not have a significant effect on shock duration, mechanical ventilation duration, ICU LOS, hospital LOS, or in-hospital mortality.

Optimal Age-Based Preventive Maintenance Policy for a System Subject to Cumulative Damage Degradation and Random Shocks

This research investigates the problem of cumulative degradation and random shocks a system like a centrifugal pump may experience during normal and adverse operating conditions. An accelerated life testing method was employed to determine the degradation of the pump under cumulative damage degradation and random shocks conditions. An age- Based policy was used to determine the optimum time interval that will minimize the total expected cost of the system. The random shock increases the number of failures and hence reduces the reliability of the system. The total expected preventive maintenance cost obtained varies from N1700.00 (One thousand seven hundred naira) to N16,000.00 (sixteen thousand naira), depending on the shock and shock duration. The methodology presented is useful and thus recommended for use to study cumulative damage degradation and random shocks for similar systems.

A framework of current based defibrillation improves defibrillation efficacy of biphasic truncated exponential waveform in rabbits

Defibrillation is accomplished by the passage of sufficient current through the heart to terminate ventricular fibrillation (VF). Although current-based defibrillation has been shown to be superior to energy-based defibrillation with monophasic waveforms, defibrillators with biphasic waveforms still use energy as a therapeutic dosage. In the present study, we propose a novel framework of current-based, biphasic defibrillation grounded in transthoracic impedance (TTI) measurements: adjusting the charging voltage to deliver the desired current based on the energy setting and measured pre-shock TTI; and adjusting the pulse duration to deliver the desired energy based on the output current and intra-shock TTI. The defibrillation efficacy of current-based defibrillation was compared with that of energy-based defibrillation in a simulated high impedance rabbit model of VF. Cardiac arrest was induced by pacing the right ventricle for 60 s in 24 New Zealand rabbits (10 males). A defibrillatory shock was applied with one of the two defibrillators after 90 s of VF. The defibrillation thresholds (DFTs) at different pathway impedances were determined utilizing a 5-step up-and-down protocol. The procedure was repeated after an interval of 5 min. A total of 30 fibrillation events and defibrillation attempts were investigated for each animal. The pulse duration was significantly shorter, and the waveform tilt was much lower for the current-based defibrillator. Compared with energy-based defibrillation, the energy, peak voltage, and peak current DFT were markedly lower when the pathway impedance was > 120 Ω, but there were no differences in DFT values when the pathway impedance was between 80 and 120 Ω for current-based defibrillation. Additionally, peak voltage and the peak current DFT were significantly lower for current-based defibrillation when the pathway impedance was < 80 Ω. In sum, a framework of adjusting the charging voltage and shock duration to deliver constant energy for low impedance and constant current for high impedance via pre-shock and intra-shock impedance measurements, greatly improved the defibrillation efficacy of high impedance by lowering the energy DFT.

A Method to Estimate Dynamic Buckling Response of an Unstiffened Plate Elastically Restrained Along all Edges Under In-Plane Impact

Unstiffened plates in structures are usually welded or fastened to supporting members, providing rotational restraint stiffness to the plate. Previous studies have shown that neglect of rotational restraint stiffness at the edges of a plate in a structure can introduce deviations in the analysis of dynamic elastic buckling. In this study, the in-plane impact-induced dynamic elastic buckling responses of isotropic imperfect unstiffened plates with four elastically restrained edges are analytically investigated, based on the large-deflection theory of thin plate. The evolution of the peak deflection predicted by the proposed analytical method is found to be consistent with the responses available from the literature. Then the method is further used to estimate the deformation map of an unstiffened plate with four elastically restrained edges, and the effects of rotational restraint stiffness, initial geometric imperfection and shock duration on the dynamic buckling response of the plate are examined. The results show that the critical dynamic buckling load and the maximum deflection response of the plates are significantly influenced by the rotational restraint stiffness as well as the first-order initial geometric imperfection, and thus cannot be neglected in the analysis of dynamic buckling.

Variasi Lama Kejutan Panas pada Suhu yang Sama terhadap Tingkat Penetasan Telur (HR) Ikan Lele Dumbo (Clarias gariepinus)

<p><em>Species, temperature shock duration, fertilization temperature from different climates can cause different hatching results, so it is necessary to do research on the treatment of variations in heat shock at the same temperature, to obtain information about the hatching rate (HR) of African catfish (Clarias gariepinus). The method used is completely randomized design (3x3). The results of the egg hatching rate (HR), with variations in the heat shock at the same temperature (35⁰C), </em><em>showed the highest rate of hatching dumbo catfish eggs at heat shock one minute 233.00%, then heat shock two minutes 212.00%, and heat shock three minutes 200.00% respectively.</em><em></em></p>