Intensive care medicine experimental
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Intensive Care Med Exp · Dec 2015
Effects of early hemodynamic resuscitation on left ventricular performance and microcirculatory function during endotoxic shock.
Microcirculation and macrohemodynamics are severely compromised during septic shock. However, the relationship between these two compartments needs to be further investigated. We hypothesized that early resuscitation restores left ventricular (LV) performance and microcirculatory function but fails to prevent metabolic disorders. We studied the effects of an early resuscitation protocol (ERP) on LV pressure/volume loops-derived parameters, sublingual microcirculation, and metabolic alterations during endotoxic shock. ⋯ Early hemodynamic resuscitation was effective to restore macrohemodynamia and myocardial contractility. Despite MAP and MFI were relatively preserved, the persistent microvascular dysfunction could explain metabolic disorders. The relationship between micro- and systemic hemodynamia and their impact on cellular function and metabolism needs to be further studied during endotoxic shock.
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Intensive Care Med Exp · Dec 2015
Computational simulation indicates that moderately high-frequency ventilation can allow safe reduction of tidal volumes and airway pressures in ARDS patients.
A recent prospective trial using porcine models of severe acute respiratory distress syndrome (ARDS) indicated that positive-pressure ventilation delivered by a conventional intensive care ventilator at a moderately high frequency allows safe reduction of tidal volume below 6 ml/kg, leading to more protective ventilation. We aimed to explore whether these results would be replicated when implementing similar ventilation strategies in a high-fidelity computational simulator, tuned to match data on the responses of a number of human ARDS patients to different ventilator inputs. ⋯ Our study supports the proposition that moderately high-frequency respiratory rates can allow more protective ventilation of ARDS patients and highlights the potential role of high-fidelity simulators in computing optimised and personalised ventilator settings for individual patients using this approach.
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Intensive Care Med Exp · Dec 2015
Alveolar instability (atelectrauma) is not identified by arterial oxygenation predisposing the development of an occult ventilator-induced lung injury.
Improperly set mechanical ventilation (MV) with normal lungs can advance lung injury and increase the incidence of acute respiratory distress syndrome (ARDS). A key mechanism of ventilator-induced lung injury (VILI) is an alteration in alveolar mechanics including alveolar instability or recruitment/derecruitment (R/D). We hypothesize that R/D cannot be identified by PaO2 (masking occult VILI), and if protective ventilation is not applied, ARDS incidence will increase. ⋯ PaO2 remained clinically acceptable while alveolar instability persisted at all levels of PEEP (especially PEEP <9 cmH2O). Therefore, PaO2 levels cannot be used reliably to guide protective MV strategies or infer that VILI is not occurring. Using PaO2 to set a PEEP level necessary to stabilize the alveoli could underestimate the potential for VILI. These findings highlight the need for more accurate marker(s) of alveolar stability to guide protective MV necessary to prevent VILI.
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Intensive Care Med Exp · Dec 2015
Mesenchymal stromal cells are more effective than the MSC secretome in diminishing injury and enhancing recovery following ventilator-induced lung injury.
The potential for mesenchymal stem cells (MSCs) to reduce the severity of experimental lung injury has been established in several pre-clinical studies. We have recently demonstrated that MSCs, and MSC-secreted factors (secretome), enhance lung repair and regeneration at 48 h following ventilation-induced lung injury (VILI). We wished to determine the potential for MSC therapy to exert beneficial effects in the early recovery phase following VILI when ongoing injury coexists with processes of repair, and to compare the efficacy of MSC therapy to the use of the secretome alone. ⋯ The immunomodulating and/or reparative effect of MSCs is evident early after VILI in this model. MSC-conditioned medium was not as effective as the cells themselves in diminishing injury and restoring lung structure and function.
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Intensive Care Med Exp · Dec 2015
Catheter securement systems: comparison of two investigational devices to a sutureless securement device, a securement dressing, and sutures in a pig model.
Catheter securement is critical for the success of infusion therapy and to prevent complications. Our purpose was to compare the strength of catheter securement achieved with two investigational adhesive securement devices to two securement products and also to sutures using an in vivo animal model. ⋯ The two investigational devices appear to be a promising alternative for catheter securement, superior to sutures and the securement dressing, and non-inferior to the securement device.