Intensive care medicine experimental
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Intensive Care Med Exp · Oct 2021
Computed tomographic assessment of lung aeration at different positive end-expiratory pressures in a porcine model of intra-abdominal hypertension and lung injury.
Intra-abdominal hypertension (IAH) is common in critically ill patients and is associated with increased morbidity and mortality. High positive end-expiratory pressures (PEEP) can reverse lung volume and oxygenation decline caused by IAH, but its impact on alveolar overdistension is less clear. We aimed to find a PEEP range that would be high enough to reduce atelectasis, while low enough to minimize alveolar overdistention in the presence of IAH and lung injury. ⋯ Our findings in a large animal model suggest that titrating a PEEP to respiratory mechanics or oxygenation in the presence of IAH is associated with increased alveolar overdistension.
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Intensive Care Med Exp · May 2021
The effect of targeting Tie2 on hemorrhagic shock-induced renal perfusion disturbances in rats.
Hemorrhagic shock is associated with acute kidney injury and increased mortality. Targeting the endothelial angiopoietin/Tie2 system, which regulates endothelial permeability, previously reduced hemorrhagic shock-induced vascular leakage. We hypothesized that as a consequence of vascular leakage, renal perfusion and function is impaired and that activating Tie2 restores renal perfusion and function. ⋯ Hemorrhagic shock-induced renal impairment cannot be restored by standard fluid resuscitation, nor by activation of Tie2. Future treatment strategies should focus on reducing angiopoietin-2 levels or on activating Tie2 via an alternative strategy.
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Measurements of cerebrospinal fluid (CSF) lactate can aid in detecting infections of the central nervous system and surrounding structures. Neurosurgical patients with temporary lumbar or ventricular CSF drainage harbor an increased risk for developing infections of the central nervous system, which require immediate therapeutic responses. Since blood gas analyzers enable rapid blood-lactate measurements, we were interested in finding out if we can reliably measure CSF-lactate by this point-of-care technique. ⋯ Blood gas analyzers measure CSF-lactate with sufficient reliability and can help in the timely detection of a developing meningitis. In addition to and triggering established CSF diagnostics, CSF-lactate measurements by blood gas analyzers may improve surveillance of patients with CSF drainage. This study was retrospectively registered on April 20th 2020 in the German trial register. The trial registration number is DRKS00021466.
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Intensive Care Med Exp · Dec 2020
Continuous external negative pressure improves oxygenation and respiratory mechanics in Experimental Lung Injury in Pigs - A pilot proof-of-concept trial.
Continuous external negative pressure (CENP) during positive pressure ventilation can recruit dependent lung regions. We hypothesised that CENP applied regionally to the thorax or the abdomen only, increases the caudal end-expiratory transpulmonary pressure depending on positive end-expiratory pressure (PEEP) in lung-injured pigs. Eight pigs were anesthetised and mechanically ventilated in the supine position. Pressure sensors were placed in the left pleural space, and a lung injury was induced by saline lung lavages. A CENP shell was placed at the abdomen and thorax (randomised order), and animals were ventilated with PEEP 15, 7 and zero cmH2O (15 min each). On each PEEP level, CENP of - 40, - 30, - 20, - 10 and 0 cmH2O was applied (3 min each). Respiratory and haemodynamic variables were recorded. Electrical impedance tomography allowed assessment of centre of ventilation. ⋯ In this lung injury model in pigs, CENP increased the end-expiratory caudal transpulmonary pressure. This lead to a shift of lung aeration towards dependent zones as well as improved respiratory mechanics and oxygenation, especially when CENP was applied to the abdomen as compared to the thorax. CENP values ≤ 20 cmH2O impaired the haemodynamics.
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Intensive Care Med Exp · Dec 2020
Prognostic classification based on P/F and PEEP in invasively ventilated ICU patients with hypoxemia-insights from the MARS study.
Outcome prediction in patients with acute respiratory distress syndrome (ARDS) greatly improves when patients are reclassified based on predefined arterial oxygen partial pressure to fractional inspired oxygen ratios (PaO2/FiO2) and positive end-expiratory pressure (PEEP) cutoffs 24 h after the initial ARDS diagnosis. The aim of this study was to test whether outcome prediction improves when patients are reclassified based on predefined PaO2/FiO2 and PEEP cutoffs 24 h after development of mild hypoxemia while not having ARDS. ⋯ Reclassification using PaO2/FiO2 and PEEP cutoffs after 24 h improved classification for outcome in invasively ventilated ICU patients with hypoxemia not explained by ARDS, compared to classification at onset of hypoxemia.