Anesthesiology
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Observational Study
Opening Injection Pressure Consistently Detects Needle-Nerve Contact during Ultrasound-guided Interscalene Brachial Plexus Block.
Needle trauma may cause neuropathy after nerve blockade. Even without injection, nerve injury can result from forceful needle-nerve contact (NNC). High opening injection pressures (OIPs) have been associated with intrafascicular needle tip placement and nerve damage; however, the relationship between OIP and NNC is unclear. The authors conducted a prospective, observational study to define this relationship. ⋯ High OIP (≥15 psi) consistently detected NNC, suggesting that injection pressure monitoring may be useful in preventing injection against nerve roots during interscalene block.
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Diaphragm and psoas are affected during sepsis in animal models. Whether diaphragm or limb muscle is preferentially affected during sepsis in the critically ill remains unclear. ⋯ During the ICU stay, both diaphragm and psoas volumes decreased. In septic patients, the authors report for the first time in humans preferential diaphragm atrophy compared with peripheral muscles.
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Animal models of ventilator-associated pneumonia (VAP) in primates, sheep, and pigs differ in the underlying pulmonary injury, etiology, bacterial inoculation methods, and time to onset. The most common ovine and porcine models do not reproduce the primary pathogenic mechanism of the disease, through the aspiration of oropharyngeal pathogens, or the most prevalent human etiology. Herein the authors characterize a novel porcine model of VAP due to aspiration of oropharyngeal secretions colonized by Pseudomonas aeruginosa. ⋯ The authors devised a VAP model caused by aspiration of oropharyngeal P. aeruginosa, a frequent causative pathogen of human VAP. The model also overcomes the practical and legislative limitations associated with the use of primates. The authors' model could be employed to study pathophysiologic mechanisms, as well as novel diagnostic/preventive strategies.