Anesthesia, intensive care, Anesthésie, réanimation, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Sang. Coagulation sanguine. Système réticuloendothélial, Blood. Blood coagulation. Reticuloendothelial system, Anesthesie. Reanimation. Transfusion. Therapie cellulaire et therapie genique, Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy, Réanimation. Soins intensifs, Intensive care medicine, Réanimation respiratoire, Emergency and intensive respiratory care, Appareil respiratoire pathologie, Respiratory disease, Aparato respiratorio patología, Exploration radioisotopique, Radionuclide study, Exploración radioisotópica, Neutrophile, Neutrophil, Neutrófilo, Poumon pathologie, Lung disease, Pulmón patología, Pression positive résiduelle expiratoire, Positive end expiratory pressure, Presión positiva residual expiratoria, Réanimation, Resuscitation, Reanimación, Soin intensif, Intensive care, Cuidado intensivo, Tomographie émission positon, Positron emission tomography, Tomografía emisión positrones, Tomoscintigraphie, Emission tomography, Tomocentelleografía, influx constant, lower inflection point, lung injury, neutrophil, and positron emission tomography
Objectives: To compare the effects of low vs. high tidal volume (VT) with three positive end-expiratory pressure (PEEP) strategies on activated neutrophil influx into the lung. Design: Prospective, randomized controlled animal study. Setting: Animal laboratory in a university hospital. Subjects: Newborn piglets. Interventions: Surfactant-depleted piglets were randomized in littermate pairs; to PEEP of either 0 (zero end-expiratory pressure [ZEEP]; n = 6), 8 cm H2O (PEEP 8; n = 5), or 1 cm H2O above the lower inflection point (LIP) (PEEP>LIP; n = 6). Within each pair piglets were randomized to a low VT (5-7 mUkg) or high VT strategy (17-19 mUkg). After 4 hrs of mechanical ventilation, 18-fluorodeoxyglucose (18FDG) was injected and positron emission tomography scanning was performed. Measurements and Main Results: VT and PEEP changes on influx constants of 18FDG were assessed by analysis of variance. A within-litter comparison of VT was nonsignificant (p =.50). A between-litter comparison, ordered in linear trend rank, from ZEEP, to PEEP 8, to PEEP>LIP, showed a strong effect of PEEP on influx constant (p =.019). Conclusions: PEEP set above the LIP on the inspiratory limb of the pressure-volume curve affords a stronger lung protection than VT strategy.
