Variable Ventilation Associated With Recruitment Maneuver Minimizes Tissue Damage and Pulmonary Inflammation in Anesthetized Lung-Healthy Rats
| Autor: | Walter A. Zin, Luciana Moisés Camilo, Gabriel Casulari Motta-Ribeiro, Mariana Abreu, Alysson R. Carvalho, Luis Felipe Paula, Mariana Barcellos Avila |
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| Rok vydání: | 2018 |
| Předmět: |
Male
medicine.medical_specialty Atelectasis Proinflammatory cytokine Positive-Pressure Respiration 03 medical and health sciences 0302 clinical medicine 030202 anesthesiology Internal medicine Respiration Parenchyma medicine Tidal Volume Animals Respiratory system Rats Wistar Lung Tidal volume Anesthetics Dissociative business.industry Pneumonia respiratory system medicine.disease Respiration Artificial respiratory tract diseases Rats Anesthesiology and Pain Medicine medicine.anatomical_structure 030228 respiratory system Breathing Cardiology Respiratory Mechanics business |
| Zdroj: | Anesthesia and analgesia. 127(3) |
| ISSN: | 1526-7598 |
| Popis: | BACKGROUND Recruitment maneuver and positive end-expiratory pressure (PEEP) can be used to counteract intraoperative anesthesia-induced atelectasis. Variable ventilation can stabilize lung mechanics by avoiding the monotonic tidal volume and protect lung parenchyma as tidal recruitment is encompassed within the tidal volume variability. METHODS Forty-nine (7 per group) male Wistar rats were anesthetized, paralyzed, and mechanically ventilated. A recruitment maneuver followed by stepwise decremental PEEP titration was performed while continuously estimating respiratory system mechanics using recursive least squares. After a new recruitment, animals were ventilated for 2 hours in volume-control with monotonic (VCV) or variable (VV) tidal volumes. PEEP was adjusted at a level corresponding to the minimum elastance or 2 cm H2O above or below this level. Lungs were harvested for histologic analysis (left lung) and cytokines measurement (right lung). Seven animals were euthanized before the first recruitment as controls. RESULTS A time-dependent increase in respiratory system elastance was observed and significantly minimized by PEEP (P < .001). Variable ventilation attenuated the amount of concentrations of proinflammatory mediators in lung homogenate: neutrophil cytokine-induced neutrophil chemoattractant 1 (VV = 40 ± 5 and VCV = 57 ± 8 pg/mg; P < .0001) and interleukin-1β (VV = 59 ± 25 and VCV = 261 ± 113 pg/mg; P < .0001). Variable ventilation was also associated with lower structural lung parenchyma damage. Significant reductions in air fraction at dorsal and caudal lung regions were observed in all ventilated animals (P < .001). CONCLUSIONS Variable ventilation was more protective than conventional ventilation within the applied PEEP levels. |
| Databáze: | OpenAIRE |
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