Atelectasis can impair arterial oxygenation and decrease lung compliance. However, the effects of atelectasis on endotoxemic lungs during ventilation have not been well studied. We hypothesized that ventilation at low volumes below functional residual capacity (FRC) would accentuate lung injury in lipopolysaccharide (LPS)-pretreated rats. LPS-pretreated rats were ventilated with room air at 85 breaths/min for 2 hr at a tidal volume of 10 mL/kg with or without thoracotomy. Positive end-expiratory pressure (PEEP) was applied to restore FRC in the thoracotomy group. While LPS or thoracotomy alone did not cause significant injury, the combination of endotoxemia and thoracotomy caused significant hypoxemia and hypercapnia. The injury was observed along with a marked accumulation of inflammatory cells in the interstitium of the lungs, predominantly comprising neutrophils and mononuclear cells. Immunohistochemistry showed increased inducible nitric oxide synthase (iNOS) expression in mononuclear cells accumulated in the interstitium in the injury group. Pretreatment with PEEP or an iNOS inhibitor (1400 W) attenuated hypoxemia, hypercapnia, and the accumulation of inflammatory cells in the lung. In conclusion, the data suggest that atelectasis induced by thoracotomy causes lung injury during mechanical ventilation in endotoxemic rats through iNOS expression.
Animals ; Blood Pressure ; Carbon Dioxide/blood ; Cardiac Output ; Combined Modality Therapy ; Endotoxemia/*complications/immunology/pathology ; Functional Residual Capacity ; Immunohistochemistry ; Leukocytes, Mononuclear/pathology ; Lipopolysaccharides/pharmacology ; Lung/enzymology/pathology/physiopathology ; Lung Compliance ; Lung Volume Measurements ; Male ; Neutrophils/pathology ; Nitric Oxide Synthase Type II/metabolism ; Oxygen/blood ; Positive-Pressure Respiration/*adverse effects ; Pulmonary Atelectasis/*etiology/pathology/*therapy ; Rats ; Rats, Sprague-Dawley ; Thoracotomy/*adverse effects

Plastic bronchitis is an uncommon disorder characterized by the formation of bronchial casts. It is associated with congenital heart disease or pulmonary disease. In children with underlying conditions such as allergy or asthma, influenza can cause severe plastic bronchitis resulting in respiratory failure. A review of the literature showed nine cases of plastic bronchitis with H1N1 including this case. We report a case of a child with recurrent plastic bronchitis with eosinophilic cast associated with influenza B infection, who had recovered from plastic bronchitis associated with an influenza A (H1N1) virus infection 5 months previously. To the best of our knowledge, this is the first case of recurrent plastic bronchitis related to influenza viral infection. If patients with influenza virus infection manifest acute respiratory distress with total lung atelectasis, clinicians should consider plastic bronchitis and early bronchoscopy should be intervened. In addition, management for underlying disease may prevent from recurrence of plastic bronchitis.
Administration, Inhalation ; Adrenal Cortex Hormones/therapeutic use ; Antiviral Agents/therapeutic use ; Bronchitis/complications/*diagnosis/drug therapy ; Bronchoscopy ; Child ; DNA, Viral/analysis ; Dyspnea/etiology ; Humans ; Hypersensitivity/pathology ; Influenza A Virus, H1N1 Subtype/*genetics/isolation & purification ; Influenza B virus/genetics/isolation & purification ; Influenza, Human/complications/*diagnosis/drug therapy ; Male ; Oseltamivir/therapeutic use ; Pulmonary Atelectasis/drug therapy/radiography ; Real-Time Polymerase Chain Reaction ; Tachypnea/etiology ; Tomography, X-Ray Computed