Bronchoalveolar lavage with trypsin in pulmonary alveolar proteinosis

Management of complications from diagnostic and interventional bronchoscopy

From the humble beginnings as a mere curiosity, the art of bronchoscopy has progressed at a rapid pace. The millennium ushers in new technologies and refinements in established techniques to facilitate early detection of cancer, precise targeting of pulmonary nodules and infiltrates, near-total staging of the mediastinum with combined endoscopic modalities and more effective palliation of inoperable tumours. Bronchoscopists are faced with an increasing myriad of tools and equipment, each promising to carry out better than the previous. It is opportune to review the complications of established bronchoscopic techniques and how to manage them as well as new complications associated with novel technologies. In this article, we provide a concise overview of diagnostic and therapeutic bronchoscopic modalities, discussion of associated complications and their management strategies.

Bronchioalveolar lavage with perfluorochemical liquid during conventional ventilation

OBJECTIVE

Therapeutic approaches with bronchioalveolar lavage are currently used in infants with severe alveolar space-occupying material. In many circumstances, bronchioalveolar lavage has been performed in conjunction with extracorporeal membrane oxygenation.

CASE REPORT

A 2-month-old boy with severe respiratory failure requiring assisted ventilation did not respond to any conventional treatments, including surfactant. An open-lung biopsy showed intra-alveolar accumulation of proteinaceous material and foamy macrophages but was not diagnostically conclusive. Therapeutic trials with bronchioalveolar lavage using normal saline were unsuccessful, causing episodes of severe hypoxemia. Then, bronchioalveolar lavage during conventional mechanical ventilation was performed with the use of a medical-grade perfluorochemical liquid (perfluordecalin). After instillation of liquid (10 mL/kg), the lungs were refilled three times during the first 24 hrs and repeated 48 hrs later. During perfluorochemical liquid treatment, the infant's condition remained stable, with small improvements in pulmonary mechanics. Suction from the endotracheal cannula yielded only small amounts of gelatinous material. Considering the progression of the disease and just minimal pulmonary improvements by this intervention, further treatment was considered futile. Support was, thus, minimized, and the infant died a few days later. An autopsy revealed the diagnosis to be consistent with Niemann-Pick C2 disease.

CONCLUSION

This study demonstrated that bronchioalveolar lavage with perfluorochemical liquid could be performed safely during conventional mechanical ventilation without the additional support of extracorporeal membrane oxygenation in infants with severe alveolar space-occupying material.

[Pulmonary alveolar phospholipoproteinosis]

Pulmonary alveolar phospholipoproteinosis is a rare lung disease of unknown cause characterized by surfactant plugging of the alveoli. At the present time, surgical lung biopsy, long considered as the gold standard, is not necessary for positive diagnosis of pulmonary alveolar phospholipoproteinosis when computed tomography anomalies and analysis of bronchial lavage fluids present a typical pattern. Treatment requires abundant lavage, but the demonstration of anti-GM-CSF antibodies in primary forms opens new therapeutic perspectives.

Pulmonary Alveolar Proteinosis

Pulmonary alveolar proteinosis (PAP) is characterized by the accumulation of surfactant phospholipids and proteins within the lung alveoli. Important advances have been made over the past 8 years in our understanding of this disease, offering new directions for research and patient care. First, genetically altered mice that are homozygous for a disrupted granulocyte-macrophage colony-stimulating factor (GM-CSF) gene developed a lung lesion with histologic resemblance to PAP. The surfactant is thought to be catabolized or cleared mostly by alveolar macrophages, this process being dependent on GM-CSF. Second, a neutralizing autoantibody against GM-CSF was found in serum and bronchoalveolar lavage fluid of patients with idiopathic PAP but not in healthy controls, thereby raising the suspicion that human PAP may be an autoimmune disease. The relationship between the antibody and disease pathogenesis remains unclear but data suggest that the GM-CSF antibody may have a potential role as a diagnostic test. No specific therapy exists for PAP. Sequential whole lung lavage is the standard of care. Exogenous therapy with GM-CSF may improve the lung disease in some patients with PAP but this therapy is still experimental. Interventions directed at treating a relative GM-CSF deficiency by administration of GM-CSF or lowering the antibody level (i.e. by plasmapheresis or immunosuppression) may hold promise as future therapy for this rare disease.

Pulmonary alveolar proteinosis: treatment by bronchofiberscopic lobar lavage

The current mainstay of treatment for pulmonary alveolar proteinosis (PAP) is whole-lung lavage. Therapy with granulocyte-macrophage colony-stimulating factor is a possibility, although its long-term safety has not been determined. An alternative procedure is selected lobar lavage by fiberoptic bronchoscopy (FOB). We report here our experiences with lobar lavage by FOB in treating three patients with PAP. PAP was diagnosed in three patients (two men, one woman) who had dyspnea and hypoxemia after undergoing open-lung biopsy. The patients underwent lobar lavage by FOB under local anesthesia. The bronchoscope was wedged into a lobar bronchus. Approximately 2,000 mL warm normal saline solution was instilled via syringe in 50-mL aliquots through a fiberoptic bronchoscope. After undergoing multiple lobar lavages, two patients showed clinical, physiologic, and radiologic improvement. The third patient, who had more advanced disease, showed improvement only in oxygenation. The major complications were severe cough and hypoxemia during lavage. Our experience suggests that bronchoscopic lobar lavage is simple and safe, and may find application in patients in whom a whole-lung lavage with generalized anesthesia may be hazardous, and in patients with less advanced disease whose proteinaceous substances can be removed with a small volume of lavage fluid.