Improving Bronchoalveolar Lavage To Enhance Diagnostic Yield Of Pulmonary Complications

About This Grant

Lung complications are difficult to diagnose in critically ill children and linked to high mortality. Current diagnosis of complications such as infection and bleeding relies upon bronchoalveolar lavage (BAL), which has low yield (~30%) and high morbidity. Bronchoalveolar lavage involves lavage of a lung segment, with the fluid suctioned for infectious disease and other testing. Because current bronchoscopes cannot access all lung segments, nor the distal sites of lung infections, a large volume of fluid is required to interrogate the affected tissue. Injured lungs retain fluid, which leads to significant morbidity and respiratory compromise. This is most significant for critically ill children who have small airways and parenchyma with minimal pulmonary reserve. Lack of diagnosis is correlated to death. Other diagnostic tools are limited by higher morbidity (lung biopsy) or decreased specificity (blinded approaches such as the miniBAL or tracheal aspirate). Hence, a new approach to improve diagnosis and hence organism recovery is urgently needed for critically ill children. The main goal of this project is to develop a Robotic BAL (RoboBAL) device that allows the clinician to steer and access more distal sites and can include inaccessible sites (the right upper lobe), obviating the amount of fluid needed in critically ill children. This new system will be able to access the fourth tracheobronchiole division, beyond the current third division of BAL. We propose two specific aims (SAs): SA 1: Design and develop a 3.25mm robotically steerable BAL device with an integrated camera and light source and a 1.2mm actively steerable working channel for suction and irrigation of fluid. SA 2: Test the ability to access distal airways in five human cadaver lungs and compare the diagnostic yield and fluid retained after lavage with RoboBAL and SOC BAL. We propose innovative methods to assess the differences in phantom human models and human cadavers. In human cadavers, imaging will demonstrate the depth of the bronchoscope and proximity to a target (RoboBAL vs. SOC). Using a Alexa Fluor 488 labeled Ecoli, we will quantitate the recovery of the fluorescent dye and evaluate microbe capture by culture, modeling the yield of microbes. Finally, safety will be assessed by the wet/dry ratio as a surrogate for retained fluid, and inspection to determine any impediment to traverse small airways. Through accomplishing these aims, we will have determined whether we can access all fourth generation airways, and achieve superior yield with less fluid retained. Our highly interdisciplinary team with expertise in medical robotics (Dr. Desai), pulmonary complications of critically ill children and adults (Drs. Williams and Lama), radiographic imaging (Dr. Alazraki), and statistics (Dr. Switchenko) is poised to develop and test this new RoboBAL device that could enhance diagnosis and diminish morbidity, thereby leading to rapid, targeted treatment with downstream effects of decreased ventilator time, decreased intensive care, decreased antibiotic resistance, and improved outcomes with lower healthcare costs. The proposed RoboBAL system will improve diagnosis and permit targeted therapy to improve outcomes in critically ill children – see support letters.