1143 Sleep Evaluation Highlights Subtleties of Dyspnea

Abstract

Introduction: Evaluation of dyspnea can be a complex conundrum usually requiring the involvement of a multidisciplinary team. We present a case of dyspnea which exemplifies these challenges and demonstrates that through a vigilant clinical exam and tailored, comprehensive testing, a subtle change in breathing pattern may be the only clue to diagnosis. Report of Case: A 76 year old gentleman presented for evaluation of possible sleep disordered breathing after initial evaluation for dyspnea. He was a former smoker with 30 pack-year history and a recent diagnosis of Parkinson's disease. He had been experiencing progressive exertional dyspnea for one year without significant orthopnea. He remained physically active and could walk about 3?4 miles daily. Chest x-ray demonstrated mild right hemi-diaphragm elevation. Pulmonary function demonstrated mild restriction and reduced maximal respiratory pressures. “Sniff testing” was normal. Cardiac evaluation including stress ECHO was unrevealing. After pulmonary consultation, it was felt that given the mild restriction and reduced maximal respiratory pressures, the patient likely had a contributing neuromuscular problem, maybe stemming from Parkinson's and was referred for further evaluation in neurology, including muscle biopsy. Sleep evaluation was requested. Nocturnal oximetry was normal. On close examination, the patient had a possible paradoxical breathing pattern but no obvious accessory respiratory muscle use. Spirometry with supine challenge was pursued and demonstrated a 15% decline in the FVC suggestive of diaphragmatic weakness. Polysomnography was ordered to determine the role of nighttime non-invasive ventilation for symptom resolution. Conclusion: The workup for unexplained dyspnea can be challenging and usually requires a multi-disciplinary approach; in our case, the departments of neurology, pulmonary and sleep medicine. Change in nocturnal breathing pattern may be the presenting symptom of daytime dyspnea, and should warrant a sleep evaluation. In our case it played the critical role in providing appropriate next step in diagnostic and hopefully therapeutic intervention.