Abstract
INTRODUCTION: The effect of isolated unilateral or bilateral diaphragmatic dysfunction (DD), in the absence of a generalized neuromuscular disorder, on sleep disordered breathing (SDB) is not well understood. The type of positive airway pressure (PAP) device needed to treat SDB in patients with isolated DD is also not well established. METHODS: We retrospectively analyzed data on patients with isolated unilateral or bilateral DD who were referred for polysomnography (PSG) for clinical symptoms or abnormal oximetry between 1994 and 2006. RESULTS: We found 66 patients who met criteria, of whom 74.2% were males with an average age of 58.8 ± 10.9 years. 56 had isolated unilateral DD, and 10 had isolated bilateral DD. All had significant SDB with an apnea-hypopnea index (AHI) of 26.6 ± 28.4. There were no significant differences in PSG measures, arterial blood gas analysis, pulmonary function tests, or echocardiographic data, except for lower maximal inspiratory pressure in patients with bilateral DD compared to unilateral DD (40.2% ± 17.8% vs. 57.7% ± 20.5%, p = 0.02). Control of SDB with continuous PAP (CPAP) was possible in only 37.9% of patients with the rest requiring bilevel PAP (BPAP). Patients with isolated bilateral DD and SDB were 6.8 times more likely to fail CPAP than those with unilateral DD (p = 0.03). CONCLUSIONS: Most patients with isolated DD failed CPAP and required BPAP. Patients with bilateral DD were more likely to require BPAP than those with unilateral DD. Patients with isolated DD should be considered for in-lab titration to determine adequacy of therapy.