Nocturnal Hypoxia in Unilateral Diaphragmatic Paralysis

Abstract

Pulmonary function has been studied extensively in patients with unilateral diaphragmatic paralysis (UDP), but there is scarce information regarding the respiratory function during sleep in this condition. We therefore studied pulmonary function in 12 patients with UDP when awake and when asleep. Diaphragmatic dysfunction was confirmed by the demonstration of low maximal transdiaphragmatic pressures in most of our patients; paradoxical gastric pressure swing was observed in 6 patients. There was a restrictive pattern in pulmonary function tests and resting arterial blood gases were rather well preserved (range SaO₂ 90–95%). Overnight sleep monitoring showed that the time spent in REM sleep and stage 3 and 4 sleep was reduced. The mean maximum decrease in SaO₂ was 15.2 ± 6.2% and the time with an SaO₂ drop of more than 5% of the awake SaO₂ was 25.4 ± 22.8 min. None of our patients was in respiratory failure or had clinical evidence of cor pulmo-nale. We conclude that UDP leads to significant nocturnal hypoxemia but, in the absence of systemic lung disease, does not lead to chronic respiratory failure and cor pulmonale

Sleep-disordered breathing in unilateral diaphragm paralysis or severe weakness

“…An early study by DOUGLAS and CLAGETT [33] found 10-24% of patients with hemidiaphragm paralysis to be breathless. PATAKAS et al [15] described 12 patients with nocturnal hypoxia and presumed UDP, but characterised the patients insufficiently for accurate diagnosis of unilateral phrenic nerve dysfunction. As shown in the present study, only 17 out of 39 patients who were clinically suspected to have UDP actually had unilateral involvement when assessed with electrophysiological tests of the phrenic nerves.…”

“…Some studies have reported disturbed sleep, inadequate ventilation during sleep and daytime sleepiness caused by diaphragm dysfunction [8,11], while others have found little impact on the normal sleep pattern unless there is additional load on the ventilatory system [9,10,14]. Previous studies either did not focus on UDP (had mixed populations of BDP and UDP [8,9] or exclusively BDP [5,11] patients), did not distinguish between REM and non-REM (NREM) sleep-associated sleepdisordered breathing (SDB) [10], did not characterise the subjects other than with noninvasive measurements [15] or studied animal models. Therefore, the studies that did not perform invasive respiratory muscle tests did not test a homogenous population of UDP patients and it is likely that the different results reflect the heterogeneity of the patients studied, in terms of weakness and ventilatory load.…”

Sleep and breathing in neuromuscular disease

“…Subjects with isolated diaphragmatic paralysis are particularly prone to nocturnal desaturation during REM sleep [38], even with only unilateral involvement [46]. Although few detailed polysomnographic studies have been performed in such patients, REM sleep [46] and slow-wave sleep (SWS) are likely to be reduced [38,46].…”

“…Although few detailed polysomnographic studies have been performed in such patients, REM sleep [46] and slow-wave sleep (SWS) are likely to be reduced [38,46]. Daytime respiratory failure is unusual with isolated bilateral diaphragmatic paralysis unless there is coexisting intrinsic lung disease (e.g.…”

Screening for sleep-disordered breathing in neuromuscular disease using a questionnaire for symptoms associated with diaphragm paralysis

“…Whilst the majority of patients have obstructive sleep apnoea (OSA) [4,5], other causes of SDB may similarly cause health problems [6][7][8][9][10][11][12]. In the present study, we considered the group of patients with neuromuscular disease (NMD) who are affected by SDB because of weakness of the respiratory muscles [9,[13][14][15][16][17][18] influenced by posture and sleep stage [9,19] and who do not necessarily present with symptoms, such as daytime fatigue, that are measured by the Epworth Sleepiness scale (ESS) [20].…”