Sleep-disordered breathing in unilateral diaphragm paralysis or severe weakness

¹ King's College London School of Medicine, King's College Hospital, London, UK
² Guangzhou Medical College, The State Key Laboratory of Respiratory Disease, Guangzhou, China
³ St Thomas' Hospital, London, UK
⁴ Royal Brompton Hospital, London, UK

^* To whom correspondence should be addressed. E-mail: joerg.steier{at}kcl.ac.uk.

	Abstract

Few data exist concerning sleep in patients with hemidiaphragm paralysis or weakness. Traditionally such patients are considered to sustain normal ventilation in sleep.

We measured diaphragm strength to identify patients with unilateral paralysis or severe weakness. Patients underwent polysomnography with additional recordings of the transesophageal electromyogram of the diaphragm and surface electromyogram of extra-diaphragmatic respiratory muscles. We compared these data to 11 normal, healthy subjects matched for sex, age and body-mass-index.

We studied 11 patients (6men, mean(SD) age 56.5(10.0)years, body-mass-index 28.7(2.8)kg·m^-2) with hemidiaphragm paralysis or severe weakness (unilateral twitch transdiaphragmatic pressure 3.3(1.7)cmH₂O). They had a respiratory disturbance index of 8.1(10.1)·h^-1 during non-rapid-eye-movement sleep, and 26.0(17.8)·h^-1 (p<0.0001) during rapid-eye-movement sleep (control group 0.4(0.4) and 0.7(0.9)·h^-1; patient vs control group: p=ns, and p<0.0001). The diaphragm electromyogram, as a percentage of maximum, was double that of the control group in non-rapid-eye-movement sleep (15.3(5.3) vs 8.9(4.9)%max; p<0.05) and increased in rapid-eye-movement sleep (20.0(6.9)%max; p<0.05), whilst normal subjects sustained the same level of activation (6.2(3.1)%max;p=ns).

Patients with unilateral diaphragm dysfunction are at risk of developing sleep-disordered breathing during rapid-eye-movement sleep. The diaphragm electromyogram, reflecting neural respiratory drive, is doubled in patients compared to normal subjects, and increases further in rapid-eye-movement-sleep.