Most patients in intensive care units (ICUs) experience severe sleep disruption. Sleep disruption and sleep alteration may have an influence on the ability to breathe spontaneously. But, the cause of altered sleep remains unknown. Previous studies have shown that decreasing nocturnal respiratory muscle activity through mechanical ventilation might improve sleep quality. Nocturnal respiratory muscle activity may be one of the potential factor which contribute to alter sleep in the ICU. Therefore, the aim of this study is to analyse the presence of NIM activation during the night and it's consequence in an ICU population with the same pathology (COVID 19 ARDS).

Sleep alteration is a common problem among ventilated ICU patient. About one third of the patient have abnormal EEG pattern which cannot be scored by using the AASM standard criteria. Patients experience marked fragmentation, absence of deep sleep, and REM sleep is decreased, . It has been shown that sleep deprivation has a negative impact on respiratory muscle endurance. So a good sleep is essential when the respiratory system is being challenged, as in the ICU during the weaning period. Indeed, in the ICU, patients with altered sleep, had a markedly longer weaning duration than in patients with normal sleep, and are more likely to fail a spontaneous breathing trial. Many factors may influence the quality of sleep in the ICU (noise, medication, mechanical ventilation …) but few studies have focus on the cause of this altered sleep, and the cause of altered sleep remains unknown. Previous studies have shown that decreasing nocturnal respiratory muscle activity through mechanical ventilation might improve sleep quality. Mechanical ventilation can decrease the charge imposed on the respiratory pump, and allows muscle to rest. Indeed, when the charge is too high (for example after an ARDS during the weaning period), the diaphragm may be overloaded, and there could be a greater involvement of other inspiratory muscles in breathing. In other pathological condition, the neck inspiratory muscle activity is increased (e.g. COPD, amyotrophic lateral sclerosis), and sometimes this activity persist during sleep with marked degradation in sleep architecture. Nocturnal respiratory muscle activity may be one of the potential factor which contribute to alter sleep in the ICU. Ttherefore, the aim of tis study is to analyse the presence of NIM activation during the night and it's consequence in an ICU population with the same pathology (COVID 19 ARDS).

Inclusion Criteria:

• Patient above 18 year-old admitted to intensive care unit
• COVID-19 assessed by PCR on nasopharyngeal swab or pulmonary sample
• Oro-tracheal intubation for mechanical ventilation

Exclusion Criteria:

• Guardianship or curatorship
• Prisoners
• No health insurance
• Pregnancy