Evaluation of a Mechanical Device During Acute Respiratory Failure in Patients With Neuromuscular Disorders

Evaluation of a Mechanical Insufflation-exsufflation Device During Acute Respiratory Failure in Patients With Neuromuscular Disorders: a Prospective, Randomized, Controlled, Multicenter Study

The hypothesis is that a mechanical insufflation-exsufflation (MI-E) is associated with a decrease in the number of intubations and more rapid clinical improvement in children and adults with neuromuscular disease who are admitted for an acute respiratory exacerbation.In this prospective, randomised, multicenter study, 55 patients will be treated with standard treatment and a MI-E, and 55 patients with standard treatment and standard respiratory physiotherapy. The primary objective is the reduction of the number of patients requiring invasive ventilatory support (endotracheal intubation or tracheotomy) in the group treated with MI-E (MI-E group). The main secondary objectives are a reduction in hospital stay and an improvement in clinical condition, dyspnea and respiratory muscle function.

Justification Respiratory muscle weakness reduces the efficacy of the cough reflex in patients with neuromuscular disorders and exposes them to the risk of acute respiratory failure. Mechanical insufflation-exsufflation devices assist cough and have been shown to be efficient in increasing the cough expiratory flow in children and adults with neuromuscular disease and decreasing the risk of intubation in a limited population of hospitalized adults with acute respiratory failure.

Primary objective The goal is to record the efficacy of mechanical insufflation-exsufflation (MI-E) during acute respiratory failure in patients with neuromuscular disorders.The primary objective is the reduction of the number of patients requiring invasive ventilatory support (endotracheal intubation or tracheotomy) in the group treated with MI-E (MI-E group) compared to the group treated with traditional chest physiotherapy without MI-E (Control group).

Secondary objectives

In the MI-E group, compared to the Control group:

1. Decrease in the length of hospitalization in the intensive care unit (ICU)
2. Decrease in the total length of hospitalization
3. Decrease in the incidence of bronchoscopy-assisted aspiration
4. Decrease in the duration of oxygen therapy
5. Decrease in the daily length of noninvasive positive pressure ventilation (NPPV)
6. Improvement in blood gases on room air during hospitalization
7. Improvement of the peak cough flow (PCF)
8. Improvement of the vital capacity (VC), maximal inspiratory (PImax) and expiratory (PEmax) pressures, sniff nasal inspiratory pressure (SNIP), peak expiratory flow (PEF) and dyspnea during hospitalization.
9. Decrease in the number of secondary tracheotomies (for weaning of ventilatory support)

Type of study Prospective, randomized, controlled, multicenter study

Number of subjects The calculation of the number of subjects is based on two retrospective studies. In the study by VIANELLO, which included 11 adults hospitalized in the ICU for respiratory failure, the number of therapeutic failures, defined as the need for a "mini" tracheotomy or intubation, was significantly less in the group using MI-E than in a group of 16 historical control patients [2 failures in the MI-E group (18%) versus 10 failures in the control group (63%), p<0.05] (1). Another study reported 19 successes (80%) versus 5 failures on MI-E (2).

Inclusion Criteria:

Pediatric or adult patients with chronic neuromuscular disorders, such as spinal muscular atrophy, Duchenne muscular dystrophy, other congenital myopathy, or amyotrophic lateral sclerosis (ALS), hospitalized for acute respiratory failure, as defined by:

• Persistent bronchial encumbrance (> 2 days) despite regular treatment in the homecare setting, associated with-Oxygen desaturation on room air, defined by a pulse oximetry (SaO2) <95%) or
• In patients not receiving long-term NPPV: the need to institute NPPV-In patients receiving long-term NPPV: the need to increase the daily length of NPPV by at least 25%.

Exclusion Criteria:

• Need for immediate intubation (alteration in consciousness, coma, hemodynamic disorders)
• Multiple organ failure (e.g., associated cardiac failure)
• In adults: respiratory rate >30/min, pH < 7.35, PaCO2 > 50 mm Hg
• Facial deformity or anomaly which prevents the use of a mouthpiece or mask
• Patients who signed a refusal to be intubated regardless of the progression of their disease
• Patients on long-term oxygen therapy
• Tracheotomized patients
• Patients requiring the use of an intrapulmonary percussive ventilation device during hospitalization
• Acute neuromuscular disorder of known or unknown etiology
• Associated lung disease such as chronic obstructive pulmonary disease (COPD)
• Refusal of patient consent and/or parental consent in the case of a minor
• Uncooperative patients
• Patients < 4 years old