PICU EXTUBATION FAILURE: THE ROLE OF NEUROMUSCULAR DISORDERS

Objective

Neuromuscular disorders (diseases of the motor unit), can cause respiratory problems such as impaired cough reflex, chest deformity, recurrent pneumonia and acute respiratory failure; these are the worst most common complications of these diseases and the leading cause of death in such patients (1, 2). Their management hence, very often, entails admission to the Pediatric Intensive Care Unit (PICU) (3,4) and during this phase, endotracheal intubation is almost always necessary, to maintain the patency of airways and to apply Positive Pressure Ventilation (PPV). However, endotracheal intubation is always temporary, and its success or failure depends on the timely decision of its termination to restore the normal respiration or to avoid the risk of recurring respiratory failure (5, 6). We designed this study to evaluate the role of neuromuscular disorders in causing extubation failure as compared to that of other risk factors.

Materials & Methods

In an analytical cross-sectional study, the risk factors of reintubation and duration of mechanical ventilation in two groups of 30 patients each, was compared, the first successful extubation and the second with extubation failure.

Results

Neuromuscular disorders (including Spinal Muscular Atrophy, Guillain- Barre' Syndrome, Congenital Myopathies and Muscular Dystrophies) were the main underlying diseases in extubation-failure group (P= 0.0002). Hypercapnia (PaCO2>50mmHg) was shown to be the most common cause of both the first intubation (P=0.001) and reintubation (P=0.004) in the group of patients who failed extubation. The mean duration of intubation and mechanical ventilation was longer in patients with neuromuscular disorders who had extubation failure (P= 0.01).

Conclusion

This study showed that, as underlying problems, neuromuscular disorders are the most common causes of prolonged intubation which defeat weaning from the ventilator and result in reintubation by inducing hypercapnia. Therefore the weaning process needs to be done gradually in these patients, and in conjunction with supportive measures, such as close observation for at least for 72 hours following extubation to monitor any possibility of recurrence of hypercapnic respiratory failure.