Nocturnal mechanical ventilation for chronic hypoventilation in patients with neuromuscular and chest wall disorders
Abstract
Background
Chronic alveolar hypoventilation is a common complication of many neuromuscular and chest wall disorders. Long term nocturnal mechanical ventilation is used to treat an increasing number of patients.
Objectives
To examine the efficacy of nocturnal mechanical ventilation in relieving hypoventilation related symptoms in patients with neuromuscular or chest wall disorders.
Search methods
Search of the Cochrane Neuromuscular Disease Group register for randomized trials and enquiry from authors of trials and other experts in the field.
Selection criteria
Types of studies: quasi‐randomized or randomized controlled trials
Types of participants: patients with neuromuscular or chest wall disorder‐related stable chronic hypoventilation of all ages and all degrees of severity.
Types of interventions: any type and any mode of nocturnal mechanical ventilation.
Types of outcome measures:
Primary: short term and long term reversal of hypoventilation related clinical symptoms
Secondary: unplanned hospital admission rate, one year mortality, short term and long term reversal of day time hypercapnia, improvement of lung function and improvement of sleep breathing disorders.
Data collection and analysis
We identified four randomized trials. One author extracted the data and another checked them. Individual data were available from the authors of the largest study.
Main results
The four eligible trials included a total of 51 patients. The risk difference (proportion of patients) of no improvement of hypoventilation related clinical symptoms in the short term following nocturnal mechanical ventilation was significant and favoured treatment, ‐0.417 (95% CI ‐0.639 to ‐0.194). However, there was significant heterogeneity across the studies (p<0.001). Similarly, the risk difference of no reversal of day time hypercapnia in the short term following nocturnal ventilation was significant and favoured treatment, ‐0.635 (95% CI ‐0.874 to ‐0.396). The weighted mean difference of nocturnal mean oxygen saturation percent was 5.5 (95% CI 1.5 to 9.4) more improvement in patients treated with nocturnal mechanical ventilation. For the primary and most of the secondary outcome measures there was no significant difference between nocturnal mechanical ventilation and no ventilation in the long term, except for one‐year mortality. Indeed, the risk difference of death one year following implementation of nocturnal mechanical ventilation was significant and favoured treatment, ‐0.259 (95% CI ‐0.478 to ‐0.041). However, there was significant heterogeneity across the studies (p<0.001). Most of the secondary outcomes were not assessed in the eligible trials. No data could be summarised for the comparisons between invasive and non‐invasive mechanical ventilation, between intermittent positive pressure and negative pressure ventilation, and between volume‐cycled and pressure‐cycled ventilation.
Authors' conclusions
Current evidence about the therapeutic benefit of mechanical ventilation is weak, but consistent, suggesting alleviation of the symptoms of chronic hypoventilation in the short term, and in two small studies survival was prolonged. Mechanical ventilation should be offered as a therapeutic option to patients with chronic hypoventilation due to neuromuscular diseases. Further larger randomized trials are needed to confirm long term beneficial effects of nocturnal mechanical ventilation on quality of life, morbidity and mortality, to assess its cost‐benefit ratio, and to compare the different types and modes of ventilation.
PICOs
Plain language summary
Nocturnal mechanical ventilation may improve chronic hypoventilation symptoms and survival in neuromuscular diseases.
Developing weakness of respiratory muscles or alterations in breathing control is a major complication of neuromuscular and chest wall disorders. Mechanical ventilation can compensate for the respiratory deficiency and is therefore increasingly proposed to neuromuscular patients who develop chronic hypoventilation. The review found that nocturnal mechanical ventilation may relieve chronic hypoventilation related symptoms and prolong survival. However the quality of the studies is poor, and the benefit of long term mechanical ventilation should be confirmed in further trials.
