Prevention of pulmonary morbidity for patients with neuromuscular disease

Abstract

Study objective: To evaluate the effects of a respiratory muscle aid protocol on hospitalization rates for respiratory complications of neuromuscular disease.

Design: A retrospective cohort study.

Methods: A home protocol was developed in which oxyhemoglobin desaturation was prevented or reversed by the use of noninvasive intermittent positive-pressure ventilation and manually and mechanically assisted coughing as needed. The patients who had more than one episode of respiratory failure before having access to the protocol were considered to have had preprotocol periods (group 1). Other patients were given access to the protocol when their assisted peak cough flows decreased to < 270 L/min before any episodes of respiratory distress (group 2). The number of hospitalizations and days hospitalized were compared longitudinally for preprotocol and protocol access periods (group 1). In addition, avoided hospitalizations were identified as "episodes" of need for continuous ventilatory support and desaturations reversed by assisted coughing that were managed at home. Data were segregated by access to protocol and by extent of baseline ventilator use.

Results: Of the 47 group 1 patients with preprotocol periods who have subsequently had episodes, 10 had episodes before requiring ongoing ventilator use. They had 1.06 +/- 0.84 preprotocol hospitalizations per year per patient and 20.76 +/- 36.01 hospitalization days per year per patient over 3.42 +/- 3.36 years per patient vs 0.03 +/- 0.11 hospitalizations per year per patient and 0.06 +/- 0.20 hospitalization days per year per patient with protocol use over 1.94 +/- 0.74 years per patient. Of these 47 group 1 patients, 33 eventually required part-time ventilatory aid and, using the protocol as needed, had 0.08 +/- 0.17 hospitalizations per year per patient and 1.43 +/- 3.71 hospitalization days per year per patient over 3.91 +/- 3.50 years per patient, as opposed to 1.40 +/- 1.96 hospitalizations per year per patient and 20.14 +/- 41.15 hospitalization days per year per patient preprotocol and preventilator use over 5.89 +/- 6.89 years per patient. Twelve patients in group 1 eventually required continuous noninvasive ventilation and, using the protocol as needed, had 0.07 +/- 0.14 hospitalizations per year per patient and 0.39 +/- 0.73 hospitalization days per year per patient over 5.35 +/- 5.10 years per patient by comparison with 0.97 +/- 0.74 hospitalizations per year per patient and 10.39 +/- 8.66 hospitalization days per year per patient over 2.18 +/- 1.91 years per patient preprotocol and preventilator use. For the 94 patients overall when having access to the protocol, 1.02 +/- 0.99 hospitalizations per year per patient were avoided by 14 patients before requiring ongoing ventilator use over 4.82 +/- 1.61 years, 0.99 +/- 1.12 hospitalizations per year per patient were avoided by 73 part-time ventilator users over 3.21 +/- 3.15 years, and 0.80 +/- 0.85 hospitalizations per year per patient were avoided by 31 full-time ventilator users over 4.78 +/- 4.88 years. All preprotocol and protocol rate comparisons were statistically significant at p < 0.004.

Conclusion: Patients have significantly fewer hospitalizations per year and days per year when using the protocol as needed than without the protocol. The use of inspiratory and expiratory aids can significantly decrease hospitalization rates for respiratory complications of neuromuscular disease.