Congenital myotonic dystrophy: assisted ventilation duration and outcome

To clarify the relationship between initial assisted ventilation duration and outcome for patients with congenital myotonic dystrophy (CDM).

A retrospective chart review was conducted of cases of CDM that presented to the Children's Hospital of Eastern Ontario (Ottawa, Ontario, Canada) between 1980 and 2000. Inclusion criteria were conclusive testing for CDM and clinical presentation in the first 30 days of life. Duration of assisted ventilation, morbidity, mortality, and developmental outcome were measured.

A total of 23 children met the inclusion criteria. One child died at 5 days of age, and 2 others had withdrawal of ventilation. The remaining 20 children were divided into 2 groups on the basis of whether they needed > or <30 days of ventilation. In the first year of life, 25% mortality was noted in the children with prolonged ventilation, whereas no child in the short ventilation duration group died. After 1 year of age, 1 child in each group died with follow-up of 2 to 16 years. The children with prolonged ventilation needed more hospitalizations. Delays were noted in development in both groups of children at ages 1, 3, and 6 years; however, there was an improvement in motor and language scores over time in all children. Children who required ventilation for <30 days had better motor, language, and activities of daily living scores at all ages.

Children with CDM with prolonged ventilation experienced 25% mortality in the first year. The use of a specific time period of ventilation to decide on withdrawal of therapy must be reconsidered given these findings. Prolonged ventilation was followed by greater morbidity and developmental delay than children with shorter ventilation duration.