Management and long-term outcome of patients with chronic neuromuscular disease admitted to the intensive care unit for acute respiratory failure: a single-center retrospective study.

BACKGROUND: Patients with chronic neuromuscular disease represent less than 10% of those receiving mechanical ventilation in the intensive care unit (ICU). Little has been reported regarding either ICU management of acute respiratory failure (ARF) in the era of noninvasive mechanical ventilation (NIV) or long-term outcomes. OBJECTIVE: To describe the respiratory management of patients with chronic neuromuscular diseases admitted to our university hospital ICU for ARF, and the long-term outcomes. METHODS: We retrospectively analyzed patients with chronic neuromuscular diseases admitted to our ICU for a first episode of ARF between January 1, 1996, and February 27, 2007. We assessed severity of illness on ICU admission, respiratory management during ICU stay, and outcomes on June 15, 2008. RESULTS: During the study period, 87 patients (44 with hereditary and 43 with acquired neuromuscular diseases) had their first ARF episode that required ICU admission. In the hereditary-diseases group and the acquired-diseases group, respectively, the rates of NIV use during the ICU stay were 82% and 63% (P = .040), the intubation rates were 30% and 56% (P = .02), and the tracheotomy rates were 9% and 12% (difference not significant). At the final assessment (median 3 years) the mortality rate was 58%, and mortality was not significantly related to the type of neuromuscular disease. At final assessment, 46% of the patients were on NIV and 29% had tracheotomy. CONCLUSIONS: In our ICU, chronic neuromuscular disease is an uncommon cause of ARF, for which we often use NIV. These patients had a low probability of death in the ICU. Long-term outcome was independent of the type of neuromuscular disease.

A case of pneumomediastinum in a patient with acute respiratory distress syndrome on pressure support ventilation.

During mechanical ventilation for acute respiratory distress syndrome, tidal volume (V(T)) must be reduced. Once switched to pressure-support ventilation, there is a risk that uncontrolled large V(T) may be delivered. A 63-year-old man with community-acquired pneumonia required tracheal intubation and mechanical ventilation, with a V(T) of 6 mL/kg predicted body weight, PEEP of 10 cm H2O, a respiratory rate of 30 breaths/min, and F(IO2) of 0.60. Plateau pressure was 22 cm H2O. He improved and received pressure-support. Twelve days later a chest radiograph showed suspected air leaks, confirmed via computed tomogram (CT), which showed anterior pneumomediastinum. V(T) received over the previous 3 days had averaged 14 mL/kg predicted body weight. The patient was put back onto volume-controlled mode, and 2 days later there were no air leaks. In pressure-support ventilation, V(T) must be closely monitored to ensure lung-protective mechanical ventilation.