Helmet ventilation for acute respiratory failure and nasal skin breakdown in neuromuscular disorders.

Noninvasive ventilation (NIV) has been widely used to decrease the complications associated with tracheal intubation in mechanically ventilated patients with neuromuscular diseases in acute respiratory failure. However, nasal ulcerations might occur when masks are used as an interface. Helmet ventilation is a possible option in this case. We describe two patients with acute respiratory failure due to Duchenne muscular dystrophy who developed nasal bridge skin necrosis during NIV. Helmet pressure support ventilation caused significant patient-ventilator asynchrony, leading to NIV intolerance. Thus, biphasic positive airway pressure delivered by helmet was applied, which improved gas exchange and patient-ventilator interaction, allowing successful NIV.

Effect of end-inspiratory pause duration on plateau pressure in mechanically ventilated patients.

OBJECTIVE: To compare the values of plateau pressure (Pplat) recorded at different times after end-inspiratory occlusion and those of static elastance (Est,rs) and total resistance (Rrs) of the respiratory system. DESIGN: Physiological study. SETTING: Medical intensive care unit of a university hospital. PATIENTS: Eleven patients with ARDS and ten patients with COPD requiring tracheal intubation and mechanical ventilation were investigated. COPD patients were investigated on zero end-expiratory pressure (ZEEP) and ARDS patients on both ZEEP and positive end-expiratory pressure (PEEP). MEASUREMENTS AND RESULTS: Respiratory mechanics were assessed using the rapid airway occlusion technique. Tracheal pressure (Ptr) was measured downstream the endotracheal tube. Ptr was recorded 0.5 s, 1 s, 2 s, 3 s, and 5 s after a 5-s end-inspiratory occlusion. Est,rs and Rrs were computed at the same times using standard formula. In ARDS patients on ZEEP, Pplat amounted to 20+/-5, 20+/-5, 19+/-5, 19+/-5, and 18+/-5 cmH(2)O at 0.5, 1, 2, 3 and 5 s, respectively (P <0.001). In COPD patients, these values were 18+/-4 cmH(2)O, 17+/-4 cmH(2)O, 17+/-4 cmH(2)O, 16+/-4 cmH(2)O, and 16+/-4 cmH(2)O (P <0.001). Except for one ARDS patient on PEEP, Pplat was always less than 35 cmH(2)O, regardless of the time of measurement. As compared to 5 s, measurements at 0.5 s resulted in overestimation of Est,rs by 14% and 29% and in underestimation of Rrs by 34% and 24%, in ARDS and COPD patients, respectively. CONCLUSIONS: Very early post-occlusion values of Pplat were statistically greater than at 3 s or 5 s. This probably has no major impact on the occurrence of volutrauma. Clinicians must be aware, however, that Est,rs and Rrs are greatly modified by the time of recording of Pplat.