High Peak Inspiratory Pressures After a Change of Heat and Moisture Exchangers: A Case Series.

Elevated peak inspiratory pressures (PIPs) cause harm via hypoventilation, barotrauma, and hemodynamic instability. Heat and moisture exchangers (HMEs) are used during mechanical ventilation to prevent heat loss, dehydration of airway mucosa, and accumulation of dried secretions. Multiple reports detail sudden HME occlusions causing increased PIPs. We describe 4 cases of gradually increasing PIPs from progressive HME obstruction that occurred within 6 months of an institutional change to a newer model. HME obstruction should be considered when PIPs are elevated. Alternative heat and moisture preservation strategies should be contemplated, as HMEs increase airflow resistance and add another point of possible malfunction.