Introduction The use of HFOV in the treatment of pulmonary disease with increased airway resistance is controversial. The risk of dynamic air trapping, and its complications, are the main concerns. The use of HFOV in conditions such as viral bronchiolitis and status asthmaticus is increasingly advocated.
Case Report A 3.5-year-old boy was admitted with respiratory failure from status asthmaticus. Upon initial presentation, there was a pneumothorax that required drainage. Despite conventional mechanical ventilation, applying high pressures (Ppeak 45 cmH2O) and low respiratory rate, severe respiratory acidosis (pH 7.06 and PaCO2 110 mm Hg) persisted. We subsequently switched to HFOV using the following open airway strategy. The initial mean airway pressure (mPaw) was 23 cm H2O, mPaw was increased stepwise to 41 cm H2O in order to stent the airways. Power was set at maximum. The frequency was lowered from 7 to 5 Hz. After 24 hours the mPaw could be lowered to 30 cm H2O and frequency increased to 7 Hz. Additional therapy: steroids, intravenous salbutamol, magnesium, muscular paralysis and inotropes. The use of inotropes was most likely required due to HFOV-associated circulatory compromise. During HFOV a de novo pneumothorax was drained. On day 4 he was weaned to conventional ventilation and chest drains were removed. He was successfully extubated at day 6.
Conclusions This case illustrates that HFOV can successfully be used in severe status asthmaticus using the open airway strategy. Dynamic hyperinflation only caused some circulatory compromise. Pre-existing and de novo pneumothoraces were managed without difficulties.