Mechanical ventilation in severe asthma

Patients with SA, usually respond well to intensive therapy with β-agonist and systemic steroids with improvement in symptoms. If the patient's condition does not respond to the conventional medical therapy and continues to deteriorate to the point where the respiratory failure is imminent, rapid recognition of the urgency of the situation is important because it can be life-saving. The morbidity and mortality of asthma remains high; a 6-yr posthospitalized patient follow-up study found mortality of 22.6% (47). Once mechanical ventilation has been instituted, it is important to recognize the importance of various strategies to achieve ventilatory goals for these patients. Initial ventilatory goals include aboidance of hyperinflation by decreasing patient's VEI to less than 20 mL/kg while keeping Pplat less than 30 cm m/H2O. If these ventilator strategies are used correctly, the morbidity and mortality in patients with SA can be reduced (42). The physician should also recognize the importance of the detrimental effects of PEEPi, and use the various strategies to reduce the hyperinflation. The physician should also be aware of the use of sedation, as well as the use and potential complications of NMBs.