New approaches to ventilation in infants and children

Recent insights into the pathophysiology of acute lung injury have led to changes in our routine approach to mechanical ventilation in this population of patients. Heterogeneous alterations in the anatomy and function of the lung are characteristic of acute lung injury. Experimental evidence strongly suggests that traditional approaches to mechanical ventilation with normal tidal volumes applied uniformly to the injured lungs will result in repetitive alveolar overdistention in regions with normal compliance. This process, termed volutrauma, impedes lung healing and may extend damage to previously unaffected areas. This realization has led to a strategy that is designed to avoid tidal alveolar collapse using physiologic transalveolar pressures while allowing alveolar hypoventilation and hypercapnia. Debate continues regarding the risks and benefits of pressure-limited versus volume-limited mechanical ventilation to achieve this goal. Research is ongoing regarding the role and techniques for nonconventional methods of cardiorespiratory support for this severely ill group of patients.