Recruitment Maneuvers to the Extreme.

Alveolar collapse is a common problem in mechanically ventilated children, particularly those with significant lung disease, such as ARDS. Many different methods are used by clinicians to recruit collapsed alveoli, including sustained inflation or incremental increases in PEEP until recruitment is achieved. These methods have primarily been studied in animal models and adults with varying approaches for the amount and duration of pressure applied. The primary goal of a recruitment maneuver is to open atelectatic alveoli and keep them open by applying PEEP to limit the cyclic alveolar opening and closing that is associated with ventilator-induced lung injury. When and how to perform these maneuvers is controversial, and many clinicians have safety concerns regarding hemodynamic stability and the risk of barotrauma during these maneuvers.1,2 Some also question the need for recruitment maneuvers because although they usually improve oxygenation, this improvement is often transient, alveolar recruitment may not be sustained unless other adjustments to ventilator settings are made, and little evidence suggests that recruitment maneuvers improve outcomes.3 A few small studies have investigated recruitment maneuvers in children with ARDS, finding in general no clinically important effect on either hemodynamic stability or risk of barotrauma.4-6 Even fewer studies exist on the application of recruitment maneuvers in children without lung disease who are mechanically ventilated for reasons such as general anesthesia.7 Mechanically ventilated children with normal lungs are also susceptible to atelectasis. These children may be at greater risk of harm due to the creation of high transpulmonary pressures from a recruitment maneuver in the situation of relatively normal pleural pressures. Gonzalez-Pizarro et al8 sought to address the safety of recruitment maneuvers in an animal model simulating children with normal lungs, specifically targeting barotrauma in their article in this issue of RESPIRATORY CARE. The authors studied 10 anesthetized neonatal piglets subjected to 2 recruitment maneuver strategies: (1) incremental increases in positive inspiratory pressure (PIP) with no PEEP and (2) incremental increases in PEEP with a fixed driving pressure of 15 cm H2O (once a PEEP of 50 cm H2O was reached, PIP was subsequently increased by increasing driving pressure). During the study protocol, pressures were increased until an air leak was noted from chest tubes signifying pneumothorax.