Acute Care/Hospitalization

Air leak test does not accurately predict problems after breathing tube removal in children

Timing the removal of breathing tubes (endotracheal tubes [ETTs]) from critically ill children is important to help them breathe on their own again. The need to reinsert an ETT (reintubation) significantly increases the risk for problems such as longer intensive care stays or even death. Critical care specialists use an ETT air leak test (ALT) to determine if upper airway obstruction is likely after ETT removal (extubation). If the pressure required to produce an air leak is high (ALT equal to or greater than 30 cm H 0), extubation will most likely result in the need for reintubation later. However, a new study finds that the ALT does not predict who will have a successful extubation and who will not.

The researchers performed an ALT within 12 hours of a planned extubation in 59 children in a pediatric intensive care unit. Extubations were successful in 50 patients. Air leak measurement at intubation did not correlate with extubation outcomes. For 33 of these patients, the air leak was absent within 12 hours of intubation; 23 of these patients recovered an air leak before extubation, and 10 patients had no air leak for the duration of the mechanical ventilation. Only 3 of these 10 patients required reintubation. In measuring the preextubation ALT to predict outcomes, the researchers found that the air leak was absent in 28 of 59 patients. Regardless, 23 of the 28 were successfully extubated. Through the entire course of ventilation, an ALT equal to or greater than 30 cm H 0 did not predict extubation failures, nor did it increase the likelihood of having to reintubate after extubation.

According to the researchers, performing an ALT at intubation remains a useful tool to select tube size, to monitor ETT cuff inflation pressure, and to determine tracheal wall injury. However, it should not be used as the sole means to determine the timing of extubation. The study was supported in part by the Agency for Healthcare Research and Quality (HS14009).

See "The endotracheal tube air leak test does not predict extubation outcome in critically ill pediatric patients," by Angela T. Wratney, M.D., Daniel Kelly Benjamin, Jr., M.D., Ph.D., M.P.H., Anthony D. Slonim, M.D., Dr.P.H., and others, in the Pediatric Critical Care Medicine 9(5), pp. 490-496, 2008.

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