Objective: We designed an observational study to test the hypothesis that a comparison of two methods of minute ventilation, spontaneously generated with mechanically generated, would be a useful predictor of readiness for extubation in preterm infants, weighing <2000 gm, who require mechanical ventilation for >24 hours.
Study design: This observational study of 35 infants weighing < or = 2000 gm evaluated the comparison of spontaneously generated minute ventilation with mechanically generated minute ventilation to successfully predict readiness for extubation. After reaching entry criteria, infants were extubated if their spontaneously generated minute ventilation (while receiving endotracheal CPAP) was > or = 50% of the mechanically generated minute ventilation during assist/control ventilation.
Results: Of the 35 infants who had a successful trial and were extubated, 30 (86%) remained extubated for at least 24 hours. Of the five infants who failed extubation, four developed apnea and one developed stridor. Thus, a spontaneous minute ventilation of > or = 50% of mechanically generated minute ventilation predicted readiness for extubation in 86% of the patients in this observation.
Conclusion: A spontaneously generated minute ventilation that is > or = 50% of the mechanically generated minute ventilation is an objective predictor of the readiness for extubation in low birth weight infants who have been weaned to modest ventilatory support.