3-minute vs 10-minute Spontaneous Breathing Evaluations (SBE) for predicting extubation success in preterm very low...

BackgroundExtubation in preterm very low birthweight (VLBW) infants is a critical step in respiratory management. Accurately predicting extubation success is challenging because of immature respiratory control, surfactant deficiency, and limited pulmonary reserve. The Spontaneous Breathing Evaluation (SBE) has emerged as an important bedside method to assess readiness for successful extubation, although the optimal duration of this evaluation remains uncertain.MethodsThis retrospective observational study included preterm neonates between 26 and 34 weeks of gestation with birthweight <1500 g who required mechanical ventilation for more than 24 h in a tertiary NICU over a 12-month period. Infants who underwent SBE for either 3 min (Group B) or 10 min (Group A) as part of routine extubation readiness assessment were identified from clinical records. Group allocation was determined by a protocol change implemented mid-study period: infants assessed during the first 6 months underwent 10-min SBE, and those in the subsequent 6 months underwent 3-min SBE. The SBE was performed on endotracheal CPAP; failure criteria included sustained oxygen desaturation (SpO₂ <88% for >10 s), bradycardia (heart rate <100/min), apnoea requiring stimulation, or a requirement for increased FiO2 >0.1 above baseline. Extubation decisions were based on SBE performance combined with clinical readiness criteria, including stable ventilator settings, acceptable blood gas parameters, and clinician judgment.ResultsEighty-eight infants met inclusion criteria (44 in each SBE-duration group). The mean gestational age was 29.9 ± 2.1 weeks and mean birthweight was 1168 ± 258 g. The Respiratory Severity Score (RSS; calculated as FiO₂ × mean airway pressure) was significantly higher in the 10-min SBE group (1.85 ± 0.44 vs 1.67 ± 0.31; p = 0.031), indicating greater baseline respiratory severity in that group. Overall, 84% of infants tolerated the SBE and 77% achieved extubation success, while extubation failure occurred in 23%. Most SBE failures occurred within the first 3 min, regardless of total SBE duration. On univariate analysis, birthweight <1000 g (p = 0.018) and gestational age <28 weeks (p = 0.040) were associated with lower likelihood of extubation success, and RSS >2.1 strongly predicted reintubation. Multivariable logistic regression confirmed that gestational age <28 weeks (OR 0.14, 95% CI 0.03-0.61; p = 0.009) and RSS >2.1 (OR 0.09, 95% CI 0.02-0.44; p = 0.003) were independent predictors of extubation failure, while SBE duration was not independently associated with extubation outcome (p = 0.412).ConclusionIn this hypothesis-generating retrospective study, a 3-min SBE demonstrated comparable performance to a 10-min SBE in predicting extubation success among preterm VLBW infants. Gestational maturity and RSS were stronger independent predictors of outcome. These findings require confirmation in larger prospective studies before definitive clinical recommendations can be made.