Evaluating the Association of Extubation Readiness Testing Performance Variables With Reintubation After Pediatric Cardiac Surgery

Background: Patient performance on extubation readiness tests (ERTs) informs the decision to extubate after cardiac surgery. ERT pass criteria at our center include age-based breathing frequencies and weight-adjusted tidal volumes (V T ). Evidence validating these criteria in children after cardiac surgery is limited. We hypothesized that higher breathing frequency and/or lower V T during the final ERT prior to extubation, even if meeting pass criteria, would be associated with re-intubation within 48 h. Methods: This was an observational, retrospective cohort study involving children <18 years of age receiving invasive mechanical ventilation for >24 h after cardiac surgery for Society of Thoracic Surgery (STAT) Mortality category ≥3 from May 2022 to April 2024. The primary outcome was extubation failure. The secondary outcome was the interval between the first passed ERT and extubation. Factors associated with re-intubation were explored using univariate and multivariable analyses. Results: Two hundred sixty-eight subjects met inclusion criteria with a median (interquartile range) age of 58.5 (6.1–210.2) days and weight of 4.2 (3.3–7.5) kg. Thirty (11.2%) subjects experienced extubation failure. These subjects had a higher breathing frequency during the ERT (42 [36–52] vs 36 [28–44] breaths/min, P = .01). On univariate analysis, subjects who required re-intubation were younger, had longer courses of invasive mechanical ventilation, and more frequently received preoperative invasive mechanical ventilation, delayed sternal closure, or were in a higher STAT category. Multivariable analysis revealed no association between re-intubation and breathing frequency (adjusted odds ratio [aOR] = 1.02, 95% CI: 0.99–1.06), V T (aOR = 1.0, 95% CI: 0.78–1.25), or the Rapid Shallow Breathing Index (RSBI; expressed as breathing frequency/V T ) (aOR = 1.11, 95% CI: 0.96–1.27). The interval between the first passed ERT and extubation did not differ between groups (1.4 [0.5–3.6] vs 1.2 [0.4–2.4] days, P = .22). Conclusions: There was no association between the final ERT breathing frequency, V T , or RSBI and re-intubation within 48 h.