Factors Associated With Successful Extubation Readiness Testing in Children With Congenital Heart Disease

Abstract

BACKGROUND:

In children with congenital heart disease, extubation readiness testing (ERT) is performed to evaluate the potential for liberation from mechanical ventilation. There is a paucity of data that suggests what mechanical ventilation parameters are associated with successful ERT. We hypothesized that ERT success would be associated with certain mechanical ventilator parameters.

METHODS:

Data on daily ERT assessments were recorded as part of a quality improvement project. In accordance with our respiratory therapist–driven ventilator protocol, patients were assessed daily for ERT eligibility and tested daily, if eligible. Mechanical ventilation parameters were categorized a priori to evaluate the differences in levels of respiratory support. The primary outcome was ERT success.

RESULTS:

A total of 780 ERTs from 320 subjects (median [interquartile range] age 2.5 [0.6–6.5] months and median weight [interquartile range] 4.2 [3.3–6.9] kg) were evaluated. A total of 528 ERTs (68%) were passed, 306 successful ERTs (58%) resulted in extubation, and 30 subjects (9.4%) were re-intubated. There were statistically significant differences in the ERT pass rate for ventilator mode, peak inspiratory pressure, Δ pressure, PEEP, mean airway pressure ( ${\overline{\mathbf{\text{P}}}}_{\mathbf{\text{aw}}}$ ), and dead-space–to–tidal-volume ratio (all P < .001) but not for ${\mathbf{\text{F}}}_{{\mathbf{\text{IO}}}_{\mathbf{\text{2}}}}$ . ERT success decreased with increases in peak inspiratory pressure, Δ pressure, PEEP, ${\overline{\mathbf{\text{P}}}}_{\mathbf{\text{aw}}}$ , and dead-space–to–tidal-volume ratio. Logistic regression revealed neonates, Δ pressure ≥ 11 cm H₂O, and ${\overline{\mathbf{\text{P}}}}_{\mathbf{\text{aw}}}$ > 10 cm H₂O were associated with a decreased odds of ERT success, whereas children ages 1–5 years and an ${\mathbf{\text{F}}}_{{\mathbf{\text{IO}}}_{\mathbf{\text{2}}}}$ of 0.31-0.40 had increased odds of ERT success.

CONCLUSIONS:

ERT pass rates decreased as ventilator support increased; however, some subjects were able to pass ERT despite high ventilator support. We found that ${\overline{\mathbf{\text{P}}}}_{\mathbf{\text{aw}}}$ was associated with ERT success and that protocols should consider using ${\overline{\mathbf{\text{P}}}}_{\mathbf{\text{aw}}}$ instead of PEEP thresholds for ERT eligibility. Cyanotic lesions were not associated with ERT success, which suggests that patients with cyanotic heart disease can be included in ERT protocols.