Extubation After Neonatal Cardiac Surgery: The Quest To Make The First Time, The Only Time
Susan Nicolson, Viviane Nasr, Lindsey Loveland, James DiNardo
Original article
Hames DL, Abbas Q, Asfari A, Borasino S, Diddle JW, Gazit AZ, Lipsitz S, Marshall A, Reise K, Guerineau LR, Wolovits JS, Salvin JW. Extubation Failure in Neonates Following Congenital Cardiac Surgery: Multicenter Retrospective Cohort, 2017-2020. Pediatr Crit Care Med. 2025 Feb 10. doi: 10.1097/PCC.0000000000003703. Epub ahead of print. PMID: 39927824.
Longer duration of mechanical ventilation (MV) following pediatric cardiac surgery is associated with morbidity, including infection, sedative exposure, longer hospital length of stay (LOS) and poor neurodevelopmental outcomes. Premature discontinuation of MV may exacerbate low cardiac output and even precipitate cardiac arrest. Extubation failure (EF), defined as planned extubation subsequently requiring reintubation, is associated with longer ICU and hospital LOS and greater odds of mortality.1 It is essential that clinicians determine the optimal time to wean and discontinue MV.
The scientific basis for determining when a neonate is ready for extubation is imprecise. Clinical judgment, personal experience, blood gas analysis, oxygen requirements, and ventilator settings are typically used to guide the timing of extubation. These parameters generally fail to adequately assess the cardiovascular and non-respiratory organ support provided by MV. Evidence-based protocols to manage all of the components of the peri-extubation process are lacking and there is enormous inter-institutional variability in extubation management. Consequently, the decision to extubate is commonly physician-dependent rather than evidence-based, which often leads to inappropriate extubation with EF in this patient population.
In today’s PAAD, Hames et al.2 proposed that adding continuous physiologic monitoring data and risk analytics algorithms to clinical factors has the potential to assist clinicians in identifying neonates at high risk for EF. The aim was to determine the association of 2 physiologic risk analytics algorithms evaluating the probability of inadequate oxygen delivery (IDo2) and inadequate ventilation of carbon dioxide index (IVco2) using the T3 Platform (Etiometry, Boston MA) with EF in neonates receiving MV after cardiac surgery. IDo2 and IVco2 are calculated using a set of physiologic variables (vital signs, blood gas values, hemoglobin and ventilator measurements). T3 tracks these inputs from the neonate’s existing physiologic monitors. Clinical risk of inadequate oxygen delivery was defined as mixed venous oxygen saturation below a prespecified threshold of 30%, 40% and 50% and inadequate ventilation defined as a PaCO2 > 50 or 60 mm Hg in invasively ventilated patients.
The primary aim of the study was to evaluate IDo2 and IVco2 data during MV weaning in neonates recovering from cardiac surgery and any event of EF. The secondary aim was to evaluate the clinical factors associated with EF. The authors hypothesized that elevated IDo2 and IVco2 in the pre-extubation period would be associated with greater odds of EF.
A retrospective cohort study was undertaken in neonates (age < 1 month at time of surgery) receiving MV for longer than 48 hours following cardiac surgery in 8 international pediatric ICUs between 1 January 2017 and 31 December 2020 with the primary outcome EF. Exclusion criteria included: < 36 weeks gestation, weight less than 2 kg, death before primary extubation, unplanned extubation as final extubation or planned reintubation for a procedure within 48 hours of extubation.
736 neonates were analyzed with 102 (13.9%) having EF. In the reintubated patients 67 of the 102 received non-invasive respiratory support (NRS) as the initial post-extubation support. Of the 102 reintubated patients 93 (91%) had a documented etiology for EF, which included lower respiratory disease in 58, cardiac failure in 13 and upper airway obstruction in 10. Reintubation was associated with longer post-op CICU LOS, higher proportion of post-extubation cardiac arrests and death prior to hospital discharge. In multivariable analysis, preoperative respiratory support was associated with greater odds of EF. An additional 92 neonates (12.5%) required rescue non-invasive respiratory support, HFNC, CPAP and/or bilevel positive airway pressure, but avoided re-intubation.
611 neonates had pre-extubation iDo2 data and 478 had both pre-extubation IDo2 and IVco2 data. In multivariable analysis of both iDO2 and iVCO2 data, single ventricle anatomy and high IDo2 (>25) or IVco2 (>50) in the 2 hours preceding extubation were associated with greater odds of EF.
The study has several limitations. The retrospective design precludes the ability to understand the decision making of clinical teams regarding timing of extubation, extubation support, and threshold for re-intubation. The IDo2 and IVco2 data may have been available to some, but not all, clinicians at the time of extubation.
Neonates recovering from cardiac surgery are at high risk for EF. Neonates requiring pre-operative respiratory support and those with single ventricle anatomy are at greater odds of EF. IDo2 and IVco2 thresholds may provide additional information on extubation readiness in these subsets of patients. Prospective well-designed studies incorporating these thresholds to determine optimal timing for liberation from MV are needed.
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References
1. Miura S, Jardim PV, Butt W, Namachivayam SP. Extubation Failure and Major Adverse Events Secondary to Extubation Failure Following Neonatal Cardiac Surgery. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies 2020;21(12):e1119-e1125. (In eng). DOI: 10.1097/pcc.0000000000002470.
2. Hames DL, Abbas Q, Asfari A, et al. Extubation Failure in Neonates Following Congenital Cardiac Surgery: Multicenter Retrospective Cohort, 2017-2020. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies 2025 (In eng). DOI: 10.1097/pcc.0000000000003703.