Early Versus Late Extubation in Pediatric Cardiac Surgery: A Systematic Review

Introduction

The frequency of congenital heart disease (CHD) is reported to be 4 to 8 per 1000 live births and it is the leading cause of mortality in the first year of life, accounting for 2% to 5% of all neonatal deaths. ¹ As CHD accounts for a considerable surgical burden, its management requires a multifaceted, multidisciplinary approach involving multiple healthcare teams, including cardiology, cardiac/cardiothoracic surgery, anesthesia and critical care, nursing, respiratory therapy, and nutrition.

Individualized, high-quality, and resource-efficient perioperative care in pediatric cardiac surgery has evolved to become increasingly outcome-oriented in the modern area. Enhanced recovery after surgery protocols introduced more than 20 years ago have been demonstrated to improve postoperative outcomes while reducing the length of hospital stay (LOS). ² Since then, these protocols have gained wide acceptance especially for the prevention of postoperative cognitive dysfunction and reduction in the incidence of cardiac and pulmonary complications. ³

Endotracheal intubation and anesthesia play an undisputed role in the surgical management of CHD in patients with various anatomical and hemodynamic characteristics. The main goal of anesthesia in these patients is to ensure hemodynamic stability, reduce mortality and morbidity, and utilize resources economically. Fulfillment of these goals is critical for physicians to tailor anesthesia management strategies for CHD. ⁴ The advances in the surgical and anesthetic techniques, and perioperative care, have led to remarkable improvements in the clinical outcome expectations for early-stage postoperative recovery in CHD patients.^5–7 The operative time, anesthetic requirement, need for aortic cross-clamping, and use of cardiopulmonary bypass (CPB) in these patients warrants postoperative mechanical ventilation, although some patients are extubated intraoperatively as part of fast-track protocols or depending on hemodynamic stability.

However, there is significant debate around when these patients should be extubated as mechanical ventilation is unfortunately associated with serious complications, such as pneumonia, atelectasis, and increasing morbidity and mortality.^8,9 Weaning off patients from mechanical ventilation thus constitutes an important step in the early postoperative period. However, inadequate or premature extubation may result in clinical decline, which may in turn lead to reintubation, longer duration of mechanical ventilation, and increased mortality.^8,10

While patients were traditionally followed in intensive care units (ICUs) with mechanical ventilator support after cardiac surgery, recently there has been an increase in the frequency of early extubation (EE) techniques, including fast-track extubation (FTE), as opposed to conventional delayed extubation (DE) techniques. These fast-track extubation techniques are used in order to avoid the complications associated with positive pressure ventilation on a cardiovascular system, reduce airway irritation, and prevent complications. This may expedite the recovery process with minimal chances of iatrogenic consequences. There has also been growing discourse regarding whether EE may also be beneficial in pediatric patients as it potentially improves clinical outcomes, including a 30% to 50% reduction in LOS resulting not only in decreased healthcare expenses, but also a notable reduction of postoperative morbidity. ³ This practice remains controversial due to a lack of data as well as heterogeneity secondary to confounders such as patient age, anatomic complexity, and physiology. Also, studies involving children undergoing CHD surgery and EE mostly comprise only single-center experiences.^5,11,12 Even though these studies have shown that achieving EE is possible and safe in selected patients when certain patient characteristics are accounted for, none has shown a clear benefit to EE. Therefore, standards differ between centers, and currently there is no consensus about the ideal timing and strategy of extubation in such patients. ¹³ This systematic review therefore aims to evaluate the literature regarding the timing of extubation in patients with CHD while also emphasizing the need for more large-scale studies focusing on specific pediatric populations to eliminate confounders and heterogeneity.

Methods

Results

Discussion

Early extubation in the pediatric population has been a matter of keen interest in healthcare in attempts to minimize mortality and cut down on the use of healthcare resources. Our study comprehensively evaluates EE in the pediatric population postcardiac surgery.

Several studies like Harris et al reported that EE is associated with a lower rate of 4% of reintubation as compared with 23% of DE. ⁵ Our analysis finds this to be inconsistent; thereby the impact of EE on reintubation remains inconclusive.

Studies in our analysis show an ambiguous correlation between EE and reintubation because the rate of extubation is not a sole determinant of need to reintubate. Factors such as patient characteristics and complexity of surgery are risks for the need to reintubate. According to Gupta et al, patients undergoing high-complexity operations and patients undergoing operations in lower-volume centers were associated with higher likelihood for the need for postoperative mechanical ventilation and need for reintubation. ³²

Our analysis supports the view that EE leads to reduced ICU LOS.^31,33 Early extubation is associated with a decreased risk of pulmonary complications, better hemodynamics, and less inotropic support as well as reduced use of sedatives postoperatively, all contributing to faster postoperative recovery and shortened ICU LOS. ³⁴ Despite these favorable outcomes, studies such as Barash and Manrique et al did not show significant differences in this ICU LOS.^{18, 27} This variation suggests ICU LOS is influenced by factors other than the rate of extubation.

Patient characteristics are important while determining extubation outcomes like ICU LOS. According to Tirotta et al patients extubated early are older and have a shorter ICU LOS stay of 3 to 4 days as compared with younger patients who are 39 days of age or younger who have to be extubated later (>6 h of surgery), tend to have longer ICU LOS of approximately 9.5 days. ¹⁴

Our study reviewed the effect of IE and EE versus DE on mortality. Our study in alignment with previous meta-analysis suggests that DE may be associated with higher mortality while recognizing the possibility of selection bias favoring EE.^18,35 Additionally, Ozalp et al reported no deaths in the EE group, highlighting the potential impact of patient selection on outcomes. ¹⁹

The possible mechanisms behind increased mortality in DE include a higher risk of ventilator-associated infections, prolonged hemodynamic instability, and increased sedative use, leading to complications such as pneumonia and sepsis, ultimately leading to mortality.^16,20 Additionally, higher intraoperative arterial lactate levels were identified as predictors of unsuccessful EE and increased mortality risk. ²¹ This highlights the importance of metabolic status in determining the success of EE. Furthermore, patients with DE often have higher Risk Adjustment for Congenital Heart Surgery 1 and Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery mortality scores, indicating that they are inherently sicker and at higher risk of mortality. ¹⁹ This suggests that the observed mortality differences between EE and DE groups may partly result from baseline patient characteristics rather than extubation timing alone.

Patient age is a key confounder in extubation outcomes. Neioretti et al found older patients were more likely to be extubated early (P < .001), while ventilated patients were younger and more critically ill, contributing to higher mortality. These differences limit direct statistical comparisons between the groups. ¹² Furthermore, institutional protocols and perioperative management strategies may have influenced extubation timing and outcomes, introducing variability across studies.

Our study also reviewed length of hospitalization as an outcome in IE and EE versus DE; this review showed an overall declining trend for hospital stay with the IE or EE groups (<6 h) compared with DE.

All the studies included in our analysis followed this trend, except for Kim et al, which found no significant difference. This could be due to differences in how DE was defined. In Kim et al, EE was considered extubation in the OR, while DE was within 1 to 2 h after surgery. ²⁴ In contrast, our study defines DE as occurring more than 6 h postsurgery.

Early extubation after CHD surgery offers significant benefits, such as fewer complications, reduced need for sedatives, and faster recovery, ultimately leading to shorter hospital stays.^7,16,19 While CPB duration can potentially increase hospital stay and chest tube use, EE helps mitigate these effects, particularly in children under 5 years of age and those undergoing longer surgeries.^7,22 Baehner et al stratified patients based on variables such as age, weight, and surgery duration and showed that EE resulted in significantly shorter overall hospital stays (11 vs 20 days) compared with DE, suggesting that EE promotes better recovery. ¹⁵

The findings in our study are consistent with those of the previous study ³⁵ ; however, we used a greater sample size, which enhances the statistical power and significance of our results. Moreover, our study has considerable heterogeneity. There were significant differences between the EE and DE groups, including factors like age, weight, and surgery duration, risk levels of the procedures they underwent, and preoperative health conditions, which were not consistently analyzed across studies and could have influenced outcomes.^7,14,22 Early extubation patients were older, heavier, had shorter bypass times, and experienced fewer complications and chest tube days. ²² However, younger age, smaller size, longer surgeries, and higher complexity during surgery were associated with greater challenges in performing EE. ¹⁴ Additionally, our results might be influenced by the inclusion of patients with syndromes in some studies,^14,19,25,26 while other studies did not include these patients, which contributed to variability in the findings. The absence of uniform protocols across studies makes it difficult to reach consistent conclusions. Furthermore, the inclusion of both retrospective and observational studies in our analysis adds to the variability of the data.

Despite some limitations, evidence suggests that EE is safe for appropriately selected patients, with no significant adverse events reported. While not always statistically significant, EE has been shown to reduce ICU and hospital stays, improve resource utilization, decrease pulmonary complications, and is generally successful across various patient groups.^4,7,14,20 It also reduces medication use and hospital costs, particularly in younger patients or those with longer surgeries, leading to shorter stays and fewer chest tube days.^7,21,22 Consequently, many centers now consider EE a safe and beneficial practice in pediatric cardiac surgery. However, high-quality randomized controlled trials are needed to confirm its efficacy and establish clear clinical guidelines. ³⁵

Recommendations

Future researchers need to practice uniform protocols to allow consistent comparisons across studies. To strengthen future research, baseline features like age, weight, type of surgery, hemodynamic stability, respiratory function, and neurological status must be comparable across studies. Additionally, hospital protocols, intensive care management, and anesthesia practices should also be standardized. Given the predominance of retrospective and observational studies in our analysis, multicenter prospective studies focusing on pediatric cardiac patients are needed to provide stronger, more reliable evidence.

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