Set the Children Free: Making the Most of Ventilator Liberation Protocols

Invasive mechanical ventilation is not a cure for any disease; it simply supports a patient while their underlying disease resolves. Each additional day of mechanical ventilation brings risk of complications including ventilator-induced lung injury and infection.¹ Furthermore, length of ventilation is highly correlated with length of ICU stay and cost.^2,3 Therefore, efforts to liberate patients from invasive mechanical ventilation as soon as is safely possible are in the best interest of the patient. Yet the decision of when to remove invasive mechanical ventilation can be challenging, as extubation failure is also associated with increased morbidity and mortality.⁴

In this month’s issue of Respiratory Care, Loberger and colleagues⁵ present a single-center historical cohort study of a combined sedation and extubation readiness testing (ERT) protocol. Following the introduction of this protocol, length of ventilation was decreased by 23%, or 19.2 h, with no concomitant increase in extubation failure rates or unplanned extubations. Opioid doses were unchanged with protocol initiation, whereas benzodiazepine use was reduced.

Their findings are consistent with a recent very large multi-center randomized clinical trial from the United Kingdom (the SANDWICH trial), which also demonstrated reduced duration of mechanical ventilation with a similar ventilator liberation protocol focused on frequent ERTs and titration of sedation.⁶ This larger study was less proscriptive about the choice of sedative medications and had a smaller effect size (median 6-h reduction compared to mean 20-h reduction in the Loberger et al study). Some of the effect size seen may have been attributed to the differences in baseline characteristics in the 2 sample populations in the Loberger study,⁵ with subjects in the baseline cohort having more underlying extubation failure risk factors. Additionally, it is unclear if the benefits seen can be attributed to the protocolized sedation, the ERT protocol, or the combination of both interventions.

The authors should be commended for their successful implementation of these multi-professional protocols. Initiation of the protocols had a clear and favorable effect on patient care, and their publication highlights 3 concepts that are important takeaways:

First, it has been repeatedly shown that clinical protocols and care pathways reduce variability in care and improve clinical outcomes.^7-11 Whereas there will always be a place for individualization of care, reducing variability supports the efficiency of care delivery, reduces costs, and leads to more equitable care. Yet development of a protocol is only the first step; knowing the right thing to do is often easier than actually changing practice. Successful implementation of a new care pathway or protocol requires strong change management skills and buy-in from all key stakeholders. In that vein, the most successful protocols engage and utilize the multi-professional care team (eg, physicians, nurses, respiratory therapists, pharmacists, physical therapists, dieticians). Clinical pathways have been applied extensively in conjunction with respiratory care and allow respiratory therapists to practice with a higher degree of autonomy.^11,12

Second, whereas care pathways can be beneficial to patient care, it is imperative that these protocols remain organic and flexible. With new research findings, our understanding of best practices evolves, and our protocols must adapt as well. As Loberger et al⁵ highlight in their manuscript, the previous RESTORE randomized trial of a sedation protocol for mechanically ventilated pediatric subjects did not demonstrate a decrease in duration of ventilation.¹³ Yet the RESTORE trial occurred just as our understanding of pediatric ICU (PICU) delirium was evolving. Specifically, benzodiazepines were used as the primary sedative in that trial,¹³ without full recognition of the deliriogenic effects of that drug class at the time of study conception.¹⁴ Had the RESTORE trial been designed a few years later, it is likely that a different medication strategy would have been used, with reduced use of benzodiazepines and increased focus on delirium management, which may have led to different findings. This improved understanding of the risks and benefits of sedative medications likely explains the success of this latest iteration of a ventilator weaning protocol as well as the success of the recent SANDWICH trial.⁶

The third notable concept is that the timing of extubation is highly dependent on sedation practices. Whereas there have been clear benefits of ERTs, the importance of sedation management cannot be ignored. The impacts of delirium in critically ill pediatric patients appear to be far reaching and more similar to adults than previously recognized and are closely tied to cumulative exposure of sedative medications.¹⁴ Whereas the natural disease course and resolution of an underlying lung disease may be largely out of the control of the bedside clinician, the level of sedation and delirium management of a patient is a clearly modifiable factor. During the weaning phase of respiratory failure, there are also benefits of spontaneous breathing that will be optimized by a patient who is more awake and cooperative, including lung recruitment and improved ventilation/perfusion ratio matching.¹⁵

Use of extubation readiness protocols and bundles is a core recommendation of the International Clinical Practice Guidelines for Pediatric Ventilator Liberation, developed by a panel of experts in pediatric critical care and respiratory failure.¹⁶ This recommendation is based on the synthesis of evidence of multiple randomized trials and quality improvement studies that suggest reductions in ventilator weaning time and extubation failure in this population. The same guidelines recommend a targeted sedation management strategy, but stop short of recommending for or against a sedation titration protocol, largely based on the conflicting results of the RESTORE and SANDWICH trials.^13,6 We suspect that a growing newer evidence base, including this study by Loberger et al,⁵ will continue to support use of sedation titration protocols in mechanically ventilated children.

The concept of a combined sedation and ERT protocol has been demonstrated in adults¹⁷ and is conceptually in line with the ABCDEF bundle, which has been associated with improved liberation from mechanical ventilation and reduced mortality in critically ill adults.¹⁸ The same bundle has been applied to pediatric patients but much more inconsistently.^19,20 In a recent survey, only 14% of PICUs reported routine use of spontaneous awakening trials, and 53% reported routine use of ERTs. Daily sedation interruption, used successfully in adults, has yet to become a routine practice in most PICUs. Unlike adult studies, limited data exist regarding the benefits of daily sedation interruption with some potential for harm.^21,22 Ongoing efforts to minimize time on the ventilator will require comprehensive protocols addressing the many aspects of ventilator management and weaning.²³ In the future, potential application of the ABCDEF bundle, either as a whole or with various components included, should be explored in pediatric patients to determine any potential benefit or harm.

We must recognize that the study in this month’s edition of Respiratory Care represents a single center’s experience with a ventilation liberation protocol. Application in other centers may demonstrate outcomes more similar to the SANDWICH trial⁶ or even fewer notable outcomes, either due to protocol adherence, variance in other management strategies, or differences in patient population. The time frame of the study by Loberger et al⁵ also is fairly short, and it remains to be seen if this protocol implementation will achieve sustained change in practice and outcomes, especially in patients with more preexisting extubation failure risk factors.

• Copyright © 2022 by Daedalus Enterprises