Continuous Versus Bolus Feeds in Bronchiolitis: Is it Time to Stop the Debate? Free

Bronchiolitis is the most common cause of hospitalization for children < 12 months of age.1 Treatments such as bronchodilators, corticosteroids, or antiviral agents are ineffective and supportive measures remain the mainstay of treatment. The American Academy of Pediatrics clinical practice guideline includes a strong recommendation to meet the child’s hydration needs by either nasogastric (NG) or intravenous fluids.¹  NG hydration is the preferred route for nonoral hydration in many parts of the world^2–6  where it is recognized as an option that offers cost benefits, avoids painful intravenous sticks, and provides better nutrition than isotonic fluids.^2–4,6,7  Best practice for administering NG fluids in infants with bronchiolitis has yet to be established.

The randomized control trial in this month’s Hospital Pediatrics by Courtney et al⁸  is the first study to compare bolus and continuous NG feeds in infants with bronchiolitis. NG tube placement for rehydration and provision of nutrition was already standard practice in this large freestanding children’s hospital in Australia; however, there was variation in the use of continuous versus bolus feeding. This practice variation was ascribed to theoretical concerns related to increased risk of respiratory effort and possible aspiration in infants with full stomachs.

In this open, parallel-group superiority trial, infants < 12 months of age who had a 50% decrease of expected oral intake over the previous 12 to 24 hours were randomized to either bolus or continuous NG feeds. Patients were recruited from the emergency department and general care units. Most infants were judged to have moderate illness, and about half of them were on room air. However, 44% received high flow nasal canula (HFNC) support. Using an intention to treat model, authors found that there was no difference in the primary outcome of length of stay (LOS) between bolus and continuously fed infants (median [interquartile range] 54.2 [40.25–82.00] vs 56 [38.0–78.8]). However, surprisingly, they noted an association of increased admissions to the PICU (28.6% vs 11.2%, P = .004) in the continuously fed group compared with the bolus group. No infant had clinically significant aspiration in either group and vital signs taken near feeding initiation were similar.

A strength of this study is the randomized, parallel-group superiority design. However, it is not feasible to blind the providers to the nature of feeds (bolus versus continuous), and the open design may have introduced unconscious bias among providers. In many institutions, continuous feeds are commonly used in children on HFNC support. For example, 43% of children with bronchiolitis on HFNC had continuous feeds compared with 15.8% on bolus feeds in a study by Babl et al.⁶  Thus, children on continuous feeds may be perceived to be sicker, leading to a higher rate of intensive care admissions in this population. More investigation is needed to clarify the association found in this study between increased intensive care admissions and continuous feeds. Furthermore, discharge was delayed past “fit for discharge” criteria in a slightly higher proportion of children (36% vs 26%) with continuous feeds compared with bolus feeds. Delays were primarily ascribed to awaiting discharge clearance by the medical team. The difference does not reach statistical significance; however, it may be another indication that these children are viewed as sicker, or that there are underlying factors in the clinical course of children on continuous feeds that lead to hesitancy in clearing them for discharge.

Clinically significant differences in LOS are considered to be 24 hours in this study. However, many children admitted for bronchiolitis stay only 36 to 48 hours,⁹  and a more granular assessment of LOS would be helpful because a difference of 6 to 8 hours may be significant to families and health care systems. Finally, practitioners in Australia restrict the diagnosis of bronchiolitis to those < 12 months of age, leading to the exclusion of children older than 12 months of age in this study. However, the American Academy of Pediatrics clinical practice guideline includes this older age group (up to 24 months of age); therefore, a practice gap remains for many patients who we care for in the inpatient setting. Exploring these issues in future studies is important to determine enteral feeding options in this population (12–24 months).

The study by Courtney et al⁸  helps address a common clinical question where there is limited evidence: the best mechanism of enteral feeding for infants hospitalized with bronchiolitis who cannot orally feed. Previous studies comparing these strategies have focused on birth hospitalizations of preterm infants and those with low birth weights.^10,11  Applying this research to otherwise healthy infants who need short-term nutritional and hydration support is problematic because the physiology and needs of older infants and those with an acute respiratory illness may be different than preterm and low birth weight infants. A small study comparing NG feeds in mechanically ventilated children of various ages found that bolus feeds were associated with higher energy and protein delivery without aspiration.¹²  In studies of longer-term NG feeding plans, continuous feeds may be associated with loss of breast milk nutrients,¹³  increased feeding residuals,¹⁰  mismatch with hormonal cues, less patient mobility, and additional cost.¹⁴  However, these concerns are less of a consideration in the scenario of an acute, short hospitalization for bronchiolitis, which is the focus of this current study.

Another important concern is the risk of clinically significant aspiration, which is a commonly cited barrier when considering oral or NG feeds in infants with bronchiolitis.^15,16  Although proving safety in rare events is challenging, multiple studies of children with bronchiolitis fed while on HFNC suggest aspiration is rare.^6,17,18  Furthermore, in a study of mechanically ventilated children with a variety of illnesses who were fed by NG versus postpyloric feeds, aspiration was not detected in either group.¹⁹  It is reassuring that the current study by Courtney et al⁸  of patients also found no episodes of clinically significant aspiration in infants receiving continuous or bolus feeds.

Nutritional support and hydration using NG tubes have been evaluated in bronchiolitis; however, previous studies have lacked a standard administration approach^2,3,16,20  or have described a mixed approach that limits interpretation.^4–6  Without a firm recommendation, providers may default to their personal or institutional practice, which feels like the standard of care but is largely based upon anecdotal experience. Furthermore, in the absence of evidence, we often default to what might theoretically be the “safest.” However, in the best-case scenario, this anecdotal approach can prevent us from moving forward and, at its worst, it may actually be harmful. The findings of Courtney et al⁸  strengthen the existing evidence that pulmonary aspiration is rare in continuous and bolus feeds, and in addition, these feeding strategies are associated with equivalent LOS. With these observations, we can decrease the complexity of the “how” of NG feeding an infant and enable operationalizing nutrition. In many instances, NG bolus feeds may be optimal. They more closely mimic the timing and natural rhythm of bottle and breastfeeding, and they can be easily paired with oral feeding, both of which may appeal to parents.

Decisions to feed infants with respiratory distress because of bronchiolitis can be complex and involve many different provider types. Qualitative study of parent, nursing, and physician perspectives may be beneficial to illuminate opportunities and barriers that inform choices about bolus and continuous NG feeds. Understanding these factors may improve success rates of quality improvement projects that seek to increase NG bolus feeds in patients admitted with bronchiolitis.

A key component of quality improvement methodology is to reduce variation in practice, followed by moving it in the desired direction. This study by Courtney et al⁸  is an important step toward standardizing the approach to NG feeds using bolus feeds in patients admitted with bronchiolitis who cannot orally feed. Although future studies may explore nutrition-related innovations that improve outcomes, LOS, and patient experience, this current study suggests that NG bolus feeds are well-tolerated and should be considered as an important starting point in patients with bronchiolitis who cannot orally feed.