OBJECTIVES:

In children hospitalized for bronchiolitis, enteral nutrition (EN) practices during noninvasive ventilation (NIV) vary widely. We sought to assess the potential impact of EN by observing changes in physiometric indices (heart rate [HR] and respiratory rate [RR]) before and after EN initiation.

METHODS:

We performed a retrospective cohort study in children <2 years of age hospitalized for bronchiolitis receiving NIV from 2017 to 2019 in a quaternary ICU. The primary outcome was patient HR and RR before and after EN initiation. Descriptive data included demographics, anthropometrics, comorbidities, NIV parameters, EN characteristics, and general hospital outcomes. Analyses included paired comparative and descriptive statistics.

RESULTS:

Of the 124 children studied, 85 (69%) were permitted EN at a median of 12 (interquartile range [IQR]: 7 to 29) hours. The route was oral (76.5%), nasogastric (15.3%), or postpyloric (8.2%) and was predominantly started during high-flow nasal cannula (71%) at flow rates of 1 (IQR: 0.7 to 1.4) L/kg per minute. After EN initiation, reductions in the median RR (percentage change: −11 [IQR: −23 to 3]; P < .01) and HR (percentage change: −5 [IQR: −12 to 1]; P < .01) were noted. Those permitted EN were younger (5 [IQR: 2 to 11] vs 11 [IQR: 3 to 17] months; P < .01) and more likely to have bronchopulmonary dysplasia (19% vs 5%; P = .04). Malnutrition rates, comorbidities, admission timing, flow rates, length of stay, and NIV duration did not differ for those provided or not provided EN. No aspiration events were observed.

CONCLUSIONS:

Reductions between pre- and postprandial RR after EN initiation among children hospitalized for bronchiolitis on NIV were observed without clinically significant aspiration. These findings support existing data that suggest that EN is safe during NIV and may lessen distress in some patients.

Acute bronchiolitis is a major cause of hospitalization in children, with an incidence of 13.5 to 17.9 per 1000 person-years and direct hospital costs in excess of US$700 million per year.1,2  In cases progressing to acute respiratory failure, noninvasive ventilation (NIV), such as heated humidified high-flow nasal cannula (HFNC) or bilevel noninvasive positive pressure ventilation (NIPPV), is applied to improve oxygenation, ventilation, and work of breathing.37  The application of NIV chronologically corresponds with reductions in mechanical ventilation (MV) rates in the past 2 decades from >30% to 4% to 7%.810  However, NIV is reported as a common barrier to enteral nutrition (EN) initiation in this population.1113 

Guidelines from the American Society for Parenteral and Enteral Nutrition (ASPEN), the Society of Critical Care Medicine (SCCM), and the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) recommend EN initiation within 24 to 48 hours of hospitalization in critically ill children to preserve gastric mucosal integrity, maintain motility, and diminish adverse effects from malnourishment.14,15  Malnutrition is present in up to 46% of children hospitalized for bronchiolitis13,16  and impacts mortality, MV duration, and length of stay (LOS).1722  Anecdotally, EN during NIV is postponed on account of perceived risk of aspiration-related respiratory failure (ARRF) or, for those who fail to respond to NIV, aspiration during intubation. Although these events are rare,23,24  disparate practices exist both regionally and by provider, including timing, route, and type of EN.25,26 

For children, a state of bad temperament or irritability from hunger, sometimes referred to as “hanger,”27  may anecdotally mimic respiratory distress or generate alarming vital signs that prolong LOS.27  It remains unclear if EN is therapeutic by promoting coping and soothing during NIV. To assess these knowledge gaps, we hypothesized that initiation of EN would correlate with paired reductions in the heart rate (HR) and respiratory rate (RR) during NIV. We planned to describe relationships between EN and duration of NIV and assess the relationships by groups defined by the NIV modality (HFNC versus NIPPV), the route of EN (by mouth versus enteric tube), the percentage change (%∆) in physiometric variables.

We performed a single-center retrospective observational cohort study of children <2 years of age who were admitted from November 2017 to May 2019 to a 28-bed PICU within a 259-bed quaternary children’s hospital for the diagnosis of acute bronchiolitis and received NIV (either HFNC or NIPPV). We excluded children with comorbid cystic fibrosis, congenital airway anomalies, interstitial lung disease, pulmonary hypertension, critical congenital heart disease, and neuromuscular disease; children receiving chronic outpatient NIV; children with parenteral nutrition dependence; and encounters with incomplete vital sign documentation. We did not exclude subjects with neonatal bronchopulmonary dysplasia. Comparative cohorts were identified by EN status during NIV and, among those receiving EN, we assessed the type of NIV, the route of EN, and the percentage change in the respiratory rate (%∆RR). This study was reviewed and approved by an institutional review board.

Primary outcomes were the HR and RR within 1 hour of EN initiation, which were manually obtained by bedside staff from cardiorespiratory monitoring in the emergency center and PICU as part of standard care. If multiple data points were noted, a mean value was calculated, and comparisons were made by using paired change (∆) and %∆ in the HR and RR. Secondary outcomes included NIV duration and nonresponse rates, defined as an escalation to invasive MV or a transition from HFNC to NIPPV. Descriptive data included demographics, anthropometrics (ie, weight-for-age z score [WAZ]), comorbidities, the Pediatric Logistic Organ Dysfunction 2 predicted death rate (PELOD-2 PDR),28  respiratory outcomes (ie, MV rate, NIV settings, and ARRF rate), general hospital outcomes (ie, LOS, mortality, and extracorporeal life support rates), and nutrition data (route, type, timing, and goal volumes). Nutrition goals were determined by anthropometric measurements, the Institute of Medicine’s Dietary Reference Intakes,29  and the Holliday-Segar equation.30  Respiratory failure was defined as ARRF if the clinician observed emesis or clinical or radiographic evidence of aspiration and escalated the patient to respiratory support or temporally began invasive ventilation after nutrition initiation, bolus nutrition, or emesis.23 

Bronchiolitis care is guided by a clinical pathway developed in collaboration between emergency center, PICU, and hospital medicine services. Initiation of NIV in infants and young children with bronchiolitis is begun after attempts at nasopharyngeal suctioning, a trial of regular nasal cannula oxygen, an appraisal of work of breathing, and/or an assessment for hypercapnia. Flow rates >1.5 L/kg per minute, absolute HFNC flow rates >12 L/min, or a fraction of inspired oxygen >50% results in PICU admission. NIPPV in this population is managed in the PICU. The decision to intubate a patient or switch NIV interfaces is at the discretion of an attending physician guided by examination and, at times, available radiographic and laboratory data. If on HFNC and once absolute flow is weaned to 5 L/minute, patients are transitioned to a regular nasal cannula and transferred to the general pediatric ward.

Consistent with the ASPEN, SCCM, and ESPNIC guidelines,14,15  children are routinely ordered EN within 24 hours of hospitalization in consultation with registered dietitians. In the division of critical care medicine, a range of EN practices is observed. This includes withholding EN during NIV, provision of age-appropriate by mouth ad libitum EN, or breastfeeding ad libitum. If by mouth nutrition is not tolerated (ie observed emesis, dysphagia, or choking), a nasogastric or transpyloric tube is placed. Children may have a enteric tube placed without a trial of by mouth nutrition when receiving NIPPV. Nutrition volumes are escalated in a stepwise fashion until goals, identified by a minimum resting energy expenditure accounting for alterations in energy consumption related to critical illness, are achieved.29,30 

Descriptive data are reported as proportions, mean ± SD, or median (interquartile range [IQR]). Children on NIV without EN provided were included in the analysis as part of EN-negative cohorts. Data normalcy was assessed by using Shapiro-Wilk testing. Comparative statistics were used to assess those with and without EN administration, including the χ2 test, Student’s t test, and paired testing. In subgroup analyses, additional multicohort testing included Kruskal-Wallis one-way analysis of variance. Type I error was set at 0.05. All analyses were performed in Stata version 15.1 (Stata Corp, College Station, TX).

During study, 124 children receiving NIV for bronchiolitis were admitted to the PICU and met study criteria. Of those, 85 (69%) were provided EN. Sample demographic, comorbidity, and admission characteristics are listed in Table 1. Compared with those for whom EN was withheld, those who were provided EN were younger (median age 5.3 [IQR: 2.1 to 11.9] vs 11.5 [IQR: 3.5 to 17] months; P < .01), had greater incidence of chronic lung disease (18.8% vs 5.1%; P < .01), and had a lower PELOD-2-PDR (0.3 [IQR: 0.3 to 0.9] vs 0.9 [IQR: 0.5 to 1.1] %; P = .04). Moderate to severe malnutrition on admission (WAZ < −2) was present in 15.8% of patients, and preexisting gastroesophageal reflux disease was noted in 12.9%. In an exploratory logistic model to predict provision of EN during NIV that included independent variables of patient age, presence of chronic lung disease, presence of NIPPV versus HFNC, and the PELOD-2-PDR, patient age in months was found to be inversely associated with EN during NIV (adjusted odds ratio: 0.9; 95% confidence interval [CI]: 0.85–0.97; P < .01).

TABLE 1

General Sample Characteristics Among Children Who Received or Did Not Receive EN During NIV for Acute Respiratory Failure Secondary to Bronchiolitis

VariablesDid Not Receive EN (n = 39)Received EN (n = 85)P
Age, median (IQR), mo 11.5 (3.5 to 17) 5.3 (2.1 to 11.9) <.01 
Sex ratio, male/female 1.8:1 2.4:1 .47 
Admission wt, median (IQR), kg 9.4 (5.5 to 10.8) 6.6 (4.5 to 9.1) <.01 
 WAZ, median (IQR) −0.11 (−1.33 to 0.48) −0.59 (−1.63 to 0.34) .24 
 WAZ < −2, n (%) 4 (10.3) 18 (21.2) .13 
PELOD-2-PDR, median (IQR), % 0.9 (0.5 to 1.1) 0.3 (0.3 to 0.9) .04 
History of previous intubation, n (%) 8 (20.5) 15 (17.7) .7 
Comorbidities, n (%)    
 Allergic rhinitis 1 (2.6) 0 (0) .13 
 Atopic dermatitis 4 (10.3) 2 (2.4) .05 
 Bacterial pneumonia 10 (25.6) 10 (11.8) .05 
 Chronic lung disease 2 (5.1) 16 (18.8) .04 
 Craniofacial anomaly 0 (0) 2 (2.4) .33 
 Diaphragmatic hernia 0 (0) 3 (3.5) .23 
 Gastroesophageal reflux 5 (12.8) 11 (12.9) .98 
 Genetic disorders 1 (2.6) 2 (2.4) .94 
 Prematurity (<35 wk gestation) 11 (28.2) 26 (30.6) .78 
 Seizure disorder 1 (2.6) 2 (2.4) .94 
Day of illness, median (IQR),d 2 (1 to 3) 3 (2 to 4) .06 
Positive viral testing result, n (%)    
 Respiratory syncytial virus 15 (38.5) 45 (52.9) .17 
 Rhinovirus or enterovirus 15 (38.5) 28 (32.9) .54 
 Influenza 2 (5.1) 4 (4.7) >.99 
 Adenovirus 2 (5.1) 3 (3.5) .64 
 Parainfluenza virus 2 (5.1) 2 (2.4) .58 
 Coronavirus 2 (5.1) 1 (1.2) .23 
 Human metapneumovirus 1 (2.6) 5 (5.9) .66 
Evening admission (7 pm to 7 am), n (%) 19 (48.7) 41 (48.2) .96 
Prescribed stress ulcer prophylaxis, n (%) 17 (43.6) 15 (17.7) <.01 
NIPPV, n (%) 10 (25.6) 33 (38.8) .16 
VariablesDid Not Receive EN (n = 39)Received EN (n = 85)P
Age, median (IQR), mo 11.5 (3.5 to 17) 5.3 (2.1 to 11.9) <.01 
Sex ratio, male/female 1.8:1 2.4:1 .47 
Admission wt, median (IQR), kg 9.4 (5.5 to 10.8) 6.6 (4.5 to 9.1) <.01 
 WAZ, median (IQR) −0.11 (−1.33 to 0.48) −0.59 (−1.63 to 0.34) .24 
 WAZ < −2, n (%) 4 (10.3) 18 (21.2) .13 
PELOD-2-PDR, median (IQR), % 0.9 (0.5 to 1.1) 0.3 (0.3 to 0.9) .04 
History of previous intubation, n (%) 8 (20.5) 15 (17.7) .7 
Comorbidities, n (%)    
 Allergic rhinitis 1 (2.6) 0 (0) .13 
 Atopic dermatitis 4 (10.3) 2 (2.4) .05 
 Bacterial pneumonia 10 (25.6) 10 (11.8) .05 
 Chronic lung disease 2 (5.1) 16 (18.8) .04 
 Craniofacial anomaly 0 (0) 2 (2.4) .33 
 Diaphragmatic hernia 0 (0) 3 (3.5) .23 
 Gastroesophageal reflux 5 (12.8) 11 (12.9) .98 
 Genetic disorders 1 (2.6) 2 (2.4) .94 
 Prematurity (<35 wk gestation) 11 (28.2) 26 (30.6) .78 
 Seizure disorder 1 (2.6) 2 (2.4) .94 
Day of illness, median (IQR),d 2 (1 to 3) 3 (2 to 4) .06 
Positive viral testing result, n (%)    
 Respiratory syncytial virus 15 (38.5) 45 (52.9) .17 
 Rhinovirus or enterovirus 15 (38.5) 28 (32.9) .54 
 Influenza 2 (5.1) 4 (4.7) >.99 
 Adenovirus 2 (5.1) 3 (3.5) .64 
 Parainfluenza virus 2 (5.1) 2 (2.4) .58 
 Coronavirus 2 (5.1) 1 (1.2) .23 
 Human metapneumovirus 1 (2.6) 5 (5.9) .66 
Evening admission (7 pm to 7 am), n (%) 19 (48.7) 41 (48.2) .96 
Prescribed stress ulcer prophylaxis, n (%) 17 (43.6) 15 (17.7) <.01 
NIPPV, n (%) 10 (25.6) 33 (38.8) .16 

Patient RR and HR before and after initiation of EN during NIV are depicted in Fig 1. The paired median RR was reduced from 44 (IQR: 37 to 57) to 33 (IQR: 32 to 50) breaths per minute (P < .01), accounting for a median %∆ of −11% (P < .01). Similarly, the paired median HR reduced from 147 (IQR: 131 to 162) to 138 (IQR:127 to 158) beats per minute (P < .01), accounting for a median %∆ of −5% (P < .01). More than 35% of those provided EN exhibited a reduction in the %∆RR of ≥20%. In cohorts defined by %∆RR (ie, any increase in the %∆RR, a decrease between 0% and 20%, and a decrease of ≥20%), no differences in clinical characteristics or patient outcomes were noted (Table 2). Of the 21 of 85 (25%) children who experienced an increase in the %∆RR after initiating EN, the median %∆RR was 9% (IQR: 4% to 14%), equivalent to 4 (IQR: 2 to 6) breaths per minute. Compared with those with decreased postprandial RR, children with an increased RR had equivocal HFNC flow rates applied (0.9 [IQR: 0.5 to 1.6] vs 1.1 [IQR: 0.7 to 1.4] L/kg per minute; P = .26), and a similar proportion were fed during NIPPV (14% vs 22%; P = .54).

FIGURE 1

Paired RRs and HRs before and after EN initiation during NIV for acute respiratory failure from bronchiolitis. A, RR. B, HR.

FIGURE 1

Paired RRs and HRs before and after EN initiation during NIV for acute respiratory failure from bronchiolitis. A, RR. B, HR.

Close modal
TABLE 2

Descriptive Comparison of Children on NIV Admitted for Bronchiolitis With a Stratification Based on the %∆RR After EN Initiation

Variables>0% ∆ in RR (n = 21)−20% to 0% ∆ in RR (n = 34)≤−20% ∆ in RR (n = 30)P
Age, median (IQR), mo 4 (2 to 8.3) 6.7 (2.4 to 13.6) 6.3 (2.8 to 13.7) .35 
Sex ratio, male/female 1.6:1 1.9:1 1.6:1 .62 
Admission wt, median (IQR), kg 6.9 (4.5 to 8.2) 6.1 (4.3 to 9.8) 7.3 (4.7 to 9.6) .64 
 WAZ, median (IQR) −0.9 (−2.6 to 0.17) −0.5 (−1.53 to 0.52) −0.59 (−1.71 to 0.43) .52 
 WAZ < −2, n (%) 5 (24) 7 (21) 6 (20) .81 
PELOD-2-PDR, median (IQR), % 0.9 (0.3 to 0.9) 0.3 (0.3 to 0.9) 0.3 (0.3 to 0.9) .53 
History of previous intubation, n (%) 5 (24) 4 (12) 6 (20) .47 
Comorbidities, n (%)     
 Bacterial pneumonia 3 (14) 4 (12) 3 (10) .89 
 Chronic lung disease 5 (24) 6 (18) 5 (17) .79 
 Gastroesophageal reflux 3 (14) 1 (3) 7 (23) .51 
 Genetic disorders 0 (0) 1 (3) 1 (3) .95 
 Prematurity (<35 wk gestation) 8 (38) 10 (29) 8 (27) .67 
Day of illness, median (IQR), d 3 (2 to 6) 3 (1.5 to 4) 3 (2 to 4) .49 
Positive viral testing result, n (%)     
 Respiratory syncytial virus 14 (66) 19 (56) 12 (40) .65 
 Rhinovirus or enterovirus 9 (43) 13 (38) 7 (23) .19 
 Influenza 1 (5) 3 (88) 0 (0) .62 
 Adenovirus 1 (5) 2 (6) 0 (0) .87 
 Parainfluenza virus 0 (0) 1 (3) 1 (3) .95 
 Coronavirus 0 (0) 0 (0) 1 (3) >.99 
 Human metapneumovirus 2 (10) 2 (6) 1 (3) .65 
Evening admission (7 pm to 7 am), n (%) 14 (66) 14 (41) 13 (43) .14 
Stress ulcer prophylaxis, n (%) 4 (19) 5 (21) 6 (20) .84 
Noninvasive interface, n (%)     
 Noninvasive positive airway pressure 3 (14) 6 (18) 8 (27) .5 
 HFNC 18 (86) 28 (82) 22 (73) — 
Duration of NIV support, mean ± SD, d 3 ± 2.3 2.4 ± 1.5 1.9 ± 1.4 .67 
LOS, median (IQR), d 5.6 (4 to 7.6) 4.8 (3.3 to 7.6) 3.4 (2.3 to 6.9) .47 
Route of EN, n (%)     
 Breastfed 5 (24) 4 (11) 4 (13.3) — 
 Bottle-fed 9 (43) 21 (63) 22 (73.3) .23 
 Nasoenteral tube fed 7 (33) 9 (26) 4 (13.3) — 
Variables>0% ∆ in RR (n = 21)−20% to 0% ∆ in RR (n = 34)≤−20% ∆ in RR (n = 30)P
Age, median (IQR), mo 4 (2 to 8.3) 6.7 (2.4 to 13.6) 6.3 (2.8 to 13.7) .35 
Sex ratio, male/female 1.6:1 1.9:1 1.6:1 .62 
Admission wt, median (IQR), kg 6.9 (4.5 to 8.2) 6.1 (4.3 to 9.8) 7.3 (4.7 to 9.6) .64 
 WAZ, median (IQR) −0.9 (−2.6 to 0.17) −0.5 (−1.53 to 0.52) −0.59 (−1.71 to 0.43) .52 
 WAZ < −2, n (%) 5 (24) 7 (21) 6 (20) .81 
PELOD-2-PDR, median (IQR), % 0.9 (0.3 to 0.9) 0.3 (0.3 to 0.9) 0.3 (0.3 to 0.9) .53 
History of previous intubation, n (%) 5 (24) 4 (12) 6 (20) .47 
Comorbidities, n (%)     
 Bacterial pneumonia 3 (14) 4 (12) 3 (10) .89 
 Chronic lung disease 5 (24) 6 (18) 5 (17) .79 
 Gastroesophageal reflux 3 (14) 1 (3) 7 (23) .51 
 Genetic disorders 0 (0) 1 (3) 1 (3) .95 
 Prematurity (<35 wk gestation) 8 (38) 10 (29) 8 (27) .67 
Day of illness, median (IQR), d 3 (2 to 6) 3 (1.5 to 4) 3 (2 to 4) .49 
Positive viral testing result, n (%)     
 Respiratory syncytial virus 14 (66) 19 (56) 12 (40) .65 
 Rhinovirus or enterovirus 9 (43) 13 (38) 7 (23) .19 
 Influenza 1 (5) 3 (88) 0 (0) .62 
 Adenovirus 1 (5) 2 (6) 0 (0) .87 
 Parainfluenza virus 0 (0) 1 (3) 1 (3) .95 
 Coronavirus 0 (0) 0 (0) 1 (3) >.99 
 Human metapneumovirus 2 (10) 2 (6) 1 (3) .65 
Evening admission (7 pm to 7 am), n (%) 14 (66) 14 (41) 13 (43) .14 
Stress ulcer prophylaxis, n (%) 4 (19) 5 (21) 6 (20) .84 
Noninvasive interface, n (%)     
 Noninvasive positive airway pressure 3 (14) 6 (18) 8 (27) .5 
 HFNC 18 (86) 28 (82) 22 (73) — 
Duration of NIV support, mean ± SD, d 3 ± 2.3 2.4 ± 1.5 1.9 ± 1.4 .67 
LOS, median (IQR), d 5.6 (4 to 7.6) 4.8 (3.3 to 7.6) 3.4 (2.3 to 6.9) .47 
Route of EN, n (%)     
 Breastfed 5 (24) 4 (11) 4 (13.3) — 
 Bottle-fed 9 (43) 21 (63) 22 (73.3) .23 
 Nasoenteral tube fed 7 (33) 9 (26) 4 (13.3) — 

—, not applicable.

Of the 85 children permitted EN, 65 (76.5%) received by mouth nutrition, including 80% who were fed age-appropriate formula or expressed breast milk and 20% who were directly breastfed. The remaining 20 of 85 (23.5%) received EN via nasogastric (n = 13) or transpyloric (n = 7) tubes. Time to initiation of EN was a median of 12 (IQR: 7 to 29) hours. A majority of children were fed during HFNC (60 of 85 [71%]), with a median weight-adjusted flow rate of 1 (IQR: 0.7 to 1.4) L/kg per minute at EN initiation. Compared with those on NIPPV (20 of 85 [29%]), no differences in physiometric variables were observed for those who were fed on HFNC (Supplemental Table 3). Although interruptions in EN were not uncommon (noted in 29 [34.1%] of children), no episodes of ARRF were recorded. Of those with an interruption, most (27of 29 [93%]) had nutrition paused because of perceived dyspnea a median of 7 (IQR: 6 to 11) hours after initiation. All but 1 child successfully restarted EN during NIV without subsequent interruptions. Compared with children fed by mouth, children fed via enteral tubes had a longer hospital LOS and NIV duration (Supplemental Table 4). By discharge, a greater proportion of children achieved nutrition goals (volume, caloric, and protein) among those provided EN during NIV compared with those who did not receive EN (60 of 85 [70.1%] vs 20 of 39 [51.2%]; P = .04). Only 45 of 85 (53%) achieved all nutrition goals during NIV exposure.

Nearly all subjects were first trialed on HFNC (123 of 124 [99.1%]). Peak weight-adjusted HFNC flow rates were no different between those who received and those who did not receive EN (1.4 [IQR: 1.1 to 1.9] vs 1.3 [IQR: 1.1 to 1.6] L/kg per minute; P = .21). Of those transitioned to NIPPV, the maximum peak inspiratory pressure was greater (26 [IQR: 24 to 30] vs 22 [IQR: 18 to 25] cm H2O; P < .01) in those for whom EN was withheld, but no differences were noted for positive end-expiratory pressure or intermittent mandatory ventilation rates. For the entire sample, 10 of 85 (8%) were intubated a median of 0.5 (IQR: 0.2 to 1.8) days after hospitalization and 2 required extracorporeal life support within 12 hours of hospitalization. Eight (21%) were intubated after a trial of NIPPV, and only 1 was fed on HFNC before transition to NIPPV and subsequent MV. The child who was provided EN before MV did not have aspiration at intubation, was fed during the HFNC trial, and was subsequently transitioned to NIPPV for an additional 1.3 days (status: nil per os [NPO]) before intubation. The total NIV duration was 2.1 ± 1.6 days for all subjects and was not observably different for subjects on HFNC who did and did not receive EN (2.3 ± 1.7 vs 1.5 ± 1.1 days; P = .06). For children on NIPPV, those provided EN during NIV experienced a longer duration of NIV exposure (3.7 ± 1.6 vs 0.9 ± 0.7 days; P < .01) compared with those for whom EN was withheld. The median hospital LOS was 4 (IQR: 2.7 to 6.9) days, and no statistically significant differences were observed between cohorts who received and did not receive EN (4.8 [IQR: 1 to 7.1] vs 3.4 [2.1 to 5.8] days; P = .07). No mortalities were observed.

In this retrospective observational cohort study, we assessed children admitted to a PICU on NIV with acute respiratory failure secondary to bronchiolitis and observed notable reductions in the RR (by 11%) after EN initiation. Nutrition was initiated early (median of 12 hours after admission) and predominantly as by mouth ad libitum (76.5%). Children who did not receive EN were older by a median of 6.2 months, and a decreased proportion achieved goal nutrition by hospital discharge compared with peers who were provided EN during NIV. We noted no episodes of aspiration, and a majority of those who were intubated were intubated within the first 24 hours of hospitalization. Although we hypothesized that reductions in the HR and RR after EN initiation might result in rapid weaning from NIV, we were unable to detect a shortened NIV duration or LOS. The inability to detect these differences may be the result of inadequate study power. The observed physiometric improvements after EN may reflect a therapeutic response from reduced patient hunger, improved irritability, and self-soothing.

In patients without a contraindication to EN, the 2017 ASPEN and SCCM and 2020 ESPINIC guidelines recommend starting EN early during hospitalization to preserve gastric mucosal integrity, maintain motility, and diminish adverse effects related to malnourishment.14,15  Yet infants admitted for acute respiratory failure from bronchiolitis receiving NIV face several barriers to receiving EN. Leong et al26  found that hospital nutrition protocols were absent in 68% of Canadian PICUs and that barriers to initiating EN in nonintubated children included NIPPV, chest physiotherapy, and perceived distress. Similarly, Canning et al31  assessed nutritional practices during NIV in Australia and New Zealand and found that EN protocols were absent in 80% of facilities and that 21% of physicians reported purposefully withholding EN in children during NIPPV. In a US cross-sectional study by Canarie et al,11  the presence of NIV was associated with delayed EN initiation (odds ratio: 3.37; 95% CI: 1.69–6.72). These data are echoed by Leroue et al,13  who noted reduced odds of early EN initiation for children receiving NIPPV (odds ratio: 0.4; 95% CI: 0.25–0.63). In bronchiolitis, 39% of clinicians in pediatric tertiary centers in Europe reported intentionally withholding EN during HFNC therapy, and 56% reported withholding EN for PICU admission.25  In our study, we noted comparable variation, with 31% withholding EN until successful weaning the child from NIV.

Apprehensions arise regarding EN from perceived ventilation-swallowing dysfunction when children experience elevated airway pressures and flow rates during bilevel NIPPV or HFNC therapy. In the context of bronchiolitis, comorbidities may exist, including airway edema, increased secretions, airway obstruction, and resultant tachypnea. These symptoms may result in dysphagia, emesis, and aspiration, which, hypothetically, could induce ARRF. Recent publications by our research group23  and Slain et al24  suggest that clinically relevant aspiration is exceedingly rare in bronchiolitis. One concern is that in children who progress to respiratory failure, elevated gastric volumes at the time of intubation could result in aspiration.32  In 2 studies, authors observed the presence of lipid-laden macrophages during a blind laryngeal lavage in children hospitalized for bronchiolitis.33,34  However, those children experienced spontaneous resolution in a 4-week follow-up assessment, and data are confounded by comorbid gastroesophageal reflux disease. Our findings resonate with existing literature because we observed no ARRF and 90% of intubated subjects were under NPO orders during NIV before MV. Providers appeared cautious in our study because EN was started a median of 12 hours after admission, which did not vary by admission timing (night versus day shift). We speculate that providers attempt to gauge trajectory before EN initiation and can apply selection bias to identify children who would soon require invasive respiratory support.

It could be argued that early EN initiation during NIV may not be essential in bronchiolitis. Afterall, we noted a mean NIV duration of 2.1 days, and only 15.8% had moderate-severe malnutrition. However, Weisgerber et al35  noted a shorter LOS in children with bronchiolitis who were provided EN within 24 hours of admission. Halvorson et al36  found that clinical factors that correlated with hospital LOS were NPO status (r = 0.36) and a RR >60 breaths per minute (r = 0.33). In a similar population, Shadman et al37  found that time to hospital discharge was shorter among children provided any EN (hazard ratio 2.17; 95% CI: 1.34–3.50) and among children receiving exclusive oral nutrition (hazard ratio 2.13; 95% CI: 1.31–3.45). Although we were not able to detect differences in LOS or NIV duration, the observed physiometric reductions are consistent with those in previous publications. Presumably, if the RR and HR are improved, it is plausible that providers observing physiologic stability would be inclined to wean respiratory support.

One hypothesis to explain our findings is that the provision of EN is, in and of itself, therapeutic because it soothes a hungry, irritable infant. In a randomized controlled trial comparing nonnutritive sucking with and without sucrose for procedural pain relief in infants, improved pain scores, reduced crying time, and a lowered HR were noted.38  Similarly, in systematic reviews, sucrose and skin-to-skin care for painful procedures in infants have been shown to reduce agitation and pain.39,40  Breastfeeding may be as effective as sucrose, cuddling, and topical anesthetics in reducing pain and crying duration in infants undergoing vaccination.41  In our study, we noted that young children, as compared with toddlers, were more frequently fed, and we suspect a provider bias exists regarding the importance of provision of EN. Abdel Razek and Az El-Dein42  assessed infants undergoing immunization who were breastfed versus those receiving skin-to-skin time alone and noted a reduced HR in the breastfed group. Finally, the ASPEN, SCCM, and ESPNIC guidelines do not recommend routine stress ulcer prophylaxis prescribing solely for NPO status in critical illness. Yet we noted greater prescribing frequency in those with NPO status during NIV. Physiologic stability may represent a therapeutic response in a hungry, irritable child with concurrent bronchiolitis.

Finally, hospitalization of a critically ill child is associated with significant parental stress and may result in posttraumatic stress symptoms in as many as 5% to 28% of families.43  Parental anxiety is multifactorial and related to team communication, parental comprehension, family dynamics, support networks, severity of illness, and perceived loss of control.44,45  One means to limit familial toxic stress is to permit parents to resume routine responsibilities, such as providing EN and feeding rituals.46  Although the rate of achieving goal nutrition by discharge may be confounded by a generally short LOS in this population, enabling a family to partake in a child’s health care is of value, potentially builds resilience, and warrants further investigation.

Physiometric variables are likely influenced by a variety of covariates, including fever, pain, fatigue, inflammation, or agitation from routine care (ie, intravenous access, respiratory therapies, or even the measuring of the metrics themselves). Only 5% of children had fever at the time of EN initiation, and pain scores were not recorded in our study. Our center, like many others,26  does not follow a standardized pathway for NIV weaning. As a result, both selection bias and practice variation among the 11 intensivists in our center may confound results. This study was conducted at a quaternary pediatric referral center, and outcomes are generalizable to sites with similar volume, resources, and patient case mix. We cannot account for regional variation in disease severity or clinical practice variation. Physiometric data were recorded after the initial provision of EN and not throughout patients’ NIV exposure. This was purposeful to draw chronological proximity to EN as opposed to other covariates. By not recording further physiometric data, we cannot draw conclusions regarding persistent ∆ in the HR and RR and their potential effect on study outcomes. Reductions in physiometric variables may be the result of a cumulative therapeutic NIV effect rather than purely postprandial interactions. No children were on nasal continuous positive airway pressure, and we cannot draw conclusions regarding this interface. No physiometric data were assessed in the EN-negative cohort, and therefore we cannot draw conclusions regarding how these factors might have influenced the decision to initiate or withhold EN.

In this retrospective cohort study, we assessed the impact of EN on physiometric variables in children with bronchiolitis receiving NIV. We noted a reduction in the RR (−11%) after initiation of EN, without observed aspiration. Of those who required MV, 90% were never provided EN during the NIV trial, suggesting that clinicians apply selection criteria that limit aspiration risks. Although a period of NPO observation after admission to assess clinical trajectory may be warranted, systematic persistent NPO status for PICU admission or NIV exposure in bronchiolitis should be reconsidered. Future research must be focused on (1) the impact of EN on physiologic stability throughout exposure to NIV, (2) whether physiometric variables correlate with comfort scales postprandially, (3) familial stress reduction from reallocating responsibilities to parents in critical illness, and (4) assessing therapeutic EN out of the PICU environment.

Dr Sochet provided contributions to the conception of the work, acquisition of data, interpretation of data, and drafting and revision of the manuscript; Ms Nunez provided contributions to the conception of the work, acquisition of data, and drafting and revision of the manuscript; Dr Wilsey provided contributions to the conception of the work and drafting and revision of the manuscript and provided content expertise; Dr Morrison and Ms Bessone provided contributions to the drafting and revision of the manuscript and provided content expertise; Dr Nakagawa provided contributions to the conception of the work, interpretation of data, and drafting and revision of the manuscript and provided senior mentorship; and all authors approved the final manuscript as submitted.

FUNDING: No external funding.

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Competing Interests

POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.

FINANCIAL DISCLOSURE: Dr Nakagawa receives author royalties from Wolters Kluwer UpToDate and was a consultant for Fresenius Kabi. Ms Bessone is a consultant for Nutricia North America; the other authors have indicated they have no financial relationships relevant to this article to disclose.

Supplementary data