Feeding efficiency and respiratory integration in infants with acute viral bronchiolitis

Oral Feeding on High-Flow Nasal Cannula in Children Hospitalized With Bronchiolitis

OBJECTIVE

Oral feeding by children with bronchiolitis on high-flow nasal cannula (HFNC) is questioned, resulting in high practice variability. Our objective was to determine the incidence of aspiration pneumonia and adverse feeding events in otherwise healthy children with bronchiolitis on HFNC who fed orally from admission.

METHODS

We conducted a single-center, retrospective chart review, in a tertiary children's hospital, of 876 children who were <24 months old, admitted for bronchiolitis, and treated with HFNC in the pediatric ward from March 2017 to May 2020. Primary outcomes included the incidence of aspiration pneumonia and adverse feeding events. Secondary outcomes included escalation of care, frequency and duration of nil per os status, length of stay, and 7-day readmission.

RESULTS

Most patients (77.2%) met inclusion criteria and were fed orally within 2 hours of admission. The average maximum HFNC flow rate was 8 L/min (1 L/kg/min); the average maximum respiratory rate was 62 ± 10. Adverse feeding events occurred in 11 patients (1.6%), of which 3 had a concern for possible microaspiration. None were diagnosed with or treated for aspiration pneumonia. Few patients (8.1%) were made nil per os while on HFNC but returned to oral feeding by discharge.

CONCLUSION

Among those with bronchiolitis on HFNC who received oral nutrition on admission, there were few incidences of adverse feeding events and no diagnoses of aspiration pneumonia, suggesting that oral feeding while on HFNC can be well-tolerated in similar populations. However, this study was limited by its single-center retrospective design, and future prospective studies are needed.

Respiratory Syncytial Virus is the Most Common Causative Agent of Viral Bronchiolitis in Young Children: An Updated Review

BACKGROUND

Viral bronchiolitis is a common condition and a leading cause of hospitalization in young children.

OBJECTIVE

This article provides readers with an update on the evaluation, diagnosis, and treatment of viral bronchiolitis, primarily due to RSV.

METHODS

A PubMed search was conducted in December 2021 in Clinical Queries using the key terms "acute bronchiolitis" OR "respiratory syncytial virus infection". The search included clinical trials, randomized controlled trials, case control studies, cohort studies, meta-analyses, observational studies, clinical guidelines, case reports, case series, and reviews. The search was restricted to children and English literature. The information retrieved from the above search was used in the compilation of this article.

RESULTS

Respiratory syncytial virus (RSV) is the most common viral bronchiolitis in young children. Other viruses such as human rhinovirus and coronavirus could be etiological agents. Diagnosis is based on clinical manifestation. Viral testing is useful only for cohort and quarantine purposes. Cochrane evidence-based reviews have been performed on most treatment modalities for RSV and viral bronchiolitis. Treatment for viral bronchiolitis is mainly symptomatic support. Beta-agonists are frequently used despite the lack of evidence that they reduce hospital admissions or length of stay. Nebulized racemic epinephrine, hypertonic saline and corticosteroids are generally not effective. Passive immunoprophylaxis with a monoclonal antibody against RSV, when given intramuscularly and monthly during winter, is effective in preventing severe RSV bronchiolitis in high-risk children who are born prematurely and in children under 2 years with chronic lung disease or hemodynamically significant congenital heart disease. Vaccines for RSV bronchiolitis are being developed. Children with viral bronchiolitis in early life are at increased risk of developing asthma later in childhood.

CONCLUSION

Viral bronchiolitis is common. No current pharmacologic treatment or novel therapy has been proven to improve outcomes compared to supportive treatment. Viral bronchiolitis in early life predisposes asthma development later in childhood.

Bolus Versus Continuous Nasogastric Feeds for Infants With Bronchiolitis: A Randomized Trial

BACKGROUND AND OBJECTIVES

Infants hospitalized with bronchiolitis are commenced on nasogastric feeding to maintain hydration. Feeding strategies vary according to physician or institution preference. The current study hypothesized that continuous nasogastric feeding would prolong length of stay (LOS) when compared to bolus feeding.

METHODS

A randomized, parallel-group, superiority clinical trial was performed within an Australian children's hospital throughout 2 bronchiolitis seasons from May 2018 to October 2019. Infants <12 months hospitalized with bronchiolitis and requiring supplemental nasogastric feeding were randomly assigned to continuous or bolus nasogastric regimens. LOS was the primary outcome. Secondary outcome measures included pulmonary aspirations and admissions to intensive care.

RESULTS

The intention-to-treat analysis included 189 patients: 98 in the bolus nasogastric feeding group and 91 in the continuous group. There was no significant difference in LOS (median LOS of the bolus group was 54.25 hours [interquartile range 40.25-82] and 56 hours [interquartile range 38-78.75] in the continuous group). A higher proportion of admissions to intensive care was detected in the continuous group (28.57% [26 of 91] of the continuous group vs 11.22% [11 of 98] of the bolus group [P value 0.004]). There were no clinically significant pulmonary aspirations or statistically significant differences in vital signs between the groups within 6 hours of feed initiation.

CONCLUSIONS

No significant difference in LOS was found between bolus and continuous nasogastric feeding strategies for infants hospitalized with bronchiolitis. The continuous feeding group had a higher proportion of intensive care admissions, and there were no aspiration events.

Nasogastric tube, a warning sign for high-flow nasal cannula failure in infants with bronchiolitis

High-flow nasal cannula (HFNC) therapy is routinely used in the treatment of infants with bronchiolitis. This study sought to identify markers associated with failure of HFNC therapy that serve as warnings for early staging of other ventilatory support products. A retrospective study of infants with a diagnosis of bronchiolitis, receiving HFNC and admitted to the pediatric intensive care unit from January 2016 to June 2017, was conducted. The subjects were divided into two study groups according to the success or failure of HFNC therapy. Risk factors were assessed using the following variables: age, time between hospital admission and start of HFNC, equipment model, and the need for a nasogastric tube. Eighty-one infants were studied, and 18 (21.7%) of them exhibited therapy failure. The results of the logistic models showed that the chances of failure for patients requiring a nasogastric tube during HFNC use were more likely than those for patients with oral nutrition (OR = 8.17; 95% CI 2.30–28.99; p = 0.001). The HFNC failure was not associated with the device used (OR = 1.56; 95% CI 0.54–4.52; p = 0.41), time between hospital admission and HFNC installation (OR = 1.01; 95% CI 0.98–1.03; p = 0.73), or age (OR = 0.98; 95% CI 0.82–1.17; p = 0.82). Among late outcomes evaluated, the patients with therapy failure had longer total durations of O₂ use (p < 0.001) and longer hospital stays (p < 0.001). The need to use a nasogastric tube during HFNC use was associated with HFNC therapy failure and can be considered as a marker of severity in children with bronchiolitis.

Nutritional management of young infants presenting with acute bronchiolitis in Belgium, France and Switzerland: survey of current practices and documentary search of national guidelines worldwide

Feeding difficulties are common in young infants presenting with acute bronchiolitis, but limited data is available to guide clinicians adapting nutritional management. We aimed to assess paediatricians' nutritional practices among Western Europe French speaking countries. A survey was disseminated to describe advice given to parents for at home nutritional support, in hospital nutritional management, and preferred methods for enteral nutrition and for intravenous fluid management. A documentary search of international guidelines was concomitantly conducted. Ninety-three (66%) contacted physicians responded. Feeding difficulties were a common indication for infants' admission. Written protocols were rarely available. Enteral nutrition was favoured most of the time when oral nutrition was insufficient and might be withheld in case of severe dyspnoea to decrease respiratory workload. Half of physicians were aware of hyponatremia risk and pathophysiology, and isotonic intravenous solutions were used in less than 15% of centres. International guideline search (23 countries) showed a lack of detailed nutritional management recommendations in most of them.Conclusion: practices were inconsistent among physicians. Guidelines detailed nutritional management poorly. Awareness of hyponatremia risk in relation to intravenous hypotonic fluids and of the safety of enteral hydration and nutrition is insufficient. New guidelines including detailed nutritional management recommendations are urgently needed. What is Known? • Infants presenting with acute bronchiolitis face feeding difficulties. • Underfeeding may promote undernutrition, and intravenous hydration with hypotonic fluids may induce hyponatremia. What is New? • Physicians' nutritional practices are inconsistent and awareness of hyponatremia risk and pathophysiology is insufficient among physicians. • Awareness of hyponatremia risk and pathophysiology is insufficient among physicians. • The reasons for enteral nutrition withholding in bronchiolitis infants are not evidence based, and national guidelines of acute bronchiolitis across the world are elusive regarding nutritional management. • National guidelines of acute bronchiolitis across the world are elusive regarding nutritional management.

Swallowing outcomes in children after slide tracheoplasty

INTRODUCTION

Slide tracheoplasty is now considered gold standard treatment for long segment congenital tracheal stenosis. Outcomes are typically focused upon airway patency. Dysphagia is often reported in children undergoing cardiothoracic surgery, but not specifically after slide tracheoplasty. This study was carried out to describe the nature and prevalence of dysphagia following slide tracheoplasty for long segment congenital tracheal stenosis.

METHODS

Retrospective case note review was conducted on a series of patients who underwent swallow evaluation following slide tracheoplasty between 2006 and 2014. A clinical swallow assessment was carried out by a Speech and Language Therapist with videofluoroscopic evaluation of swallowing where indicated. Logistic regression assessed the impact of gender, feeding history, weight, tracheal diameter, stenting and co-morbidities on the likelihood of having post-operative dysphagia.

RESULTS

43 out of 83 slide tracheoplasty patients underwent swallow evaluation. Dysphagia was identified in 30 (70%) of 43 patients. Videofluoroscopy was undertaken in 22 of these patients. All patients who had a videofluoroscopy presented with altered swallow physiology. Aspiration risk was confirmed in 15 patients with frank aspiration seen in 9. Pre-operative history of dysphagia was present in 9 patients. There were two cases of vocal fold palsy. The presence of a stent was the strongest predictor of post-operative dysphagia with an odds ratio of 10.6 (95% CI 1.2-92.8).

CONCLUSIONS

This study documents a high prevalence of post-operative dysphagia in a pediatric population following slide tracheoplasty. In most cases there was no history suggestive of dysphagia pre-operatively. Swallowing needs to be assessed after slide tracheoplasty and longitudinal studies are required.

Dysphagia and associated clinical markers in neurologically intact children with respiratory disease

OBJECTIVE

The identification of oropharyngeal aspiration is paramount since it can have negative consequences on a compromised respiratory status. Our hypothesis was that dysphagia in neurologically intact children with respiratory disease is associated to specific clinical markers.

STUDY DESIGN

Using the medical files we conducted a retrospective, observational cohort study on children admitted to the pediatric hospital unit due to respiratory disease. We collected data on specific parameters of a clinical swallowing assessment and dysphagia was classified according to the Dysphagia Management Staging Scale. We also included the following clinical markers: age, days of hospitalization, need for orotracheal intubation (OTI), duration of orotracheal intubation (in hours), number of previous hospital admissions due to respiratory disease, number of previous hospital admissions due to other causes, and previous orotracheal intubations.

RESULTS

The final study sample consisted of 102 patients (mean age of 5.88 months). For the purposes of statistical analysis, the patients were grouped according to the classification of dysphagia (ie, no dysphagia, mild dysphagia, and moderate-severe dysphagia). Data analysis indicated that the clinical markers of orotracheal intubation (P = 0.042), duration of orotracheal intubation (P = 0.025), and days of hospitalization (P = 0.037) were significant in children with moderate-severe dysphagia.

CONCLUSIONS

Our data indicate that neurologically intact children with respiratory disease who were submitted to prolonged OTI (ie, over 48 h) should be prioritized for receiving a detailed swallowing assessment.

Nutrition and High-Flow Nasal Cannula Respiratory Support in Children With Bronchiolitis

OBJECTIVES

No guidelines are available regarding initiation of enteral nutrition in children with bronchiolitis on high-flow nasal cannula (HFNC) support. We hypothesized that the incidence of feeding-related adverse events (AEs) would not be associated with HFNC support.

METHODS

This retrospective study included children ≤24 months old with bronchiolitis receiving HFNC in a PICU from September 2013 through April 2014. Data included demographics, respiratory support during feeding, and feeding-related AEs. Feeding-related AEs were extracted from nursing documentation and defined as respiratory distress or emesis. Feed route and maximum HFNC delivery were recorded in 8-hour shifts (6 am-2 pm, 2 pm-10 pm, and 10 pm-6 am).

RESULTS

70 children were included, with a median age of 5 (interquartile range [IQR] 2-10) months. HFNC delivery at feed initiation varied widely, and AEs related to feeding occurred rarely. Children were fed in 501 of 794 (63%) of nursing shifts, with AEs documented in only 29 of 501 (5.8%) of those shifts. The incidence of AEs at varying levels of respiratory support did not differ (P = .092). Children in the "early feeding" (fed within first 2 shifts) group (n = 22) had a shorter PICU length of stay (2.2 days [IQR 1.4-3.9] vs 3.2 [IQR 2.5-5.3], P = .006) and shorter duration of HFNC use (26.0 hours [IQR 15.8-57.0] vs 53.5 [IQR 37.0-84.8], P = .002), compared with children in the "late feeding" group (n = 48).

CONCLUSIONS

In this small, single-institution patient cohort, feeding-related AEs were rare and not related to the delivered level of respiratory support.

Nutritional status, metabolic state and nutrient intake in children with bronchiolitis

Nutrition has a coadjuvant role in the management of children with acute diseases. We aimed to examine nutritional status, macronutrient requirements and actual macronutrient delivery in bronchiolitis. The nutritional status was classified according to WHO criteria and resting energy expenditure (MREE) was measured using an indirect calorimeter. Bland-Altman analysis was used to examine the agreement between MREE and estimated energy expenditure (EEE) with standard equations. Based on the ratio MREE/EEE in relation to Schofield equation on admission, we defined the subjects' metabolic status. A total of 35 patients were enrolled and 46% were malnourished on admission, and 25.8% were hypermetabolic, 37.1% hypometabolic and 37.1% normometabolic. We performed a 24-h recall in 10 children and 80% were overfed (AEI: MREE >120%). Mean bias (limits of agreement) with MREE was 8.9 (-73.9 to 91.8%) for Schofield; 61.0 (-41 to 163%) for Harris-Benedict; and 9.9 (-74.4 to 94.2%) for FAO-WHO equation. Metabolism of infants with bronchiolitis is not accurately estimated by equations.

[Clinical signs of dysphagia in infants with acute viral bronchiolitis]

Objective:

To determine the occurrence of clinical signs of dysphagia in infants with acute viral bronchiolitis, to compare the respiratory parameters during deglutition, and to ensure the intra- and inter- examiners agreement, as well as to accomplish intra and interexaminators concordance of the clinical evaluation of the deglutition.

Methods:

This was a cross-sectional study of 42 infants aged 0-12 months. The clinical evaluation was accompanied by measurements of respiratory rate and pulse oximetry. A score of swallowing disorders was designed to establish associations with other studied variables and to ensure the intra- and interrater agreement of clinical feeding assessments. Caregivers also completed a questionnaire about feeding difficulties. Significance was set at p<0.05.

Results:

Changes in the oral phase (prolonged pauses) and pharyngeal phase (wheezing, coughing and gagging) of swallowing were found. A significant increase in respiratory rate between pre- and post-feeding times was found, and it was determined that almost half of the infants had tachypnea. An association was observed between the swallowing disorder scores and a decrease in oxygen saturation. Infants whose caregivers reported feeding difficulties during hospitalization stated a significantly greater number of changes in the swallowing evaluation. The intra-rater agreement was considered to be very good.

Conclusions:

Infants with acute viral bronchiolitis displayed swallowing disorders in addition to changes in respiratory rate and measures of oxygen saturation. It is suggested, therefore, that infants displaying these risk factors have a higher probability of dysphagia.

Clinical practice guideline: the diagnosis, management, and prevention of bronchiolitis

This guideline is a revision of the clinical practice guideline, "Diagnosis and Management of Bronchiolitis," published by the American Academy of Pediatrics in 2006. The guideline applies to children from 1 through 23 months of age. Other exclusions are noted. Each key action statement indicates level of evidence, benefit-harm relationship, and level of recommendation. Key action statements are as follows:

[Food intake during the previous 24h as a percentage of usual intake: a marker of hypoxia in infants with bronchiolitis: an observational, prospective, multicenter study]

BACKGROUND

Hypoxia associated with bronchiolitis is not always easy to assess on clinical grounds alone. The aim of this study was to determine the value of food intake during the previous 24h (bottle and spoon feeding), as a percentage of usual intake (24h FI), as a marker of hypoxia, and to compare its diagnostic value with that of usual clinical signs.

METHODS

In this observational, prospective, multicenter study, 18 community pediatricians, enrolled 171 infants, aged from 0 to 6 months, with bronchiolitis (rhinorrhea+dyspnea+cough+expiratory sounds). Infants with risk factors (history of prematurity, chronic heart or lung disorders), breast-fed infants, and infants having previously been treated for bronchial disorders were excluded. The 24h FI, subcostal, intercostal, supracostal retractions, nasal flaring, respiratory rate, pauses, cyanosis, rectal temperature and respiratory syncytial virus test results were noted. The highest stable value of transcutaneous oxygen saturation (SpO2) was recorded. Hypoxia was noted if SpO2 was below 95% and verified.

RESULTS

24h FI greater or equal to 50% was associated with a 96% likelihood of SpO2 greater or equal to 95% [95% CI, 91-99%]. In univariate analysis, 24h FI less than 50% had the highest odds ratio (13.8) for SpO2 less than 95%, compared to other 24h FI values and other clinical signs, as well as providing one of the best compromises between specificity (90%) and sensitivity (60%) for identifying infants with hypoxia. In multivariate analysis with adjustment for age, SpO2 less than 95% was related to the presence of intercostal retractions (OR=9.1 [95% CI, 2.4-33.8%]) and 24h FI less than 50% (OR=10.9 [95% CI, 3.0-39.1%]). Hospitalization (17 infants) was strongly related to younger age, 24h FI and intercostal retractions.

CONCLUSION

In practice, the measure of 24h FI may be useful in identifying hypoxia and deserves further study.

Food intake during the previous 24 h as a percentage of usual intake: a marker of hypoxia in infants with bronchiolitis: an observational, prospective, multicenter study

Background

Hypoxia associated with bronchiolitis is not always easy to assess on clinical grounds alone. The aim of this study was to determine the value of food intake during the previous 24 hours (bottle and spoon feeding), as a percentage of usual intake (24h FI), as a marker of hypoxia, and to compare its diagnostic value with that of usual clinical signs.

Methods

In this observational, prospective, multicenter study, 18 community pediatricians, enrolled 171 infants, aged from 0 to 6 months, with bronchiolitis (rhinorrhea + dyspnea + cough + expiratory sounds). Infants with risk factors (history of prematurity, chronic heart or lung disorders), breast-fed infants, and infants having previously been treated for bronchial disorders were excluded.

The 24h FI, subcostal, intercostal, supracostal retractions, nasal flaring, respiratory rate, pauses, cyanosis, rectal temperature and respiratory syncytial virus test results were noted. The highest stable value of transcutaneous oxygen saturation (SpO2) was recorded. Hypoxia was noted if SpO2 was below 95% and verified.

Results

24h FI ≥ 50% was associated with a 96% likelihood of SpO2 ≥ 95% [95% CI, 91–99]. In univariate analysis, 24h FI < 50% had the highest odds ratio (13.8) for SpO2 < 95%, compared to other 24h FI values and other clinical signs, as well as providing one of the best compromises between specificity (90%) and sensitivity (60%) for identifying infants with hypoxia. In multivariate analysis with adjustment for age, SpO2 < 95% was related to the presence of intercostal retractions (OR = 9.1 [95% CI, 2.4-33.8%]) and 24h FI < 50% (OR = 10.9 [95% CI, 3.0-39.1%]). Hospitalization (17 infants) was strongly related to younger age, 24h FI and intercostal retractions.

Conclusion

In practice, the measure of 24 h FI may be useful in identifying hypoxia and deserves further study.

Effects of nasal continuous positive-airway pressure on nutritive swallowing in lambs

Current knowledge suggests that, to be successful, oral feeding in preterm infants should be initiated as soon as possible, often at an age where immature respiration still requires ventilatory support in the form of nasal continuous positive airway pressure (nCPAP). While some neonatologist teams claim great success with initiation of oral feeding in immature infants with nCPAP, others strictly wait for this ventilatory support to be no longer necessary before any attempt at oral feeding, fearing laryngeal penetration and tracheal aspiration. Therefore, the aim of the present study was to provide a first assessment of the effect of various levels of nCPAP on bottle-feeding in a neonatal ovine model, including feeding safety, feeding efficiency, and nutritive swallowing-breathing coordination. Eight lambs born at term were surgically instrumented 48 h after birth to collect recordings of electrical activity of laryngeal constrictor muscle, electrocardiography, and arterial blood gases. Two days after surgery, lambs were bottle-fed under five randomized nCPAP conditions, including without any nCPAP or nasal mask and nCPAP of 0, 4, 7, and 10 cmH(2)O. Results revealed that application of nCPAP in the full-term lamb had no deleterious effect on feeding safety and efficiency or on nutritive swallowing-breathing coordination. The present study provides a first and unique insight on the effect of nCPAP on oral feeding, demonstrating its safety in newborn lambs born at term. These results open the way for further research in preterm lambs to better mimic the problems encountered in neonatology.

Central pattern generation involved in oral and respiratory control for feeding in the term infant

PURPOSE OF REVIEW

Drinking and eating are essential skills for survival and benefit from the coordination of several pattern generating networks and their musculoskeletal effectors to achieve safe swallows. Oralpharyngoesophageal motility develops during infancy and early childhood, and is influenced by various factors, including neuromuscular maturation, dietary and postural habits, arousal state, ongoing illnesses, congenital anomalies, and the effects of medical or surgical interventions. Gastroesophageal reflux is frequent in neonates and infants, and its role in neonatal morbidity including dysphagia, chronic lung disease, or apparent life-threatening events is not well understood. This review highlights recent studies aimed at understanding the development of oral feeding skills, and cross-system interactions among the brainstem, spinal, and cerebral networks involved in feeding.

RECENT FINDINGS

Functional linkages between suck-swallow and swallow-respiration manifest transitional forms during late gestation through the first year of life, which can be delayed or modified by sensory experience or disease processes, or both. Relevant central pattern generator (CPG) networks and their neuromuscular targets attain functional status at different rates, which ultimately influences cross-system CPG interactions. Entrainment of trigeminal primary afferents accelerates pattern genesis for the suck CPG and transition-to-oral feed in the RDS preterm infant.

SUMMARY

The genesis of within-system CPG control for rate and amplitude scaling matures differentially for suck, mastication, swallow, and respiration. Cross-system interactions among these CPGs represent targets of opportunity for new interventions, which optimize experience-dependent mechanisms to promote safe swallows among newborn and pediatric patients.

The First Year of Human Life: Coordinating Respiration and Nutritive Swallowing

This study provides the first documented report of the maturation of breathing-swallowing coordination during feeding in ten healthy term human infants through the first year of life. A total of 15,073 swallows were obtained across ten assessments between 48 h and 12 months of age. Midexpiratory swallows represented the dominant pattern of breathing-swallowing coordination within the first 48 h (mean = 45.4%), but the prevalence of this pattern declined rapidly in the first week to 29.1% (p = 0.012). Inspiratory-expiratory swallows increased with age (p < 0.001), particularly between 9 (37.0%) and 12 months (50.4%). Between 72.6% and 75.0% of swallows were followed by expiration in the latter 6 months, which is an adult-like characteristic. These data suggest that while postswallow expiration is a robust feature of breathing-swallowing coordination from birth, two major shifts in the precise patterns occur: the first after 1 week of postnatal feeding experience and the second between 6 and 12 months, most likely due to neural and anatomical maturation.

Nutritive and non-nutritive swallowing apnea duration in term infants: implications for neural control mechanisms

The impact of bolus ingestion and level of consciousness on swallowing apnea duration (SAD) in healthy term infants has not been adequately explored despite the likely contribution of swallowing apnea to upper airway protection against aspiration. SAD during wakefulness, sleep, and feeding (breast or bottle) of 10 term infants was measured 10 times from birth to 1 year of age. Nineteen thousand four hundred and two swallows were analyzed. Irrespective of age, SAD during feeding was significantly shorter than SAD of non-nutritive swallowing (during wakefulness and sleep). SAD did not change significantly within the first year of life in any of the three conditions and there was no change in the relative durations of nutritive, wake and sleep conditions with age. The absence of an age effect implies that the neural mechanisms controlling SAD are fundamentally brainstem-mediated and largely hard-wired at birth in healthy term neonates.

Current treatment for acute viral bronchiolitis in infants

This paper provides an update and critical review of available data on the treatment of acute viral bronchiolitis in previously healthy infants, with special focus on new or promising therapies. The main potential benefits of medical assistance in these patients reside in the careful monitoring of their clinical status, the maintenance of adequate hydration and oxygenation, the preservation of the airway opened and cleared of secretions and the option to perform parental education. There is no convincing evidence that any other form of therapy will reliably provide beneficial effects in infants with bronchiolitis and currently, any treatment beyond supportive care should be prescribed on a case-by-case basis with watchful appraisal of its effects. Therapies such as ribavirin, IFN, vitamin A, antibiotics, mist therapy or anticholinergics, have not demonstrated any measurable clinical effect. Several studies and meta-analyses with beta(2)-agonists and corticosteroids have failed to show any benefit of significant extent, however, physicians keep favouring their use. Presently, adrenaline has received rather consistent support from clinical trials but it is not yet widely prescribed. There are other therapeutic strategies, for instance, heliox, hypertonic saline, noninvasive ventilation, physical therapy techniques, thickened feeds or palivizumab that have shown promising potential benefits, but evidence supporting its use is still limited and further studies should be warranted. In the meantime, infants with acute viral bronchiolitis should be treated following evidence-based clinical practice guidelines, keeping the patient central in the process and being sensitive to social, cultural and familiar influences on their treatment strategy.

Influence of sleep state on frequency of swallowing, apnea, and arousal in human infants

Apnea and arousal are modulated with sleep stage, and swallowing may interfere with respiratory rhythm in infants. We hypothesized that swallowing itself would display interaction with sleep state. Concurrent polysomnography and measurement of swallowing allowed time-matched analysis of 3,092 swallows, 482 apneas, and 771 arousals in 17 infants aged 1-34 wk. The mean rates of swallowing, apnea, and arousal were significantly different, being 23.3 +/- 8.5, 9.4 +/- 8.8, and 15.5 +/- 10.6 h(-1), respectively (P < 0.001 ANOVA). Swallows occurred before 25.2 +/- 7.9% and during 74.8 +/- 6.3% of apneas and before 39.8 +/- 6.0% and during 60.2 +/- 6.0% of arousals. The frequencies of apneas and arousals were both strongly influenced by sleep state (active sleep > indeterminate > quiet sleep, P < 0.001), whether or not the events coincided with swallowing, but swallowing rate showed minimal independent interaction with sleep state. Interactions between swallowing and sleep state were predominantly influenced by the coincidence of swallowing with apnea or arousal.