Infants with viral bronchiolitis demonstrate two distinct patterns of nocturnal oxyhaemoglobin desaturation

Frequency, Timing, Risk Factors, and Outcomes of Desaturation in Infants With Acute Bronchiolitis and Initially Normal Oxygen Saturation

IMPORTANCE

Little is known about the natural course of oxygen desaturation in acute bronchiolitis. Information on risk factors associated with desaturation as well as the time to desaturation in infants with bronchiolitis could help physicians better treat these infants before deciding whether to hospitalize them.

OBJECTIVE

To prospectively determine the frequency of desaturation in infants with bronchiolitis, along with the time to desaturation and risk factors associated with desaturation, and to compare infants who were hospitalized with those discharged home and evaluate risk factors for rehospitalization.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted during the 2017 to 2018 and 2018 to 2019 respiratory syncytial virus seasons in a tertiary care pediatric emergency department in Switzerland. Included individuals were 239 otherwise-healthy infants aged younger than 1 year, diagnosed with acute bronchiolitis and oxygen saturation of 90% or more on arrival. Data were analyzed from July 2019 to October 2020.

EXPOSURES

After receiving triage care, study participants admitted to the emergency department were equipped with a pulse oximeter to continuously record oxygen saturation (Spo2 levels), regardless of subsequent hospitalization or discharge home.

MAIN OUTCOMES AND MEASURES

The primary outcome was desaturation (ie, Spo2 < 90%) during the first 36 hours.

RESULTS

Of 239 infants enrolled, with a median (interquartile range [IQR]) age of 3.9 (1.5-6.5) months, 116 (48.5%) were boys and desaturation occurred in 165 infants (69.0%). Median (IQR) time to desaturation was 3.6 (1.8-9.4) hours. The rate of desaturation was similar between infants hospitalized and those discharged home (137 of 200 infants [68.5%] vs 28 of 39 infants [71.8%]; difference, -3.3%; 95% CI, -18.8% to 12.2%; P = .85). A more severe initial clinical presentation with moderate or severe retractions was the only independent risk factor associated with desaturation (odds ratio, 2.73; 95% CI, 1.49 to 5.02; P = .001). Of 39 infants discharged home, 22 infants (56.4%) experienced major desaturations. However, infants with desaturations, including those with major desaturations, had rates of rehospitalization similar to those of infants without desaturations (8 of 28 infants [28.5%] vs 3 of 11 infants [27.3%]; difference, 1.2%; 95% CI, -29.9% to 32.5; P > .99).

CONCLUSIONS AND RELEVANCE

These findings suggest that rates of desaturation in infants with acute bronchiolitis were high and similar between infants who were hospitalized and those discharged home. A more severe initial clinical presentation was the only risk factor associated with desaturation. However, for infants discharged home, desaturation was not a risk factor associated with rehospitalization.

Decision-making in acute viral bronchiolitis: A universal guideline and a publication gap

Background

Acute viral bronchiolitis is very common in infants and children up to 2 years. Some patients develop serious respiratory symptoms and need to be hospitalized. In 2014, the American Academy of Pediatrics (AAP) published a guideline on acute bronchiolitis which has gained global acceptance. We hypothesized that a publication gap, which is increasingly perceived in clinical medicine, might have also affected these universal recommendations.

Methods

We determined the proportion of published and unpublished studies registered at ClinicalTrials.gov that were marked as completed by October 1^st 2018. The major trial and literature databases were used to search for publications. In addition, the study investigators were contacted directly.

Results

Of the 69 registered studies on the treatment of acute viral bronchiolitis, only 50 (72%) have been published by November 2019. Published trials contained data from n = 9403 patients, whereas n = 4687 patients were enrolled in unpublished trials. Median time to publication was 20 months, and only 8 of 50 trials were published within 12 months after completion. Only 40% of the clinical trials that were completed after the release of the AAP guideline were subsequently published as compared to 80% before 2014.

Conclusion

There is a significant publication gap regarding therapy of acute viral bronchiolitis that may have influenced certain recommendations of the AAP guideline. In turn, recommendations of the guideline might have discouraged investigators to publish their results after its release.

Nocturnal oximetry in children with obstructive lung disease or sleep-disordered breathing

OBJECTIVES

Although progress has been made in the standardized interpretation of nocturnal oximetry in children with obstructive sleep-disordered breathing (SDB), no evidence exists on oximetry abnormalities in other respiratory disorders. We aimed to compare obstructive lung disease (OLD) and SDB regarding nocturnal oximetry parameters.

METHODS

We analyzed oximetry recordings from children with (i) OLD (obliterative bronchiolitis; cystic fibrosis); (ii) snoring and adenotonsillar hypertrophy (SDB); and (iii) no respiratory disorder (controls). The three groups were compared regarding: (i) oxygen desaturation of hemoglobin index (SpO₂ drops ≥3%/h-ODI3) and (ii) basal SpO₂ (average SpO₂ between SpO₂ drops). The associations of oximetry parameters (natural logarithm) with study group were tested using linear regression including age as covariate.

RESULTS

Data of 16 subjects with OLD (median age: 7.3 years; Q25, Q75: 5.4, 12), 22 children with SDB (6.3 years; 4, 9) and 22 controls (6.8 years; 5.6, 10.3) were analyzed. Children with OLD or SDB had significantly lower basal SpO₂ than controls (91.9% [90.8, 93.4] vs 96.3% [96, 97.4] vs 97.6% [97.1, 97.9]; P < 0.01). No subjects in the SDB or control groups had basal SpO₂  < 95%. Children with SDB had significantly higher ODI3 than children with OLD or controls [8.4 episodes/h (6.2, 16.6) vs 4.4 episodes/h (3.6, 6.6) vs 2 episodes/h (1.3, 2.7); P < 0.01]. OLD had the greatest negative effect on basal SpO₂ (R²  = 0.62; P < 0.001) and SDB the greatest positive effect on ODI3 (R²  = 0.34; P < 0.001).

CONCLUSION

OLD is associated mostly with reduced basal SpO₂ , whereas SDB is characterized by elevated ODI3.

Australasian bronchiolitis guideline

AIM

Bronchiolitis is the most common lower respiratory tract disorder in infants aged less than 12 months, and research has demonstrated that there is substantial variation in practice patterns despite treatment being well defined. In order to align and improve the consistency of the management of bronchiolitis, an evidence-based guideline was developed for the Australasian population.

METHODS

The guideline development committee included representation from emergency and paediatric specialty medical and nursing personnel in addition to geographical representation across Australia and New Zealand - rural, remote and metropolitan. Formulation of the guideline included identification of population, intervention, comparator, outcomes and time questions and was associated with an extensive literature search from 2000 to 2015. Evidence was summarised and graded using the National Health and Medical Research Council and Grading of Recommendations Assessment, Development and Evaluation methodology, and consensus within the guideline group was sought using nominal group technique principles to formulate the clinical practice recommendations. The guideline was reviewed and endorsed by key paediatric health bodies.

RESULTS

The guideline consists of a usable clinical interface for bedside functionality supported by evidence summary and tables. The Grading of Recommendations Assessment, Development and Evaluation and National Health and Medical Research Council processes provided a systematic and transparent process to review and assess the literature, resulting in a guideline that is relevant to the management of bronchiolitis in the Australasian setting.

CONCLUSION

This is the first robust Australasian acute paediatric guideline and provides clear guidance for the management of the vast majority of patients seen in Australasian emergency departments and general paediatric wards with bronchiolitis.

A graphical method for comparing nocturnal oxygen saturation profiles in individuals and populations: Application to healthy infants and preterm neonates

STUDY OBJECTIVES

Pulse-oximetry (SpO₂ ) allows the identification of important clinical physiology. However, summary statistics such as mean values and desaturation incidence do not capture the complexity of the information contained within continuous recordings. The aim of this study was to develop an objective method to quantify important SpO₂ characteristics; and assess its utility in healthy infant and preterm neonate cohorts.

METHODS

An algorithm was developed to calculate the desaturation incidence, depth, and duration. These variables are presented using three plots: SpO₂ cumulative-frequency relationship; desaturation-depth versus incidence; desaturation-duration versus incidence. This method was applied to two populations who underwent nocturnal pulse-oximetry: (1) thirty-four healthy term infants studied at 2-weeks, 3, 6, 12, and 24-months of age and (2) thirty-seven neonates born <26 weeks and studied at discharge from NICU (37-44 weeks post-conceptual age).

RESULTS

The maturation in healthy infants was characterized by reduced desaturation index (27.2/h vs 3.3/h at 2-weeks and 24-months, P < 0.01), and increased percentage of desaturation events ≥6-s in duration (27.8% vs 43.2% at 2-weeks and 3-months, P < 0.01). Compared with term-infants, preterm infants had a greater desaturation incidence (54.8/h vs 27.2/h, P < 0.01), and these desaturations were deeper (52.9% vs 37.6% were ≥6% below baseline, P < 0.01). The incidence of longer desaturations (≥14-s) in preterm infants was correlated with healthcare utilization over the first 24-months (r = 0.63, P < 0.01).

CONCLUSIONS

This tool allows the objective comparison of extended oximetry recordings between groups and for individuals; and serves as a basis for the development of reference ranges for populations.

Sleep disordered breathing and sleep quality in children with bronchiolitis obliterans

The incidence of sleep-disordered breathing (SDB) increases in chronic lung diseases. Our aim was to evaluate SDB and sleep quality in children with postinfectious bronchiolitis obliterans (BO) and assess associated risk factors. We hypothesized that children with BO are at increased risk for SDB and have impaired sleep quality. We also hypothesized that severity of SDB and impairment of sleep quality is related to the severity of lung disease. Sleep Related Breathing Disorder (SRBD) subscale of the Pediatric Sleep Questionnaire (PSQ) and Pittsburgh Sleep Quality Index (PSQI) questionnaires; spirometry, impulse oscillometry (IOS), and overnight polysomnography (PSG) were performed. Twenty-one patients (14 male, median age: 8.3 years) were enrolled. Five patients (25%) had a PSQ score of >0.33, predictive of a SDB. Ten patients (48%) had poor sleep quality. Four patients (19%) had an OAHI of >1/hr. Nineteen patients (90%) had a high desaturation index. Four patients (19%) had a mean oxygen saturation of <93%. Median central apnea time was 7.5 (IQR: 6.9-9.1) seconds. Central apnea index of the patients correlated positively with R5, R10, R15, R20, Z5, and negatively with X10 and X15 at IOS. There was a positive correlation between the lowest oxygen saturation and FVC, FEV1 , X5, X10, X15, X20 while there was a negative correlation between lowest saturation and the central apnea index at PSG, R5, R10, and Z5 at IOS. Mean oxygen saturation during PSG correlated positively with FVC, FEV1, FEF(25-75), X5, X10, X15, X20 results. The risk of nocturnal hypoxia is increased in patients with BO and correlated to the severity of lung disease determined by pulmonary function tests. Although BO patients have a shorter duration of central apneas, they are more prone to desaturate.