For patients hospitalized with bronchiolitis, many hospitals have implemented clinical practice guidelines to decrease variability in care. Our hospital updated its bronchiolitis clinical pathway by lowering goal oxygen saturation from 90% to 88%. We compared clinical outcomes before and after this change within the context of the pathway update.
This was a retrospective analysis of patients <24 months old admitted to a pediatric tertiary care center from 2019 to 2021 with bronchiolitis. Patients with congenital heart disease, asthma, home oxygen, or admitted to an ICU were excluded. The data were stratified for patients admitted before and after the clinical pathway update. Statistical methods consisted of 2 group comparisons using the χ-square test for categorical variables, the Wilcoxon rank-sum test for continuous variables, and multiple regression analysis.
A total of 1386 patients were included, 779 preupdate and 607 postupdate. There was no statistically significant difference in the admission rate of patients presenting to the emergency department with bronchiolitis between the 2 groups (P value .60). The median time to room air was 40.0 hours preupdate versus 30.0 hours postupdate (P value < .001). The median length of stay was 48.0 hours preupdate versus 41.0 hours postupdate (P value < .001). Readmission rate was 2.7% within 7 days of discharge preupdate, and 2.1% postupdate (P value .51).
Decreasing goal oxygen saturation to 88% was associated with a statistically significant decrease in time spent on oxygen and length of stay for patients admitted with bronchiolitis with no increase in readmissions.
Bronchiolitis is the most common cause of lower respiratory infections in young children. It is characterized by acute inflammation, edema, and necrosis of epithelial cells lining small airways, increased mucous production, and bronchospasms.1 More often than not, bronchiolitis can be managed conservatively at home with limited therapeutic interventions required, aside from supportive care. Reasons for hospitalization include need for supplemental oxygen, frequent nasal suctioning, rehydration, and concern for impending respiratory failure.2
For patients requiring hospitalization, clinical practice guidelines and pathways have been designed to improve the management of bronchiolitis, decrease use of unnecessary interventions, and help providers develop disease-specific best practices.3–5 Bryan et al demonstrated an association between shorter lengths of stay and lower costs for patients with improved adherence to bronchiolitis clinical pathways across both inpatient and emergency department settings.4
In 2014, the American Academy of Pediatrics released a revision of the 2006 clinical practice guideline for the management of bronchiolitis. Key action statement 6a stated, “Clinicians may choose not to administer supplemental oxygen if the oxyhemoglobin saturation exceeds 90% in infants and children with a diagnosis of bronchiolitis.” It did not, however, provide evidence to support a specific oxygen saturation cut-off requiring supplemental oxygen.6
Transient oxygen desaturations often occur in healthy infants, particularly during sleep.7,8 In fact, even children who suffer from intermittent hypoxemia from diseases such as asthma have not been shown to have impaired intellectual abilities or behavioral disturbances long term.9–11 In a prospective study of the frequency and degree of hypoxemia in patients with bronchiolitis managed as outpatients, the majority (64%) of infants discharged from the hospital with bronchiolitis experienced episodes of desaturations, defined as oxygen saturation (Spo2) <90% for at least 1 minute. These patients were not more likely to experience an unscheduled medical visit or readmission than infants without desaturations.12 Despite these findings, we have been unable to identify literature describing the impact on short-term clinical outcomes of lowering the goal oxygen saturation for providing supplemental oxygen below 90% in the inpatient setting.
In November 2020, our tertiary care children’s hospital updated its bronchiolitis clinical pathway, including lowering the goal oxygen saturation for providing supplemental oxygen from 90% to 88%. The objective of this study was to compare clinical outcomes before and after lowering the goal oxygen saturation from 90% to 88%, within the context of our bronchiolitis clinical pathway update.
Methods
Study Design and Population
We conducted a retrospective chart review of patients admitted to the general pediatric floor with a diagnosis of bronchiolitis and managed on our institution’s bronchiolitis pathway between November 2019 and December 2021. The study site is a free-standing children’s hospital with 433 beds and approximately 20 000 annual admissions. The hospital is located 1000 feet above sea level. Bronchiolitis is primarily managed by the hospital medicine service (including resident “teach” teams as well as attending-only services), and high flow nasal cannula is only administered in the ICU. This study was approved by our hospital’s institutional review board.
Patients less than 24 months of age with a discharge diagnosis of bronchiolitis, identified by International Classification of Diseases, 10th Revision (ICD-10) codes, were included in our study. Qualifying ICD-10 codes are listed in Table 1. Both inpatient and observation visit types were included.
ICD-10 Codes
ICD-10 Codes . | |
---|---|
Discharge diagnosis of bronchiolitis | |
J 21.0 | Acute bronchiolitis caused by respiratory syncytial virus |
J 21.1 | Acute bronchiolitis caused by human metapneumovirus |
J 21.8 | Acute bronchiolitis caused by other specified organisms |
J 21.9 | Acute bronchiolitis, unspecified |
Congenital heart disease | |
Q 213 | Tetralogy of Fallot |
Q 251 | Coarctation of the aorta |
Q 225 | Ebstein anomaly |
Q 234 | Hypoplastic left heart syndrome |
Q 262 | Total anomalous pulmonary venous connection (return) |
Q 203 | Discordant ventriculoarterial connection (transposition of the great vessels) |
Q 200 | Common arterial trunk (truncus arteriosus) |
Home oxygen | |
Z 9981 | Dependence on supplemental oxygen |
Asthma diagnosis | |
J 45.20-J 45.2998 |
ICD-10 Codes . | |
---|---|
Discharge diagnosis of bronchiolitis | |
J 21.0 | Acute bronchiolitis caused by respiratory syncytial virus |
J 21.1 | Acute bronchiolitis caused by human metapneumovirus |
J 21.8 | Acute bronchiolitis caused by other specified organisms |
J 21.9 | Acute bronchiolitis, unspecified |
Congenital heart disease | |
Q 213 | Tetralogy of Fallot |
Q 251 | Coarctation of the aorta |
Q 225 | Ebstein anomaly |
Q 234 | Hypoplastic left heart syndrome |
Q 262 | Total anomalous pulmonary venous connection (return) |
Q 203 | Discordant ventriculoarterial connection (transposition of the great vessels) |
Q 200 | Common arterial trunk (truncus arteriosus) |
Home oxygen | |
Z 9981 | Dependence on supplemental oxygen |
Asthma diagnosis | |
J 45.20-J 45.2998 |
Patients initially admitted to an ICU or the hematology and oncology service were excluded. Additionally, patients on home oxygen, with an existing diagnosis of asthma, or with a history of congenital heart disease were excluded (Table 1).
Clinical Pathway
In November 2008, our institution created a bronchiolitis clinical pathway to help standardize care and align with the 2006 American Academy of Pediatrics evidence-based guidelines. In early 2020, a multidisciplinary task group revised and updated the clinical pathway and electronic medical record (EMR) order set, including decreasing the goal oxygen saturation level from 90% to 88%. Education regarding this change was provided to nurses, physicians, respiratory therapists, and other providers during the rollout process. Stakeholders were also reminded of other unchanged features of the pathway, such as transitioning patients from continuous to intermittent pulse oximetry when on room air, recommending using the associated order set in the electronic health record to streamline care, and reminding staff about appropriate discharge criteria.
The changes were approved in November 2020 by our institution’s Clinical Effectiveness Committee, which is led by the chief medical officer and made up of a diverse group of subspecialists including representatives from emergency medicine, hospital medicine, pulmonology, and critical care. Education of providers and key stakeholders regarding the updated clinical pathway and EMR order set was completed by the end of 2020. The updated pathway was uploaded to our institution’s clinical pathway Web site, which is accessible to all trainees and providers (Appendix A).
For data analysis, the preupdate cohort was defined as data collected from November 2019 to November 17, 2020. This included patients managed on the original clinical pathway who met our study’s inclusion criteria. The postupdate cohort was defined as data collected from November 18, 2020 to December 2021. This included patients managed on the updated clinical pathway who met our study’s inclusion criteria.
Data Collection
Patients who met the study’s inclusion criteria were identified via a bronchiolitis pathway data dashboard, which was created in November 2019 by our institution’s quality and Information Technology departments for the purpose of monitoring ongoing quality improvement efforts related to bronchiolitis. Metrics captured by the dashboard include patient medical record number, number of admissions, length of stay in hours, number of transfers to the ICU, hours on room air before discharge, and number of readmissions to the hospital at 7 days to an acute care floor. Additional demographic characteristics for each patient were collected via manual chart review of the EMR using the medical record number obtained from the dashboard and included patient’s age in months at discharge, gender, race, and insurance.
Statistical Analysis
The data were summarized using frequencies and proportions for categorical variables and median, interquartile ranges for continuous variables. Group comparisons were conducted using the χ-square test for categorical variables, the Wilcoxon rank-sum test for continuous variables, and 95% confidence intervals for the differences between proportions and medians. Multiple regression analysis was used to account for the effects of age, race, and insurance and provide adjusted estimates for the differences. Based on a fixed sample size of 1386 patients (779 preupdate and 607 postupdate), the study was powered to detect a difference in proportion of 6% in the admission rate between the preupdate versus postupdate groups, a difference of 2.4 hours in time to room air and a difference of 2.3 hours in length of stay, given a type I error rate α = 0.05 and a type II error rate β = 20% corresponding to a power of 80%. Power calculations were performed based on a 2-sided χ squared test and the statistical significance level was set at 0.05. Statistical analyses were performed using the statistical software package SAS 9.4 (SAS Institute, Cary, NC).
Results
A total of 1386 unique patients were included, 779 preupdate and 607 postupdate (Fig 1). Small but statistically significant differences were noted for age, race, and insurance type (Table 2).
Patient Demographics
. | Preupdate (N = 779), n (%) . | Postupdate (N = 607), n (%) . | P . |
---|---|---|---|
Gender | .66 | ||
Male | 418 (53.7) | 333 (54.9) | |
Female | 361 (46.3) | 274 (45.1) | |
Patient’s age in months (median [IQR]) | 5.0 (10.0) | 7.0 (12) | .0031 |
Race | .0002 | ||
White or Caucasian | 338 (43.4) | 281 (46.3) | |
Hispanic or Latino | 280 (35.9) | 183 (30.1) | |
Black or African American | 57 (7.3) | 41 (6.8) | |
Native American | 60 (7.7) | 40 (6.6) | |
Asian | 10 (1.3) | 2 (0.3) | |
Other | 34 (4.4) | 60 (9.9) | |
Insurance type | .0127 | ||
Private | 205 (26.3) | 195 (32.1) | |
Medicaid | 499 (64.1) | 364 (60.0) | |
Indian Health Services | 58 (7.4) | 34 (5.6) | |
None | 16 (2.1) | 8 (1.3) | |
Other | 1 (0.1) | 6 (1.0) |
. | Preupdate (N = 779), n (%) . | Postupdate (N = 607), n (%) . | P . |
---|---|---|---|
Gender | .66 | ||
Male | 418 (53.7) | 333 (54.9) | |
Female | 361 (46.3) | 274 (45.1) | |
Patient’s age in months (median [IQR]) | 5.0 (10.0) | 7.0 (12) | .0031 |
Race | .0002 | ||
White or Caucasian | 338 (43.4) | 281 (46.3) | |
Hispanic or Latino | 280 (35.9) | 183 (30.1) | |
Black or African American | 57 (7.3) | 41 (6.8) | |
Native American | 60 (7.7) | 40 (6.6) | |
Asian | 10 (1.3) | 2 (0.3) | |
Other | 34 (4.4) | 60 (9.9) | |
Insurance type | .0127 | ||
Private | 205 (26.3) | 195 (32.1) | |
Medicaid | 499 (64.1) | 364 (60.0) | |
Indian Health Services | 58 (7.4) | 34 (5.6) | |
None | 16 (2.1) | 8 (1.3) | |
Other | 1 (0.1) | 6 (1.0) |
IQR, interquartile range.
Admission rate, defined as the number of patients admitted to the pediatric floor after presenting to the emergency department, between the 2 groups was similar with a preupdate admission rate of 33.6% versus 34.4% postupdate (P value .60). Patients in the preupdate group had a median time to room air of 40.0 hours, whereas patients in the postupdate group had a median time to room air of 30.0 hours (P value < .001), a reduction of 10.0 hours between the 2 groups. Patients in the preupdate group had a median length of stay (LOS) of 48.0 hours, whereas patients in the postupdate group had a median LOS of 41.0 hours (P value < .001). Using a multivariable analysis, controlling for age, race, and insurance, the mean difference of LOS remains significant with an adjusted difference of 8.1 hours (P value .004). There was no statistically significant change in the number of ICU transfers between the 2 groups, with a transfer rate of 4.5% (35 of 779) patients preupdate versus 4.8% (29 of 607) patients postupdate (P value .80).
The readmission rate within 7 days of discharge was 2.7% (21 of 779) in the preupdate group, and 2.1% (13 of 607) in the postupdate group (P value .51) (Table 3).
Clinical Data
. | Preupdate (N = 779) . | Postupdate (N = 607) . | Differencea (95% CI) . | P . |
---|---|---|---|---|
Admission rate, % | 34.4 | 33.6 | 0.8% (−2.2 to 3.7) | .60 |
% of patients requiring oxygen, n (%) | 568 (72.9) | 462 (76.1) | −3.2% (−7.8 to 1.4) | .18 |
Time to room airb (median [IQR]) | 40.0 (61.0) | 30.0 (41.0) | 10.0 (4.3 to 15.5) | <.001 |
Time on room air before dischargeb (median [IQR]) | 19.0 (18.0) | 19.0 (19.0) | 0.0 (−1.8 to 1.8) | .34 |
Transferred to ICU, n (%) | 35 (4.5) | 29 (4.8) | −0.3% (−2.5 to 1.9) | .80 |
Length of stayb (median [IQR]) | 48.0 (52.0) | 41 (40.0) | 7.0 (2.5 to 11.4) | <.001 |
Readmission within 7 d of discharge, n (%) | 21 (2.7) | 13 (2.1) | 0.6% (−0.11 to 2.2) | .58 |
. | Preupdate (N = 779) . | Postupdate (N = 607) . | Differencea (95% CI) . | P . |
---|---|---|---|---|
Admission rate, % | 34.4 | 33.6 | 0.8% (−2.2 to 3.7) | .60 |
% of patients requiring oxygen, n (%) | 568 (72.9) | 462 (76.1) | −3.2% (−7.8 to 1.4) | .18 |
Time to room airb (median [IQR]) | 40.0 (61.0) | 30.0 (41.0) | 10.0 (4.3 to 15.5) | <.001 |
Time on room air before dischargeb (median [IQR]) | 19.0 (18.0) | 19.0 (19.0) | 0.0 (−1.8 to 1.8) | .34 |
Transferred to ICU, n (%) | 35 (4.5) | 29 (4.8) | −0.3% (−2.5 to 1.9) | .80 |
Length of stayb (median [IQR]) | 48.0 (52.0) | 41 (40.0) | 7.0 (2.5 to 11.4) | <.001 |
Readmission within 7 d of discharge, n (%) | 21 (2.7) | 13 (2.1) | 0.6% (−0.11 to 2.2) | .58 |
IQR, interquartile range.
Mean differences are not adjusted.
Measured in hours.
Discussion
Though previous studies have demonstrated that infants with bronchiolitis who experience desaturations below 90% had comparable rates of return to care to infants without desaturations, few have specifically addressed the short-term clinical outcomes of changing the goal oxygen saturation for providing supplemental oxygen for hospitalized patients.12 This study describes an association between lowering the goal oxygen saturation from 90% to 88%, with decreased time to room air and length of stay without a significant increase in hospital readmissions.
Oxygen supplementation has been identified as one of the prime determinants of LOS in hospitalization for patients with bronchiolitis.13 In a large, prospective study, Mansbach et al examined time to clinical improvement in bronchiolitis and risk of clinical worsening after improvement utilizing a dichotomized estimated oxygen saturation (≥90% or not) with the lower limit of 88% as 1 element of their clinical improvement criteria, in addition to criteria such as stable retractions and respiratory rate.14 They concluded that 96% of children continued to improve once they had an estimated average room air oxygen saturation ≥90% and lowest room air oxygen saturation of 88%. This supports our clinical pathway lowering the goal oxygen saturation from 90% to 88% and was associated with significant decreases in time spent on supplemental oxygen, as well as LOS.
We found that decreasing the goal oxygen saturation to 88% was associated with a decrease in median LOS by 7 hours with no significant difference in 7-day readmission rate. Length of stay is an important indicator of medical service utility that can help assess the efficiency of hospital management and patient quality of care.15 Extrapolating our results to the preupdate group, had this update been in place, the preupdate cohort could have resulted in a decrease in approximately 5400 patient hours. Decreased LOS has been associated with decreased risk of hospital-acquired conditions and infections and is also associated with improvement in treatment outcomes and mortality rates.15 Shorter hospital stays reduce the burden of medical fees while lowering the overall social costs. This also allows for improved bed availability for patients who require hospitalization during times of high bed capacity and can avoid other problems related to throughput, such as staff shortages to meet the demand volume.15–17
Providers frequently make decisions for admission and use of supplemental oxygen based on oxygen saturations obtained from pulse oximetry.18 Studies have identified that the accuracy of pulse oximetry varies significantly as a function of the Spo2 range. For example, Ross et al conducted a study to determine the performance of pulse oximetry for children in the range of 65% to 97% compared with arterial oxygen saturation and concluded that there is significant variability in the bias (Spo2–Sao2), precision, and accuracy of pulse ox as a function of Spo2 in the range of 76% to 90%.18 Regardless, pulse oximetry remains a sole driving force on the decision to administer oxygen. The clinical pathway update led to reeducation of caregivers, including nurses, respiratory therapists, and physicians, on the use of pulse oximetry at our institution. Though the recommendation did not change from the original pathway, renewed education regarding the transition from continuous to intermittent pulse oximetry checks when on room air could have introduced confounding effects that may have impacted LOS. However, McCulloh et al identified that intermittent pulse oximetry monitoring of nonhypoxemic patients with bronchiolitis did not shorten hospital length of stay when compared with continuous pulse oximetry.19 Mahant et al found similar results when comparing the effect of intermittent versus continuous pulse oximetry on length of hospital stay as well.20 Therefore, we believe any confounding impact that a change in pulse oximetry may have had on our results was small and insignificant.
This study is limited in its design by being retrospective and conducted at a single center. With regards to the clinical pathway, the change in goal oxygen saturations was considered the most significant change, and during the education and dissemination of the pathway institution-wide, the modified goal oxygen parameter was specifically emphasized. However, other nominal changes made to the bronchiolitis pathway, as well as reeducation during the rollout process, may also have impacted clinical outcomes. The coronavirus disease 2019 pandemic likely had an impact on our study as well. Initially, we saw a sharp decline in the number of patients presenting with bronchiolitis in the spring of 2020 through early 2021, followed by a surge in cases during the summer of 2021. Given a very unusual pattern of illness, it is reasonable to be concerned that these results are not generalizable to a typical bronchiolitis season. Finally, since time variables were not collected, we were not able to use an interrupted time series analysis to describe secular trends during the study time frame and are unable to fully assess the impact of each of these described limitations on our results.
Conclusions
Lowering the goal oxygen saturation to 88%, within a bronchiolitis clinical pathway, was associated with a significant decrease in time spent on oxygen and a 7-hour decrease in LOS for patients admitted with bronchiolitis with no increase in readmissions. As this was a single center study, not powered to assess differences in rare outcomes, next steps would include pursuing a prospective or multicenter study to further support our results and assess for secondary financial and safety benefits.
FUNDING: No external funding.
CONFLICT OF INTEREST DISCLOSURES: The authors have indicated they have no conflicts of interest relevant to this article to disclose.
Dr Briggs conceptualized the project, led data collection, analysis, and interpretation and drafted the initial manuscript; Drs Gupta, Thakkar, and Librizzi supervised the conceptualization and design of the study; Dr Temkit contributed to the design of the study and conducted analysis and interpretation of data; Dr Engel supervised the conceptualization and design of the study and supervised data collections; and all authors critically reviewed and revised the manuscript and approved the final manuscript as submitted.
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