Effect of a Hospital-wide High-Flow Nasal Cannula Protocol on Clinical Outcomes and Resource Utilization of Bronchiolitis Patients Admitted to the PICU

Discussion

Currently there is a paucity of available evidence for clinical outcomes of HFNC use in bronchiolitis. To date, our study is the second largest (N = 290) to investigate HFNC use in bronchiolitis and the first to examine its association with hospital LOS. Although patients initially admitted to the PICU for HFNC accounted for only half of the total bronchiolitis patients on HFNC in our institution, examining this cohort gives a concrete, easily comparable group in which to evaluate outcomes associated with a ward HFNC protocol. We found implementation of this protocol was associated with both reduced total LOS and total hospital charges for patients with bronchiolitis initially admitted to the PICU. Additionally, we found that weaning of HFNC was faster during the second time period when HFNC was available on the wards.

The reduced total hospital charges are entirely attributed to the shorter total LOS in the after group. Although LOS is the main driver of reduced total hospital charges, it is nonetheless notable. The etiology of the reduced LOS in the after group is unclear. However, we found that after the introduction of an HFNC wards protocol, 30% of patients initially admitted to the PICU were transferred to the general wards while still requiring HFNC, with the majority (82.4%) to a hospitalist service. Although no study to date has compared patient outcomes between pediatric general wards and PICU management of bronchiolitis, we present evidence that general wards care is associated with lower LOS and lower total hospital charges for bronchiolitis patients initially admitted to the PICU after the availability of HFNC use on the general wards. The applicability of these findings to other diagnoses and methods of management in the 2 settings is unclear. A recent review article comparing pediatric hospitalist versus nonhospitalist systems of care in 11 studies found mixed results in LOS and cost,¹⁶ but none of the reviewed studies compared HFNC management for bronchiolitis.

There were a greater number of overall patients in the after cohort, and therefore more patients who received HFNC therapy. Although this increased use may result in less ill patients being placed on HFNC, and thus explain the reduced LOS, we instead found that the after group had more severe bronchiolitis when comparing APR-DRG severity levels between the 2 groups, and the reduced LOS remained statistically significant when controlling for severity.

There are limitations to our study. A significant limitation of a single-site nonrandomized, preintervention-postintervention study design is difficulty in controlling for confounding variables. Although we compare some baseline patient demographic characteristics, there is the possibility the outcome differences could be explained by seasonal variation, patient level factors, or other unmeasured confounding variables. Additional limitations of a before and after assessment is the lack of control for secular trends, and the absence of controls for the intervention of interest.

We had more patients in the after group cohort (170 vs 120). A previous study found that increased inpatient prevalence of bronchiolitis is associated with a decrease in resource utilization.¹⁷ Therefore, it is possible the increased volume in our after group may explain the reduced LOS via changes in PICU utilization rather than be simple artifact.

HFNC has been increasingly used in bronchiolitis because of its tolerance and ease of use but is restricted to the ICU setting in many pediatric hospitals. Our findings are generalizable only to hospitals that perform HFNC on the general wards, but our study may be relevant to institutions looking for more evidence to allow HFNC use on the general wards due to its association with decreased hospital LOS and hospital charges.

The patients in our study have the specific clinical condition of initial PICU admission. We did not compare all patients who were on HFNC at some time during hospitalization and therefore excluded those patients initially admitted to the floor and subsequently transferred to the PICU; thus, we cannot comment on that cohort.

We used APR-DRG severity levels to measure severity rather than patients’ respiratory distress scores, which have been used in a recent study of ICU bronchiolitis management,¹⁸ due to the inconsistent documentation of respiratory scores in our charts. The indications for intubation (ie, hypercapnia, respiratory fatigue, persistent apneas) were not recorded so we are unable to comment whether intubation was a subjective decision by individual intensivists or based on specific clinical factors.

LOS was measured in integer number of days. We were unable to measure LOS in actual time between admission and discharge, which may result in the difference in LOS being overstated. Additionally, we were unable to quantify total length of time in the PICU and therefore could not directly compare PICU LOS between the 2 groups or how PICU LOS contributed to overall hospital charges. We can hypothesize that the PICU LOS was greater in the before group because this group had significantly more days of HFNC, which before the wards protocol would need to occur solely in the PICU.

In terms of cost, it is difficult to address the true cost reduction because the value is multifactorial and includes payer, hospital, patient, and physician provider variables. We restricted cost analysis to the total billable hospital charges.

Although we showed reduced total LOS and hospital charges for bronchiolitis patients initially admitted to the PICU with the availability of HFNC on the general wards, more research is required to provide additional evidence of the patient outcomes and associated cost of HFNC use in bronchiolitis.