Effects of a Clinical Pathway for High Flow Nasal Cannula Therapy in Bronchiolitis Outside of the Intensive Care Unit
Respiratory support with High Flow Nasal Cannula (HFNC) therapy has been shown to reduce work of breathing and, in retrospective studies, to reduce intubation rates in infants with acute bronchiolitis cared for in the ICU. More recently, the use of HFNC has spread outside of the intensive care setting. The effects of HFNC use in the acute care setting, especially on the risk of respiratory deterioration and on hospital length of stay, are largely unknown, and no practice guidelines exist that address its use.
We conducted a comprehensive literature search and convened a group of stakeholders to design an evidence- and expert-consensus-based clinical pathway to guide HFNC use in bronchiolitis in the emergency department (ED) and acute care units (ACU). Our clinical pathway provided guidance for the initiation, assessment, and weaning of HFNC therapy for patients with bronchiolitis. In addition, it introduced the idea of a 90 minute team huddle to identify responders and nonresponders to therapy, with nonresponders transferred to the ICU. To analyze the effects of this intervention, we identified patients with simple bronchiolitis seen between Oct 1 2011 and April 1 2014 on the basis of ICD-9 code criteria. Outcomes of interest were tracked using an EPIC/Cerner database as well as retrospective chart review.
From Oct 2011 to Sept 2013, 6.5% of admitted patients with simple bronchiolitis (n=561) were treated with HFNC. Between Dec 10, 2013, when our clinical pathway was introduced, and April 1, 2014, 49 patients were treated with HFNC per protocol, representing 23% of patients admitted for simple bronchiolitis (n=214). Of the 49, 28 remained on the ACU and 21 were transferred to the ICU, most often within 4 hours of starting HFNC. The overall rate of intubation for patients with simple bronchiolitis fell to 0.47% from 1.24% (OR 0.34, CI=0.04 to 2.82). Median hospital LOS for patients with simple bronchiolitis remained the same at 1.8 days. Rates of ICU admission increased, from 7.5% to 15%, and median ICU LOS decreased from 71 to 62 hours.
Institution of a HFNC clinical pathway outside of the ICU resulted in nonsignificant trend toward decreasing intubation. A greater percentage of patients were admitted to the ICU than expected, or that was noted in the only other study of HFNC for bronchiolitis outside of the ICU. This may be due to safety checks built into the pathway, which mandated ICU admission for patients who did not have an immediate clinical response. Most patients transferred did not require an increase in HFNC flow rate. The increase in HFNC use did not increase inpatient LOS, despite its use in a greater proportion of admitted patients. Further study should seek to prospectively determine the effect of HFNC in preventing intubation, address the effects of HFNC on the cost of bronchiolitis care.