High-flow nasal cannula effectiveness in acute bronchiolitis: a retrospective study

Joana Baptista de Lima, Department of Pediatrics, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal
Inês Aires Martins, Department of Pediatrics, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal
Joana Queirós, Department of Pediatrics, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal
Sara Monteiro, Department of Pediatrics, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal
Telma Barbosa, Pediatric Pneumology Unit, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal
M. Guilhermina Reis, Pediatric Pneumology Unit, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal; ICBAS - School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal
Lurdes Morais, Pediatric Pneumology Unit, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal
Ana Ramos, Pediatric Pneumology Unit, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal
Manuel Ferreira Magalhães, Pediatric Pneumology Unit, Centro Materno Infantil do Norte, Unidade Local de Saúde de Santo António, Porto, Portugal; ICBAS – School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal; Center for Health Technology and Services Research (CINTESIS), Faculty of Medicine, University of Porto, Porto, Portugal; Department of Community Medicine, Information and Health Decision Sciences (MEDCIDS), Faculty of Medicine, University of Porto, Porto, Portugal

Introduction and Objectives: Acute bronchiolitis (AB) is a leading cause of hospital admission in pediatric patients. The main objective of this study was to evaluate the effectiveness of high-flow nasal cannula (HFNC) oxygen therapy in AB. Methods: Retrospective cohort study. Patients (1–24 months of age) admitted with AB in a tertiary hospital were included, comparing the periods before ('preHFNC:Apr/2018–Nov/2019) and after the introduction of HFNC ('postHFNC:Nov/2019–Apr/2022). The outcome measure of effectiveness was transfer to the intensive care unit (ICU). Effect measures were relative risk (RR), absolute risk reduction (RRA) and number needed to treat (NNT). Results: Of the 486 patients included, 196 were preHFNC and 290 were postHFNC. Of the latter, 46 (14.9%) required HFNC. Treatment with HFNC was associated with a significant reduction (p < 0.001) in respiratory rate, use of accessory muscles, wheezing and, consequently, an improvement in the WARM score. In the postHFNC period, there were fewer transfers to the ICU (21.4% vs. 13.8%, p = 0.027), with RR = 0.66, RRA = 7.6% and NNT = 13. In patients treated with HFNC, daycare attendance (p = 0.036; OR 91.7) and a higher WARM score 24 hours after HFNC (p = 0.009; OR 16.2) were predictors of transfer to the ICU (Hosmer-Lemeshow: x 2 = 0.82, p = 0.976). In the survival curve for time to ICU admission, preHFNC patients were transferred earlier (p = 0.013). None of the patients under HFNC required invasive ventilation. Discussion: The introduction of HFNC in the treatment of AB reduced the need for the ICU and was associated with a clinical improvement in several respiratory parameters. On the basis of the NNT, it is estimated that three to four ICU admissions were avoided in the postHFNC period.

Keywords: Pediatric respiratory care. Intensive care unit. Invasive ventilation. Respiratory rate. Respiratory distress.