Introducing high-flow nasal cannula oxygen therapy at the intermediate care unit: expanding the range of supportive pulmonary care

BACKGROUND: Non-invasive respiratory support is a frequent indication for intermediate care unit (IMCU) admission. Extending the possibilities of respiratory support at the IMCU with high-flow nasal cannula oxygen therapy (HFNC) may prevent intensive care unit (ICU) transfer and invasive ventilation. However, the safety and limitations of HFNC administration in the stand-alone IMCU setting are not yet studied. This study therefore aims to investigate to what extent and in which patients HFNC can safely be administered at a stand-alone mixed surgical IMCU. METHODS: A case series, using retrospectively collected data, was performed after the first year of introducing HFNC at a stand-alone IMCU. The following variables were collected: indication to start HFNC, vital parameters and arterial blood gas measurements. Primary outcome was 30-day mortality. Secondary outcome was transfer to the ICU. RESULTS: A total of 96 admissions were included. The indications to start HFNC at the IMCU were predominantly pathologies of pulmonary origin (n=67, 69.8%). Less frequent indications were prolonged support postweaning (n=15), non-pulmonary sepsis (n=7) and post-trauma resuscitation (n=6). The average PaO(2)/FiO(2)ratio at start of HFNC was 152 (95% CI 139 to 165). 30-day mortality was 7, of which 5 were admitted with treatment restrictions (no ICU policy) and 2 deaths were unrelated to HFNC. Transfer to the ICU occurred in 18 (18.8%) admissions, of which 12 received invasive mechanical ventilation. Reason for ICU transfer was mainly PaO2/FiO2 ratio<100 under maximum non-invasive treatment (n=12, 66.7%). Application of HFNC at the IMCU prevented 162 days of ICU admission. DISCUSSION: Administration of HFNC at a stand-alone surgical IMCU may be safe as it expands the range of supportive possibilities and thereby reduces the need for ICU admissions. Pulmonary indications to start HFNC increase the risk of ICU transfer and mechanical ventilation. LEVEL OF EVIDENCE: Level VI.