High-Flow Nasal Oxygen in
the Adult Emergency
Department
Ammara Doolabh
James Hughes
Princess Alexandra Hospital Emergency Department
High-Flow Nasal Oxygen
 “High-flow”, “Airvo”, “Optiflow”, “HFNO”
 Widely used and studied in paediatric populations
 Recently introduced into adult populations
 Limited literature on use in adult populations
 Particularly ED Setting (single study on management of
hypoxemic respiratory failure)
 Focus on hypoxemic respiratory failure
High-Flow Nasal Oxygen
 Able to generate flow dependent positive pressure
within the upper airways
 Associated increase in end expiratory lung volumes
 Nasopharyngeal dead-space washout and oxygen
reservoir
 Improvements in a number of clinical parameters
(Oxygenation, HR, RR, dyspnoea scores, supraclavicular recession, thoraco-abdominal asynchrony)
 Useful for both “stepping-up” and “stepping-down”
respiratory support
HFNO in the ED
 Improvements as early as 15 minutes after
commencement
 Better patient tolerance and adherence (compared to
systems requiring a face-mask)
 Lower cost per use (compared to NIV)
 Acceptable usage for caregivers (set-up and
management) within an ED setting
Objectives
To explore the role of HFNO in an
adult emergency department
- Indications for use
- Outcomes of use
Our Study
 Explorative, retrospective study
 Chart review
 Patients 18 years or older
 Received HFNO within the PA Hospital Emergency
Department
 2014 Calendar Year
 Ethical Approval from both Metro South Health and
University of Queensland School of Medicine Human
Research Ethics Committees
Results
 39 patients identified
 Male patients: 29 (74.4%)
 Age range: 24-90 years
 Mean age: 60 years (SD 17.201)
Pre-HFNO Oxygenation
Indications for HFNO Use
 35 patients with pre-HFNO blood gas values available
 Patients with normal blood gas analysis:
 “Step-up”: 3
 “Step-down”: 1
Diagnoses
Influenza Status
 18 Patients with Nasopharyngeal Swab and PCR
Analysis for Influenza A and Influenza B
Clinical Effects of HFNO
110
70
105
60
50
100
40
95
30
90
20
85
10
80
0
0
30
60
90
120
150
180
210
Respiratory Rate (breaths per min) and
Fraction of Inspired Oxygen (%)
Oxygen Saturations (SpO2 %) and Heart Rate (beats per
min.)
Changes in Heart Rate, Respiratory Rate, Oxygen Requirement
and Saturations Over Time Post Commencement of HFNO
240
Time Post Commencement (min.)
Heart Rate (beats per min.)
SpO2 (%)
Respiratory Rate (breaths per min.)
FiO2 (%)
Effects of HFNO on Carbon
Dioxide Levels
 16 patients with both pre-HFNO and post one hour of
HFNO Blood Gas Analyses available
 6 hypercapnic patients, 10 normocapnic patients
Cessation of HFNO and
Post-HFNO Oxygenation
HFNO Patients
(n=39)
Discharged to Ward
on HFNO (n=27)
Condition
Improved (n=7)
NRB (n= 1)
NP (n=4)
HFNO Ceased in ED
(n=12)
Patient Refusal
(n=1)
HM (n=1)
Unsatisfactory
Progress(n=2)
NRB(n=2)
NIV Commenced
(n=2)
CPAP (n=1)
BiPAP (n=1)
RA(n=2)
HM = Hudson Mask, NRB = Non-Rebreather Mask, NP = Nasal Prongs, RA = Room Air
Limitations
 Small number of patients
 Retrospective nature of the study
 Missing data / data inconsistencies
 Lack of comparison or control arm
 Causal relationship cannot be established
 Results can be attributed to “regression-to-the-mean” or
concurrent treatments
 Only focused on outcomes within the ED
Conclusion
 HFNO is useful for a number of indications within the
PA ED
 Associated with improvements in a number of clinical
parameters
 HFNO may be useful in the ED management of
hypercapnic patients
 Questions for further research
 Role of HFNO in management of hypercapnia
 Outcomes of ED HFNO patients beyond the ED
Thank You