Humidified High Flow Nasal Cannula (HFNC): Fad or Serious

Humidified High Flow Nasal
Cannula (HFNC): Fad or Serious
Management Strategy
Julie Jackson, BAS, RRT-ACCS, RCP
Unity Point Health Des Moines
Conflict of Interest
I have no real or perceived conflict of interest that relates
to this presentation. Any use of brand names is not in any
way meant to be an endorsement of a specific product, but
to merely illustrate a point of emphasis.
Objectives
š  Describe the mechanisms of Action for Humidified High
Flow Nasal Cannula (HFNC) Therapy
š  Understand how HFNC is effectively used
š  Understand when HFNC is not to be used
š  Review the current literature surrounding the application
of HFNC therapy
š  Review case studies where HFNC was applied
Mechanism of Action For High Flow
Nasal Therapy
š  5 proposed mechanisms of action
š  Washout of Nasopharyngeal dead space
š  Reduced work of breathing
š  Improved mechanics
š  Reduced metabolic cost of gas conditioning
š  Provision of positive expiratory pressure
Dysart, K., et.al; Respiratory Medicine 2009; 103: 1400-1405
Mechanisms of Action
š  Washout of nasopharnygeal dead space
š  Common reason for invasive ventilation - hypercapnia
and apnea secondary to hypercapnia
š  If dead space in nasopharyngel cavity is reduced,
alveolar ventilation will be greater portion of minute
ventilation
š  HF Therapy has demonstrated an immediate impact on
ventilation rates and improved oxygenation, indicating
dead space is reduced.
š  Animal studies of tracheal gas insufflation support that
dead space washout is a lung protective strategy for ALI
š  Dysart, K., et.al; Respiratory Medicine 2009; 103:
1400-1405
Mechanisms of Action
š  Reduced Work of Breathing (WOB)
š  Nasopharyngeal surface area, distensibility of the
nasopharynx and gas volume all contribute resistance to
gas flow.
š  HF therapy provides nasopharyngeal gas flows that are
equal to, or greater than, patient’s peak inspiratory flow,
decreasing resistance, which then translates into
reduction in resistive WOB
š  Dysart, K., et.al; Respiratory Medicine 2009; 103:
1400-1405
Mechanisms of Action
š  Improved Mechanics
š  Even short periods of inspiring gas at ambient
temperature and humidity can significantly decrease
pulmonary compliance
š  Improved pulmonary compliance with HF therapy
š  Dysart, K., et.al; Respiratory Medicine 2009; 103:
1400-1405
Mechanisms of Action
š  Reduced Metabolic Cost of Gas Conditioning
š  Energy costs associated with conditioning of inspired
gases by the upper airway
š  Cost is higher when gas is cool and dry
š  Increased in minute ventilation that accompanies lung
pathologies means volume of gas requiring conditioning
is greater
š  Warm and humidified gas reduces the energy required
for gas conditioning
š  Dysart, K., et.al; Respiratory Medicine 2009;
103:1400-1405
Mechanisms of Action
š  Provision of Distending Pressure
š  Ventilatory mechanics improved by providing distending
pressure to lungs – improve lung compliance and gas
exchange
š  Potential for positive expiratory pressure effect with HF
therapy depending on leak rate, size of prongs, nose and
requires mouth to remain closed.
Dysart, K., et.al; Respiratory Medicine 2009; 103: 1400-1405
What is Heated, Humidified High Flow
Nasal Cannula Therapy (HFNC)
š  An oxygen delivery system which blends oxygen/
air from 21-100%
š  Can be administered via wide bore nasal cannula or
trach adapter from 1Lpm to 60Lpm.
š  Provides humidity enriched oxygen therapy for patients
in mild to moderate respiratory distress.
š  Does not augment tidal volume and thus does not
facilitate CO2 removal.
š  Provides flow rates that exceed patient inspiratory flow
rates at various minute volumes
š  It is not a substitute for invasive or non-invasive therapy
in acute crisis.
š  However, it may provide a bridge from post-extubation
to conventional oxygen delivery devices, bridge to NIPPV
or may give some patients NIPPV free hours.
Where Does the Clinician Intervene with
Nasal High Flow Therapy in the Care Cycle?
Invasive
ventilation
High Flow Nasal Therapy
Non-invasive
ventilation
Face
mask oxygen
Humidity therapy
High Flow Nasal Therapy
Nasal cannula
HFNC Therapy Benefits
There are five key benefits:
š  Delivers a high FIO2 accurately
š  Meets the patient’s ventilatory demands
š  Provides patient comfort
š  May provide some positive airway pressure
š  Optimizes mucociliary clearance
Systems Available
š  Several systems available for hospital use
š  Optiflow – Fisher & Paykel
š  Vapotherm – Vapotherm, Inc
š  Comfort Flow – Teleflex Medical
š  Work via the same principal but the difference is in the
total flow rate that is achievable
š  More companies coming out with similar technology
Optiflow System
š  Flow rates range from 1Lpm to 60Lpm
š  Oxygen delivery 21-100%
š  Heated, humidified system
š  Delivery system – nasal cannula or trach adaptor
š  4 Cannula sizes
š  Home Option – Airvo and Airvo2
Optiflow
The prongs are wide bore dispersing the flow as it enters the n
and reduces the jetting effect associated with standard nasal c
Vapotherm
š  Flow rates 1Lpm to 40Lpm
š  Oxygen Delivery 21-100%
š  Heated, humidified system
š  Delivery system via Nasal Cannula
š  7 different cannulas depending on size of patient
š  In hospital transport unit available
š  Home option – not available for home use at this time
due infection control issues related to cleaning
Vapotherm
Comfort Flow
š  Teleflex medical product
š  Flow rates 1-60Lpm
š  Oxygen Delivery 21-100%
š  Heated, humidified system using conchatherm or
conchasmart technology
š  Delivery system via Nasal cannula
š  4 different cannulas ranging from neonates-adults