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High Flow Nasal Cannula�Outside the PICU

Pediatric Critical Care Fellows

December 2022

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High Flow Nasal Cannula (HFNC)

Bronchiolitis
Pneumonia
Asthma exacerbation
Disordered breathing (i.e. apnea)
Post-extubation respiratory management
Post-extubation stridor and croup
Congenital cardiac lesions

General indications

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HFNC Components

Flow meter

Up to 60 L/min (LPM)

Air-O₂ blender

Delivers 21-100% oxygen to nares

Heater
Humidifer
Patient interface (prongs)

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Benefits of HFNC in children

Reduce respiratory distress

Ability to meet/exceed patient’s inspiratory flow demands
Reduce work of breathing, tachypnea

Improved oxygen delivery to lower airways
Decrease rate of intubation in bronchiolitis
Less skin breakdown and improved comfort compared to CPAP/BiPAP
Improved patient mobility

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Mechanisms of action?

CO₂ washout in the anatomical dead space
Positive airway pressure
Thin secretions & improve mucocilliary clearance
Decrease nasal irritation
Decrease patient work to heat & humidify air
Reduces upper airway (nasopharyngeal) resistance
Provides some alveolar ventilation that is greater than the patient’s minute ventilation

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Management of HFNC

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Managing HFNC

Flow and FiO2 are related but may also function differently
Flow 🡪 work of breathing (airways)

PCCM will typically max at 2 L/min/kg before escalating to NiPPV
Patient will be weaned to ≤ 1 L/min/kg prior to transferring to hospitalist/pulmonology team

FiO₂ 🡪 hypoxemia (parenchyma)

Maintain at 60% while on HFNC
Maintain at 100% on wall cannula (non-blended)

Monitoring

Cardiac monitoring, HR, RR, SpO₂, and respiratory assessments
Vital signs q2h
Riley Hospital Respiratory score (RHRS) q2h

Diet

NPO if worsening
Multiple studies show success in feeding while on HFNC, but each patient is different

Airway clearance

Oral, NP suctioning as ordered

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Adverse events while on HFNC

Pneumothorax/pneumomediastinum
Delayed intubation in those who are decompensating
Nasal mucosa trauma
Patient discomfort or agitation
Gastric distension
Poor efficacy with lack of reliable mucus clearance
Increased hospital length of stay?

RT to assess q2, per pathway

Lastly, adverse events to look out for while your patient is on HF include pneumothorax, pneumomediastinum, which is oftentimes rare. It can delay invasive mechanical ventilation in a decompensating child. Most studies show that decompensation in a child on HF with bronchiolitis occurs within the first 24 hours of initiation. Ultimately, if required for a long time, it can lead to nasal mucosal trauma dn discomfort. Sometimes the extra oxygen and flow can lead to gastric distension, which may be another indication to hold off feeds for these children. Worsening may occur because the child has been placed on HF and so staff may presume they do not need suctioned any further. And then there are studies that show it may increase patient length of stay, which brings us to our proposed weaning protocol.

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Penn State Health Children’s Hospital

High Flow Nasal Cannula (HFNC) Use and Weaning Guidance

PCCM Service Initiates HFNC

Start HFNC at 1.5L/kg/min (FiO2 of 0.6) and assess Riley Hospital Respiratory Score (RHRS) (Table 1)

Table 2 – HFNC Weaning Guidance
All Patients	RTs to assess and obtain RHRS q2h When RHRS 0-1, wean HFNC flow by 0.5 L/min/kg q2h until 1 L/min/kg is reached Once 1 L/min/kg is reached, follow weight-based weaning guideline (below)
Weight-based weaning guideline
<10 kg	Wean by 2 LPM q2h to 2 LPM, then transition to 2 LPM wall cannula
10 – 30 kg	Wean by 4 LPM q2h to 4 LPM, then transition to 3 LPM wall cannula^ⱡ
>30 kg	Wean by 5 LPM q2h to 10 LPM, then transition to 3 LPM wall cannula
RN/RT may continue to wean nasal cannula to OFF for SpO₂ > 92% unless patient has congenital heart disease, pulmonary hypertension, home O₂requirement, or otherwise directed by medical team.
^ⱡFor patients on adult-sized nasal cannula prongs, minimum flow is 10 LPM.

Calculate RHRS

(Table 1)

RHRS: 0-1

RHRS: 2

Wean flow per HFNC weaning guidelines (Table 2)

Reassess in 2 hours

Increase flow by 0.5 L/min/kg to maximum 2L/min/kg and contact physician team

Designate team member (RN, RT, APP, physician) to reassess in 15-30 minutes

Maintain flow rate

Reassess in 2 hours

Guideline for Management of HFNC by Non-PCCM Service-Lines

All patients who require HFNC are initially admitted to Pediatric Critical Care Medicine (PCCM) service

Care may be transitioned to intermediate level of care and/or Pediatric Hospitalist or Pediatric Pulmonary Medicine team at discretion of PCCM Attending for patients meeting the following criteria (exceptions at the discretion of attending physicians):

Diagnosis of bronchiolitis or uncomplicated pneumonia
Receiving ≤ 1 L/min/kg flow and FiO2 ≤ 0.6
Total Flow < 20 LPM
RHRS of 0-1 for two consecutive assessments

Intermediate level of care patients on the Pediatric Hospitalist or Pediatric Pulmonary Medicine team may receive care in the PIMCU or PPCU. PCCM patients regardless of level of care to receive care on the fourth floor of PSCH.

Exclusion criteria for transition of HFNC patient off PCCM service:

Weight < 5kg
Status asthmaticus
Comorbidities including: primary cardiac diagnosis, pulmonary hypertension, neuromuscular weakness, and disordered control of breathing (e.g. apneic events)

Once HFNC is weaned to 1 L/min/kg, weaning should proceed according to Table 2 – HFNC Weaning Guideline

Modifications to weaning may be made only at the discretion of the attending physician

Last Updated: 12/12/2022

Table 1 – Riley Hospital Respiratory Score (RHRS)

HFNC FiO₂should remain at 0.6

Wall cannula FiO₂ is 1.0

RHRS: >3

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Basic elements of new HFNC guideline

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HFNC pathway

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Riley Hospital Respiratory Score (RHRS)

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Guideline for weaning HFNC

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Questions?