High Flow Nasal Cannula for Patient Care Units- ACH ACH Hospital Pediatrics Fall Retreat September 16/17 2011

Oxygen Delivery Systems Blow by Nasal cannula Low-flow- 1-4 LPM delivers 25-40% FiO2 (limit flow to 2 LPM in infants) High-flow- delivers heated and humidified O2 - up to 8LPM (infants); up to 40 LPM (children/adults); may be better tolerated than O2 by face mask Masks Simple – flow rates: 5-10 LPM delivers 35-50% FiO2 (unreliably) Partial rebreathing- flow rates 10-12 LPM delivers 50-60% FiO2 Nonrebreathing- flow rates of 10-15 LPM delivers FiO2 up to 95% Enclosure systems Hoods – flow rates 10-15 LPM delivers FiO2 of 80-90 % Tents – using high flow rates can deliver up to 50% FiO2 Ventilation bags Self-inflating Flow-inflating

High Flow Nasal Cannula (HFNC) Key benefits over nasal prongs: Delivery of up to 100% oxygen more accurately Anatomical dead space flushed Providing warmed + humidified gas reduces metabolic work (in adults estimated at 156 cal/min) Providing warmed + humidified gas improves conductance and pulmonary compliance Positive airway pressure throughout the respiratory cycle Overcomes inspiratory resistance May be able to provide positive distending pressure for lung recruitment (up to 5-6 cm H2O- depending on mouth open and leak in very small infants) – unreliably!!! Potentially aids in mucociliary clearance Mechanism of Action Washout of nasopharyngeal dead space, which contributes to improved alveolar gas exchange Distensibility of the nasopharynx increases resistance on inspiration normally; HF provides flow rates that can match this inspiratory resistance and thus attenuate this resistance, improving WOB Warmed and humidified gas improves conductance and pulmonary compliance Warmed and humidified gas reduces the metabolic work associated with gas conditioning High flow can be titrated to provided positive distending pressure for lung recruitment

Uses in Pediatrics • RDS of prematurity • Bronchiolitis • Apnea of prematurity • Chronic Lung Disease • Infants susceptible to nasal trauma/maintaining mucosal integrity • Infants weaning from invasive ventilation and CPAP *Indications for use are non-specific; no formal recommendations are available for specific clinical indications Key patient populations where HFNC has been shown to be a potentially effective treatment option:

“Criteria” for use Effective spontaneous respiratory effort Requirement for moderate to high amounts of oxygen when NP or facial mask not amenable CO2 elimination maintained

CPAP vs HFNC 3 key problems with CPAP making HFNC attractive: Mechanical difficulties of maintaining CPAP apparatus in nose CPAP commonly causes nasal septum trauma CPAP is tightly affixed to nose and face- causes intolerance with patient movement, trauma, need for sedation, etc. Mechanism of Action Washout of nasopharyngeal dead space, which contributes to improved alveolar gas exchange Distensibility of the nasopharynx increases resistance on inspiration normally; HF provides flow rates that can match this inspiratory resistance and thus attenuate this resistance, improving WOB Warmed and humidified gas improves conductance and pulmonary compliance Warmed and humidified gas reduces the metabolic work associated with gas conditioning High flow can be titrated to provided positive distending pressure for lung recruitment

Consider HFNC a bridge between Low Flow NP and CPAP While HFNC may provide some positive pressure, it is not regulated and highly variable (but give HFNC the “respect” given to non-invasive modes of ventilation)

Basic Set-up

Potential Complications Respiratory Failure Excessive condensation in the tubing Aspiration (above/below) Potential for infection Barotrauma with unmeasured CPAP Pneumothorax Subcutaneous scalp emphysema, pnemo-orbitis, pneumocephalus has been described in one neonate on HFNC Pulmonary hemorrhage Nasal septal damage

Other considerations Need for NG to decompress stomach Ability to orally feed Nare occlusion

Guidelines for HFNC Use At ACH Will be initiated and stabilized in PICU/NICU prior to transfer to Unit 2 Currently only being used for patients with chronic oxygen needs and/or craniofacial anomalies Patients on HFNC MUST be on CRM Patients will go to Unit 2, Yellow Hallway and preferably Purple Team Respirology consult is mandatory

Guidelines cont’d RT to assess the patient AT MINIMUM of q4h RN to assess the patient AT MINIMUM of q4h (alternating q2h with RT assessment) Orders for HFNC must include: Flow rate and FiO2 Signage will be placed at the bedside of these patients by RT Weaning can only be ordered by Respirology and Hospital Pediatrics

Weaning of HFNC Indications: Once patient FiO2 is <40% Disease process is improving Order can be specific or written “as tolerated” must be in discussion with Hospital Pediatrician and Respirology Drop flow in increments of 1-2 LPM <6 mos of age: once flow is 2 LPM consider changing to regular nasal prongs > 6 mos of age: once clow is 3 LPM consider changing to regular nasal prongs

QUESTIONS??