Noninvasive Ventilation in Pediatric Respiratory Failure: Does It Work?

James D. Fortenberry MD FCCM, FAAP

Director, Critical Care Medicine

Children’s Healthcare of Atlanta at Egleston

Clinical Associate Professor

Emory University School of Medicine

Atlanta, Georgia USA

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History of Ventilation

Noninvasive ventilation: foundation of concept of mechanical ventilation• 1876: First iron lung• 1889: Alexander Graham Bell-first iron lung for

newborn infant• 1920’s: Drinker iron lung• 1940’s: Polio epidemics• 1960’s: Rise of positive pressure ventilation• 1990’s: Resurgence of interest in NIV

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First Reported Use of Noninvasive Ventilation

And the Lord God formed man of the dust of the ground and breathed into his nostrils the breath of life, and man became a living soul.

-- Genesis 2:7

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What is Noninvasive Ventilation?

Delivery of ventilatory support without the use of an invasive artificial airway

Role in:• Chronic respiratory insufficiency:obstructive

sleep apnea• Acute respiratory failure

Hypoxemic Hypercarbic

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What is Noninvasive Ventilation?

Modalities• Negative pressure: inspiration lowers

pressures surrounding chest wall, augments tidal volume, more physiologic Iron lung Cuirass

• Positive pressure (NIPPV): generates positive pressure flow to meet need in spontaneously breathing patient Current standard

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Noninvasive Positive Pressure Ventilation

Modes of Delivery• Volume ventilator• Pressure-controlled

Continuous (CPAP) Bilevel (BiPAP® is trade name): cycles

between inspiratory (IPAP) and expiratory (EPAP) pressures

• Intermittent• Continuous

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Modes of BiPAP

Spontaneous: response to threshold level of patient inspiratory flow to provide IPAP with extra flow, EPAP after peak

Spontaneous/Timed: cycle added in event of apnea Timed: intermittent pulses at set rate only Continuous PAP (CPAP) Problems:

• infant may have difficulty achieving sufficient inspiratory flow to trigger

• Mask leak prolongs inflation time

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NIPPV: Mechanisms of Action

• Stabilize chest wall• “Unload” diaphragm and accessory muscles of

breathing• Increase tidal volume/minute ventilation• Increase FRC• Prevent atelectasis• Decrease auto-PEEP/stent airways• Maintain upper airway patency/ decrease apnea

and hypopnea

How well NIPPV provides these is undocumented

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NIPPV: Potential Benefits

• Avoidance of risks of intubation• Improved bedside caregiver time• Decreased nosocomial pneumonia• Potential decreased ICU length of stay, mortality• Decreased costs

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NIPPV: Initiation in Children

• Varied approaches• General BiPAP settings: IPAP 12, EPAP 6

cmH2O

• Blended oxygen flow to titrate• Bedside caregiver presence high initially• Sedation often needed in children to tolerate

Ketamine bolus/infusion our choice

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NIPPV: Delivery Systems

• Conventional ventilators• CPAP device

Aladdin• Bilevel device:

BiPAP (Respironics) Knightstar (Puritan-Bennett)

• High flow nasal cannula devices: Vapotherm

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NIPPV: Interface modes and systems

• Mask• Nasal• Full face

• Type of mask• Mask vs. pillows/cannula

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Nasal Mask

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Full Face Mask

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Nasal Prong Devices

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Nasal Pillow Devices

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Interfaces for NIPPV

Nasal Advantages

• Less aspiration risk• Easier secretion

clearance• Less dead space• Easier fit in adults

Disadvantages• Mouth leak• Higher resistance

through nasal passages• Nasal irritation• Potential nasal

obstruction• Fit in infants?

Oronasal Advantages

• Better control of mouth leak

• Better for mouth breathers

Disadvantages• More dead space• Claustrophobia• Higher aspiration risk• More difficulty in

speaking• Risk if vent malfunction• Greater sedation need in

kids?

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NIPPV: Potential Indications

Cardiogenic pulmonary edema Hypercarbic respiratory failure/COPD Hypoxemic respiratory failure Peri-extubation Immunocompromised patients Asthma

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NIPPV: Contraindications

• Significant altered mental status/inability to protect airway

• Hemoptysis• Facial injuries• NP obstruction• Airway foreign bodies• Significant cardiovascular instability

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NIPPV: Potential Complications

• Acute unrecognized deterioration• Nasal/facial erosions• Aspiration• Abdominal distention (GE sphincter pressure up

to 25 cmH2O)

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NIPPV: What is the evidence for its benefit?

Fifteen suitable randomized controlled trials for COPD

Eight suitable RCTs in AHRF 2 major meta-analyses No pediatric RCTs

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NIPPV Meta-Analysis: Effect on ICU Mortality in COPD

-- Significant mortality benefit with NIPPV for COPD(Lightowler JV, et al., BMJ 2003;326:185)

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NIPPV For COPD/Obstructive Airways Diseases

Conclusions: strongest support for a NIPPV indication• COPD-NIPPV now considered a “standard of

care”• Asthma-potential benefit, less evidence

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NIPPV Meta-Analysis: Effect on Intubation in AHRF

-- Significant benefit on need for intubation (Keenan et al., Crit Care Med 2004;32:2520)

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NIPPV Meta-Analysis: Effect on ICU Length of Stay in AHRF

-- Significant NIPPV benefit on ICU length of stay(Keenan et al., Crit Care Med 2004;32:2520)

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NIPPV Meta-Analysis: Effect on ICU Mortality in AHRF

-Significant mortality benefit demonstrated(Keenan et al., Crit Care Med 2004;32:2520)

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NIPPV Meta-Analysis: NIPPV Benefit As A Function of Unit Mortality

-- Outcome benefit increases with increased overall ICU mortality (Keenan et al., Crit Care Med 2004)

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NIPPV for Hypoxemic Respiratory Failure

Conclusions:• Limited evidence supports its use• “In the setting of single organ respiratory failure,

a trial of NIPPV is warranted…”• “Intubation should not be delayed if rapid

improvement does not occur”

- Caples SM, Gay. Crit Care Med 2005;33:2651

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NIPPV For Postoperative and Post-Extubation Respiratory Failure

Trials:• Use of NIPPV for respiratory distress after

extubation• Use to facilitate extubation

Results Conclusions

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NIPPV for Respiratory Failure After Extubation

37 centers 221 adults extubated with respiratory failure within

48 hours Randomized to face mask NIPPV or standard

therapy

- Esteban et al., N Engl J Med 2004;350:2452

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NIPPV for Respiratory Failure After Extubation

- Esteban et al., N Engl J Med 2004;350:2452

NIPPV Standard Therapy

Need for re-intubation

48 % 48 %

Death 25 %(RR 1.78, 95% CI 1.03-3.20)

14 %

Time from respiratory failure to re-intubation

12 hours

(p = 0.02)

2. 5 hours

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Impact of NIPPV vs. Intubation on Nosocomial Pneumonia

- NPPV associated with decreased nosocomial pneumonia/infections

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NIPPV For Immunocompromised Patients

Avoidance of infectious complications beneficial 2 RCTs of NPPV vs. standard therapy

• 40 solid organ transplants (Antonelli, JAMA 2000)

• NPPV decreased intubation and ICU mortality• 52 neutropenic patients (Hilbert, NEMJ 2001)• NPPV: Fewer intubations, decreased mortality

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Effect of NIPPV on Caregiver Time

0

10

20

30

40

50

60

70

80

90

100

First8

Hrs

2nd8

Hrs

NPPV

Control

0

20

40

60

80

100

120

140

First8

hrs

2nd8

hrs

NPPV

ControlMin

utes

- Kramer et al., AJRCCM 1995;151:1799

Min

utes

Respiratory Therapist Nurse

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Why NIPPV Might Work Better in Children

• Immature chest wall more highly compliant• Predicted FRC closer to total lung capacity• Increased pharyngeal tone needed at expiration

to maintain FRC• Fewer fatigue-resistant muscle fiber types in

infant diaphragm• Prone to asynchrony of thorax and abdomen =

retractions

Marginal increase in positive pressure support may be more helpful in child

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NIPPV in Pediatrics: Clinical Experience

Limited in children 9 published case series (no RCTs) AHRF: combined 73 reported cases - only 8%

required intubation Acute hypercarbic respiratory failure: combined 34

reported cases- 16% required intubation

- Akingbola et al., Ped Crit Care Med 2001;2:164

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Early Experience With NIPPV (BiPAP) in Children

28 children Median age 8 years (4-204 months) AHRF: Mean P/F 141, A-a 271 Most common diagnosis: pneumonia BiPAP: median IPAP 12 (8-16), EPAP 6 (5-8) Median duration of BiPAP 72 hours Improvement in all parameters Only 3/28 required intubation/reintubation

- Fortenberry et al., Chest 1995; 108:1059

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Early Experience With NIPPV (BiPAP) in Children

- Fortenberry et al., Chest 1995; 108:1059

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NIPPV: Pediatric Experience in Varied Settings

Use in 34 hypercapnic or hypoxemic children with impending respiratory failure in PICU: decreased dyspnea, only 3 intubated (Padman CCM, 1998)

Pediatric OSA: decreased apnea (Padman Clin Pediatr 2002)

Acute chest syndrome in HbSS: 24/25 improved respiratory distress (Padman Del Med J 2004)

Liver transplant/ respiratory insufficiency (Chin Liver Transpl 2005)

• 15 children (2.5 months-15 years; previously reintubated)

• Hypercarbia improved• 13 of 15 remained extubated

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NIPPV in Pediatric Status Asthmaticus

Theoretical benefits• Offset of auto-PEEP with airway obstruction• Reduce inspiratory WOB without hyperinflation• “Unload” diaphragm• Improve delivery of bronchodilators• Avoid PPV: high risk in asthma

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NIPPV in Pediatric Status Asthmaticus

Limited case reports Prospective crossover trial

• BiPAP (10/5) vs. standard therapy• 20 asthmatic children• Median 4 yrs, 2 mo-14 yrs

– Thill et al., Pediatr Crit Care Med 2004;5:337

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NIPPV in Children With Lower Airway Obstruction: Effect on Asthma Score

0

1

2

3

4

5

6

AM W D Total CAS

Control

NIPPV

– Thill et al., Pediatr Crit Care Med 2004;5:337

* * *

*

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New Aspects of NIPPV: Vapotherm

A high flow nasal cannula: up to xx LPM Warms and humidifies high flows of gas for patient

delivery Water and gas circuit separate: Gas warmed and

humidified through vapor transfer cartridge: pressurizes water into molecular vapor

Potential benefits: positive pressure support in a more comfortable interface• Infants, neonates

Vapor transfer cartridge requires disinfection

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Vapotherm 2000i

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Vapotherm: Mechanism of Action

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Vapotherm: Infection Problems

CDC Public Health Notification (12/2005):• Contamination: 29 institutions in 16 states• Ralstonia spp. (GNR similar to Pseudomonas,

Burkholderia) from instruments and 40 pediatric patients

• Majority probably colonization; one active infection; ? one death

• Disinfecting protocol ineffective• “…encouraged to weigh the risk of bacterial

contamination against the benefits Vapotherm might provide…”

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Vapotherm: Voluntary Recall

Vapotherm, Inc. issues voluntary recall (1/2006) Children’s of Atlanta removed all devices Replacement: other high-flow nasal cannulas

(Fisher-Paykel: 10-12 LPM flow; Aladdin): limited by flow

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NIPPV: Conclusions

NIPPV offers potential benefits for:• Acute/chronic hypercarbic respiratory failure• Acute hypoxemic respiratory failure-less certain• Immuno-compromised host to avoid intubation• Post-extubation failure: high risk for deterioration

Benefit of NIPPV in children• Anecdotal-hypercarbia/AHRF• Likely helps in selected cases to avoid intubation

or re-intubation• We need a randomized study!