Noninvasive Ventilation in Pediatric Respiratory Failure: Does It Work

1. 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

2. 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

3. 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.

4. 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

5. 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

6. 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

7. 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

8. 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

9. NIPPV: Potential Benefits Avoidance of risks of intubation Improved bedside caregiver time Decreased nosocomial pneumonia Potential decreased ICU length of stay, mortality Decreased costs

10. 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

11. NIPPV: Delivery Systems Conventional ventilators CPAP device Aladdin Bilevel device: BiPAP (Respironics) Knightstar (Puritan-Bennett) High flow nasal cannula devices: Vapotherm

12. NIPPV: Interface modes and systems Mask Nasal Full face Type of mask Mask vs. pillows/cannula

13. Nasal Mask

14. Full Face Mask

15. Nasal Prong Devices

16. Nasal Pillow Devices

17. 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?

18. NIPPV: Potential Indications Cardiogenic pulmonary edema Hypercarbic respiratory failure/COPD Hypoxemic respiratory failure Peri-extubation Immunocompromised patients Asthma

19. NIPPV: Contraindications Significant altered mental status/inability to protect airway Hemoptysis Facial injuries NP obstruction Airway foreign bodies Significant cardiovascular instability

20. NIPPV: Potential Complications Acute unrecognized deterioration Nasal/facial erosions Aspiration Abdominal distention (GE sphincter pressure up to 25 cmH2O)

21. 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

22. NIPPV Meta-Analysis: Effect on ICU Mortality in COPD

23. 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

24. NIPPV Meta-Analysis: Effect on Intubation in AHRF

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

26. NIPPV Meta-Analysis: Effect on ICU Mortality in AHRF

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

28. 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”

29. NIPPV For Postoperative and Post-Extubation Respiratory Failure Trials: Use of NIPPV for respiratory distress after extubation Use to facilitate extubation Results Conclusions

30. 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

31. NIPPV for Respiratory Failure After Extubation

32. Impact of NIPPV vs. Intubation on Nosocomial Pneumonia

33. 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

34. Effect of NIPPV on Caregiver Time

35. 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

36. 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

37. 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

38. Early Experience With NIPPV (BiPAP) in Children

39. 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

40. 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

41. 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

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

43. 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

44. Vapotherm 2000i

45. Vapotherm: Mechanism of Action

46. 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…”

47. 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

48. 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!