Nasal Cannula Intermittent Mandatory Ventilation (NC-IMV)

1. Nasal Cannula Intermittent Mandatory Ventilation(NC-IMV)

2. Introduction • With increased survival of very low birth weight (VLBW) infants, the number of infants who require prolonged mechanical ventilation (MV) has increased • The pulmonary management of these infants is directed at minimizing the need for prolonged MV to reduce ventilator-induced trauma and oxygen toxicity • Early extubation often presents difficulties because of upper-airway instability, poor respiratory drive, alveolar atelectasis, and residual lung damage Khalaf et al Pediatrics 2001; 108:13-17

3. Background • Use of Nasal respiratory support (NARES) is on the rise to decrease post-extubation failures, bronchopulmonary dysplasia (BPD), and for the treatment of apnea of prematurity • CPAP, by various means, commonly is used to wean premature infants from mechanical ventilation

4. NCPAP Failure Rates • NCPAP use is associated with failure rates of 20 to 80% in preterm infants • Reasons for failure include recurrent apnea/ bradycardia/desaturations or respiratory acidosis requiring intubation or re-intubation Ramanathan et al J Perinatol October 2010; 30:S67-S72

5. Background • The addition of a back-up rate by using NIPPV not only adds intermittent distending pressure above PEEP but also increases flow delivery in the upper airway • Friedlich et al J Perinatol 1999; 19:413-418 • Barrington et al Pediatrics 2001; 107:638-641

6. NCPAP vs. NIPPV for NARES • Additionally, NIPPV has been shown to decrease NCPAP failure rates to 5 -20%

7. Background • Typical nasal interfaces used: • Short bi-nasal prongs • Inca prongs or Argyle Prongs • Nasopharyngeal prongs • Nasal mask with SiPAP machine • Variable flow devices • Infant Flow Drivers with nasal prongs or nasal mask. • Problems with these nasal interfaces • Cumbersome • Mucosal irritation, bleeding, nasal trauma • Obstruction due to secretions in the nose or nasopharynx

8. Background • High flow nasal cannula systems are increasingly adopted because of the ease of use • Vapotherm, Fisher Paykel HFNC • However, these HFNC systems have no ability to measure or limit the pressure delivered to the baby • There are no pop-off valves in these systems • Only pop-off is at 20 PSI to protect the device and not to protect the baby • Can generate significant amount of distending pressures at the nasal interface • Air leaks have been reported

9. Indications • To facilitate extubation of mechanically ventilated neonates • As a primary mode of support for neonates with respiratory distress • Infants with moderate-to-severe apnea

10. Materials • We use a time-cycled pressure and flow limited (TCPFL) intermittent mandatory ventilation via nasal cannula (NC-IMV) • This system gives us the ability to control pressure and flow rate with the use of nasal cannula while safely delivering rate, PIP, PEEP and limit the flow rate to 6 or 7 LPM

11. Materials • Nasal cannula-short tubing • Connected to larger adapter • Larger circuit • Same humidity, but heating at 40°C

12. Materials

13. NC-IMV Set-Up • Set up: Conventional Ventilator (Viasys) • Mode: Time Cycled Pressure Limited SIMV mode (TCPL-SIMV) • Reason: To allow us to be able to control the flow rate. • Flow Rate: • 6 LPM if using Neonatal size Nasal cannula • 7 LPM if using Infant size Nasal cannula • IMV rate: started at a maximum of 40 bpm • PIP: Same as the most recent Conventional Ventilator PIP (max 30 CmsH2O) • PEEP: 5 cmsH2O • Insp. Time: 0.5 seconds

14. NC-IMV Set-Up • Select appropriate Nasal cannula according to patient’s size • Babies <1Kg • Premie NeoTech RAM Nasal Cannula (2.0mm ID) • Babies 1-2.5Kg • Newborn NeoTech RAM Nasal Cannula (2.5mm ID) • Babies >2.5Kg • Infant NeoTech RAM Nasal Cannula (3.0mm ID)

15. Weaning Protocol • Wean PIP first • Once PIP was around 10, rate was decreased to 10 • If infant remained stable, switched to NC-CPAP • If infant was stable for 12-24 hours on NC-CPAP, switched to low flow nasal cannula (<2 LPM)

16. Results: (n=183) No cases of nasal injury or gastric or ear drum perforation were seen within the 1,168 days of NC-IMV. One pt with pneumothorax. Now have treated >300pts for >3,000 days of NC-IMV Ramanathan R, Andaya S et al, SPR Meetings, Vancouver, May 2010

17. Previous Studies • All infants tolerated NC-IMV • All infants tolerated feeds during NC-IMV • No cases of nasal injury, or gastric perforation were seen • NC-IMV failure rate requiring intubation in our study population was 8%

18. Conclusion • NC-IMV is feasible and well tolerated. • TCPFL NC-IMV allows clinicians to limit pressures and can be delivered safely to neonates • Therefore, it appears that NC-IMV may be used in facilitating extubation of mechanically ventilated neonates, as a primary mode of support for neonates with respiratory distress, and for the treatment of apnea of prematurity • While reducing obstacles such as mucosal irritation, bleeding, nasal trauma, or obstruction due to secretions in the nose or nasopharynx.

19. A NOVEL MEANS FOR DELIVERING NASAL INTERMITTENT POSITIVE PRESURE VENTILATION IN INFANTS VIA THE NASAL CANNULA (NC): MEASUREMENTS OF DELIVERED PARAMETERS IN A NASAL AIRWAY/LUNG MODEL

20. NC-IMV • Nasal Cannula Intermittent Mandatory Ventilation (NC-IMV) is a novel means of delivering pressure controlled NIPPV breaths noninvasively to neonates requiring respiratory support. • We have previously reported that NC-IMV is feasible and well tolerated in a large number of neonates. • However, pressures or volume delivered to the patient is not known. Ramanathan et al Pediatric Academic Society, May 2010; Abstract 1472.217

21. Hypothesis • NC-IMV is sufficient to provide measurable ventilation effects and pressure, using 3 different cannula devices, in a lung model using a realistic "leaky” neonatal airway model

22. Objective • To determine the magnitude of pressure and volume delivered to an infant nasal airway/lung model • Using different sized nasal cannula • At different peak inspiratory pressure (PIP) settings during constant flow, time-cycled, pressure-limited ventilation.

23. Methods • We configured a neonatal test lung to simulate an apneic premature infant (CL:0.8 mL/cmH20; R:75 cmH20/L/sec). • A realistic infant nasal airway model was attached to the test lung.

24. Methods • 28 week premature infant airway model that was reconstructed from a head CT scan and a rapid prototyping device

25. Methods Schematic of Experimental set-up

26. Methods • Set up: Conventional Ventilator (Viasys) • Mode: Time Cycled Pressure Limited SIMV mode (TCPL-SIMV) • Flow Rate: 7-9 LPM • IMV rate: 40 bpm • PEEP: 5 cmsH2O • Insp. Time: 0.5 seconds • The nasal airway was ventilated at PIP of 10, 15, 20, 25, and 30 cmH20

27. Methods • Nasal cannulae used • Neonatal nasal cannula (Fisher Paykel, Auckland, NZ): ID 1.5 mm • Infant nasal cannula (Fisher Paykel, Auckland, NZ) : ID 1.8 mm • New prototype nasal cannula(Neotech Ram Nasal Cannula®) : ID of 3 mm

28. Results with ID 1.5 mm Results with ID 1.5 mm Fisher Paykel Neonatal Nasal Prongs

29. Results with ID 1.8 mm Fisher Paykel Infant Nasal Prongs

30. Results with ID 3 mm Results with ID 3 mm Neotech Ram Nasal Cannula®

31. Results • Under all testing conditions, there was detectable PLUNG, VLUNG, and PEEP during NC-IMV. • There was a linear relationship between PIP applied by the ventilator and VLUNG/PLUNG up to 30 cmH20.

32. Results • The Neotech Ram Nasal Cannula® provided greater PLUNG, VLUNG, and PEEP than the other infant nasal cannulae during NC-IMV.

33. Poiseuille’s Law πr4ΔP Q = ________ 8μL • Increased ID to 3mm • Increased ID of delivery tubing to 3 or 3.5mm • Shortened length of delivery tubing • Changed shape of prongs

34. Thank You

35. NCPAP: Extubation Failures ~20-80% (8 Studies; 2001-2009) % Bi-Nasal vs. Single Prongs IFD vs. V-CPAP NCPAP vs. Surf+NCPAP* IFD vs. B-CPAP Ramanathan R. J Perinatol 30:S67-S72; October 2010