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:
Barrington et al Pediatrics 2001; 107:

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 hours on NC-CPAP, switched to low flow nasal cannula (<2 LPM)

16. Results: (n=183) 15 (8 %) Range 385 – 4167 23 – 41 109 (60 %) 1 -124
Birth weight (g)
385 – 4167
Gestational Age (weeks)
23 – 41
BW < 1500 g (n) (%)
109 (60 %)
NC-IMV start (days)
1 -124
Duration of NC-IMV (days)
1 - 49
NC-IMV Failures, (%)
15 (8 %)
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

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

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

30. Neotech Ram Nasal Cannula®
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