Care of the Preterm Infant:Non-invasive Ventilation and Other Related

Important Stuff

SE Courtney, MD MSProfessor of PediatricsStony Brook University Medical Center

Opening the Lung

Congratulations! Baby is at OPTIMAL MEAN AIRWAY PRESSURE

Pressure

Benefit

Optimal Mean Airway Pressure

AtelectasisOverdistension

CPAP/PEEP: DR and beyond

• CPAP/PEEP should be used from the beginning

• If a self-inflating bag must be used, equip it with a PEEP valve

• Consider T-piece resuscitator

Finer NN et al, Resuscitation 2001

Use of oxygen

Oxygen Toxicity

• Retinopathy of prematurity• Increased days on ventilator• Increased days on oxygen• Increased incidence/severity of BPD

Finer N and Leone T. Oxygen saturation monitoring for the preterm infant: The evidence basis for current practice. Pediatr Res 2009;65:375-380

Oxygen in the Delivery Room

• A blender and pulse oximeter should be used• Start with 30 or 40% oxygen in the preterm

infant• Saturations of around 80% at 5 minutes are

normal

Oxygen in the NICU

• Saturations of 85-93% appear to be safe

Temperature control

Admission temperature <36 degrees centigrade is an independent risk factor for mortality in the preterm infant.

CPAP and Non-invasive Ventilation

Goal of Mechanical Ventilation

To get the patient OFF mechanical ventilation!

• Airway trauma• Infection• Decreased mucus clearance• Over-ventilation• Air leak• Contribution to BPD

NCPAP is probably a good thing

• CPAP Reduces mortality and respiratory failure in RDS

• Early CPAP reduces need for mechanical ventilation

• CPAP post-extubation can prevent extubation failure

• NO STUDY has shown reduction in BPD with use of CPAP under any conditions (testimonials don’t count)

NCPAP/NIV

• Constant-flow– conventional– bubble

• Variable-flow– Infant Flow– Bi-level

• NIPPV

Not all CPAP is created equal:Know your equipment

• Variable-flow NCPAP recruits lung volume well and decreases work of breathing. Care must be taken to avoid nasal trauma.

• Bubble NCPAP: pressures must be monitored; they will be higher than the depth of the underwater expiratory tube.

CPAP by Conventional Ventilator

• Constant flow of air/oxygen.• CPAP provided by changing orifice size at expiratory port of the ventilator, thus providing back-pressure.• Variety of prongs, usually bi-nasal.• Convenient, easily available, inexpensive.

“Bubble” NCPAP

“Bubble” NCPAP – Do We Know What We’re Doing?

Bias Flow (Liters/min) 4 6 8 10 12

Mea

n (+

/- SD

) Pre

ssur

e (c

mH 2O

)

2

4

6

8

10

12

No Leak

(set

NC

PAP)8

4

Ventilator: open symbolsBubble: solid symbols

Kahn DJ et al, Pediatric Research 2007;62:343.

Kahn et al, Pediatrics, 2007

3 5 7 4 2135

140

145

150

3 5 7 4 291

92

93

94

95

96

97

Set NCPAP (cmH2O)

Set NCPAP (cmH2O)

B-NCPAP V-NCPAP

B-NCPAP V-NCPAP

Hea

rt R

ate

(m

in-1

)Sa

O2

(%)

3 5 7 4 2

TcO

2 (m

mH

g)

50

55

60

65

70

3 5 7 4 2

TcC

O2

(mm

Hg)

46

48

50

52

54

56

Set NCPAP (cmH2O)

Set NCPAP (cmH2O)

B-NCPAP V-NCPAP

B-NCPAP V-NCPAP

Courtney et al, Bubble vs ventilator NCPAP, J Perinatol 2010

Pp=0.01

Variable-Flow (Infant Flow) CPAP• Flow is varied to deliver the required CPAP pressure. • The direction of flow depends on the pressures generated by the patient.• On inspiration, the CPAP flow is towards the nasal cavity, assisting in inspiration• On exhalation, the flow is down the expiratory branch of the CPAP tubing.

Childs, Neonatal Intensive Care, 2000

What Do We Know AboutVariable-Flow NCPAP?

• Provides a very stable mean airway pressure • Decreases work of breathing• Increases lung volume recruitment

Adapted from Moa G and Nilsson K. Acta Paediatr 1993;82:210.

C = Cannula

A = Aladdin (Infant Flow)

I = Inca Prongs (Conventional Ventilator)

Courtney SE, Pyon KH, Saslow JG et al. Pediatrics 2001;107:304-308

Pandit PB, Courtney SE, Pyon KH et al. Pediatrics 2001;108: 682-685

38.1 38.5

0

20

40

60

80

100

Conventional Infant Flow

Failu

re (%

)

Stefanescu et al, Pediatrics 2003;112:1031

Secondary Outcomes

Conv IF P

Days on O2 77.2 65.7 0.03

Length of Stay 86.3 73.7 0.02

Stefanescu et al, Pediatrics 2003;112:1031

Stefanescu et al, Pediatrics 2003;112:1031

58%

16%

15%

3%8%

Apnea / bradycardia

FiO2>0.5, CPAP>8 cm

PaCO2>65, pH<7.25

Surgery

Other

Apnea Hypoxia

Hypercarbia

NCPAP with a Rate:(NIMV, NIPPV)

NIMV for reducing apnea and extubation failure• Synchronized (?)NIMV reduces the incidence of extubation failure and possibly apnea more effectively than NCPAP.• “Synchrony” done with Graesby capsule and Infant Star ventilator• No information is available on non-synchronized NIMV.• Current studies ongoing

Owen LS, Morley CJ, Davis PG. PAS 2009

SiPAP

What is SiPAP?– A small (2-3 cmH2O), slow,

intermittent increase in CPAP pressure for a duration up to 3 seconds to produce a “Sigh”

– Enables the infant to spontaneously breathe throughout the cycle

0

2

4

6

8

10

12

14

0 2 4 6 8 10

CPAP Pressure

Volu

me

Chan

ge (m

l/kg)

5.5 ml/kg

Small increases in IF CPAPpressure can change lungvolume by 4-6 ml/kg.

Unlike NIPPV, SiPAP pressure riseis only 2-3 cmH2O

Adapted from Pandit PB, Courtney SE, Pyon KH et al. Pediatrics 2001;108: 682-685

SiPAP can therefore potentially:

• Recruit lung volume

• Decrease work of breathing

• Stimulate the respiratory center

Patients who may benefit from SiPAP:

• Infants weaning from mechanical ventilation

• Premature infants that don’t require aggressive support

• Infants with apnea

Nasal Bilevel vs Continuous Positive Airway Pressure in Preterm Infants. Migliori C et al, Pediatr Pulmonol

2005;40:426.

Nasal CPAP vs Bi-level nasal CPAP in preterm infants with RDS: a randomized control study. Lista G et al, Arch Dis Child Fetal Neonatal Ed. 2009

40 infants enrolled, mean GA 30wks, BW 1400g.

IF-CPAP SiPAP P

Respiratory support (d) 6.2 ± 2 3.8 ± 10 0.025

O2 dependency (d) 13.8±8 6.5 ± 4 0.027

GA at discharge (wk) 36.7± 2.5 35.6±1.2 0.02

SiPAP vs NCPAPWork of Breathing and Respiratory Parameters

S. Courtney, M. Weisner, V. Boyar, R. Habib

• 17 infants <1200gms birth weight, on NCPAP for mild respiratory distress

• Each infant own control; order of application randomized and data collected in two periods for a minimum of one hour, with 15 min on each device in each period (ie, CPAP/SiPAP, CPAP/SiPAP

• Data collected using calibrated respiratory inductance plethysmography; esophageal balloon for estimation of pleural pressure

• Continuous monitoring of saturation, pulse, transcutaneous oxygen and carbon dioxide

Minute Ventilation

Minute Ventilation

Period I Period II

MV

(ml/k

g/m

in)

220

240

260

280

300

320

CPAP SiPAP CPAP SiPAP

n=13 P=0.037

Synchronized Non-invasive ventilation

Shortcut to Graph.PNG.lnk

Conclusions about SiPAP

• Appears to be at least as effective as NCPAP

• May improve gas exchange and decrease minute ventilation (?decrease WOB)

• Synchrony may be useful

NCPAP by Nasal Cannula

NCPAP by Cannula

• Uncontrolled positive pressure may be generated with nasal cannula• Amount of positive pressure generated will depend on cannula size, flow rate, and shape of nasal passages.• High humidity, high flow cannulas also may pose an infection risk.

Nasal Cannula Use

Current literature would support that gas delivered by nasal cannula:• be heated and humidified• not exceed 1 L/min in infants <1500gm• not exceed 2 L/min in infants >1500gm

If CPAP is desired, a CPAP device should be used.

Non-invasive Ventilation is not appropriate when…

• Infant cannot maintain oxygenation (FiO2 > 0.5-0.6)

• PCO2 >60• pH < 7.25• Increased work of breathing• Apnea

Questions…………….• Over the long term, is any one form of NCPAP more advantageous than any other?• Is non-invasive ventilation combined with NCPAP advantageous? Is S-NIPPV better?• When should NCPAP be initiated?• When and how should surfactant be given for babies on NCPAP only?

• What levels of pH and PCO2 are “safe” for babies on NCPAP?

Keep an open mind and something useful may fall into it.