care of the preterm infant: non-invasive ventilation and other r elated i mportant stuff
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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.
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