Care of the Preterm Infant: Non-invasive Ventilation and

Report
Care of the Preterm Infant:
Non-invasive Ventilation and Other
Related Important Stuff
SE Courtney, MD MS
Professor of Pediatrics
Stony Brook University Medical Center
Opening the Lung
Congratulations! Baby is at OPTIMAL MEAN AIRWAY PRESSURE
Optimal Mean Airway Pressure
Benefit
Overdistension
Atelectasis
Pressure
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
12
Ventilator: open symbols
Bubble:
solid symbols
10
8
8
6
4
4
No Leak
2
4
6
8
10
Bias Flow (Liters/min)
Kahn DJ et al, Pediatric Research 2007;62:343.
12
(set NCPAP)
Mean (+/- SD) Pressure (cmH 2O)
“Bubble” NCPAP – Do We Know
What We’re Doing?
Kahn et al, Pediatrics, 2007
70
150
B-NCPAP
V-NCPAP
Heart Rate (min-1)
65
TcO2 (mmHg)
B-NCPAP
Pp=0.01
V-NCPAP
60
55
50
145
140
135
3
5
7
4
2
3
Set NCPAP (cmH2O)
5
7
4
2
Set NCPAP (cmH2O)
97
56
B-NCPAP
96
V-NCPAP
SaO2 (%)
TcCO2 (mmHg)
54
52
50
95
94
93
48
B-NCPAP
92
V-NCPAP
46
91
3
5
7
4
Set NCPAP (cmH2O)
2
3
5
7
4
2
Set NCPAP (cmH2O)
Courtney et al, Bubble vs ventilator NCPAP, J Perinatol 2010
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 About
Variable-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
100
Failure (%)
80
60
40
38.1
38.5
Conventional
Infant Flow
20
0
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
16%
Apnea
Hypoxia
Apnea / bradycardia
58%
FiO2>0.5, CPAP>8 cm
PaCO2>65, pH<7.25
Hypercarbia
Surgery
15%
3%
8%
Stefanescu et al, Pediatrics 2003;112:1031
Other
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
Small increases in IF CPAP
pressure can change lung
volume by 4-6 ml/kg.
14
Volume Change (ml/kg)
Unlike NIPPV,
SiPAP pressure rise
is only 2-3 cmH2O
12
10
8
6
5.5 ml/kg
4
2
0
0
2
4
6
8
10
CPAP Pressure
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 NCPAP
Work 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
320
Minute Ventilation
280
260
240
220
MV (ml/kg/min)
300
n=13
P=0.037
CPAP
SiPAP
Period I
CPAP
SiPAP
Period II
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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