Transcript CPAP – A GENTLE VENTILATION

CPAP – A “GENTLE”
VENTILATION
DR ASHOK MODI
MD, DNB, MRCP(UK)
CONSULTANT NEONATAL INTENSIVIST
Bhagirathi Neotia Woman & Child Care
Centre
CONTENTS
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Introduction
Historical aspects
How it works
Methods
Indications
Weaning
Adverse effects
Introduction
• Respiratory distress in a just born baby- bad
news!
– For doctors – Inconvenience, complications(BPD)
– More so for family – death, handicap, cost
• Solution – CPAP
– Doctors – convenient, less likely to go wrong
– Family – baby saved, low cost
• Do I need to tell more?
– Continuous distending pressure to upper & lower
airways, spontaneously breathing, throughout
What is CPAP ?
A technique of airway Management
which :-
in
1. Positive intrapulmonary pressure is
applied artificially to the airways , whereby
Distending Pressure is created in the
Alveoli
2. Spontaneously breathing baby
3. Throughout the respiratory cycle
Historical aspects
• Harrison – 1st increased alveolar pressure
during expiration in RDS; Abolition of the
grunt in RDS – deterioration
• Gregory et al(1971) – used CPAP 1st in
spontaneously breathing neonate in RDS
• Last 3 decades – long way to newer devices
with better knowledge of physiology & biophysics
What does it do?
• Prevents alveolar atelectasis, enhances
& maintains FRC
• Decreases total airway resistance
• Regularises breathing pattern
• Improvement in surfactant metabolism
• Splints chest wall, airways & Pharynx
• Reduces work of breathing
What does it do?
• Results in reopening of
collapsed/unstable alveoli – Increased surface area for gas exchange
– Preserves surfactant esp if applied early
– Prevents Intrapulmonary shunting
• Net result improved oxygenation &
ventilation
How to deliver CPAP
• Delivery of continuous positive airway
pressure requires 3 components –
1. Flow circuit(warm & humidified)
2. An airway interface
3. A positive pressure system
Airway Interface
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Single nasal prongs
Binasal prongs(Short & Long)
Nasopharyngeal prongs
Endotracheal tube
Head boxes, nasal cannulae, face masks
Short binasal prongs most effective,
least invasive
Positive pressure system
• Fluid column(Bubble CPAP)
• Resistance applied at the expiratory
valve e.g Draeger
/ Ventilator
• Pressure generation at nasal level
• CPAP generation in the immediate
vicinity of nasal airway by converting
kinetic energy e.g Infant flow driver
DEVICES
• Infant Flow Driver –unique fluid
mechanics(fluidic flip action)
• Bubble CPAP – oscillatory vibrations
• Infant Ventilator with CPAP mode
• Which is the best?
Optimal pressure
• No compelling Data
• Traditional 4 –6 cm of water
• However some studies as high as 10 cm
H2O
• Tailored to baby’s needs
• Increments by 1 cm of water
• Guided by CXR
INDICATIONS
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Mild to moderate RDS
Apnoea of prematurity
After extubation
Alternative to mechanical ventilation
( INSURE)
• Presence of poorly expanded or infiltrated
lung fields on CXR
• Tracheomalacia or abnormalities of lower
airways
CONTRA-INDICATIONS
• Definite need for intubation & Ventilation
– Upper airway anomaly e.g choanal atresia, cleft lip
& palate, TOF
– Cardiovascular instability & impending arrest
– Unstable respiratory drive
– Untreated CDH
– When CPAP is failing
• Bronchiolitis
Monitoring & Care
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Minimal handling/Sedation
Nasal prongs of right size in place(FIXATION)
Orogastric tube
Care of the nares
Change of posture
Vitals & Continuous pulse oximetry
Blood gas, haematological, radiological &
biochemical monitoring
Is CPAP Helping?
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Reduction in respiratory rate
Stabilization or reduction in Fio2
Resolution of grunting
Reduction in degree of sternal &
intercostal recession
When is CPAP failing
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Recurrent apnoeic attacks
Spontaneous episodes of desaturation
Increasing oxygen requirements
Worsening respiratory distress
Agitation not relieved by simple
measures
• Worsening blood gases
WEANING
• Once baby very stable with minimal
respiratory distress, normal blood gas &
improving CXR
• Fio2 gradually weaned to 40 – 50%
• Then pressure decreased in steps of 1
cm of water until 3 – 4 cm
Not without its complications
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Do not take CPAP lightly!
Pulmonary air leaks
Excessive pressure- compromise o2
Abdominal distension
Hypotension
Local – excoriation, scarring, deformity
Setting an simple CPAP
To conclude
• Gentle & poor man’s ventilation
• Easy to set up & minimal training
• Save babies with RDS in developing
countries vs headbox O2
• Lots of unanswered questions yet –
– Optimal device
– Ideal pressure