Protocol For Administering CPAP
Definition (CPAP):
Continuous distending pressure (CDP) is a method of delivering low pressure distension
to the lungs during the respiratory cycle. Methods of achieving this include positive end
expiratory pressure (PEEP) during mechanical ventilation, continuous positive airways
pressure (CPAP) applied to the upper airway (usually nose) and continuous negative
expiratory pressure (CNEP). In preterm infants the application of CDP either as CPAP of
CNEP is associated with reduced respiratory failure and reduced mortality..
Positive pressure therapy via a facemask was first described in 1936, in the treatment of
acute respiratory insufficiency. Gregory first described its use in neonates in 1971. Since
this time many devices and routes of administration have been described. Indications for
CPAP have been refined and the potential pitfalls have been elucidated.
CPAP refers to the application of positive pressure to the airway of spontaneously
breathing infant throughout the respiratory cycle.
How does it work?
CPAP predominantly helps by preventing collapse of the alveoli with marginal stability.
This results in better recruitment of alveoli thus increasing the functional residual
capacity (FRC).
Components of CPAP System:
1- Gas source: to provide continuous supply of warm humidified and blended
gases (air and oxygen).
2- Pressure generator: To creates the positive pressure in the circuit.
3- Patient interface: To connect the CPAP circuit to the infant's airway.
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Physiological Effects of CPAP
Continuous positive airway pressure has been shown to increase arterial oxygen content.
The mechanisms by which this is achieved are complex and probably due to a
combination of the factors outlined below.
1. Increases functional residual capacity.
2. Reduces right to left shunting by reducing the ventilation: perfusion mismatch.
3. Decreases airway resistance by increasing pharyngeal cross-sectional area.
4. Reduces obstructive apneas.
5. Stabilizes the respiratory rate.
6. Reduces the severity of central apnoea.
7. Protective effect on surfactant.
8. Decreases alveolar edema.
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The physiologic effect of CPAP are represented in figure (1) below :
CPAP
Prevents collapse of
alveoli with marginal
stability
Stabilizes the
chest wall
Splints open
Upper airway
Stretches Lung
and pleura
upper airway
Conservation of
Endogenous surfactant
Recruitment of
more alveoli
Reduce airway
resistance
Maintains Lung
at FRC
Reduce
obstructive
apnea
Reduce work of
breathing
Increased alveolar surface
area for gas exchange
Stimulates
stretch
receptors
Reduce mixed and
central apnea
Improves V/Q mismatch
and Reduces
intrapulmonary shunt
PaCO₂
PaO₂
Reduces PVR
Improves pH
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FRC: Functional residual capacity
V/Q: Ventilation –perfusion ratio
PVR: Pulmonary vascular resistance
PaCO₂ & PaO₂ : Partial pressure of carbon –di-oxide and oxygen respectively
in the arterial blood
Oxygen Devices:
A- Low Flow Dev. (variable performance)
 Nasal canola: you can give from 1-5 liters of O₂ & it provides 2%
of O₂ concentration above 21% for each liter.
 Simple face mask: you can give from 5-10 liters of O₂ & it
provides 3-4% of O₂ concentration above 21% for each liter.
Below 5 liter of O₂ there will be rebreathing & above 10L there
is wastage.
 Mask with reservoir (bag) with rebreathing valve: can give
10- 15 L of O₂ with concentration of O₂ up to 60%.
 Mask with reservoir (bag) with non rebreathing valve: give 1015 L of O₂ with 100% O₂.
B- High Flow Dev. (Fixed Performance):
- eg. Venture you can give fixed flow with fixed O₂ concentration.
Can be used in Chronic obstructive pulmonary disease (COPD),
Gasping breathing, Chiny- stocke breathing.
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CPAP pressure generators
Continuous flow device
Variable flow device
Vary the CPAP pressure by a
mechanism other than flow variation
The desired CPAP level is
generated by varying the flow
1- Infant ventilator /Stand-alone
CPAP machines:
Pressure is generated by the
exhalation valve and adjusted by
varying the expiratory orifice size .
Common examples:
2- Bubble CPAP :
Pressure is generated by
submerging the expiratory limb
into a water chamber and adjusted
by altering its depth.

Infant flow driver (IFD)

ViasysSiPAP
CPAP pressure is generated at the airway
proximal to the infant’s nares.
Figure 2 :Types of CPAP device
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Patient interface CPAP delivery:
Various device used for CPAP delivery;




Nasal prongs (single /double or binasal )
Long (or) nasopharyngeal prongs
Nasal cannulae
Nasal Masks
Face mask ,endotracheal , and head box are no longer used for CPAP delivery in
neonates.
Endotrcheal CPAP is not recommended because it has beed found to increase the work
of breathing.
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Table 1: Advantage and disaadvantages of commom CPAP patient interfaces
Delivery System
Nasal prongs(single /binasal )
Example;
 Argyle
 Hudson
 IFD prongs
Nasopharyngeal prongs
(e.g. using a cut endotracheal
tube )
Advantages



Simple device
Lower
resistance
Mouth leak acts
like a pop-off
mechanism
Easy availability
 Economical
 More secure
fixation





Nasal cannulae ( with an
Ease of application
outer diameter of 3mm and
flows up to 2 L/min ) Length
is estimated by measuring
the distance from the
earlobe to the tip of the chin
or nose ;tube placement is
conifirmed by direct
visualization of the tip behind
the uvula
Nasal masks
Disadvantages
Minimal nasal trauma
Relatively
difficult to fix
Risk of trauma to
nasal septum
and turbinates
Leak through
mouth means
end expiration
pressure is
variable
More easily
blocked by
secretion Likely
to get kinked
Unreliable
pressure
 May need high
flows to
generate
pressure
 FiO₂ delivered
may be high
 Large leaks
around the
cannulae.
Difficulty in obtaining a
tight seal
(IFD,infant flow driver)
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Remarks
Studies have shown
that they are more
effective than
nasopharyngeal prongs
( in post-extubation
setting )
Through more
economical and easily
available , they are
found to be inferior to
short binasal prongs
 Mainly tried in
apnea of
prematurity
paucity of data
in other
conditions
 Still
experimental
New generation masks
are yet to be studied
Indication for CPAP
1- An alternative to intubation & Ventilation for the Respiratory Distress
Syndrome (RDS) in presence of increased work of breathing as indicated
by a 30-40% increase above the normal in RR, suprasternal ,substernal
retractions, grunting and nasal flaring.
Objective criteria is inability to maintain PaO₂ greater than 50 mmHg with
FiO₂ of < or = 60% provided that PaCo₂ level of 50 mmHg and PH> or = 7.25.
Goal of therapy in RDS is PaO₂ 50-70mmHg, PaCO₂ of 40-65mmHg, pH 7.257.40
Good clinical status and CXR Shows the presence of poorly expanded &/or
infiltrated lung field.
2- Pulmonary edema/pulmonary hemorrhage.
3- Atelectasis (also secondary to meconium aspiration).
4- Apnea of prematurity. It has been found that CPAP halves the incidence
of apneic episodes.
5- Recent extubation in preterm VLBW infants.
6- Trachealmalacia/Laryngomalacia or other similar abnormality of the
lower airways.
7- TTNB/ delayed adaptation.
8- Weaning chronically ventilator-dependent infants
CPAP can also be used to differentiate between cyanosis due to pul. or
cardiac disease by increase in PaO₂ with CPAP of more than 20mmHg that can
rule out CHD in FiO₂ of 80-100%.
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Contraindications for CPAP
The important contraindications for CPAP include:
1- Progressive respiratory failure with PaCO₂ levels > 60 mmHg and /or
inability to maintain oxygenation (PaO₂ < 50 mmHg)
2- Certain congenital malformations of the airway ( choanal atresia
,cleft palate, trachea esophageal fistula , congenital diaphragmatic
hernia , etc.)
3- Severe cardiovascular instability (hypotension)
4- Poor respiratory drive (frequent apnea and bradycardia) that is not
improved by CPAP.
Guidelines for CPAP therapy
CPAP is started at pressure of 5cm of water with FiO₂ of 40-50%.
 If no improvements of RD with the above values, or worsen or
oxygenation is impaired pressure is increased in 1-2 cm till
maximum8-10 cm water. Often there is dramatic rise in PaO₂
with little or no change in PaCO₂ or PH.
 If still the oxygenation is compromised Fio2 is increased in steps
of 5-10% increments of oxygen to reach max of 80%.
BGA is the primary method used to determine CPAP effectiveness
that should be measured 10-15 minutes after each change of
pressure or O₂.
 If there is increase in PaCO₂ or decrease in PaO₂ the pressure
should be reduced.
The optimal CPAP PRESSURE is not known and may depend on the
patient condition.
But in general patient with RDS of relatively stiff lung & accepted FiO₂
with a chest radiograph showing opaque lungs may need higher
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pressure to support the lung expansion than a baby with a low FiO₂
that treated for apneic episodes.
 It is necessary to remember that do not raise FiO₂ before
raising pressure for hypox emia.
Optimal flow rate should be provided which is 6-8L/min in preterm
and 8-10L/min to full term baby
OPTIMAL CPAP
• Is that level of distending pressure that result in maximum PaO₂ and
lowest FiO₂ without increase in PaCO₂ or any adverse effect on
circulatory status, with stabilization of RR, no RD, pink color and normal
CRT and blood pressure? The saturation should be between
90-93%, PaO₂ 60-80mmHg and PaCO₂ of 35-45mmHg and PH of 7.3-7.4.
• An easy bedside method is to look at X-ray chest. On optimal settings
the number of posterior intercostals spaces above the diaphragm
should be (7-8).if < 5 spaces increase CPAP, if lungs are hyper inflated> 8
spaces or the dome of diaphragm is flattened, decrease CPAP.
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Monitoring of Baby on CPAP:
•
•
•
•
•
Continuous monitoring of SO2
RR,CRT.BP,PR.Temp Q 1Hrly
Abdgirth,UOP Q2Hrly.
BGA :Q8Hrly
Small amount of feeding (10ml) can be started if the baby is
hemodynamically stable through (OG) tube and can be increased
gradually
Early CPAP :
It is important to note that CPAP helps mainly by preventing the
alveolar collapse have occurred, CPAP might not help much.
Therefore, all preterm infants (<35 weeks) with any sign of
respiratory distress (tachypnea / chest in–drawing / grunting) should
be started immediately on CPAP.
Prophylactic CPAP:
Extending this logic, some have advocated use of prophylactic CPAP
(before the onset of respiratory distress) in preterm VLBW infants as
majority of them would eventually develop respiratory distress.
However, there is no evidence for any additional benefit with this
approach; indeed, there are concerns regarding increased adverse
effects such as intraventricular hemorrhage. Hence, prophylactic
CPAP is NOT recommended at present.
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How to set up a CPAP apparatus?
The steps in setting-up a bubble CPAP are summarized in Panel 2 as
below in page (13).
How to fix the CPAP delivery system (nasal canola)
The most difficult aspect of using nasal CPAP is the positioning and
fixation of the patient interface. The optimal technique of fixation
depends on the type of delivery system used; the exact technique
used does not matter as long as the device is secure and not
traumatizing.
Short binasal prongs: It is important to choose the appropriate size
and prong that snugly fits in the nasal cavity to avoid a significant
leak. However, to avoid causing any injury, it should be fixed straight
and not pressed hard against the nasal septum.
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Protocol for CPAP therapy
Protocol for CPAP therapy in the three most common conditions
Monitoring while on CPAP
The following parameters need to be monitored while the infant is
on CPAP:
1. Continuous monitoring of respiratory rate, heart rate, SpO₂.
2. Serial monitoring of
 Severity of respiratory distress by using Downes or
Silverman score
 Arterial blood gases(ABGs)
 Perfusion –CFT, BP, peripheral pulses ,urine output
 Abdominal girth
The target saturation and blood gases during CPAP therapy are:
SpO₂ - 87-93 %; PaO₂- 50 to 80 mmHg; PaCO₂- 40 to 50 mmHg
Steps of Initiation and Nursing care during CPAP
A- How to set-up a bubble CPAP?
1- Connect the air and oxygen tubing (pressurized gases from
either central manifold or from compressor and oxygen
cylinder respectively)
2- Attach both to the air-oxygen blender
3- Set the flow using flow meter (usually at 5-8 L/min)
4- Set up the aspiratory limp :
a) From the flow meter to the humidifier and
b) From the humidifier to the patient end (e.g. nasal
cannula); fill water in the humidifier and humidify the
gases to 34-37 C.
5- Set up the expiratory limb – from the patient end to a
chamber filled with sterile water .Immerse it under water up
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to the required depth (which is determined by the intended
pressure –e.g. to deliver 4 cm H₂O, immerse up to 5cm mark in
the tube).
6- Attach a pressure manometer at the patient end
7- Set required pressure and FiO₂, low pressure alarm and apnea
alarm
8- Occlude the patient end of the ventilator circuit with your
palm and observe if;
 Bubbling occur in the water chamber – if there are no
bubbles , look for any leak in the circuit; if no leak is
found ,increase the flow by 1 L/min and recheck.
 The set pressure is delivered (see the manometer
reading)- if it is less than the set pressure, look for any
leaks in the circuit / around the canola. If no leak is
found, increased the flow and recheck.
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B- Initiation of CPAP
1- Place a roll under infants shoulder to slightly extend the neck.
2- Application of prongs:
 Choose the correct size prong (the prongs should fill the
nasal opening without stretching the skin)
 Apply a thin strip of Tegaderm on overlying skin of
septum.
 Place the prongs with the curve downwards and fix as
shown in figure 4.
3- Attach the patient end of the ventilator circuit to the canola.
4- Attach a pulse - oximeter to the infant.
C-Nursing Care
1- Monitor the infant frequently; observe if the baby is comfortable.
2- Pass an orogastric tube. Keep the proximal end of tube open .if
the infant is being fed while on CPAP, close the tube for half an
hour after giving feeds it open for the next 90 minutes( if fed 2
hourly).
3- Do regular but gentle nasal suction to clear the mucus 4 hourly or
as and when required.
4- Clean the nasal canola and check its patency once per shift>
5- Change the infant's position regularly every 2-4 hours and check
the skin condition frequently for redness and sores.
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Hazards/ Complications of CPAP
CPAP through less invasive and generally safer than IMV is not
free of side effects.
1- Pulmonary air leaks are probably the most important clinically
significant adverse effect of CPAP. It occurs following over
distension of the lungs caused by inappropriately high
pressures. They tend to occur, when the lung compliance
starts improving and the oxygen requirements also show a
reduction .one has to note that the two recent trials on CPAP
for RDS have shown either a trend or a definite increase in the
incidence of pneumothorax. Therefore; extra vigilance is
required during CPAP therapy.
2- Decreased cardiac output due to reduction in the venous
return, decreased right ventricular stroke volume, and altered
distensibility of left ventricle. This effect can be minimized by
using optimal CPAP and achieving adequate intravascular
volume.
3- Impedance of pulmonary blood flow with increased pulmonary
vascular resistance (with inappropriately high CPAP pressure).
4- Gastric distension and CPAP belly syndrome. These
complications are rarely seen nowadays. The risk is further
minimized by routine use of orogastric tube.
5- Nasal irritation, damage to the septal mucosa, or skin damage
and necrosis from the fixing devices.
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Table 2 : Protocol for CPAP therapy in the three common neonatal
conditions
Indication
Apnea of
prematurity
RDS
How to initiate CPAP
Pressure
FiO₂
What to do if there is
no improvement?
Pressure
FiO₂




Failure of CPAP

Weaning from CPAP
-When to wean

-How to wean

Post Extubation
Start at 5cm H₂O
0.5( titrate based on
SpO₂)


Start at 4cm H₂O
0.21- 0.4 ( as
decided by SpO₂)

Increase in steps of 12cm
H₂O to reach a maximum
of 7-8cm H₂O
Increase in steps of 0.05
(if oxygenation is still
compromised ) up to a
maximum of 0.8


Worsening
respiratory
distress ( as indicated by
Silverman
scoring
)
and/or
hypoxemia
(PaO₂<50mmHg)/hyperca
rbia (PaCO₂> 60 mmHg )
despite CPAP pressure of
7-8cm H₂O and FiO₂ of
0.8
When there is no
respiratory distress and /
blood gases are normal
Reduce FiO₂ in steps of
0.05 to 0.4 ,then
decrease pressure in
steps of 1-2cm H₂O until
3-4 cm H₂o ( infants
clinical condition will
guide the speed of
weaning )

Increase up to 5cm
H₂O (further
increase is not
warranted usually
in this conditionmay lead to
hyperinflation)
FiO₂ increase does
not help much
Recurrent episodes
of apnea requiring
PPV

Same as for RDS
No episodes of
apnea/desaturation
/bradycardia for at
least 12-24 has hrs
Same as for RDS

Same as for RDS



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

Start at 4-5cm
H₂O
0.05
to
0.1
above the preextubation FiO₂
Increase in steps
of 1-2cm H₂O to
reach a
maximum of 78cm H₂O
Increase in steps
of 0.05 to a
maximum of 0.8
CPAP Failure: this can be suspected if:
• Increase in Pco2 above 65mmHg /or PH < 7.25 on two consecutive
occasions.
• Fio2 of 0.8 at pressure of 8cm H2o to keep sat. O₂>90% for more than 4
hours consecutively.
• More than 3 apneic episodes/hour requiring stimulation and ventilation.
• Progressive metabolic acidosis, pulmonary edema, resp. muscle fatigue
with lack of nutrition may lead to initiation of mechanical ventilation.
• Improper fixation of CPAP device and frequent dislodgments, with
excessive secretion obstruct airway or nasal prongs
• Low flow rate in the circuit and faulty machine delivering lower pr. Or
Fio2 than displayed by the screen
• CPAP failure is more in ELBW < 1000gm and in babies with severe HMD
or pneumonia.
Delay in CPAP use is more likely to be associated with failure
Conclusion
CPAP has been well established as the first line therapy in the
management of respiratory distress in preterm VLBW infants. It helps
by preventing alveolar collapse maintaining airway stability and chest
wall. Various device, both for pressure generation and for delivery of
CPAP, are available for use in neonates . The advantage of each
device , method of fixation of short binasal prongs , and a protocol for
initiation of CPAP have been discussed in this protocol .
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References
1- Sankar MJ, Deorari AK. CPAP – A gentler mode of ventilation. J Neonatol 2007;
21:160-5
2- Upadhyay A, Deorari AK. Continuous positive airway pressure - a gentler
approach to ventilation. Indian Pediatr 2004;41:459-69
3- Gregory GA, Kitterman JA, Phibbs RH, et al: Treatment of idiopathic respiratory
distress syndrome with continuous positive airway pressure. N Engl J Med
1971;284:333-40
4- Kattwinkel J, Nearman HS, Fanaroff AA, Katona PG, Klaus MH. Apnea of
prematurity. Comparative therapeutic effects of cutaneous stimulation and nasal
continuous positive airway pressure. J Pediatr 1975;86:588-92
5- Avery ME, Tooley WH, Keller JP, et al. Is chronic lung disease in low birth weight
infants preventable? A survey of eight centers. Pediatrics 1987;79:26-30
6- Courtney SE, Barrington KJ.Continuous positive airway pressure and noninvasive
ventilation. Clin Perinatol. 2007;34:73-92
7- Anonymous. Continuous Positive Airway Pressure Machines. In: Deorari AK, Paul VK
(eds). Neonatal Equipment. 3rd edn. New Delhi: Sagar Publications 2006: p 129-137
8- De Paoli AG, Davis PG, Faber B, Morley CJ. Devices and pressure sources for
administration of nasal continuous positive airway pressure (NCPAP) in preterm
neonates. Cochrane Database of Syst. Rev. 2002: CD002977.
9- Sreenan C, Lemke RP, Hudson-Mason A, et al. High-flow nasal cannulae in the
management of apnea of prematurity: a comparison with conventional nasal
continuous positive airway pressure. Pediatrics 2001;107:1081–3
10- Gittermann MK, Fusch C, Gittermann AR, Regazzoni BM, Moessinger AC. Early
nasal continuous positive airway pressure treatment reduces need for intubation
in very low birth infants. Eur J Pediatr 1997;156:384-8
11- Poets CF, Sens B. Changes in intubation rates and outcome of VLBW -a population
based study. Pediatrics 1996;98:24-7
12- Verder H, Robertson B, Greisen G, Ebbesen F, Albertsen P, Lundstron JT. Surfactant
therapy and nasal continuous positive airway pressure for newborns with
respiratory distress syndrome. Danish-Swedish Multicentre Study Group. N Engl J
Med 1994; 331: 1051-5.
Downloaded from www.newbornwhocc.org 19
AIIMS- NICU protocols 2008
13- Subramaniam P, Henderson-Smart DJ, Davis PG. Prophylactic nasal continuous
positive airways pressure for preventing morbidity and mortality in very preterm
infants. Cochrane Database of Syst.Rev.2005: CD001243.
14- Hall RT, Rhodes PG: Pneumothorax and pneumomediastinum in infants with
idiopathic respiratory distress syndrome receiving CPAP. Pediatrics 55: 493, 1975.
15- Buckmaster AG, Arnolda G, Wright IM, Foster JP, Henderson-Smart DJ. Continuous
positive airway pressure therapy for infants with respiratory distress in non tertiary
care centers: a randomized, controlled trial. Pediatrics 2007;120:509-18
16- Morley CJ, Davis PG, Doyle LW, Brion LP, Hascoet JM, Carlin JB; COIN Trial
Investigators.Nasal CPAP or intubation at birth for very preterm infants. N Engl J
Med 2008;358:700-8
17- Tittley JG, Fremes SE, Weisel RD, Christakis GT, Evans PJ, Madonik MM, et al.
Hemo-dynamic and myocardial metabolic conse-quences of PEEP. Chest
1985;88:496-502
20 ‫ من‬19 ‫الصفحة‬
18- Poulton EP, Oxon DM; Left sided heart failure with pulmonary oedema: its treatment with the
"pulmonary plus pressure machine". Lancet 1936; 231: 981
19- Gregory GA, Kitterman JA, Phibbs RH et al: Treatment of idiopathic respiratory distress
syndrome with continuous positive airway pressure. New England Journal of Medicine 1971;
284: 1333
20- Chemick V. Hyaline membrane disease therapy with continuous distending pressure. New
England Journal of Medicine 1973; 289: 302
21- Haman S, Reynolds EOR: Methods for improving oxygenation in infants mechanically ventilated
for severe hyaline membrane disease. Archives of Diseases in Childhood 1973; 48: 612
22- Goldsmith JP, Karotkin EH: Assisted ventilation of the neonate: Saunders, 3rd Edition, 1996.
23- Alex AG, Aronson RM, Onal E, Lopata M. Effects of positive airway pressure on upper airway and
respiratory muscle activity. Journal of Applied Physiology. 1987; 62(5): 2026-30.
24- Cotton RB, Lindstrom DP, Kanarek KS, Sundell H, Stahlman MT. Effect of positive-end-expiratorypressure on right ventricular output in lambs with hyaline membrane disease. Acta Paediatrica
Scandinavica. 1980; 69(5): 603-6.
25- Miller MJ, Carlo WA, Martin RJ. Continuous positive airway pressure selectively reduces
obstructive apnea in preterm infants. Journal of Pediatrics 1985; 106: 91-4.
26- Speidel BD, Dunn PM. Effect of continuous positive airway pressure on breathing pattern of
infants with respiratory-distress syndrome. Lancet. 1975; 1(7902):302-4.
27- Speidel BD, Dunn PM. Use of nasal continuous positive airway pressure to treat severe recurrent
apnoea in very preterm infants. Lancet 1976; 2(7987): 658-60.
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