CPAP therapy provides positive airway pressure throughout the respiratory cycle to help stabilize the lungs. It has various physiological effects like decreasing respiratory rate and increasing functional residual capacity. CPAP can be applied through nasal prongs, masks, or endotracheal tubes. It is commonly used to treat respiratory distress syndrome, meconium aspiration syndrome, and apnea of prematurity. Optimal CPAP levels depend on the underlying lung disease and physiology. CPAP is generally well-tolerated but high levels can cause side effects like air leaks or decreased cardiac output. Close monitoring is needed when applying and weaning infants from CPAP support.

1. CPAP therapy
in the Newborn
Thrathip Kolatat M.D.
Neonatal Intensive Care Unit
Department of Pediatrics
Faculty of Medicine Siriraj Hospital

2. Continuous
Positive
Airway
Pressure
(CPAP)

3. CPAP
l the application of positive
airway pressure
throughout the respiratory
cycle during spontaneous
respiration
l history
l Harrison 1968: described
grunting in neonates as
naturally producing end-
end-
expiratory pressure
l Gregory et al, 1971:
introduced the clinical use
of distending pressure in
neonates

4. Physiologic effects of CPAP
l pulmonary mechanics
l cardiovascular stability
l pulmonary vascular resistance

5. Pulmonary effects
l decrease respiratory rate, tidal volume
and minute volume
l regularization of respiration
l increase FRC and thoracic gas volume
l decrease lung compliance and
dynamic compliance
l decrease total airway resistance
l protective effect on surfactant

6. Effect of CPAP on FRC in the infants with RDS
20
15
10
FRC (ml/kg)
Control
5
+4 torr
0
2 3 4
Age (days)

7. Effect of different CPAP levels on PaO2
300
200
Pa o(torr)
2
100
0
4 8 12 16 20
CPAP (torr)

8. Cardiovascular effects
l compromise venous return results in diminished cardiac
output
l depend on lung compliance
l sign and symptom: tachycardia, metabolic acidosis,
hypotension, decreased dynamic compliance, carbon dioxide
retention
l decrease peripheral and regional blood flow
l decrease oxygen available to tissue
l increase extra-pulmonary shunting secondary to an
increase in pulmonary vascular resistance

10. Effects of CPAP
l Renal function
l decrease renal blood flow
l decrease urine output and urinary sodium excretion
l increase antidiuretic hormone and aldosterone
l Gastrointestinal function
l decrease gastrointestinal blood flow
l abdominal distention (CPAP belly syndrome)
l Intracranial pressure (head box CPAP)
l increase intracranial pressure
l intracranial bleeding

11. Pressure volume curve
is divided into 3 regions
l region A: low lung Turbulent
High-Velocity
Laminar
Low-Velocity
Flow Region Flow Region
volume, low compliance
and high resistance. The .08 10,000
Airway Cross-Section in cm2
Normal
Resistance (cm H2O/L(ml) s)
P/V slope is low Newborn
1000
Volume per
.06
Lung
l region B: optimal lung .04 100
volume and increases .02 10
HMD Lung
lung compliance 2
l region C: high lung 0 5 10 15 20
volume, low lung Airway Generation2O)
Pressure (cmH
compliance
Pressure- volume curve

12. Type
of
CPAP

13. Clinical applications of CDP or CPAP
l respiratory distress syndrome
l meconium aspiration syndrome
l apnea of prematurity
l postoperative thoracotomy
l patent ductus arteriosus
l postoperative celosomia
l weaning patients from primary lung disease
l differentiation of primary lung disease from primary
cardiac disease
l as adjunct to intermittent positive ventilation
l sleep apnea
l bronchomalacia

14. Clinical applications of CPAP
Low (2-3 cm H2O)
Use Side effects
l maintenance of lung volume in l may be too low to maintain
VLBW infants adequate lung volume or
l during weaning adequate oxygenation
l during hyperventilation in
PPHN
Medium (4-7 cm H2O)
Use Side effects
l increasing lung volume in If lungs have normal compliance
surfactant deficiency l over distention
l stabilizing areas of atelectasis l impede venous return
l stabilizing obstructed airway l air leak

15. High (8-10 cm H2O)
Use Side effects
l preventing alveolar collapse l air leak
with poor CL and poor lung l decreased CL if over distended
volume l may impede venous return
l improving distribution of
l may increase PVR
ventilation
l CO2 retention
Ultrahigh (11-15 cm H2O)
Use Side effects
l tracheal or bronchial collapse l air leak
l markedly decreased CL or l decreased CL if over distended
severe obstruction l may impede venous return
l preventing white-out or re- l may increase PVR
establishing lung volume during l CO2 retention
ECHO

16. Tracheomalacia

17. Optimal CPAP level
Disease Physiology Optimal CPAP level
Acute RDS l significant A-a gradient l PaO2
l rapid change compliance l oxygen consumption
l oxygen delivery
Small premature l small A-a gradient l lung compliance
infant weaning off l weak respiratory muscles
CPAP l increased chest wall
compliance
BPD on 60% l decreased compliance l pulmonary mechanics:
oxygen l increased resistance resistance, compliance
4-day-old RDS l congestive heart failure l balance between
and PDA and pulmonary edema cardiac output and
pulmonary blood flow

18. Clinical use of CPAP
l clinical indications l follow up and
l sign of atelectasis on weaning
chest film l follow-up PaO2 within
l chest wall retraction 15-20 min.
l require FiO2>0.5 l weaning
l display rapidly l after oxygenation
progressive lung disease was improved
l initial pressure setting l extubation from
l nasal or nasopharyngeal: CPAP 3-4 cm H2O
6 cm H2O
l endotracheal: 4 cm H2O

19. Nursing care of CPAP
l method l nursing care
l nasal l continuous care (oxygen,
l nasopharyngeal pressure)
l endotracheal tube l care of airway
l face mask l prevent obstruction
l components l prevent irritation of
l oxygen nares
l temperature and l skin care
humidity l abdominal distention
l pressure l NPO

20. Indication of CPAP
Atelectatic disorders
l PaO2 below 50-60 mm Hg in FiO2>0.6
l recurrent apnea
Initial setup
l CPAP 6 cm H2O
l increase 2-cm. increments q 15 min. to a max.
of 10 cm H2O or 12 cm H2O
l increase FiO2 0.05-0.10 if PaO2<50 mm H2O

21. Respiratory distress syndrome
l improve survival rate,
especially larger infants
l modify course of the disease
l lower max.FiO2 required,
reduce total amount of time
under O2 and the need for
mechanical ventilation

22. Early CPAP in RDS
l was proved to be more beneficial in the
atelectatic disease
l lower peak pressure required in infants treated
with CPAP
l enhance surfactant conservation
l reduce the need for IMV by 20%, except infants
with birth weight <1500 g.
l improve mortality and decrease the incidence
of BPD
l prevent need for prolong intubation which
reduce the incidence of acquired subglottic
stenosis

23. Failure of CPAP therapy in RDS
l very low birth weight infant
l late application of CPAP
l severity of RDS
l associated disease e.g. sepsis,
hypotension
l infants with severe degree of extra-
pulmonary shunt
(Fox and coworkers, 1977)

24. CPAP in apnea of prematurity
l the application of low-level CPAP decrease
the incidence of apnea of prematurity
(compared to other forms of stimulation)
l improve oxygenation
l stimulation or inhibition of pulmonary reflexes
l alveolar stabilization
l mechanical splinting of airway; reduce
supraglottic resistance in both inspiration and
expiration
l some investigators recommended the early
use of CPAP as a preventive measure of
apnea of prematurity

25. CPAP in an infant with MAS
l pathology of meconium
aspiration
l atelectasis
l large airway obstruction
l V/Q abnormalities
l application of low-to moderate
level CPAP
l resolution of atelectasis
l stabilization of terminal
airway
l incidence of pneumothorax:
not increased
l precautions in case with PPHN

26. Adverse effects of CPAP
l pulmonary air leaks
l type of CPAP
l lung compliance
l gestational age
l gastric dilation and rupture
l hypotension
l increase pulmonary vascular resistance
l chronic lung disease ?

27. Complication of face mask CPAP