Continuous Positive Airway Pressure
Commencement and Set-Up of CPAP

 

 Reviewed by Victoria Wells -
Nurse Educator
May
2009
Clinical Guidelines Back Newborn Services Home Page

Process        Follow the steps below to set up Hudson CPAP Circuit

Step Action Rationale
1 Use disposable self-filling humidifier top with a 1 litre bag of water attached. Adequate humidity will prevent drying of secretions.
2 A flow of 6-10 litres per minute is delivered via a blender. An oxygen analyser is used continuously and calibrated once a shift:
  • To air if O2 <60%
  • To 100% O2 if >60%
 A flow of 6-10 L/m:
  •  provides adequate pressure to wash out carbon dioxide from the system
  •  compensates for the normal air leakage from tubing connections
  •  generates adequate CPAP pressure (verified by bubbling of the water in the cpap generator).

N.B The baby should receive the specific percentage of oxygen required.
3 A pressure relief valve is part of the circuit with the valve fixed to blow off at 17cm H2O. This ensures that any pressure in excess of 17cm H2O will blow off the pressure relief valve should the expiratory line become occluded. This is a safety precaution only. The pressure relief valve does not affect the CPAP pressure.
4 Occlude pressure line connection port with white plug provided. This completes the CPAP circuit.

NB:  check the CPAP circuit is complete (bubbling) before applying to baby.
5 The default pressure is set at 6cm H2O
  • Pressures greater than this (up to 10cm H2O) may be used.
This controls the pressure generated in the system. It is important to check the water level and adjust for evaporation, if required.
6 Place a roll under the infant’s neck to slightly extend the neck. Ensures optimum airway.
7
  • Suction airway prior to application of CPAP prongs.
  • Pass an orogastric tube and aspirate stomach contents (a larger baby may not need an indwelling tube if Nil By Mouth)
 If these procedures are done prior to prong placement then less handling is required after infant is on CPAP.
8 Preductal SaO2 probe in place. (preferably right arm) Optimal saturation maintained according to unit target saturations
9 CPAP hat is applied to baby – it must not be too tight a fit as this causes excessive moulding to the head but should be sufficiently snug to stay in place.
  • Ribbed stockinette is available in two sizes to make hats
  • Individual hats are also available for infants weighing approximately 1000-2000 grams
 A snug fitting hat is a must. The hat is the anchor for the prongs. A loose hat will allow any movement of the head to dislodge the prongs.
10 Applying the prongs.  Gently insert the prongs that fit the nares snugly without causing pressure:
  • Place curve side down into the baby’s nose (follow the natural curve of the nose)
  • Adjust the angle of the prongs and the way the corrugated tubing is twisted until the correct positioning is achieved.
Infant Size

Prong Size
<700g 0
700-1250g 1
1250-2000g 2
2000-3000g 3
>3000g 4
>4000g 5
  • Apply duoderm base tapes to cheeks with rough (hook side) velcro patches attached.
  • Wrap ‘soft’ (loop side) velcro around the prongs.
  • Nasal prongs should fill the nasal opening completely without stretching the skin or putting undue pressure on the nares (blanching around the rim of the nostrils suggests that the prongs are too large).
  • The corrugated tubing will not be touching the baby’s skin.
  • There will be no lateral pressure on the septum causing it to be pinched or twisted.
  • There will be a small space between the tip of the septum and the bridge between the prongs.
11 Secure the inspiration and expiration lines to the CPAP hat using small safety pins and rubber bands.  Ensure safety pins are away from the eyes. If prongs are correctly positioned in the nose and the tubing allowed to sit naturally in place, rotating pressure on the prongs is avoided.
12 Position chin strap. This can be simply made using non-elastic tape and gauze.
  • Cut a piece of tape that will reach from one side of the hat across under the chin and attach to the other side of the hat.
  • The tape needs to be backed with folded gauze to prevent the adhesive contacting the skin.
  • The jaw is gently pulled forward, closing the mouth.
  • A pacifier (dummy) may be used with the chinstrap in place if this will help the baby settle.
 An air leak via the mouth will reduce the effectiveness of the system by allowing a significant loss of positive pressure.

Keeping the design simple will be both cost-effective and convenient, as the chinstrap may need replacing every few hours. It will easily become soiled and the tape loses its adhesives each time it is detached from the hat for suctioning or feeding.

The strap will not be so firm as to prevent the infant from crying or yawning.