Bubble CPAP in Resource-Poor Settings
Written on Wednesday 08 April, 2009
Before I left the UK to start work in Kisiizi, I had some very interesting conversations with a Rima Vaitkute (consultant neonatologist in Plymouth). Rima trained in Lithuania, and told me how to construct a simple ‘bubble CPAP’ (Continuous Positive Airway Pressure) circuit. The ‘how-to’ diagram was duly packed along with all of the other things that might be useful when working in a resource-poor setting.
We now use the CPAP on children’s ward and special care at least fortnightly. It has been useful in preterm babies with RDS, neonatal pneumonia and infants with severe pneumonia or bronchiolitis. It has literally saved lives in some cases, and has significantly improved care in others.
We have the benefit of a very stable electricity supply at Kisiizi, and use oxygen concentrators to provide oxygen. The concentrators have a water reservoir through which the oxygen is passed before going to the patient. If you are using piped oxygen or cylinders, a further reservoir is needed.
What you need:
- Oxygen supply (we use oxygen concentrators)
- Oxygen tubing
- Nasal cannulas (large, long, flexible ones are best to give a good seal)
- Tape to attach the tubing
- Glass bottle with tight-fitting rubber bung (we use our IV fluids bottles), filled with distilled water.
- 2 large gauge needles (white or needle from grey IV cannula is ideal)
The nasal cannula tubing is attached to the oxygen concentrator as usual, with a flow rate of 2L/min. Where the tubing splits into two before reaching the patient, one end is cut, and the short end sealed to prevent leakage. The long end is attached to another piece of oxygen tubing (ensuring no leak) and is connected to a needle, the end of which is under the water in the sealed glass bottle. A further needle (this time above the water) allows the oxygen to escape. The number of centimetres that the 1st needle is below the water gives you the cm H2O CPAP pressure (although in practice, we’ve found that it is ‘on’ or ‘off’).
Large, long, flexible nasal prongs are the most effective, as they provide a good seal and therefore good CPAP. If the prongs are much smaller than the baby’s nostrils, a better seal can be achieved by folding a piece of gauze and making 2 holes for the prongs to pass through into the baby’s nostrils.
Check that the circuit is working by occluding the nasal prongs: you should see bubbles coming from the needle into the water. When attached to the baby, you may not see bubbles in the water, but the baby blowing ‘CPAP bubbles’ and an improvement in oxygen saturation (if you can measure this!) should confirm that it is effective.
The staff and patients at Kisiizi are grateful for the advice given by Rima for this CPAP circuit!