Who should undergo oxygen saturation testing?
- All infants who remain in supplementary oxygen when they are otherwise ready for home
- Infants born at <32 weeks gestation, with a diagnosis of BPD, who have discontinued oxygen therapy within 2 weeks of the expected date of discharge OR who have significant respiratory symptomatology at that time
- Infants of any gestation who required > 28d of respiratory support who have discontinued supplementary oxygen, within 2 weeks of the expected date of discharge
When should testing occur?
Saturation testing for babies with BPD should occur when the infant has met the following criteria
- They are 36wks corrected gestational age (CGA) or greater
- Medically
- Have satisfactory growth.
- Have an O2 dependency of no more than 0.5 L/min via nasal
- Can maintain a mean SpO2 of93% or greater, during most activities, without frequent or prolonged desaturation episodes, as assessed by bedside saturation monitoring.
- They have had stable O2 requirements for the preceding week.
- Systemic steroids, where prescribed, have been discontinued at least 1 week prior to testing.
- They have had no recent changes to other medications that may affect respiratory function g. diuretics, inhaled steroids.
- Feeding orally by breast/bottle for at least 48 hours.
Unless home nasogastric feeds are part of the discharge plan. - Free of apnoeic episodes and off caffeine citrate therapy for >7days
Testing Description:
- Duration: 12 – 24 hours – must include periods of sleep and wakefulness
- Minimum equipment: Saturation monitor capable of data download and analysis
- Location: In the local neonatal unit
- Oxygen flow during test:
- In air if O2 recently discontinued
- An increment of 0.1 L/min equal to, or higher, than the most recent flow rate required as judged by bedside testing. If ideal flow is unclear use 2 different flow rates for periods of 12h each. g. 0.1 L/min and 0.2 L/min
- Clinical evaluation:
- Inform nurses in room that oxygenation study ongoing
- Record any change to position, feeding or cares in an activity diary
- Document background (e.g. Handling / choking spell) if any significant desaturation events
Interpretation of results
Infants who are in air or a fixed oxygen level would pass their oxygen study if:
- Mean SpO2 ≥ 93% in air, or chosen fixed oxygen level.
- SpO2 does not fall below minimum* for more than 5% of the total oxygen study time.
- There are no significant† desaturation/bradycardia episodes
†Deep (>10%) or prolonged (>3min) episodes unrelated to movement or technical artefacts
Where these criteria are not met:
- If mean saturation < 93%, consider repeating test in 0.1 L/min higher oxygen flow
- If there an unacceptable number or severity of desaturations, consider and treat other diagnosis (GORD, immaturity, central apnoeas, airway control etc). Repeat test after incidents settle
Discharge Planning (complete discharge checklist)
- Perform an “air challenge” – 30 mins breathing air. Ensure SpO2 does not fall <80%
- Offer Vaccination – 1st dose Palivizumab (if criteria met). Influenza if > 6 months old
- Consider additional Investigations – If in high levels of Oxygen (>0.5 L/min) OR if there are significant respiratory symptoms.
- CXR,
- Capillary gas,
- ECG/ECHO (for pulmonary hypertension)
- FBC (for anaemia – top up if Hb < 85g/l)
- Monitoring – Apnoea monitor only at consultant request
- Rooming in - for 1-2 days before discharge
- Liaison Visit – within 24h of discharge
- Illness following discharge – Ensure parents understand when and where to seek help if infant becomes unwell
Weaning/follow up protocol
- Clinical review at intervals of ≤4 weeks should determine that the patient is well, achieving adequate growth, and does not have significantly increased work of breathing.
- Apply a saturation monitor and observe saturation values in a resting state for > 15 mins. If the mean saturation values are >93% the baby should be observed for the remainder of the visit (at least 15 min) with the oxygen flow rate reduced by 0.1L/min. If the baby was previously in 0.1L/min then they should be observed in room air.
- If the baby remains well saturated in the reduced flow rate (mean saturation >93%) then the baby should remain on this flow rate for the duration of a 12-24 hour saturation recording. Parents should be given instructions to resume the previous oxygen flow rate if they have concerns about their baby’s breathing or if saturation levels fall consistently below 90%
Outcomes
- Satisfactory recording - The mean SpO2 during the recording is >93%, with < 5% of the artefact free recording being below minimum*, and with no significant desaturation episodes.
Action - The patient should remain on the reduced oxygen flow rate and be reviewed within 4 weeks - Evidence of potential hyperoxia – The mean saturation during the recording is >96% with no significant desaturation episodes.
Action - The patient should remain on the reduced oxygen flow rate and consideration given to an early reassessment with a further reduction in the oxygen prescription - Inadequate saturation during sleep - Satisfactory daytime recording but Mean saturations falling to <93% during sleep, or >5% of recording is below minimum*, or there are prolonged or frequent desaturation episodes.
Action - The patients should be returned to the previous oxygen flow rate during sleep OR for 24h per day, at the discretion of the clinical team. Further reassessment within 4 weeks - Unsatisfactory recording – The mean saturation on the reduced oxygen flow rate is <93% OR >5% of the recording is below baseline OR there are prolonged or frequent desaturation episodes.
- Action - The patient should be returned to their original oxygen flow rate and arrangements made for reassessment within 4 weeks
N.B. – repeated failure to be able to wean the oxygen prescription over a 6 month period may require further investigation or discussion with the respiratory team.