PT  - JOURNAL ARTICLE
AU  - Sandra Olive
AU  - Orion Twentyman
AU  - Crichton Ramsay
TI  - Comparison of fingertip and earlobe pulse oximetry with arterial blood gas results
AID  - 10.1183/13993003.congress-2016.PA3702
DP  - 2016 Sep 01
TA  - European Respiratory Journal
PG  - PA3702
VI  - 48
IP  - suppl 60
4099  - http://erj.ersjournals.com/content/48/suppl_60/PA3702.short
4100  - http://erj.ersjournals.com/content/48/suppl_60/PA3702.full
SO  - Eur Respir J2016 Sep 01; 48
AB  - Background: Pulse oximetry is routinely used to assess oxygenation, determine oxygen administration and support clinical decision-making.Aims and Objectives: Anecdotal observations noted marked differences between fingertip and earlobe saturations. This study assessed the agreement between fingertip and earlobe pulse oximetry (SpO2) with oxygen saturations obtained from arterial blood gas samples (SaO2).Methods: 68 patients attending the chest clinic who required arterial blood gas (ABG) analysis had concurrent fingertip and earlobe pulse oximetry recorded. Saturations were measured using a handheld pulse oximeter (BCI 3301 or BCI WW1000) with interchangeable fingertip and earlobe sensors and ABG's analysed on a Radiometer ABL90 Flex Analyser.Paired t tests were used to compare: 1) Fingertip SpO2 with ABG SaO2 & 2) Earlobe SpO2 with ABG SaO2.Results: Fingertip and earlobe SpO2 were both significantly different from the SaO2.1) The fingertip SpO2 differed from the SaO2 by a mean of -0.71% with 95% CI of -1.3% to -0.14% (p=0.015).2) The earlobe SpO2 differed from the SaO2 by a mean of +4.2% with 95% CI of +3.2% to +5.0% (p=0.0001).Conclusion / Discussion: There was a significant lack of agreement between SpO2 measurements and SaO2. This was large enough for the earlobe SpO2 to be unreliable for oxygen therapy titration. The reason for the discrepancy is not apparent nor whether the difference is specific to this equipment. If these results are generalisable, earlobe SpO2 is an inappropriate measurement for determining oxygen administration or clinical decision-making. This also has implications for the monitoring methods used to implement the BTS Emergency Oxygen Guidelines (O'Driscoll et al 2008).