Dear Dr T Mallinson,
Thank you for your kind words regarding my article, and the additional points you have provided. The objective of this article was to consider the best practice in the out-of-hospital environment, keeping the article short and concise to this subject. As the target audience is particularly varied, I attempted to cater for as many readers as possible.
There were further areas, such as those you have provided that I wished to include, but removed to reduce both the length and required pre-existing knowledge on the physics of light. I have discussed the accuracy during hypoxaemia and its relation to SaO2, but thank you for raising this point again.
I agree that the duration of use in the out-of-hospital setting would reduce the risk of pulse oximetry causing physical harm to a patient to be highly improbable, but thank you for raising this issue. The lack of lateral movement and close proximity of the LEDs and photoreceptors of the clip-on type probes used on adults should reduce any chance of the Penumbra effect, but this may be an issue with the adhesive probes that are utilised for paediatric patients on a non-paralleled plane. Again, this is a consideration when discovering a suitable site for pulse oximetry so thank you for raising this.
Thank you again for the response to my article. Your feedback is greatly appreciated.
Yours Sincerely,
Mr B Matthews