Why is pulse oximetry so important?
Once a patient starts losing oxygen, a doctor has less than three minutes to prevent risk of brain damage, heart failure and death.
A healthy body should never fall below 95% oxygen saturation, and oximeters can detect changes as small as 1%. Before oximeters were invented, experienced clinicians would only notice signs of hypoxia (oxygen starvation) when patients became cynaosed – literally their skin began turning blue, with oxygen saturation damagingly low at 85%.
Introduced in 1985, pulse oximeters were rapidly adopted by anaesthesiologists as the universal standard of care in operating theatres, emergency, recovery and neonatal units and all wards (especially in paediatric wards). Oximeters are used in the treatment of pneumonia; they can be used to prevent neonatal blindness – they are a key component of the WHO Safe Surgery Checklist.
In most high-income countries where pulse oximetry is universal across the perioperative process, anaesthesia has become very safe: rates of mortality directly attributable to anaesthesia are typically less than 1 in 50,000 procedures. In low income countries the rate is often at least ten times higher than this, and can be up to 1000 times higher.
Upgraded to the highest level of recommendation in the updated 2010 International Standards for a Safe Practice of anaesthesia, developed and endorsed by the World Federation of Societies of Anaesthesiology, pulse oximetry is essentially mandatory – and dangerously scarce in low-resource countries.