A&D MEDICAL UP-200 Pulse Oximeter

For most healthy adults at rest, a normal SpO2 reading sits between 95 and 100 per cent. Readings between 94 and 95 per cent may be acceptable for some individuals with chronic lung conditions, where a lower baseline is expected — your GP or specialist will advise on your personal target range if this applies to you. A reading consistently below 95 per cent in someone without a known respiratory condition is worth discussing with a GP. A reading below 92 per cent warrants same-day medical attention, and below 90 per cent is a medical emergency.

The UP-200 is designed for resting measurements and is most accurate when the finger and hand are completely still. Movement during measurement significantly affects the quality of the photoplethysmographic signal and will produce unreliable or error readings. If you have been advised by a healthcare professional to monitor your oxygen levels during exertion — for example as part of managing a respiratory condition — they will guide you on the appropriate equipment and approach. For general home use, resting measurements are the most meaningful baseline to track.

It is completely normal for the displayed SpO2 and pulse rate to shift slightly in the first few seconds after applying the oximeter, as the device acquires and analyses the signal from your fingertip. Wait for the figures to settle and remain consistent before recording your reading. If the reading continues to fluctuate erratically without settling, check that your finger is inserted fully to the sensor window, that your hand is completely still, and that your finger is warm and dry. Persistent instability may indicate poor peripheral circulation in that finger — try a different finger or warm your hands further.

Yes. Dark, opaque, or metallic nail polish, as well as gel and acrylic nail coverings, can absorb or scatter the light emitted by the oximeter sensors, resulting in an inaccurate or undetectable reading. The device works by measuring how much red and infrared light is absorbed by the blood in your fingertip — anything that interferes with this light transmission will affect the result. Remove nail polish from the finger you intend to use before measuring, or use an unpainted finger on the same hand.

No, and this is an important limitation to be aware of. Pulse oximeters measure haemoglobin saturation but cannot distinguish between haemoglobin bound to oxygen and haemoglobin bound to carbon monoxide. In carbon monoxide poisoning, the device will display a falsely normal SpO2 reading even as the patient's blood oxygen delivery is severely compromised. If you suspect carbon monoxide exposure, leave the building immediately and call 999. Do not attempt to use a pulse oximeter to assess the situation.

The UP-200 is designed for adult fingertips, and its accuracy on small children's fingers cannot be assumed. If you need to monitor a child's oxygen saturation, speak to your GP or paediatrician, who can advise on an appropriate paediatric-sized oximeter or arrange clinical monitoring. A standard adult finger oximeter used on a small child's finger will not give a reliable reading and should not be relied upon for clinical decision-making regarding a child's respiratory status.

If your SpO2 reading falls below 90 per cent on repeated measurements and you cannot attribute this to a technical cause such as cold hands or nail polish, call 999 or go to A&E immediately. If it falls below 92 per cent and you are experiencing significant breathlessness, confusion, chest pain, or your lips or fingertips look blue, this is also a medical emergency requiring 999. If readings are below 95 per cent but you are not experiencing acute symptoms, contact your GP or call 111 for same-day advice rather than waiting for a routine appointment.

Pulse rate readings from a pulse oximeter may be less reliable in the presence of significant arrhythmias, as the device calculates pulse from the photoplethysmographic waveform rather than directly from electrical cardiac activity. SpO2 readings may also be affected in some cases. If you have a known arrhythmia and are using this device as part of a home monitoring routine, discuss the appropriateness and limitations of pulse oximetry with your GP or cardiologist, who can advise on whether additional or alternative monitoring approaches are needed.