Pulse oximeters, like smoke alarms and carbon monoxide detectors, are late 20th century devices which many of us would feel naked working without. They monitor non-invasively and in real-time to warn of unseen changes in oxygenation and perfusion, as near-perfect end-organ observers. Their presence, outlined in this book, in various hostile environments or where sedation is practised, has been particularly welcomed by medical staff everywhere.

The author John Moyle, an engineer and anaesthetist/intensivist, is a gifted, concise writer. This second edition details clinical and physical matters with equal clarity and includes a new chapter on foetal oximetry, where trends in (already low) saturations correlate well with sampling as reasonable predictors of outcome or to advise on the timing of interventions.

His well-referenced text should be available to all new and existing users of thesedevices. Whilst sensitive to the rights of publishers, it would be wonderful if instrument manufacturers would bulk-buy and distribute this book with their products! A good buy nonetheless.