Novel oesophageal blood oxygen sensors in adult and neonatal monitoring
Professor R. M. Langford, St Bartholomew’s Hospital
Professor A. Petros, Great Ormond Street Hospital for Children
Dr J. May
Pulse oximeters are widely used in paediatric anaesthesia and intensive care for measuring oxygen levels in arterial blood, however they have some severe limitations. The technique relies on the presence of adequate peripheral arterial pulsations. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia, vasoconstriction, and low cardiac output, oxygenation readings become extremely unreliable or cease. The problem arises because conventional sensors must be attached to the most peripheral parts of the body, such as the finger or toe, where pulsatile flow is most easily compromised. Hence, pulse oximetry becomes unreliable in a significant group of adults and children just at the time when accurate readings are most needed. To overcome this limitation, the oesophagus is proposed as a new area for measuring blood oxygen saturation on the hypothesis that at this central anatomical area perfusion may well be better preserved. The new developed optical sensor technologies will directly benefit critically ill patients where current commercial technologies cannot support their need.