Pulse oximetry in acute asthma.

The predictive value of pulse oximetry was evaluated in 100 patients who attended the emergency department with acute asthma. Oximetry after treatment with a cut off point of less than 91% had a sensitivity of 42% and specificity of 78% for unfavourable outcome, and oximetry before treatment had a sensitivity of 36% and a specificity of 57%. Despite its low sensitivity, oximetry after treatment does seem to have a role in minimising diagnostic errors in the emergency department, but only when used in conjunction with clinical assessment.