Pulse oximetry monitoring outside the intensive care unit: progress or problem?

To evaluate the use of continuous pulse oximetry monitoring in general care units.

Hemoglobin oxygen saturation data collected prospectively by use of pulse oximetry with concurrent review of the medical record.

General medical-surgical nursing units in a large, tertiary care university hospital.

Forty patients on two nursing units monitored with continuous, bedside pulse oximetry at the request of their primary physicians.

All patients had continuous pulse oximetry monitoring. A research associate visited the bedside two or three times daily and recorded saturation compared with time data from the previous 8.75 hours. Patients were studied for 36 hours or until pulse oximetry monitoring was discontinued. Episodes of desaturation were counted. Patient charts were reviewed for documentation of desaturation in either nursing or physician notes. Orders adjusting oxygen therapy or other respiratory therapy within 12 hours of any desaturation episode were also recorded.

Thirty of the 40 patients (75%) had at least one episode of desaturation to less than 90%; 23 (58%) had at least one episode to less than 85%. Desaturation episodes were documented in nursing notes for only 33% of those patients who desaturated to less than 90% and in physician notes in only 7% of cases. Changes in respiratory therapy were ordered in 20% of patients who desaturated to less than 90% and in only 26% who desaturated to less than 85%.

Despite their repeated occurrence, episodes of hypoxemia were rarely documented in either nursing or physician notes. Further, even in patients who had episodic desaturation, pulse oximetry monitoring had little effect on changes in physician-directed respiratory care.