Pulse oximetry in the recovery room

Area of Science:

• Anesthesiology
• Critical Care Medicine
• Respiratory Physiology

Background:

• Percutaneous pulse oximetry is a non-invasive method for assessing haemoglobin oxygen saturation (SO2).
• Establishing normal SO2 ranges in healthy individuals is essential for clinical interpretation.
• Post-operative hypoxemia is a common concern in recovery room settings.

Purpose of the Study:

• To determine the normal range of haemoglobin oxygen saturation (SO2) in healthy volunteers.
• To evaluate the impact of supplemental oxygen on SO2 levels in post-operative patients.
• To assess the appropriateness of a 90% lower alarm limit for pulse oximetry in the peri-operative period.

Main Methods:

• Haemoglobin oxygen saturation (SO2) measured non-invasively using a pulse oximeter in 150 healthy volunteers.
• SO2 levels monitored in 350 post-operative patients in the recovery room.
• Comparison of SO2 values between patients receiving and not receiving supplemental oxygen.

Main Results:

• In healthy volunteers, SO2 was below 94% in 13.3% of cases, with none below 90%.
• Post-operatively, 16.7% of patients not receiving supplemental oxygen had SO2 below 90%, compared to 1.1% of those receiving oxygen.
• Supplemental oxygen administration increased SO2 above 90% in all patients who were initially below this threshold.
• SO2 above 94% was observed in 86.7% of volunteers, 73.9% of patients on supplemental oxygen, and only 55.3% of patients not receiving supplemental oxygen.

Conclusions:

• Supplemental oxygen should be administered to all recovery room patients unless SO2 monitoring is available.
• A lower alarm limit of 90% is suitable for the Criticare Systems 501 oximeter during the peri-operative period.
• Pulse oximetry is a valuable tool for guiding oxygen therapy and ensuring adequate oxygenation post-surgery.