Near real-time notification of gaps in cuff blood pressure recordings for improved patient monitoring

Blood pressure monitoring during anesthesia is an American Society of Anesthesiology standard. However, the anesthesia provider sometimes fails to engage the patient monitor to make periodic (generally every 3-5 min) measurements of Non-Invasive Blood Pressure (NIBP), which can lead to extended periods (> 5 min) when blood pressure is not monitored. We describe a system to automatically detect such gaps in NIBP measurement and notify clinicians in real-time to initiate measurement. We applied a decision support system called the Smart Anesthesia Messenger (SAM) to notify the anesthesia provider if NIBP measurements have not been made in the last 7 min. Notification messages were generated only if direct arterial blood pressure was not being monitored. NIBP gaps were analyzed for 9 months before and after SAM notification was initiated (12,000 cases for each period). SAM notification was able to reduce the occurrence of extended NIBP gaps > 15 min from 15.7 +/- A 4.5 to 6.7 +/- A 2.0 instances per 1,000 cases (p < 0.001). In addition, for extended gaps (> 15 min) the mean gap duration declined from 23.1 +/- A 2.0 to 18.6 +/- A 1.1 min after SAM notification was initiated (p < 0.001). However, for 7-15 min gaps, SAM notification was not effective in reducing the occurrence. The maximum gap encountered before SAM was 64 min, while it was 27 min with SAM notification. Real-time notification using SAM is an effective way to reduce both the number of instances and the duration of inadvertent, extended (> 15 min) gaps in blood pressure measurements in the operating room. However, the frequency of gaps < 15 min could not be reduced using the current configuration of SAM.