RAPID Response to questions from readers

(formerly Dear SIRS)

Editorial Commentary: The Challenges of Designing Monitoring Displays and Alerts

Rapid Response Article: Monitoring Gaps

In this issue of the Newsletter, Dr. Sheron McLean describes a challenge to designing monitoring displays and alerts. Specifically, Dr. McLean identifies the potential for blood pressure monitoring gaps when using a non-invasive blood pressure (NIBP) monitor. The American Society of Anesthesiologists Standards for Basic Anesthetic Monitoring indicate that “Every patient receiving anesthesia shall have arterial blood pressure and heart rate determined and evaluated at least every five minutes.*1 The asterisk refers to the option to alter that interval based upon the discretion of the anesthesia professional as long as the variance is documented in the chart. Current NIBP monitoring devices can be set to cycle at a pre-defined interval, but as Dr. McLean notes, there will be conditions when the measurements are paused intentionally, or the device may be unable to make a measurement. Designing a device that can accommodate these real-world conditions can be a challenge for an engineer. Cory Stahl from GE Healthcare describes the configuration options in their device designed to address these challenges while meeting the needs of different care settings.

One design challenge is how long to continue to display a blood pressure measurement as it ages. The clinician may not observe the measurement as soon as it is completed so it needs to be sustained for some period of time. Should the measured value be removed at the end of the selected measurement interval? What about a single manual measurement? How long should that be displayed? How long is a blood pressure measurement useful, i.e., reflective of the patient’s physiology? To avoid lapses in blood pressure monitoring that extend beyond 5 minutes, the user must respond to any audible alerts or recognize the indications in the display that a measurement has not occurred for five minutes. Those of us in practice know the not uncommon scenario of being absorbed in patient care only to look up at the monitor and realize that more than five minutes have elapsed since the last blood pressure measurement.

Another problem is when and how to alert the user when there is a monitoring lapse. Suppose there is an audible alert every time the device fails to make a measurement. This may be helpful in some circumstances, but undoubtedly will increase the number of nuisance alarms as cuffs are intentionally disconnected or repositioned and measurement attempts are repeated. What should that alert consist of? A gentle audible reminder or a loud alarm? What should the monitor display indicate and will it be noticed? Will the information on the display help the clinician to solve the problem? Clearly there is the potential to add to the problem of nuisance alarms and alarm fatigue without improving the frequency of blood pressure measurement.

One solution described by Dr. McLean to help conform to anesthesia monitoring standards is an independent system that knows the clinical application and the prevailing monitoring standard that can alert the user to a monitoring lapse. This approach adds complexity to the devices needed in the clinical environment in addition to patient monitors, but is likely a viable solution with the use of electronic medical records. These types of alerts have been implemented in a variety of systems at the bedside, but the question remains of how best to alert the clinician to the potential monitoring lapse. Is a visual indicator sufficient? How big is the notice and can it obscure the patient record? Should there be an audible component? If so, how intrusive should it be? In this solution, we still lack any coordination between the electronic medical record and the monitoring device it is working with.

Dr. Julian Goldman and his colleagues in the Medical Device “Plug-and-Play” (MD PnP) Interoperability Program have been advocating an elegant solution for many years.2 The concept under that program is to have an Integrated Clinical Environment (ICE) where devices communicate with one another. Imagine that when the anesthesia record is initiated, all medical devices connected to the patient are then aware of the context of the care. It will become easier for engineers to coordinate the functions of different devices and to design useful alerts and notifications around compliance with standards and care protocols while minimizing false alarms. Further, the clinician will no longer need to manage multiple devices and understand display options from different manufacturers.

Blood pressure measurement is fundamental to safe anesthesia care. I can recall the time when we used manual blood pressure measurement during anesthesia care and am grateful for the automated devices that undoubtedly provide more frequent blood pressure measurement when caring for patients in the operating room. Modern anesthesia practice benefits from excellent devices to help care for patients. As this discussion highlights, however, there is opportunity for better patient and provider centered designs.


Dr. Feldman is chair, APSF Committee on Technology, and professor of Clinical Anesthesiology, Children’s Hospital of Philadelphia Perelman School of Medicine, Philadelphia, PA.

Dr. Feldman has received consulting compensation from Micropore, Dräger Medical, GE Medical, and Medtronic.


  1. American Society of Anesthesiologists. Standards for basic monitoring (1986). Available at https://www.asahq.org/~/media/Sites/ASAHQ/Files/Public/Resources/standards-guidelines/standards-for-basic-anesthetic-monitoring.pdf. Accessed March 2, 2019.
  2. Goldman JM. Solving the interoperability challenge: safe and reliable information exchange requires more from product designers. IEEE Pulse. 2014;5:37–39.

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