Interfacing Monitoring Systems with Ventilators: How Well Do They Communicate Alarms?

Within healthcare organizations, there is a growing focus on the connectivity between medical devices. Of particular interest is being able to connect ventilators to physiologic monitoring systems, largely because ventilators are life-critical devices. Such connectivity introduces the ability to improve alarm management by allowing local ventilator alarms to annunciate at the physiologic monitoring system’s central station and at ancillary annunciation devices (e.g., pagers). This helps clinicians to respond quickly to alarming ventilators without having to be within earshot of the ventilator. Connectivity can also allow clinicians to view ventilator alarm limits, measured values, and waveforms at the central station. It may also facilitate transmission of patient data from ventilators to electronic medical records (EMRs); see the box below. With remote access to alarms and patient data, clinicians may be better able to prioritize their response to patient needs.

But getting systems to talk to each other without problems is not easy. To find out how well current ventilator-monitoring system interfacing technology works, we tested the connectivity between seven physiologic monitoring systems and two ventilators. Although our testing only covered some of the systems and devices on the market, we think it provides a good sense of the state of the technology.

What we found was that most interfaces didn’t function as desired, especially in the area of alarms. Our biggest concern with many of the monitoring system-ventilator combinations we tested is the central station’s failure to clearly communicate one or more high-priority ventilator alarms.1 In one pairing, the central station failed to issue any alarm in response to some high-priority ventilator alarms. In several other pairings, alarms were issued, but the central station displayed nondescript warning messages that didn’t accurately convey the risk.

Many of the monitoring systems we tested conveyed ventilator alarms with a lower priority than is assigned by the ventilator itself; some of these systems treated several high-priority ventilator alarms as medium priority. Other systems conveyed a single priority for all ventilator alarms independent of the priority annunciated by the ventilator. In only one system did the central station alarms consistently mirror ventilator alarms, including alarm escalation by the ventilator (i.e., the automatic change of a medium-priority alarm to high priority after a set period). Since clinicians rely on alarm priority to appropriately triage responses to emergent needs, the display of an incorrect alarm priority at the central station could increase patient risk.

In some cases, physiologic monitoring systems presented either no visual alarm or no audible alarm at the central station when a ventilator was disconnected from the bedside monitor. Moreover, many of the components that connect the monitoring system to the ventilator are vulnerable to unintended disconnection. If a disconnection occurs and no alarm is issued, clinicians may not realize that the monitoring system is no longer providing remote annunciation of ventilator alarms.

Though less concerning than the aforementioned ventilator alarm issues, the monitoring systems also exhibited mixed results in displaying other ventilator data. For instance, no system was able to display waveforms from one of the two ventilator models used in our testing, and several systems were unable to display waveforms from either ventilator model. Also, one system did not show important ventilator numeric values on the central station display.

The above problems indicate that connectivity technology still has a long way to go to ensure reliable and safe integration. It is therefore vital for hospitals to understand how well the systems they plan to integrate (or have already integrated) exchange alarm and other data, and the potential clinical impact of any limitations in that exchange. This article will help you accomplish that: Not only do we share our judgments for the systems we tested, but we also provide a checklist to help you test your own monitoring system-ventilator pairing—a step that is essential to patient safety.

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