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A History of Alarms: Back to Basics

CalmWave Blog

A History of Alarms: Back to Basics

The use of vital signs alarms, also known as medical alarms, has a long history dating back to the early days of medicine. Medical alarms are now overabundant in modern intensive care units. But why were these alarms created in the first place? In order to answer this question, we should start by distinguishing a few key terms.

Alarms vs. Alerts

Alarms are the actual sounds emanating from medical monitors. These beeps, dings, bells, and chimes are what one typically hears when walking into an intensive care unit (ICU). The incessant noise of alarms are designed to communicate critical, life-threatening, and time-sensitive patient conditions to nurses or other caretakers. 

Alerts, on the other hand, are the data that is actually received and displayed on monitors or nurse call systems. This data can come from bedside vital signs monitors. An electronic medical record system can also alert a nurse that a patient has met the criteria to be released from the hospital. Ultimately, alerts are “what the alarm can be converted to at the endpoint of a system.” 

To give an example, a physiological monitor like a pulse oximeter attached to a patient’s finger sends alerts (data) about that patient’s condition to the nurse’s desktop monitor. If the patient’s oxygen levels dip below a critical threshold, an alarm (bell sound) begins ringing from the monitor, thus telling nurses to check on the patient and attend to the situation. 

The Genesis of Medical Alarms

The origin of vital signs alarms can be traced back to the early days of modern medicine, when doctors and nurses first began monitoring patient vital signs such as heart rate, blood pressure, and respiratory rate. The earliest forms of vital signs monitoring were manual, with healthcare professionals periodically checking and recording patient vital signs.

The use of alarms to alert healthcare professionals to changes in vital signs began in the 1950s and 1960s with the development of electronic vital signs monitors. These monitors were designed to continuously monitor patient vital signs and alert healthcare professionals to any changes or abnormalities. One of the first medical monitoring systems, developed in the 1950s, was called the ‘cardiotachoscope,’ and it allowed clinicians to view electrocardiograph and heart rate data during surgeries. This system not only projected real-time vital signs data, but it also had alarms that would sound if the patient’s heart rate was too high or too low. 

The use of vital signs alarms was driven by the need to quickly and accurately detect changes in a patient’s condition in order to provide timely and appropriate care. With the continuous monitoring provided by electronic vital signs monitors, healthcare professionals were able to more quickly identify and respond to changes in patients’ conditions, leading to improved patient outcomes.

Modern Medical Alarming: It Comes With a Cost

As medical technology advanced, so too did the technology used in medical alarms. In the 20th century, electronic vital signs monitors became common, allowing for more precise monitoring of a patient’s vital signs. These monitors were able to compile more and more patient vital sign data (i.e. heart rate, blood pressure, oxygen saturation), display that data in real-time to the clinicians, and sound alarms that would alert caregivers when a patient’s vital signs were outside of normal ranges. However, these devices acted as a double-edged sword. While there were massive improvements in precision of vital sign monitoring via electronic tools, that also came with a cost: overburdening clinicians with an abundance of often-unnecessary alerts. 

It is difficult to say exactly how many vital signs alarms go off in modern hospitals at any given time, as this can vary greatly depending on the size and type of hospital, the number of patients being monitored, and other factors. Studies have shown, though, that the rate of non-actionable  alarms from medical devices–including vital signs monitors–is quite high. One study found that up to 90% of alarms from medical devices are non-actionable alarms, meaning that they do not indicate a real clinical issue. Suddenly, clinicians are being fed too much information on their patients, to the extent  where they’re running to a patient’s room in response to a shrill bell that’s simply demonstrating a patient’s pulse oximeter fell off their finger. All of these non-actionable alarms can cause alarm fatigue among healthcare providers. This can lead to healthcare providers becoming desensitized to the constant stream of alarms, thus decreasing their response time to actionable legitimate alarms. 

Non-actionable alarms can also hinder patient recovery. Sleep is valuable for all patients, but noisy ICU rooms are not an ideal place to rest and heal. Lack of sleep can cause scary side effects for patients, including delirium. Studies have shown that up to 80% of ICU patients experience ICU delirium, and those symptoms can be long-lasting. 

The Future of Medical Alarms

Ultimately, medical alarms were implemented to reinforce a common objective of hospitals: to provide the highest-quality care for their patients. But when clinicians are burnt out and alarms are being missed due to desensitization, is anyone really benefiting? CalmWave is working to improve patient outcomes in healthcare by using artificial intelligence to decrease the amount of erroneous alarms that are produced in intensive care units. CalmWave aims to restore the utility of medical alarming systems by reducing non-actionable alarms, thus improving the clinical work environment and optimizing patient care. To learn more about the future of medical alarm systems, request a demo today. 


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