I came across some interesting posts in the Biomed Listserv. A biomed from a 250 bed hospital is looking for feedback on GE and Philips telemetry systems. This 260 bed community hospital is going to buy a 12 channel system, and ramp up to about 150 of the devices over the next few years. All sorts of questions came to my mind, and came to this fellow as well:

Instead of what to purchase, please assure that you ask the question - from a clinical patient perspective - what are you attempting to accomplish? Telemetry is intended to allow patients to ambulate and improve their outcome and therefore leave the hospital sooner. It was developed specifically to assist post open heart patients get out of bed and let clinical staff still watch the heart. If you are installing hundreds of channels of telemetry to just add monitoring - what is the patient benefit?

Also the clinical operating concerns can not be underestimated. What nurse is responsible for patient care? How many nurses per floor? Is there a central station, monitor techs? Most telemetry systems in hospital are (my opinion) not properly set up technically or operationally.

Most patients on telemetry do not ambulate, so why not have bedside monitoring? Most nurses taking care of patients on telemetry can not even see the ECG being technically transmitted as only the monitor tech can. Most monitor techs are not licensed to manage patient care - RN's are. Most telemetry units also lack physician criteria for admission and discharge causing the need to always have more telemetry. I think most adult hospitals could benefit from the lessons learned at pediatric hospitals. If the patient needs to be monitored and is not ambulatory, put a networked bedside monitor at the patient bedside. Some vendors - Spacelabs - even have modules that allow for telemetry to be at bedside for those patients that require same.

Great questions. Fitting the monitoring device to match the patient profile is important. And effective alarm notification is essential.

Every hospital has some unmonitored patients that could benefit from being monitored. Patients on pain medications, especially PCA pumps, should be monitored. According to the literature, almost half of all cardiopulmonary arrests in hospitals are unwitnessed. While the survival rate of witnessed codes is 22%, the survival rate for unwitnessed codes is just 1%. Increased monitoring can reduce adverse events, improve outcomes, reduce length of stay, and minimize legal liability.

For these reasons and more, the current standard of practice for patient monitoring is changing. A greater number of hospitals are using telemetry monitors to monitor previously unmonitored patients. Patients that would normally not qualify for the telemetry unit or some other high dependency unit are being monitored - and usually this means telemetry packs.

Telemetry is a good choice because these patients are usually ambulatory, and telemetry transmitters are light weight and small. At the same time, telemetry monitors are a bad choice for several reasons. Telemetry transmitters have no local alarms; you can be right next to a patient in arrest, and unless you see their lips turn blue (or some other physical sign) you won't know there's an alarm condition. Telemetry alarms traditionally annunciate at the central station, and some installations include additional audible alarms, message panels or flashing lights. A related weakness of telemetry transmitters is the lack of a display. To view the patient's physiological parameters you must leave the patient and go to the central station.

Another telemetry system limitation mentioned above is the requirement to have someone actually watch the central station displays. Some hospitals have monitor techs man central stations in a central location - frequently called the "war room." While this is a safe approach, it is also very expensive - an 800 bed hospital can spend $1 million per year on their war room. Other hospitals distribute their monitoring techs on individual nursing units. Depending on patient volumes on nursing units, this could be more expensive than the centralized approach. Finally, many hospitals put central stations in nursing stations and make the nurses on the unit responsible for surveillance. This is certainly the most cost effective approach, but also the most vulnerable to alarm fatigue, especially when you have one or two patients who constantly throw off false positive alarms.

The final challenge is cost. Telemetry monitors, as inadequate as they are, cost about $8,000 per channel - still too high for the many hospitals that have yet to adopt broader patient monitoring. A contributing factor to cost is the use of WMTS by GE and Philips. While both vendors justify their use of WMTS on the fact that it is a "protected" frequency, that provides protection only against intentional interference (people purposely using the same frequency). The major source of interference in hospitals is from unintentional interference - noisy hair dryers, florescent light ballasts, elevator motors, microwave ovens, the list is endless. While WMTS is a frequency band authorized by the FCC, there is no mandate to use it. In fact, there are no operating standards for WMTS to ensure coexistence between vendors. When they first switched their access points over to WMTS, GE and Philips interfered with each other's systems. It was only a gentlemens agreement (and time) that facilitated technical adjustments to allow both vendor's systems to operate in the same hospital. Systems using WMTS simply cost more money than systems that use your hospital's infrastructure - and the wider you deploy their proprietary WMTS infrastructure the more it will cost you when you want to change vendors (and you always do, sooner or later).

While we can't solve the cost issue today, there are alternatives to the traditional telemetry monitor. Our perfect solution would include a real patient worn monitor, meaning a device with a display and local alarms, and you really should have both ECG and SpO2. Such devices include the new Draeger Infinity telemetry system, and a couple of Welch Allyn monitors - the Micropaq and the Propaq LT. The Draeger monitors run on 802.11 b/g, and Welch Alllyn just announced support for 802.11a/b/g on their monitors at HIMSS. None of these products is perfect, but you get important clinical features and you're not investing unecessarily in a proprietary infrastructure that only works with one vendor's products - and in the case of GE, only supports telemetry - all their patient monitors run on WiFi.

Pictured above is the Draeger Infinity telememetry monitor, shown in bedside dock with trickle charge.

UPDATE: Reader Dan Davis MD suggests that most hospitals looking to broaden their patient monitoring are trying to reduce failure to rescue incidents (that's patients who have an adverse event, go into cardiopulmonary arrest and usually die). Certainly saving lives is a primary motivator for increased patient monitoring. But I would argue that there is a greater need (and hopefully market demand) for electronic surveillance that alerts caregivers long before patients become obvious failure to rescue statistics. This requires the ability to identify patients who are pre-arrest, at a stage when clinical intervention is less expensive and much more successful. Patients who arrest in hospitals have low survival rates - 22% for witnessed arrests and a grim 1% for unwitnessed codes.

Dan also mentions Hoana Medical, and their passive non-invasive sensors that can be incorprated into patient beds as a possible solution. I've written about them a number of times (here, here and here), and they have a very interesting system - check them out. The only thing that I can see that keeps it from becoming a natural choice for hospitals is that the kind of patients who would benefit most (currently unmonitored patients) are also active - they are encouraged to get up and walk around. Hospitals need solutions that cover patients in bed and when ambulatory.