Vasotrac APM205A Blood Pressure Monitor FAQs

	How accurate is the Vasotrac compared to an arterial line?
	Several clinical studies comparing the accuracy of the Vasotrac system to arterial lines have been conducted. The data shows that there is a 0.97 correlation Coefficient compared to measurements taken by a well managed indwelling radial artery catheter. Most recently, studies have been completed showing the accuracy correlation of the Vasotrac to arterial catheters in children. Preliminary results show the correlation to be greater than 0.90. Additional accuracy studies are underway at Arkansas Children's, Children's Boston and University of Chicago.

	How does the Vasotrac system work?
	The Vasotrac system uses technology unlike any other blood pressure monitoring system. It consists of a wrist module and a monitor/display that are connected by a cable. The wrist sensor is placed where the radial artery passes over the flat portion of the radius bone (the distal edge of radius). This position allows the sensor to measure the amplitude of the radial pulse, as pressure is increased against the artery. Analysis of the wave shape, form, and other characteristics are used to calculate the patient's systolic, diastolic, and mean arterial pressure.

	What does the patient feel?
	Comfort! Because the Vasotrac does not occlude blood flow, discomfort is minimal. Several comparative studies on comfort versus a cuff based system have been conducted, and the results overwhelmingly favored Medwave's technology.

	How does it compare with other continual, non-invasive measurement systems?
	The Vasotrac system is unique. Its accuracy is comparable to measurement obtained using an indwelling radial artery catheter. It provides continual blood pressure readings, can be used on virtually all adult and many pediatric patients, and does not require calibration. Other monitors which offer continual non-invasive blood pressure also must use a traditional BP cuff. This introduces a potential weakness due to known accuracy concerns with the cuff, as well as introducing discomfort for many patients.

	Is the Vasotrac/Vasotrax cost effective?
	Initial investment in a Vasotrac is comparable to a traditional automated NIBP system. Many users have reported a reduced need for inserting A-lines in patients because of the Vasotrac. With just 15 A-lines avoided, Vasotrac has paid for itself. The Vasotrax allows for each caregiver to have their own blood pressure monitor. A customer could purchase 5 Vasotrax monitors for the price of one automatic cuff monitor.

	How well does the technology work on difficult patients?
	Vasotrac works well on patients with very high or low blood pressure. Slight changes in blood pressure are detected down to 40mmHg and up to 240mmHg (systolic). In addition the Vasotrac wrist sensor has been used in clinical studies to monitor blood pressure in a series of morbidly obese patients. Vasotrac can also be used to monitor patients with peripheral vascular disease, moderate hypothermia, compromised cardiac output, and abnormal heart rhythms. Unlike cuff based systems, the Vasotrac has three wrist guides fitting patients with wrist sizes of 11cm (1 yr. old) to 22cm (several hundred pounds). The Vasotrax like all other Blood Pressure Monitors works best when patients are seated and not moving excessively.

	Is the Vasotrac/Vasotrax difficult to use?
	Both monitors are designed to press the sensor down to the radial artery, pressing against the radius bone. Therefore the sensor must be positioned at the distal edge of the radius bone, this takes less than 20 seconds. The "start" soft key is pressed, and in approximately 15 heartbeats blood pressure, pulse and a waveform are displayed.

	Can the Vasotrac system be used on pediatric patients?
	Arkansas Children's Hospital validated the performance of the Vasotrac monitor in children. During the summer of 2001, the U.S. Food and Drug Administration cleared the Vasotrac for patients with wrist sizes of 11cm or larger.

	Can the Vasotrac/Vasotrax system be used on other arteries such as the brachial or dosalis pedis?
	Medwave's technology is designed to be used with an artery and bone together. Therefore arteries such as the brachial are located in an area with too much soft tissue and does not have an adequate bone behind the artery. However, other locations are being investigated, and clinical validation will occur in the near future.

	How much clinical experience is there using the Vasotrac/Vasotrax?
	The Vasotrac has evolved as a product over the last several years. Initially the focus was in Anesthesia because of the ability to reduce invasive catheters. Recently, Vasotrac Monitors have been sold into Cardiology, Sleep Labs, Intensive Care Units, Emergency Departments, Outpatient Centers, and many other locations where traditional NIBP monitors do not meet the needs. The Vasotrax hand held unit can be found in the EMS/EMT environment, General Floors and Physician Offices.