PRESS RELEASE
March 7, 1995
Gentle sampling without blood samples

Microdialysis is a new technique for
continuous samplings from tissue fluid in different organs without any blood being used. This makes it possible to carry out very frequent sampling and recording of chemical trends in the patient.
The method is designated as very gentle. A single jab and the patient's
state of health can be followed for several days.
- Here we see completely new possibilities within, among other things, intensive, neonatal and diabetes care, states Professor Urban Ungerstedt who developed the method.

The most usual method of taking samples from the body is carried out today through blood samples. But the blood's chemical composition is an average value of the tissue fluid in all the organs that it runs through.
- Taking blood is therefore not suitable if one wants to follow the development of the chemistry in a certain tissue or a certain organ, explains Urban Ungerstedt. At the Karolinska Institute he has been developing the method for 20 years. In the same period more than 2,500 scientific articles have been published about progressive laboratory trials with the new technique of following man's chemical processes.

Artificial blood vessel
In microdialysis a microdialysis catheter is inserted into the tissue or organ. The catheter functions as an "artificial blood vessel" i.e. the substances in the tissue fluid diffuse in the catheter and are taken further with the fluid to a micro-test tube where they are collected. A battery driven pump delivers a slow flow and the substances manage to move backwards and forwards across the catheter so that the concentration in the sample is equal to the same concentration in the tissue fluid.

Analysis of chemical trends close to the patient
The micro-test tube is placed in a microdialysis analyser close to the patient which after a few minutes shows the result in the form of trend curves on a screen. The system is designed for the maximum possible mobility and can simply be transported between rooms, departments or operating theatres. This makes it possible to read off chemical trends without interruption over several days, to give warning in time and to follow the effect of a treatment directly at the patient.
- This entails reduced stress and low risks of infection for the patients. The method should give nursing personnel greater scope for well directed and gentle methods of care, concludes Professor Urban Ungerstedt.


Captions:
A. Microdialysis pump
B. Microdialysis catheter which is inserted under the
skin
C. Micro-test tube
D. Microdialysis analyser
E. Graphs which show changes in the body's chemistry


For further information please contact:
Head of Marketing Peer Model
CMA Microdialys AB
Roslagsvägen 101
S-104 05 Stockholm
Tel: +46 8 674 63 10
Fax: +45 8 16 60 50


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