The Ehlers-Danlos syndrome and regional anesthesia.

Background:

Ehlers-Danlos syndrome is a group of rare genetic disorders caused by a defect in collagen synthesis. Several patients from the Dutch Ehlers-Danlos patient organisation claimed that for them regional and local anaesthesia techniques did not work as good as would be expected. However, up to now there is no proof or explanation for this phenomenon. Hence this research project has started on request of the Ehlers Danlos patient organisation.



Ehlers-Danlos patients are to be expected to need frequent operations. The benefits and risks of regional in comparison with general anesthesia might be different in this group than in healthy people. With the results of this study it might become possible to make a more valid choice for the type of anaesthesia for the Ehlers-Danlos patients in the future.



Objective of the study:

Aim of this study is measuring the effects of locoregional anaesthesia in EDS patients and comparing these effects with those in a healthy control group. The results of this study can be used to make a more valid choice for the type of anaesthesia for the Ehlers-Danlos patients in the future.



Study design:

This study concerns a prospective case-control study of the effects of locoregional anaestesia on Ehlers-Danlos patients versus a healthy control group




Study population:

25 people from 18 to 65 years old with al types of EDS except type IV, proven by a geneticist or person with comparable expertise.

25 controls, each matched with a person from the EDS-group for age and sex.




Intervention (if applicable):

1. An ulnar nerve block on the non dominant arm with 3 ml lidocaine 2%;

2. EMLA-cream, 1.5 gram applicated on the dorsal side of the contralateral hand, covered with foil;

3. three times a field block of 3 by 3 cm by means of three subcutanous injections on the dorsal side of the thorax. One will be five ml lidocaine 1%, one lidocaine 2% en one NaCl 0.9%.




Primary study parameters/outcome of the study:

Analgesia in the region of the ulnar nerve within 60 minutes after application of an ulnar nerve block. This will be demonstrated by stimuli from a neurostimulator above 20 mA which will not be regarded as painful in case of an adequate block.

Locoregional anesthesia does not work as well in patients with the Ehlers-Danlos syndrome as in people who do not have this syndrome.

The intervention and measurements will take two hours. After this time subjects can safely go home, there will be no further follow up.

1. an ulnar nerve block on the non-dominant arm with 3 ml lidocaine 2%;

2. application of 1.5 gram EMLA-cream on the dorsal side of the contralateral hand, covered with foil;

3. three times a fieldblock of 3 by 3 cm by means of three subcutaneous injections on the dorsal side of the thorax; one with lidocaine 1%, one lidocaine 2% and one with NaCl 0.9%.