The Ehlers-Danlos syndrome and regional anesthesia

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.

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.

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

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%.

Burden:
Completing a questionnaire at home, amplified with a physical examination in
hospital on the day of the measurements to evaluate the risks of regional
anaesthesia for the subject.
Application of EMLA-cream on the back of the hand, followed by an ulnar nerve
block, performed as in clinical practice.
Finally three subcutanous injections on the on the dorsal side of the thorax
are administered.

Risks
1) In high dose local anaesthetics can give intoxication. The administered dose
of lidocain in this study is far below this toxic dose (pg 14 protocol). If
nevertheless symptoms of intoxication do occur, all equipment, medication,
nurses and staff are present to treat this immediately. For this reason all
injections will take place in the OR, after which monitoring will be continued
in the recovery room
2) Every injection can cause a haematoma.
3) The onset and duration of the analgesic effects are averages from
literature. Analgesia can be longer than expected but will always be temporary.
4) There is a theoretical risk of ulnar neuropathy after an ulnar block. In
literature there is no case report of ulnar neuropathy after an ulnar block
with lidocaine; the occurrence is extremely unlikely.