Atrotech Atrostim PNS Anwenderhandbuch Seite 7

Atrostim PNS
1 INTRODUCTION
A phrenic nerve stimulator should be used only if mental function is (almost) normal
and a diagnosis is established of persistent intermittent (sleep apnea, CAH) or
continuous (brain stem lesion, functional spinal cord transsection, central respiratory
muscle paralysis, RMP) central apnea. The phrenic nerve stimulator will work only if
the phrenic nerve and the diaphragm muscle are normal. For the muscle, hypotrophy
due to paralysis still means "normal".
2 PRE-OPERATIVE ASSESSMENT
The following measures are recommended to affirm the above conditions before
implantation is planned.
1. Affirmation of central apnea. For safety reasons, the reaction to
hypoxia should not be tested. For patients with sleep apnea, a full
sleep study in an appropriately equipped laboratory should be
performed.
For all other patients, the reaction to increasing p
RMP is present, no diaphragm function should become apparent.
Use of the accessory ventilatory muscles in the neck may be
noticed. The increase of carbon dioxide may cause discomfort and
even severe stress to the patient. The patient therefore should be
carefully observed during the test, and above all, should be informed
about the test beforehand.
The easiest way to raise p
dead space to the tubing of the ventilator. During rebreathing a
FIO
2
should be kept to avoid hypoxia. Under permanent control of
endexpiratory carbon dioxide concentration (p
frequent blood gas analysis p
would cause the individual patient to breath spontaneously. For
normal subjects, a p
exceeded. No diaphragm movements should become observable.
2. A diagnosis of central apnea should be established by a neurologist.
Preferably, he should not be a member of the group who is caring
for the patient and plans the implantation.
3. A diagnosis of sleep apnea should be established by sleep analysis
in a well equipped sleep laboratory (Farmer et al. 1978, Olson 1986).
April 2002
Presurgical procedure
of at least 0.3 (30% of oxygen in the inspired gas mixture)
CO
a 2
CO is through rebreathing by adding
a 2
CO is increased to a level which
a 2
of 60mmHg (8 kPa) should not be
1
Presurgical procedure
CO is tested. If
a 2
CO ) or by aid of
ET 2