ZOLL M Series Defibrillator Rev YH - Manual (Page 13)

General Information
1-5
External Pacemaker (Pacer Version
Only)
Non-invasive Transcutaneous Pacing (NTP) is an
established and proven technique. This therapy is easily
and rapidly applied in both emergency and non-
emergency situations when temporary cardiac
stimulation is indicated.
Some M Series products may contain an optional
demand pacemaker consisting of a pulse generator and
ECG sensing circuitry. The output current of the
pacemaker is continuously variable from 0 to 140 mA
and the rate is continuously variable from 30 to 180
pulses per minute (ppm).
The pacing output pulse is delivered to the heart by
specially designed ZOLL MFE Pads placed on the back
and the precordium.
The characteristics of the output pulse, together with the
design and placement of the electrodes, minimize
cutaneous nerve stimulation, cardiac stimulation
threshold currents, and reduce discomfort due to skeletal
muscle contraction.
The unique design of the M Series products allow clear
viewing and interpretation of the electrocardiogram
(ECG) on the display without offset or distortion during
external pacing.
Proper operation of the device, together with correct
electrode placement, is critical to obtaining optimal
results. Every operator must be thoroughly familiar with
these operating instructions.
Intended Use — Pacemaker
This product may be used for temporary external cardiac
pacing in conscious or unconscious patients as an
alternative to endocardial stimulation.
Note: This device must not be connected to internal
pacemaker electrodes.
The purposes of pacing include:
Resuscitation from standstill or bradycardia of any
etiology:
Noninvasive pacing has been used for resuscitation from
cardiac standstill, reflex vagal standstill, drug induced
standstill (due to procainamide, quinidine, digitalis, b-
blockers, verapamil, etc.) and unexpected circulatory
arrest (due to anesthesia, surgery, angiography, and
other therapeutic or diagnostic procedures). It has also
been used for temporary acceleration of bradycardia in
Stokes-Adams disease and sick-sinus syndrome. It is
safer, more reliable, and more rapidly applied in an
emergency than endocardial or other temporary
electrodes.
As a standby when standstill or bradycardia might be
expected:
Noninvasive pacing may be useful as a standby when
cardiac arrest or symptomatic bradycardia might be
expected due to acute myocardial infarction, drug
toxicity, anesthesia or surgery. It is also useful as a
temporary treatment in patients awaiting pacemaker
implants or the introduction of transvenous therapy. In
standby pacing applications, noninvasive pacing may
provide an alternative to transvenous therapy that avoids
the risks of displacement, infection, hemorrhage,
embolization, perforation, phlebitis and mechanical or
electrical stimulation of ventricular tachycardia or
fibrillation associated with endocardial pacing.
Suppression of tachycardia:
Increased heart rates in response to external pacing
often suppress ventricular ectopic activity and may
prevent tachycardia.
Pacemaker Complications
Ventricular fibrillation will not respond to pacing and
requires immediate defibrillation. The patient’s
dysrhythmia must therefore be determined immediately,
so that appropriate therapy can be employed. If the
patient is in ventricular fibrillation and defibrillation is
successful, but cardiac standstill (asystole) ensues, the
pacemaker should be used.
Ventricular or supraventricular tachycardias may be
interrupted with pacing but in an emergency or during
circulatory collapse, synchronized cardioversion is faster
and more certain. (See Synchronized Cardioversion
Section.)
Electromechanical dissociation may occur following
prolonged cardiac arrest or in other disease states with
myocardial depression. Pacing may then produce ECG
responses without effective mechanical contractions,
and other treatment is required.
Pacing may evoke undesirable repetitive responses,
tachycardia, or fibrillation in the presence of generalized
hypoxia, myocardial ischemia, cardiac drug toxicity,
electrolyte imbalance, or other cardiac diseases.
Pacing by any method tends to inhibit intrinsic
rhythmicity. Abrupt cessation of pacing, particularly at
rapid rates, can cause ventricular standstill and should
be avoided.
Noninvasive Temporary Pacing may cause discomfort of
varying intensity, which occasionally can be severe and
preclude its continued use in conscious patients.
Similarly, unavoidable skeletal muscle contraction may
be troublesome in very sick patients and may limit
continuous use to a few hours. Erythema or hyperemia
of the skin under the MFE Pads often occurs; this effect
is usually enhanced along the perimeter of the electrode.