Pacing - ZOLL M2 Operator's Manual

Chapter 1 General Information

Pacing

Ventricular fibrillation does not respond to pacing and requires immediate defibrillation.
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Therefore, the patient's dysrhythmia must be determined immediately, so appropriate
therapy can be employed. If the patient is in ventricular fibrillation and defibrillation is
successful but cardiac standstill (asystole) ensues, use the pacemaker.
Ventricular or supraventricular tachycardias can be interrupted with pacing, but in an
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emergency or during circulatory collapse, synchronized cardioversion is faster and more
certain.
Pulseless electrical activity (PEA) can occur following prolonged cardiac arrest or in other
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disease states with myocardial depression. Pacing might then produce ECG responses
without effective mechanical contractions, making other effective treatment necessary.
Pacing can evoke undesirable repetitive responses, tachycardia, or fibrillation in the
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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,
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particularly at rapid rates, can cause ventricular standstill and should be avoided.
Noninvasive temporary pacing can cause discomfort of varying intensity, which
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occasionally can be severe and preclude its continued use in conscious patients.
Transcutaneous pacing may cause discomfort ranging from mild to severe, depending on the
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patient's tolerance level, muscle contractions and electrode placement. In certain cases,
discomfort may be decreased by slightly relocating the pacing pads.
Unavoidable skeletal muscle contraction might be troublesome in very sick patients and
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might limit continuous use to a few hours. Erythema or hyperemia of the skin under the
hands-free therapy electrodes often occurs; this effect is usually enhanced along the
perimeter of the electrode. This reddening should lessen substantially within 72 hours.
There have been reports of burns under the anterior electrode when pacing adult patients
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with severely restricted blood flow to the skin. Prolonged pacing should be avoided in these
cases and periodic inspection of the underlying skin is advised.
There are reports of transient inhibition of spontaneous respiration in unconscious patients
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with previously available units when the anterior electrode was placed too low on the
abdomen.
Always verify that the patient is being effectively paced by palpating his/her pulse rate and
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comparing it to the pacer rate setting.
Artifact and ECG noise can make R-wave detection unreliable, affecting the HR meter and
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the demand mode pacing rate. Always observe the patient closely during pacing operations.
Consider using asynchronous pacing mode if a reliable ECG trace is unobtainable.
It is important to monitor the patient closely to verify that both mechanical and electrical
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capture are occurring. Electrical capture can be verified by observing the presence of a large
ectopic beat after the pacing pulse is delivered. The size and morphology of the beat are
dependent on the patient. Mechanical capture can be verified by checking for signs of
increased blood flow i.e., reddening of the skin, palpable pulses, increased blood pressure,
etc. Continuously observe the patient during pacing administration, to insure capture
retention. Do not leave the patient unattended when administering external pacing therapy.
WARNING! This device can only be used for external pacing of patients and cannot be used for
internal pacing. Do not connect internal pacing lead wires to the ZOLL M2 monitor/
defibrillator.
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