Pacemaker Care

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                                                    Caring For a Patient With a Pacemaker


An artificial pacemaker is a small device that uses electrical impulses to help control heart dysrhythmias.

A block in the heart’s electrical conduction system or a malfunction of the heart’s natural pacemaker (the SA node) can cause a heart dysrhythmia. The primary purpose of the pacemaker is to sustain an adequate heart rate that will maintain sufficient blood pressure & perfuse all organs adequately.

In some patients, artificial pacemakers are used externally to address a temporary need, and in other patients with permanent conditions, pacemakers are implanted surgically.

Whether temporary or permanent, a pacemaker provides an electrical stimulus traveling through lead wires to stimulate the myocardium (heart muscle) to depolarize and contract.

The parts of a pacemaker include the battery/brains, known as the pulse generator, and lead wires that have electrodes on the ends.

The pulse generator houses the pacemaker’s energy source and controls. The nurse should verify that the rate prescribed matches the rate set on the pulse generator.

The mode of pacing can be set on demand or asynchronous. Demand pacing senses the heart’s impulses and paces only when the patient needs it. Asynchronous pacing mode sets the pacemaker to fire at a fixed rate regardless of the heart’s ability to generate impulses.

TEMPORARY PACING is necessary for short-term management of dysrhythmias until the patient’s rhythm is stabilized or a permanent pacemaker can be inserted.

Normally, all types of temporary pacing are by demand, in which the pacemaker delivers electrical current only when the heart’s rate falls below the preset rate. They are typically used for less than three days. Temporary pacemakers include transcutaneous, transvenous, epicardial, & transesophageal.

Types of TEMPORARY PACING include:
     Transcutaneous
     Transvenous
     Epicardial
     Transesophageal

Transcutaneous external pacing is primarily for unstable rhythms in emergency situations, requiring two electrodes on the chest, either in the anterior/lateral position or the anterior/posterior position.

With a transvenous pacemaker, the pacer wire is inserted through a large vein into the right ventricle, with the leads attached to an external pulse generator box.

Epicardial pacing is most commonly used with cardiac surgery patients undergoing an open thoracotomy. Temporary lead wires are sutured loosely to the outermost layer of the heart, exposed through the skin, and connected to an external pulse generator similar to transvenous pacing.

Transesophageal pacing involves placing an electrode in the esophagus through the nose or by a pill-electrode that is swallowed. The electrode connects to an external pulse generator by a wire. This type of pacing is commonly used only for atrial pacing in sinus bradycardia, supraventricular tachycardia or for diagnostic studies.

When caring for a patient with a temporary pacemaker, there are several guidelines to follow for safe practice.

     Assess the patient’s tolerance of the heart rhythm - This is done by 
     continuous ECG monitoring, and assessing the patient’s mental status, 
     blood pressure, pulse, heart sounds, lung sounds, skin color, warmth, 
     and urinary output.

     Check the system for proper functioning - secure all connections, secure 
     generator box to the patient, check the pacing threshold every 12 hours, 
     replace the battery generator or connecting cable for failure to pace, & 
     adjust sensitivity for undersensing or oversensing (and notify the physician).

     Maintain electrical safety - Verify that wires are connected & secured to the 
     correct connector ports, keep the insulation cover over the uninsulated ends, 
     wear rubber gloves when handling exposed terminals, do not touch the patient & 
     electrical equipment at the same time, keep ungrounded electrical equipment from 
     contact with the patient, and prevent liquids from coming in contact with the 
     generator, cables, or insertion site.

     Monitor for complications at insertion site - assess the site daily for 
     infection, change dressing every 48 hours using central line dressing 
     sterile technique.

     Assess patient safety and comfort - Explain the purpose of the pacemaker 
     to decrease anxiety, position patient comfortably to avoid tension on the 
     external wires and generator, provide pain medication or sedation as needed, 
     and provide diversional activities when mobility is limited.

PERMANENT PACEMAKERS are used to treat various bradycardic arrhythmias and are implanted during a short surgical procedure, usually under local anesthesia.

The electronic control center of the pacemaker is called the pulse generator, which is encased in titanium with a lithium iodide battery inside that lasts 5-12 years. The pulse generator is attached to one or more lead wires that are threaded through large blood vessels in the upper chest into the heart.

Small electrodes at the ends of the leads attach to the inner surface of the heart and pick up the heart’s natural electrical signals and deliver the pacing pulse from the generator. The pulse generator is usually placed under the skin below the collarbone.

Most implanted pacemakers are dual-chambered pacemakers, in which an electrode is placed in the right atrium and one in the right ventricle.

If necessary, a third lead can be placed in the left ventricle with a biventricular device.

When caring for a patient with a permanent pacemaker, teach the patient before surgery about:
     The reasons for the pacemaker

     Potential complications

     Pretests: including baseline 12-lead ECG & bleeding function 
     bloodwork.

     The need for IV access for fluids, sedation, & emergency 
     medications.

     They are to have nothing by mouth for 8 hours before procedure

Preop teaching before a permanent pacemaker:
   The reasons for the pacemaker
   Potential complications
   Pretests: baseline 12-lead EKG & blood work
   IV access for fluids, sedation, & emergency medications
   Nothing by mouth 8 hours before procedure

The nurse will then..
   Assess baseline VS, peripheral pulses, and heart & lung 
   sounds.

   Assess the patient’s anxiety level - actively listen, 
   reassure, educate, & give sedation as needed.
 
   Shave & scrub the access site where the generator will be 
   implanted.

   Maintain a sterile field.

   Keep a cardiac monitor on at all times during the procedure.

The nurse will…
   Assess baseline VS, peripheral pulses, and heart & 
   lung sounds.

   Assess anxiety level - actively listen, reassure, 
   educate, & give sedation as needed.

   Shave & scrub access site where generator will be 
   implanted.

   Maintain sterile field.

   Cardiac monitor at all times during procedure.
Following the procedure…
– Monitor for complications of insertion such as:
     Pneumothorax (collapsed lung)

     Hemothorax (collection of blood in the pleural cavity)

     Perforation from the pacemaker lead

     Cardiac tamponade (pressure on the heart caused by fluid build-up 
     around the heart)

*These complications are seen as shortness of breath, low blood pressure, chest pain, or a rapid heart rate.
– Monitor for lead dislodgement, seen as ECG changes or hiccups if diaphragm is being paced.

– Monitor ECG for loss of sensing, loss of capture, or failure to pace.

– Provide pain medications & interventions as needed.

– Assess insertion site for bleeding and infection.

– Apply ice pack to minimize pain and swelling for first 6 hours.

– Maintain bedrest for 12 hours.

– Restrict movement of the affected arm for 12-24 hours. After 24 hours, assist with gentle ROM exercises 3 times daily, to restore normal movement & prevent stiffness.

– Do not give aspirin or heparin for 48 hours.

– If defibrillation is necessary, avoid the area surrounding generator site.


Discharge instructions to teach the patient:
    Placement of the pacemaker generator & leads, how it works, 
    & the rate at which it is set.

    Monitor site for bleeding & infection for the first week; 
    bruising may be present.

    Avoid immersing the site in water for 3 days.

    Minimize arm & shoulder activity of affected arm and wear 
    loose covering over incision for 1-2 weeks, to prevent 
    dislodgement of new leads.

    Avoid contact sports and heavy lifting for 2 months after 
    surgery.

    Contact physician with fatigue, palpitations, or recurrence 
    of symptoms (may indicate pacemaker malfunction or battery 
    depletion).

    Take radial pulse daily before arising & notify physician for 
    rates outside those programmed (may indicate pacemaker 
    malfunction or battery depletion).

    Carry pacemaker information at all times & wear a MedicAlert 
    bracelet (pacemaker will trigger some airport security alarms).

    Discuss any possible procedures with cardiologist (some 
    procedures - MRI, electrocautery - may affect the pacemaker).

    Household appliances such as microwave ovens, radios, & gardening 
    tools will not affect the pacemaker. Cell phones currently don’t 
    appear to affect pacemakers.

Modern pacemakers have built-in features to protect them from most types of interference produced by other electrical devices, however, the patient must always be aware of their surroundings & the devices that may interfere.

Devices with possible risk include:
 
   anti-theft systems
   strong metal detectors
   MP3 player headphones (keep at least 3cm away from pacemaker)
   shock-wave lithotripsy (noninvasive treatment for kidney stones)
   power-generating equipment
   arc welding equipment
   powerful magnets
   therapeutic radiation (cancer treatment)
   TENS units for pain relief

Avoid high-voltage or radar machinery or working over large running motors.

– If interference with the pacemaker is suspected, move away from the electrical device or turn off the equipment.

Signs of pacemaker malfunction include:
     Dizziness
     Fainting
     Fatigue
     Weakness
     Chest pain
     Palpitations

– Maintain follow-up care with the physician as recommended. Between office visits, the doctor can keep track of the pacemaker’s operation through transtelephonic monitoring.

Pacemaker malfunctions should be reported to the physician and include loss of sensing, failure to capture, and failure to pace.

Loss of sensing: Pacemaker is either ‘oversensing’ and senses an external signal as an impulse & does not pace or it is ‘undersensing’ the heart’s own impulse & it paces the heart unnecessarily. (As you can see in the example of undersensing, the first 2 beats are paced, then several intrinsic beats occur, but the pacemaker fails to sense these beats, resulting in competition between paced beats and the heart’s intrinsic rhythm.) The nurse should check for electromagnetic interference & proper grounding of equipment. In undersensing, increase the sensitivity of the pacer. In oversensing, decrease the sensitivity of the pacer.

Failure to capture: Pacemaker fires but does not depolarize the ventricle – Nurse should turn patient to left side (to bring lead in better contact with endocardium), check all connections, & increase the energy delivered. (In the example, atrial pacing & capture occur after pacer spikes 1,3,5, and 7. The remaining pacer spikes fail to capture, resulting in no conduction to the ventricles, and no arterial waveform).

Failure to pace: Electrical impulse is never initiated, so there are no pacer spikes shown on the ECG strip. The nurse should keep an external or temporary pacemaker at the bedside, assessing the patient until the cause of the failure is determined & corrected.

Pacemaker malfunction: Loss of sensing
‘Oversensing’ – senses an extraneous signal as an impulse & does not pace

‘Undersensing’ – doesn’t sense the heart’s own impulse & it paces the heart unnecessarily.

Nurse should check for electromagnetic interference & proper grounding of equipment. In undersensing, increase the sensitivity of the pacer. In oversensing, decrease the sensitivity of the pacer.

*Undersensing – First 2 beats are paced, then several intrinsic beats occur, but the pacemaker fails to sense these beats, resulting in competition between paced beats and the heart’s intrinsic rhythm.

Pacemaker malfunction: Failure to capture
Pacemaker fires but does not depolarize the ventricle.

Nurse should turn patient to left side (to bring lead in better contact with endocardium), check all connections, increase the energy delivered.

*Failure to capture: Atrial pacing & capture occur after pacer spikes 1,3,5, and 7. The remaining pacer spikes fail to capture, resulting in no conduction to the ventricles, and no arterial waveform.

Pacemaker malfunction: Failure to pace
Electrical impulse is never initiated. There are no pacer spikes shown on ECG strip.

The nurse should keep an external or temporary pacemaker at the bedside, assessing the patient until the cause of the failure is determined & corrected.

Many pacemakers have the added function of an implanted cardioverter-defibrillator (ICD), which is for patients at risk for dysrhythmias that do not respond to antidysrhythmic therapy. The ICD continuously monitors heart activity & can automatically deliver a countershock to correct a perceived dysrhythmia. The teaching required for the patient with ICD insertion is similar to a permanent pacemaker insertion. However, the shock from an ICD is generally painful and patients should be advised of this in advance. Others in physical contact with the patient will experience a mild sensation with the shock delivery, but no harm is done. Most doctors recommend that patients be shock-free for 6 months before resuming driving. Emotional support is critical for patients & family, as there is often anxiety, depression, fear, & anger associated with ICD placement.

Implanted cardioverter-defibrillator (ICD)
     For patients at risk for dysrhythmias that do not 
     respond to antidysrhythmic therapy.

     Continuously monitors heart activity & can automatically 
     deliver a countershock to correct a perceived dysrhythmia.

     The shock from an ICD is generally painful and patients 
     should be advised of this in advance.

     Doctors recommend that patients be shock-free for 6 months 
     before resuming driving.

     Emotional support is critical.

End-of-life concerns:
Patients may choose to decline a pacemaker with ICD functionality, as they may interfere with the natural process of dying by continuing to function and deliver shocks. As a patient approaches the end of life, healthcare providers should discuss the options with the patient and family.

Remember, when caring for a pacemaker patient in the hospital, the ECG will continue to show pacing spikes and possible electrical activity even without a pulse. The healthcare team may choose to monitor the patient remotely, so as to avoid confusion in family members at the bedside.

Pacemaker technology is changing constantly, but the goal of therapy remains the same – to sustain an adequate heart rate that will maintain sufficient blood pressure & perfuse all organs adequately.

As a patient approaches the end of life, healthcare providers should discuss the options with the patient and family. Patients may choose to decline a pacemaker with ICD functionality, as they may interfere with the natural process of dying by continuing to function and deliver shocks.

Remember, when caring for a pacemaker patient in the hospital, the ECG will continue to show pacing spikes and possible electrical activity even without a pulse. The healthcare team may choose to monitor the patient remotely, so as to avoid confusion in family members at the bedside.

 

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