Dysrhythmia and Pacemaker Nursing Management

Pacemaker Management and Complications

Pacemakers are implanted to manage bradycardia or heart block. A key concept is capture, which occurs when a pacemaker spike is followed by a P wave (atrial capture) or a wide QRS (ventricular capture).

Pacing Modes and Failures

Modern pacemakers often use on-demand pacing, meaning they only fire if the patient's intrinsic rate drops below a set limit (usually 50–60 bpm). Nurses must be able to recognize three critical failures:

• Failure to Capture: A spike is visible, but no P wave or QRS follows it.
• Failure to Pace: No spike appears even when the heart rate drops below the set limit.
• Failure to Sense (Undersensing): The pacemaker delivers spikes even when the patient has their own intrinsic beats, potentially landing in the wrong part of the cycle.

Nursing Care and Discharge Teaching

Patients with permanent pacemakers or Implantable Cardioverter Defibrillators (ICDs) require specific education to prevent device malfunction or injury:

• Incision Care: Keep the site uncovered initially; avoid tight clothing, tub soaking, or lotions.
• Activity Restrictions: Do not lift the arm on the device side above the shoulder for 2 weeks.
• Electromagnetic Interference: Avoid MRIs and strong magnetic fields; keep cell phones on the opposite side of the body.
• ICD Shocks: Patients should keep a log of any shocks received and what they were doing at the time.

Analyzing Dysrhythmias: Common and Lethal

The nurse's first step in any dysrhythmia is to assess the patient (pulse, BP, level of consciousness) rather than just the monitor.

Exam Tip: The Hs and Ts When treating Pulseless Electrical Activity (PEA), always look for reversible causes using the "Hs and Ts" framework: Hypoxia, Hypovolemia, Hydrogen ion (acidosis), Hypo/Hyperkalemia, Hypothermia, Toxins, Tamponade, Tension pneumothorax, and Thrombus.

Critical Lab Values and Medication Administration

Electrolyte imbalances are a primary cause of dysrhythmias. The nurse must monitor these values closely:

• Potassium (3.5–5.2 mEq/L): Low $\rightarrow$ PVCs, VT; High $\rightarrow$ Peaked T waves, bradycardia.
• Magnesium (1.8–2.6 mg/dL): Low $\rightarrow$ Torsades de Pointes.
• Calcium (9–11 mg/dL): Low $\rightarrow$ Dysrhythmias.
• Digoxin: Monitor for toxicity, which can cause dysrhythmias.
• INR (for Warfarin): Target 2.0–3.0; high levels increase bleeding risk.

Antidysrhythmic Medications

When administering medications, specific nursing actions are required:

• Atropine: Give via IV push for symptomatic bradycardia; monitor for tachycardia.
• Adenosine: Give as a fast IV push followed immediately by a rapid saline flush.
• Amiodarone: Monitor closely for bradycardia and hypotension.
• Verapamil/Diltiazem: Always check heart rate and blood pressure first; hold if they are low.

Electrical Therapy: Cardioversion vs. Defibrillation

If a patient is unstable, electrical therapy may be necessary:

1. Cardioversion: Used for unstable tachyarrhythmias with a pulse. It is synchronized ("Sync ON"), meaning the shock is timed to the R wave to avoid inducing VF.
2. Defibrillation: Used for VF and pulseless VT. It is not synchronized ("Sync OFF").

Safety Protocol for Defibrillation:

• Use conductive gel or pads (never ultrasound gel).
• Ensure pads do not touch clothing, linens, or medication patches.
• Announce "Charging to [X] Joules".
• Call "CLEAR!" three times, performing a visual check each time to ensure no one is touching the patient, bed, or equipment.
• Immediately resume CPR after the shock is delivered.

The Nursing Process in Dysrhythmia Care

Effective management follows the nursing process framework:

• Assessment: Monitor vital signs, apical/radial pulses, LOC, skin, and lung sounds. Review labs (K+, Mg++, Ca++, Digoxin).
• Diagnosis: Common diagnoses include Decreased Cardiac Output, Anxiety, or Deficient Knowledge.
• Implementation: Administer ordered antiarrhythmics, correct underlying causes (e.g., treat hypoxia), and maintain continuous monitoring.
• Evaluation: Determine if the patient has stable vital signs, reduced episodes, and an understanding of their emergency plan.