Upon finding a client in cardiac arrest, the RN should administer which of the following drugs first?

A. Place one defibrillation paddle directly over the pacemaker generator: Placing a defibrillator paddle directly over the pacemaker can damage the device or its leads and may interfere with pacemaker function. This placement increases the risk of permanent pacemaker malfunction and is therefore avoided.

B. Use pediatric size paddles: Pediatric paddles are designed for children and deliver lower energy shocks. Using pediatric paddles on an adult patient is inappropriate because it may not provide adequate energy to successfully defibrillate the heart.

C. Never defibrillate a patient with a permanent pacemaker: Having a permanent pacemaker is not a contraindication for defibrillation. In life-threatening arrhythmias, defibrillation should not be withheld; instead, appropriate precautions are taken to minimize pacemaker damage.

D. Avoid placing the defibrillation paddles near the pacemaker generator: Proper defibrillation technique involves positioning paddles or pads so that the electrical current does not pass directly through the pacemaker. This protects the device while allowing effective defibrillation of the myocardium, ensuring patient safety and device integrity.

A. Slow repolarization of ventricular Purkinje fibers: Repolarization of the ventricular Purkinje fibers occurs later in the cardiac cycle and is not represented by the P wave. This process is reflected in other components of the ECG, primarily the T wave, which indicates ventricular repolarization.

B. Atrial depolarization: The P wave represents the depolarization of the atria, initiated by the sinoatrial (SA) node. It reflects the electrical impulse traveling through the atrial myocardium, which triggers atrial contraction and contributes to ventricular filling. Correct interpretation of the P wave helps assess atrial rhythm and detect abnormalities such as atrial enlargement.

C. Early ventricular repolarization: Early ventricular repolarization is part of the T wave phase and is unrelated to atrial activity. Misidentifying the P wave as representing ventricular repolarization would lead to errors in rhythm analysis and patient assessment.

D. Ventricular depolarization: Ventricular depolarization is reflected by the QRS complex, not the P wave. The QRS complex shows electrical conduction through the ventricles, triggering their contraction, and must be distinguished from atrial depolarization for accurate ECG interpretation.