The nursing is caring for a patient who has had a left radial arterial line inserted 10 minutes ago. To reduce the risk of complications, what is the priority nursing intervention?

A. The P-P and R-R distances are equal and regular: Equal and regular spacing between P-P and R-R intervals indicates that both atrial and ventricular rhythms are regular. This is a fundamental aspect of rhythm interpretation, helping to distinguish between regular and irregular rhythms such as atrial fibrillation or sinus arrhythmia.

B. The rhythm rate using a 3-second strip: Assessing the heart rate using a 3-second or 6-second ECG strip helps determine whether the rhythm is bradycardic, tachycardic, or within normal limits, which is crucial for accurate rhythm classification.

C. The duration of the U waves: U waves are typically small and follow the T wave. Although their presence can suggest conditions like hypokalemia, they are not routinely assessed in basic rhythm identification. Evaluating U wave duration is more relevant in electrolyte imbalance analysis than in identifying rhythm type.

D. There is a QRS complex after each P wave: A consistent QRS following every P wave indicates effective conduction from the atria to the ventricles. Each atrial depolarization (P wave) should be followed by a ventricular depolarization (QRS complex) if the signal is being conducted properly through the AV node. This finding supports a diagnosis of sinus rhythm and helps rule out AV blocks, where conduction may be delayed or blocked entirely.

E. P waves are present, upright and rounded: P waves that are upright and rounded in lead II suggest the electrical impulse is originating from the SA node. Their presence and morphology are essential criteria for identifying sinus rhythm and differentiating it from atrial arrhythmias like flutter or fibrillation.

A. Edema of ankles: While peripheral edema may be associated with worsening cardiac function or side effects from other medications, it is not a hallmark adverse effect of amiodarone. It warrants evaluation but is not the most urgent symptom related to this drug.

B. Shortness of breath: Amiodarone is a potent antiarrhythmic medication with several potential serious side effects, including pulmonary toxicity. This can manifest as interstitial pneumonitis or pulmonary fibrosis, which may present as new or worsening shortness of breath cough, and chest pain. This is a potentially life-threatening complication and requires immediate medical attention.

C. Fatigue after exercise: Exercise-induced fatigue can result from many conditions, including heart disease or deconditioning, but it is a nonspecific symptom. It does not point directly to a serious adverse reaction from amiodarone.

D. Abdominal fullness: Abdominal fullness is not typically associated with amiodarone. It may relate to gastrointestinal or hepatic issues, but it is not as immediately concerning as respiratory symptoms suggestive of pulmonary toxicity.