The client hospitalized with infective endocarditis develops sharp flank pain and hematuria. The nurse notifies the physician, recognizing that these clinical manifestations may indicate:

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. Blood pressure reading of 120/80: While a normal blood pressure is desirable, this value alone does not indicate improvement in fluid overload or pulmonary symptoms. It may remain normal even if respiratory status worsens or fails to improve.

B. Urine output 30 mL for one hour: Although urine output is an important measure of diuretic effectiveness, 30 mL/hr is the minimum acceptable rate, not necessarily a strong indicator of clinical improvement. More robust diuresis may be expected following IV furosemide.

C. Serum sodium level is 135 mEq/L (135–145): A normal sodium level reflects stable electrolyte status but does not directly indicate improvement in pulmonary congestion or dyspnea. Sodium may be affected by many factors unrelated to heart failure symptom relief.

D. Respiratory rate 16 per minute: A decrease in respiratory rate from 26 to 16 suggests improved oxygenation, reduced pulmonary congestion, and decreased work of breathing. It is the most direct and clinically relevant indicator of symptomatic improvement in this context.