What EKG change should the nurse identify as a sign of hypokalemia in a client with prolonged vomiting?

In cases of hypokalemia, particularly in a client experiencing prolonged vomiting, one significant EKG change that can be observed is the presence of an abnormally prominent U wave. The U wave is a deflection that follows the T wave on the EKG and becomes more prominent in the context of low potassium levels. This prominence occurs because adequate potassium is essential for proper repolarization of cardiac myocytes.

Hypokalemia affects the heart's electrical activity and can lead to various changes in the EKG tracing, including the prominence of the U wave. Elevated U waves can help healthcare providers identify the electrolyte imbalance before severe complications develop. Additionally, other EKG changes associated with hypokalemia can include flattening or inversion of T waves and possibly the development of arrhythmias, but the hallmark sign often emphasized in clinical practice is the prominent U wave.

While the other options mentioned may indicate different cardiac issues or electrolyte disorders, they are not specifically indicative of hypokalemia. For example, a wide QRS complex might suggest delays in conduction or ventricular hypertrophy, while an inverted P wave could be indicative of atrial issues or other forms of electrolyte imbalance unrelated to potassium depletion. The elevated ST segment could suggest different pathologies, such as ischemia or