A client's serum potassium level is 2.9 mEq/L. Which clinical finding does the nurse MOST expect to see?

HYPOKALEMIA is defined as serum potassium below 3.5 mEq/L. Normal range: 3.5-5.0 mEq/L. A level of 2.9 mEq/L is SIGNIFICANTLY LOW and clinically concerning. CLINICAL MANIFESTATIONS OF HYPOKALEMIA: CARDIAC: most dangerous; PVCs (premature ventricular contractions); U WAVES on ECG (prominent — a U wave following the T wave is a classic ECG sign of hypokalemia); flattened T waves; prolonged QU interval; progression to ventricular tachycardia or ventricular fibrillation if severe; MUSCLES: muscle weakness (legs first, ascending); muscle cramps; PARALYTIC ILEUS (lack of bowel sounds, abdominal distension, constipation); respiratory muscle weakness with very low K+; NEUROLOGICAL: fatigue, lethargy, confusion; RENAL: polyuria (paradoxically, hypokalemia impairs the kidney's ability to concentrate urine). CAUSES OF HYPOKALEMIA: loop and thiazide diuretics (most common); vomiting; nasogastric suction; diarrhea; sweating; poor dietary intake; increased renal excretion (hyperaldosteronism, Cushing's syndrome); alkalosis (K+ shifts into cells). TREATMENT: ORAL POTASSIUM REPLACEMENT (KCl tablets or liquid — better absorbed with food; GI irritating); IV POTASSIUM: NEVER push IV K+ directly — can cause cardiac arrest; dilute in IV fluids (typically no more than 10-20 mEq/hr via peripheral line; higher concentrations require central line); cardiac monitoring during IV K+ administration; DIETARY SOURCES: bananas, oranges, potatoes, leafy greens, tomatoes, beans. HYPERKALEMIA (contrast): K+ >5.0 mEq/L; PEAKED (TALL TENT) T WAVES on ECG; widened QRS; cardiac arrest risk; muscle weakness; causes: renal failure, ACE inhibitors, potassium-sparing diuretics, acidosis. PN ROLE: report abnormal K+ immediately; administer replacement per order; monitor ECG; assess for symptoms; teach dietary sources.