Which is a key symptom for a nurse to observe in a child with acute glomerulonephritis indicating worsening condition?

In acute glomerulonephritis, one of the critical symptoms that can indicate a worsening condition is elevated blood pressure. This occurs because inflammation and damage to the glomeruli in the kidneys can lead to an imbalance in fluid and electrolyte regulation, causing the body to retain fluid and increasing blood volume. This retained fluid generates higher pressure in the blood vessels, resulting in elevated blood pressure.

Monitoring blood pressure in children with acute glomerulonephritis is essential because significant hypertension can lead to severe complications, such as hypertensive emergencies or kidney failure. Recognizing this change helps nurses intervene early, providing necessary medical management to prevent further deterioration of the child's condition.

The other symptoms, while they can also indicate changes in the child’s condition, do not specifically signal the critical nature of increased blood pressure in this context. Recognizing that elevated blood pressure is a direct consequence of the pathophysiological changes in acute glomerulonephritis underscores its importance as a key symptom to observe.