A nurse is collecting data from a child who has sickle disease and is experiencing a vaso-occlusive crisis. Which of the following findings should the nurse expect?

A. Bradycardia: Tachycardia is more likely due to pain or hypoxia. B. Constipation: Not a hallmark feature of vaso-occlusive crisis. C. Pain: Vaso-occlusive crises are characterized by severe pain due to ischemia caused by sickled red blood cells obstructing blood flow. D. Vomiting: May occur secondary to medication or illness but is not a defining feature.