Which of the following is NOT a sign of a VP shunt infection or blockage?

The correct answer is low blood pressure, as it is not a typical sign of a ventriculoperitoneal (VP) shunt infection or blockage. Infections and blockages associated with VP shunts lead to increased intracranial pressure due to impaired cerebrospinal fluid (CSF) drainage. This often manifests through symptoms such as irritability, increased head size, and bulging fontanels, which are more directly related to the effects of elevated pressure in the cranial cavity.

Increased head size occurs as the ventricles enlarge from the fluid accumulating, while bulging fontanels indicate that the normal fontanel areas of the skull are pushed outward due to the pressure. Irritability is commonly observed as infants may show signs of discomfort and distress due to the increased intracranial pressure.

On the other hand, low blood pressure may arise due to other factors not directly associated with shunt complications. For instance, it can be a response to dehydration, sepsis, or other systemic conditions, but is not a direct indicator of a problem with the ventriculoperitoneal shunt itself. Thus, understanding these signs helps healthcare professionals monitor the status of infants with VP shunts and respond appropriately to any complications.