What should always be done prior to performing a lumbar puncture?

Prior to performing a lumbar puncture, it is crucial to check for increased intracranial pressure, which often includes assessing for papilledema. This is important because a lumbar puncture in the presence of significantly elevated intracranial pressure can lead to serious complications, such as brain herniation. Papilledema indicates that there may be swelling of the optic disc, suggesting increased pressure in the cranial cavity. A thorough evaluation of the neurological status of the patient and the presence of any signs of increased intracranial pressure helps ensure that the procedure can be performed safely. If there is any indication of elevated pressure, alternative management strategies would need to be considered.

While conducting a neurological exam is also beneficial, it is not as critical as specifically assessing for signs of increased intracranial pressure before the procedure. Other options, such as obtaining a complete blood count or ensuring the patient has fasted, are typically not required prior to a lumbar puncture.