What is a contraindication for the use of Ketamine?

The appropriate contraindication for the use of Ketamine is related to head injury. In patients with head trauma, the administration of Ketamine can lead to an increase in intracranial pressure, which could exacerbate any existing injuries. This concern is especially pertinent because Ketamine is known for its dissociative anesthetic properties, potentially leading to changes in the patient's level of consciousness and stability. As such, caution should be exercised when considering its use in individuals with the risk of worsening a head injury.

While hypersensitivity to anesthesia and severe liver disease are valid concerns when administering medications, they do not specifically relate to the unique effects that Ketamine may have on someone with head trauma. In the case of pregnant patients, the classification of pregnancy category D suggests that there is evidence of risk to the fetus, but it does not necessarily rule out the use of Ketamine in critical situations where the benefits may outweigh the risks.