Which inhalational agent is used in patients with raised intra cranial tension?
**Core Concept**
Isoflurane is a commonly used inhalational anesthetic agent, known for its ability to maintain cerebral perfusion pressure and reduce intracranial pressure (ICP). This property makes it a preferred choice in patients with raised intracranial tension.
**Why the Correct Answer is Right**
Isoflurane's mechanism of action involves decreasing cerebral metabolic rate (CMRO2) and cerebral blood flow (CBF), thereby reducing ICP. This is achieved through its effect on the cerebral vasculature, causing vasodilation and reducing the resistance to blood flow. Additionally, isoflurane's ability to decrease cerebral autoregulation allows for a more stable and controlled reduction in ICP.
**Why Each Wrong Option is Incorrect**
**Option A:** Enflurane is not the preferred choice in patients with raised ICP due to its potential to increase cerebral blood flow and metabolic rate, which could exacerbate the condition.
**Option C:** Desflurane, although a useful inhalational agent, is not typically used in patients with raised ICP due to its potential to cause airway irritation and increase sympathetic nervous system activity, which may worsen intracranial hypertension.
**Option D:** Sevoflurane, while commonly used in pediatric anesthesia, is not the preferred choice in patients with raised ICP due to its potential to cause cerebral vasodilation and increase cerebral blood flow.
**Clinical Pearl / High-Yield Fact**
In patients with raised intracranial tension, it is essential to use anesthetic agents that maintain cerebral perfusion pressure and reduce ICP. Isoflurane is a suitable choice, but the anesthesiologist must also ensure that the patient is adequately ventilated and that the anesthetic circuit is properly managed to prevent further increases in ICP.
**✓ Correct Answer: B. Isoflurane**