Ketamine contraindicated in all except?
**Core Concept**
Ketamine is a dissociative anesthetic agent that works by blocking N-methyl-D-aspartate (NMDA) receptors in the brain. It has several clinical applications, including anesthesia, sedation, and pain management. However, its use is contraindicated in certain conditions due to its potential side effects.
**Why the Correct Answer is Right**
Ketamine can increase intracranial pressure (ICP) and is therefore contraindicated in patients with head trauma, intracranial hypertension, or other conditions that may be exacerbated by increased ICP. However, in patients with chronic pain, ketamine can be used as a treatment option, making it an exception to the contraindication.
**Why Each Wrong Option is Incorrect**
**Option A:** **Severe respiratory depression** - Ketamine can cause respiratory depression, especially when used in combination with other sedatives or anesthetics.
**Option B:** **Severe hypertension** - Ketamine can increase blood pressure and heart rate due to its sympathomimetic effects, making it contraindicated in patients with uncontrolled hypertension.
**Option C:** **Severe cardiovascular disease** - Ketamine can cause myocardial ischemia and increase cardiac workload, making it contraindicated in patients with severe cardiovascular disease.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that ketamine can cause a "dissociative" state, characterized by a sense of detachment from one's body, which can be beneficial in some cases but also lead to adverse reactions if not managed properly.
**Correct Answer:** C. Severe cardiovascular disease.