In status asthmaticus, anesthetic agent used as bronchodilator:-
**Core Concept**
Ketamine is a unique anesthetic agent that has bronchodilatory properties, making it beneficial in managing status asthmaticus. Its mechanism involves the blockade of N-methyl-D-aspartate (NMDA) receptors in the central nervous system, which contributes to its bronchodilatory effects.
**Why the Correct Answer is Right**
Ketamine's bronchodilatory effects are primarily due to its ability to increase the concentration of cyclic adenosine monophosphate (cAMP) in airway smooth muscle cells. This increase in cAMP levels leads to the relaxation of airway smooth muscle, resulting in bronchodilation. Additionally, ketamine has a direct relaxant effect on the airway smooth muscle, which further contributes to its bronchodilatory effects. The combination of these mechanisms makes ketamine an effective agent in managing status asthmaticus.
**Why Each Wrong Option is Incorrect**
**Option A:** Morphine is an opioid analgesic that can actually worsen bronchospasm by releasing histamine and increasing airway resistance.
**Option B:** Thiopentone sodium is a barbiturate anesthetic that does not have significant bronchodilatory effects and may even cause histamine release, leading to bronchospasm.
**Option D:** Halothane is a volatile anesthetic that can cause bronchospasm due to its irritant effects on the airway epithelium and release of histamine.
**Clinical Pearl / High-Yield Fact**
Ketamine's bronchodilatory effects make it a valuable agent in managing status asthmaticus, but it is essential to note that it can also increase intracranial pressure and cause hallucinations, making it a double-edged sword in clinical practice.
✓ Correct Answer: C. Ketamine