very short in duration, typically referring to the time span in which a drug or a mechanism takes effect and wears off

अत्यंत अल्पकालिक

English Usage: The ultra short acting anesthetic helped the patient regain consciousness quickly after the surgery.

Hindi Usage: अत्यंत अल्पकालिक ऐनेस्थेटिक ने सर्जरी के बाद रोगी को जल्दी से होश में आने में मदद की।