Inhalational induction of anesthesia is the process of transitioning a patient from a state of consciousness to unconsciousness solely by having them inhale a volatile anesthetic agent. This method stands in contrast to the more common intravenous (IV) induction, where anesthetic drugs are injected directly into the bloodstream.
Nitrous oxide (N₂O) is frequently encountered in today’s clinical practice. This colorless, non-flammable gas has a fascinating history and remains one of the oldest anesthetic agents still in use today. It was first synthesized by English chemist Joseph Priestley in 1772, though he didn’t recognize its potential medical applications.
Isoflurane is a potent, reliable inhalational anesthetic (MAC ~1.2%) with moderate blood solubility (λB:G 1.4). Known for cardiovascular stability and bronchodilation, it uses a standard vaporizer. Pungent but less than Desflurane; suitable for pediatric maintenance. Cost-effective with minimal metabolism, making it a staple in anesthesia practice.
Desflurane is a potent inhalational anesthetic prized for its rapid emergence due to low blood solubility (MAC 6-7%). Ideal for outpatient surgery and fast wake-up needs. Requires a special heated vaporizer. Pungent and irritating, it’s contraindicated for inhalational induction. Minimal metabolism offers low toxicity risk. Key for anesthesia efficiency.
Sevoflurane is a potent, non-pungent inhalational anesthetic (MAC ~2%) with low blood solubility (λB:G 0.65). Ideal for smooth inhalational induction (especially pediatrics) and rapid emergence. Uses a standard vaporizer. Minimal airway irritation; monitor for Compound A with low-flow anesthesia. Low metabolism ensures safety.
