Awareness during Anesthesia

Groups at risk for awareness:

Awareness is due to too light plane of anesthesia. It is more likely where muscle relaxants are used. They may be due to:

1-Inadequate anesthetic dose:

-Emergency surgery

-Hypotensive anesthesia

-Cardiac surgery

-Inability to monitor dose in TIVA

-Obstetric surgery

-Normal variability in MAC

2-Resistance:

-Hypermetabolic state

-Smokers

-Obesity

-Alcoholic

3-Equipment malfunction:

-Breathing circuits

-TIVA pump malfunction or line disconnection

-Vaporizers

Prevention:

-Recognize patients at risk

-Anesthesia machine pre-use check and knowing its mechanics & mechanisms

-Periodically check vaporizer level & provide adequate MAC levels

-Benzodiazepines at induction

-Use muscle relaxants ONLY when necessary

-Use of “BIS” monitoring in high-risk groups

-Be aware that some drugs may mask signs of awareness (e.g., β-blockers mask tachycardia)

Categories: Complications in anesthesia