GENERAL ANESTHESIA

DEFINITION: A state of unconsciousness, analgesia (pain relief), muscle relaxation, and loss of reflexes, used during surgeries and invasive procedures.

COMPONENTS: 

Hypnosis: Unconsciousness.

Analgesia: Pain relief.

Muscle Relaxation: Paralysis of skeletal 

muscles.

PHASES:

Induction: Transition to unconsciousness using agents like propofol or sevoflurane (inhalation agent)

Maintenance: Sustaining anesthesia with inhalational agents (e.g. sevoflurane or isoflurane) or IV drugs (e.g. fentanyl).

Emergence: Gradual recovery of consciousness, stopping anesthetic agents.

MECHANISM OF ACTION: Depresses the CNS by enhancing GABA activity or inhibiting NMDA receptors.

TYPES OF AGENTS: Inhalational: Isoflurane, sevoflurane, desflurane.

Intravenous: Propofol, thiopentone, ketamine.

MONITORING: Continuous monitoring of ECG, blood pressure, oxygen saturation, end-tidal CO2, temperature, and neuromuscular function.

RISKS AND COMPLICATIONS :

Cardiovascular (hypotension, arrhythmias), 

Respiratory (hypoventilation, aspiration), 

Neurological (awareness, delayed emergence), 

PONV (Post Operative Nausea and Vomiting), allergic reactions.

Preoperative Assessment: Evaluate medical history, physical exam, lab tests, and obtain informed consent.

Postoperative Care: Monitoring in the PACU, pain management, and addressing complications like respiratory depression or PONV (Post Operative Nausea and Vomiting).