*Extracted from comprehensive anesthesia notes.*

Preparatory Mindset

Focus on: physiologic effects of anesthesia, drug mechanisms, airway management, and complication recognition. Exam questions often test classification systems (ASA, airway assessment) and complication management.

Core Concepts

1. Core Definition & Goals

• - Four objectives: Unconsciousness, Amnesia, Analgesia, Muscle relaxation.

1. Sleep

2. Amnesia

3. Analgesia

4. Muscle relaxation

5. Autonomic suppression

• - Inhalation


• - IV


• - IM

1. Stage 1: Conscious → loss of consciousness

2. Stage 2: Excitement phase (irregular breathing, arrhythmia)

3. Stage 3: Surgical anesthesia (ideal for operation)

4. Stage 4: Overdose (severe cardiorespiratory depression)

3. Types of Anesthetic Drugs

Inhalational anesthetics

• - MAC (Minimum Alveolar Concentration): Potency index; lower = more potent.


• - Common agents:


• ▪ Sevoflurane: fast, no airway irritation


• ▪ Desflurane: rapid emergence, irritates airway


• ▪ Isoflurane: stable


• ▪ Nitrous oxide (N₂O): weak analgesia, risk of gas expansion


• ▪ Halothane: old, risk of hepatitis

• - Propofol: fast onset/emergence, anti-emetic


• - Midazolam: sedation + amnesia


• - Ketamine: analgesia, bronchodilation, emergence delirium


• - Etomidate: hemodynamically stable


• - Thiopental: rapid induction, no analgesia

• - Fentanyl, Sufentanil, Remifentanil


• - Effects: analgesia, sedation; side effects: respiratory depression, nausea, vomiting

• - Depolarizing: Succinylcholine (rapid onset, short duration; risk: MH)


• - Non-depolarizing: Rocuronium, Vecuronium, Atracurium


• - Notes: Need ventilation; hypothermia prolongs action.

1. Preoperative preparation: assessment, NPO, IV access, consent

2. Induction: IV drugs → unconsciousness

3. Intubation: airway control

4. Maintenance: inhaled/IV agents + analgesics + relaxants

5. Emergence: stop drugs → reversal → wake up

6. Extubation: safe criteria (breathing, gag reflex, obey commands)

7. PACU/ICU transfer

5. Main Complications

• - Respiratory: depression, obstruction, aspiration, atelectasis


• - Cardiovascular: hypotension, hypertension, arrhythmia, arrest


• - Other: hypothermia/hyperthermia, delayed emergence, PONV

• - Balanced anesthesia: combine drugs for optimal effect


• - Muscle relaxants ≠ anesthesia


• - Continuous monitoring is mandatory


• - Prepare for difficult airway & emergencies

High-Yield Points

• ASA classification is a must-know for exam


• Understand differences between general vs regional anesthesia


• Complications and their management are frequently tested


• Know the Mallampati score and airway assessment criteria