Makindo Medical Notes

💉 Anesthetics are medications that produce a controlled and reversible loss of sensation. They allow patients to undergo surgery or medical interventions without pain. The goals are: 🛡️ safety, 😌 comfort, and ⚖️ stable physiology throughout the procedure. Modern anesthesia = drug therapy + vigilant monitoring + supportive care.

📌 Categories of Anesthesia

• 🔹 Local Anesthesia: Numbs a small area (e.g., dental work, sutures).
• 🔹 Regional Anesthesia: Larger area (spinal, epidural, nerve blocks) → lower body or limb anesthesia.
• 🔹 General Anesthesia: Complete unconsciousness + loss of sensation → used for major operations.

🧠 Mechanism of Action

• 💡 Anesthetics alter nerve conduction and neurotransmission.
• 🔒 Either enhance inhibitory signals (e.g., GABA activity) or block excitatory ones (e.g., NMDA receptors).
• 🧵 Local drugs act directly on peripheral nerves to block sodium channels → stop pain signals before they reach CNS.

💊 Commonly Used Drugs

• Local Anesthetics:
  • 🟢 Lidocaine: Fast-acting, often with adrenaline for prolonged effect + haemostasis.
  • 🟡 Bupivacaine: Long-acting, excellent for post-op analgesia (but more cardiotoxic).
  • 🟠 Ropivacaine: Safer profile, less cardiotoxic → popular for regional blocks.
• Regional Techniques:
  • 💉 Spinal: Into CSF → rapid profound block for lower body surgery.
  • 🧷 Epidural: Into epidural space → slower, adjustable, used in labour & ortho surgery.
  • 🖐️ Nerve Blocks: Target limb plexuses (e.g., brachial plexus for arm surgery).
• General Anesthetics (IV):
  • ⚪ Propofol: Rapid onset, smooth recovery, but can cause hypotension.
  • 🔵 Ketamine: Analgesia + sedation, maintains airway reflexes, ↑ BP/HR (useful in shock).
  • 🟣 Etomidate: Haemodynamically stable → choice for sick hearts.
• General Anesthetics (Inhaled):
  • 💨 Isoflurane: Moderate potency, safe profile.
  • 💨 Sevoflurane: Smooth induction, low airway irritation → favoured in children.
  • 💨 Desflurane: Very rapid adjustment in depth of anesthesia → quick wake-up.
• Adjuncts:
  • 😴 Midazolam: Benzodiazepine → sedation + anxiolysis.
  • 💊 Opioids (Fentanyl, Morphine): Analgesia during surgery.
  • 🦾 Muscle Relaxants (Rocuronium, Vecuronium): Facilitate intubation + muscle relaxation.

⚠️ Considerations & Side Effects

• ⬇️ Hypotension, arrhythmias.
• 😮‍💨 Respiratory depression or airway compromise.
• 🤮 Post-op nausea/vomiting.
• 🤧 Allergic reactions (rare but serious).
• 🧓 Post-op delirium/confusion (esp. elderly).

🖥️ Monitoring & Safety

• Vital signs: HR, BP, SpO₂, EtCO₂, Temp.
• 🔌 ECG for arrhythmias, BIS monitoring for depth of anesthesia.
• 🤝 Close teamwork between anesthetists, surgeons, and nurses ensures safety.

✨ Clinical Pearls: - General anesthesia = controlled coma, not natural sleep. - Regional blocks can reduce post-op opioid need. - Always weigh risks: patient comorbidities, drug allergies, surgical factors.