Anesthetic Techniques for Ambulatory Surgery

Ambulatory Anesthesia: Basics & Patient Preparation - Prep & Go!

• Definition: Surgery with same-day patient admission & discharge; no overnight hospital stay.
• Core Objectives:
  • Rapid recovery, early ambulation.
  • Minimal Post-Operative Nausea & Vomiting (PONV).
  • Effective pain control.
  • Early return to home.
• Patient Selection Criteria:
  • Primarily ASA class I & II.
  • Stable ASA III patients for selected procedures.
  • Crucial factors: age, social support, travel distance to hospital.
• Surgical Procedure Suitability:
  • Duration ideally < 90 minutes.
  • Minimal physiological disturbance.
  • Low risk of major post-op pain, bleeding, or complications.
• Preoperative Fasting (NPO) Guidelines (ASA):
  • Clear liquids: 2 hours.
  • Breast milk: 4 hours.
  • Infant formula, non-human milk, light meal: 6 hours.
  • Heavy meal (fried/fatty food, meat): 8 hours.

⭐ Clear liquids up to 2 hours before elective surgery is a key ASA guideline for adults and children.

• Premedication Goals:
  • Anxiolysis: e.g., Midazolam (short-acting).
  • Analgesia: e.g., Paracetamol, NSAIDs.
  • PONV prophylaxis: e.g., Ondansetron, Dexamethasone.
  • Aspiration prophylaxis (if high risk): e.g., H2 blockers, PPIs.

Core Anesthetic Techniques for Ambulatory Surgery - Zap & Nap Choices

Key goal: Employ short-acting agents and techniques facilitating rapid recovery and discharge.

• General Anesthesia (GA): Aim for rapid awakening, minimal Post-Operative Nausea and Vomiting (PONV).
  • TIVA (Total Intravenous Anesthesia): Propofol (e.g., 2-2.5 mg/kg induction, 100-200 mcg/kg/min maintenance), Remifentanil for short-acting analgesia.

    ⭐ Propofol is a cornerstone for TIVA in ambulatory settings due to its rapid onset, short duration, and antiemetic properties.

  • Inhalational: Sevoflurane, Desflurane (low blood:gas solubility → fast emergence).
  • Airway: Supraglottic airways (LMA) preferred over Endotracheal Tube (ETT) to ↓ airway stimulation.
• Regional Anesthesia (RA): Excellent analgesia, opioid-sparing, ↓ PONV.
  • PNBs (Peripheral Nerve Blocks): Ultrasound-guided (USG) for precision (e.g., interscalene, femoral). Single-shot or catheter.
  • Central Neuraxial: Short-acting spinals (e.g., 2-Chloroprocaine 30-60 mg, low-dose Bupivacaine <7.5 mg) or titrated epidurals. Avoids GA side effects.
• Monitored Anesthesia Care (MAC): 📌 Minimal Alteration, Conscious sedation.
  • Combines Local Anesthesia (LA) with IV sedation/analgesia (Midazolam 0.5-2 mg, Fentanyl 25-50 mcg, Propofol 25-75 mcg/kg/min).
  • Patient responsive, maintains airway reflexes & spontaneous ventilation.
• Local Anesthesia (LA): For minor superficial procedures or as adjunct.
  • Techniques: Infiltration, topical, field blocks. Often combined with MAC/light GA.

Postoperative Care & Discharge Criteria in Day Surgery - Wake & Wave

• Postoperative Care Goals:
  • Swift awakening, effective symptom management.
  • Multimodal analgesia (opioid-sparing preferred).
  • Proactive PONV control.
• Key Discharge Criteria (PADSS ≥ 9):
  • Vitals: Stable (e.g., BP/HR within 20% of baseline).
  • Orientation: Alert & oriented.
  • Pain: Controlled (e.g., VAS < 4/10).
  • PONV: Minimal or absent.
  • Mobility: Able to ambulate safely.
  • Voiding: As indicated (e.g., post-spinal, urology).
  • Support: Responsible adult escort, clear instructions.

⭐ The Post Anesthetic Discharge Scoring System (PADSS) is a validated tool; a score ≥ 9 (out of 10) is commonly required for discharge.

High‑Yield Points - ⚡ Biggest Takeaways

• MAC is preferred for rapid recovery & minimal side effects.
• Regional blocks offer excellent post-op analgesia & ↓ opioid needs.
• TIVA (e.g., propofol) allows fast emergence & clear-headed recovery.
• Use short-acting opioids & non-opioid analgesics to minimize PONV & hasten discharge.
• LMA often preferred over ET intubation for less airway trauma & quicker wake-up.
• Multimodal analgesia is vital for superior pain relief & fewer side effects.
• Rigorous patient selection & preoperative optimization are crucial for safety.