What is the recommended short‑duration general anaesthesia technique for a brief (<30 minutes) procedure in an otherwise healthy adult (American Society of Anesthesiologists physical status I–II, age 18–65)?

Short-Duration General Anesthesia for Brief Procedures (<30 minutes) in Healthy Adults

Recommended Anesthetic Technique

For brief procedures under 30 minutes in ASA I-II adults aged 18-65, use propofol-based total intravenous anesthesia (TIVA) with a short-acting opioid, which provides rapid induction, stable maintenance, and faster emergence compared to volatile agents. 1, 2, 3

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Induction Protocol

Drug Selection and Dosing

• Propofol 2.0-2.5 mg/kg IV for induction, administered as a smooth bolus over 30-60 seconds 4, 5
• Fentanyl 1-2 mcg/kg IV (or 0.5-1 mcg/kg) administered 2-3 minutes before propofol to blunt hemodynamic response and improve intubating conditions 4, 5
• Alternative opioid: Alfentanil 5 mcg/kg IV if fentanyl is unavailable 4

Muscle Relaxation (if intubation required)

• Succinylcholine 1.0 mg/kg IV (based on actual body weight) provides optimal intubating conditions at 60 seconds with predictable, short duration of action 4, 5
• Alternative: Rocuronium 0.9-1.2 mg/kg IV if succinylcholine is contraindicated, though this requires reversal with sugammadex for rapid emergence 5, 6

Critical Safety Measure

• Propofol and sevoflurane are the hypnotics of choice because their action is rapidly reversible, allowing return of spontaneous ventilation if airway control fails 4

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Maintenance Anesthesia

TIVA Approach (Preferred for <30 min procedures)

• Propofol target-controlled infusion (TCI) at effect-site concentration 0.5-1.0 mcg/ml combined with remifentanil TCI at 1-3 ng/ml 1, 6
• Never exceed propofol effect-site concentration of 1.5 mcg/ml, as this dramatically increases risk of over-sedation and hypoventilation, especially with concurrent opioid use 4, 1, 6
• Avoid bolus dosing during maintenance to prevent hemodynamic instability 1, 6

Alternative: Volatile Agent Maintenance

• Sevoflurane 1.0-2.0 MAC provides rapid emergence with mean time to extubation of 8-11 minutes and response to commands at 9-13 minutes 2
• Sevoflurane has a nonpungent odor, does not cause respiratory irritability, and is suitable for mask induction if needed 2
• Shorter emergence times (statistically significant) compared to isoflurane and propofol maintenance in outpatient surgery 2

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Essential Monitoring Requirements

Depth of Anesthesia

• Processed EEG monitoring (BIS or Entropy) targeting BIS 40-60 is mandatory when using TIVA with neuromuscular blockade to prevent awareness and avoid excessive depth 1, 6
• Initiate before induction and continue until full recovery from neuromuscular blockade 6

Neuromuscular Monitoring

• Quantitative train-of-four (TOF) monitoring is obligatory when muscle relaxants are used 4, 6
• Document TOF ratio ≥0.90 before extubation to confirm adequate reversal 4, 1, 6

Hemodynamic Monitoring

• Standard ASA monitoring (ECG, blood pressure, pulse oximetry, capnography) is sufficient for healthy ASA I-II patients 1
• Have vasopressors immediately available (ephedrine or metaraminol) as propofol causes mild hypotension without compensatory tachycardia 1, 7

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Emergence and Recovery Protocol

Extubation Criteria

• Ensure return of airway reflexes and adequate tidal volumes before extubation 1, 6
• Verify TOF ratio ≥0.90 if neuromuscular blockade was used 4, 1, 6
• Extubate awake in sitting position for optimal airway protection 1, 6

Recovery Advantages of Propofol-Based Technique

• Propofol TIVA provides significantly faster emergence with rapid return of airway reflexes compared to volatile agents 1, 3
• Reduced postoperative nausea and vomiting (PONV) compared to volatile anesthetics, a major advantage for ambulatory surgery 1, 6, 8, 3
• Time to eligibility for discharge from recovery area: 87-103 minutes for propofol-based techniques in outpatient surgery 2

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Common Pitfalls and How to Avoid Them

Respiratory Depression Risk

• The combination of propofol and remifentanil carries significant risk of respiratory depression when doses exceed recommended ranges 1
• Caution with respiratory depression when using remifentanil TCI—avoid bolus dosing 4, 1
• Titrate opioids carefully as they improve intubating conditions but increase risk of prolonged apnea 4

Awareness Risk

• Propofol lacks amnestic properties when used as sole agent—one case of intraoperative awareness was reported in a study using propofol without adjuvants 9
• Consider adding midazolam 0.03 mg/kg (approximately 2 mg) before induction to reduce awareness risk without compromising recovery in day-case surgery 10
• BIS monitoring 40-60 prevents awareness when using TIVA with neuromuscular blockade 1, 6

Hemodynamic Instability

• Propofol causes cardiovascular depression (15-20% decrease in systolic blood pressure) that is well-tolerated in healthy patients but requires slower administration and dose reduction in high-risk patients 2, 7
• Pre-administration of fentanyl or alfentanil reduces the propofol induction dose requirement by 20-80% and improves hemodynamic stability 4, 7

Inadequate Analgesia

• Propofol does not have marked analgesic effects—adequate pain therapy with local anesthetics, NSAIDs, or opioids is mandatory for postoperative analgesia 7
• Plan transition analgesia before emergence, as remifentanil's ultra-short duration leaves no residual analgesia 8

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Special Considerations for Brief Procedures

Why TIVA is Preferred for <30 Minutes

• Propofol's rapid elimination via high metabolic clearance ensures clinical effects decline rapidly even after continuous infusion, making it ideal for short procedures 8, 3
• Context-sensitive half-time of remifentanil is significantly shorter than other opioids, providing predictable offset regardless of infusion duration 8
• "Smooth" recovery profile distinguishes propofol from traditional anesthetic regimens, with consistent advantages in early recovery time 3

Economic and Practical Factors

• While propofol cost may be higher than volatile agents, reduced PONV, faster discharge eligibility, and improved patient satisfaction often justify its use in ambulatory settings 8, 3
• Sevoflurane is a reasonable alternative if TIVA equipment is unavailable, providing similarly rapid emergence (8-11 minutes to extubation) 2