What is the recommended anaesthetic management for a patient undergoing laparoscopic sleeve gastrectomy?

Anaesthetic Management for Laparoscopic Sleeve Gastrectomy

Use total intravenous anaesthesia (TIVA) with propofol and multimodal analgesia including bilateral transversus abdominis plane (TAP) blocks, intravenous dexamethasone, paracetamol, and NSAIDs, while minimizing opioids to reduce postoperative nausea and vomiting and improve recovery outcomes. 1, 2

Preoperative Preparation

Fasting Guidelines

• Allow clear fluids up to 2 hours before induction and solids (light meal) up to 6 hours preoperatively 1
• Carbohydrate loading is not routinely recommended due to insufficient evidence in bariatric surgery, despite low compliance rates (15%) 1

Airway and Positioning Assessment

• Assume all obese patients have sleep-disordered breathing regardless of formal testing 1
• Plan for difficult airway management with ramping position (tragus level with sternum) for preoxygenation and intubation 1

Intravenous Access

• Establish two peripheral IV cannulae while in theatre, as access is often difficult in obese patients 1
• Consider ultrasound guidance for unusual sites (upper arm, anterior chest wall) if standard sites fail 1

Induction of Anaesthesia

Airway Management

• Perform tracheal intubation with controlled ventilation as the technique of choice, given increased work of breathing in obese patients 1
• Use rapid sequence induction if indicated, with either rocuronium 0.9-1.2 mg/kg or succinylcholine 1-2 mg/kg 1, 3
• Consider rocuronium over succinylcholine due to availability of sugammadex for emergency reversal 1
• Size tracheal tubes based on ideal body weight 1

Induction Agents

• Induce with propofol 2 mg/kg (consider lean body weight dosing in obese patients) 3, 4
• Add remifentanil or fentanyl for induction analgesia 5, 4

Maintenance of Anaesthesia

Primary Technique: TIVA

TIVA with propofol is superior to volatile anaesthetics for laparoscopic sleeve gastrectomy, providing significantly lower postoperative nausea and vomiting (PONV), reduced pain scores, decreased analgesic requirements, and shorter recovery times 1, 5

• Target propofol effect-site concentration of 0.5-1 mcg/ml for maintenance 3
• Avoid doses exceeding 1.5 mcg/ml to prevent over-sedation and hypoventilation 3
• Use processed EEG monitoring (BIS or Entropy) targeting BIS 40-60 to prevent awareness and avoid excessive depth 3
• Avoid BIS values below 35 and burst suppression patterns to reduce postoperative delirium risk 3

Alternative: Volatile Anaesthetics

If TIVA is not available, use desflurane or sevoflurane (faster onset/offset than isoflurane), though this increases PONV risk 1

Ventilation Strategy

• Calculate tidal volumes based on ideal body weight 1
• Apply sufficient PEEP and recruitment manoeuvres to reduce intra- and postoperative atelectasis 1
• Consider pressure-controlled ventilation for greater tidal volumes at given peak pressures 1
• Position patient in slight sitting position (trunk flexion) during laparoscopy to allow increased abdominal excursion and lower airway pressures 1

Neuromuscular Blockade

• Use quantitative neuromuscular monitoring throughout the procedure 3
• Document train-of-four ratio ≥0.90 before extubation to ensure complete reversal 3

Multimodal Analgesia Protocol

Regional Anaesthesia

Perform ultrasound-guided bilateral TAP blocks as a core component of the analgesic regimen 2

• This recommendation represents an update from previous guidelines and provides superior analgesia 2
• Can be performed laparoscopically if ultrasound unavailable 2

Systemic Analgesics

• Administer intravenous dexamethasone intraoperatively for both analgesia and PONV prophylaxis 2
• Give paracetamol (acetaminophen) intraoperatively and postoperatively 2, 6
• Administer NSAIDs or COX-2 inhibitors (e.g., etoricoxib preoperatively) 2, 6
• Perform port-site local anaesthetic infiltration 2

Opioid-Sparing Strategy

• Minimize intraoperative and postoperative opioids to reduce ORAE and improve recovery 1, 4, 6
• Reserve opioids for rescue treatment only 2
• Avoid gabapentinoids (no longer recommended based on updated evidence) 2

Opioid-Free Anaesthesia Option

Consider complete opioid-free anaesthesia using dexmedetomidine 0.5 mcg/kg/h, ketamine 0.5 mg/kg/h, and lidocaine 1 mg/kg/h infusions, which further improves quality of recovery, reduces morphine consumption, and shortens time to discharge 4

PONV Prophylaxis

Implement aggressive multimodal PONV prevention, as bariatric patients have multiple risk factors (female, non-smoker, laparoscopic surgery >1 hour, gastric surgery, opioids) 1

• Use TIVA with propofol (avoids volatile anaesthetics) 1
• Administer antiemetics from three of six drug classes: 5-HT3 antagonists, dexamethasone, butyrophenones, NK-1 antagonists, antihistamines, anticholinergics 1
• Minimize opioids through multimodal analgesia and regional techniques 1
• Avoid fluid overload 1

Fluid Management

Use individualized goal-directed fluid therapy (GDFT) guided by stroke volume optimization 1

• Both restrictive and excessive fluid administration worsen outcomes 1
• GDFT improves tissue oxygenation and optimizes cardiac performance 1

Emergence and Extubation

Reversal and Monitoring

• Reverse neuromuscular blockade guided by nerve stimulator before waking the patient 1
• Ensure return of airway reflexes and adequate tidal volumes before extubation 1, 3

Extubation Technique

• Extubate awake in sitting position 1, 3
• Have an extubation plan in accordance with Difficult Airway Society guidelines, as NAP4 and NAP5 showed high incidence of problems during extubation in obese patients 1
• Insert nasopharyngeal airway before waking in patients with confirmed OSA to mitigate partial airway obstruction 1, 3

Recovery Position

• Maintain head-up position throughout recovery 1
• Monitor oxygen saturations continuously until mobile postoperatively 1

Postoperative Care

Respiratory Support

• Reinstate home CPAP immediately upon return to ward if patient uses it at home 1, 3
• Apply CPAP in PACU if oxygen saturation cannot be maintained with supplemental oxygen alone 1
• Observe for signs of hypoventilation, apnoea, or hypopnoea with oxygen desaturation before PACU discharge 1

Monitoring Level

• Consider level-2 care if long-acting opioids required and patient not stabilized on CPAP preoperatively 1

Key Safety Considerations

Common Pitfalls to Avoid

• Do not use succinylcholine without immediate availability of sugammadex if choosing rocuronium, as aspiration risk remains during reversal 1
• Do not extubate until fully awake with adequate neuromuscular function (train-of-four ≥0.90), as residual blockade significantly increases respiratory complications 3
• Do not rely on volatile anaesthetics alone, as TIVA provides superior outcomes specifically for sleeve gastrectomy 1, 5
• Avoid excessive anaesthetic depth (BIS <35) to prevent postoperative delirium 3
• Do not use carbohydrate loading routinely, as evidence is insufficient and compliance poor in bariatric surgery 1

Haemodynamic Management

• Have vasopressors immediately available (ephedrine or metaraminol) as propofol increases vasopressor requirements in obese patients 3
• Consider invasive arterial blood pressure monitoring before induction when feasible 3