Parotidectomy – Anesthetic Considerations

Parotidectomy is the surgical removal of the parotid gland, primarily performed for benign or malignant tumors, chronic infections, or inflammatory conditions. The procedure presents unique anesthetic challenges due to the risk of facial nerve injury, airway concerns, and postoperative complications.

1. Indications for Parotidectomy

✅ Neoplastic Conditions:

• Benign tumors: Pleomorphic adenoma (most common), Warthin’s tumor, oncocytoma.

• Malignant tumors: Mucoepidermoid carcinoma, adenoid cystic carcinoma, acinic cell carcinoma.

✅ Non-neoplastic Conditions:

• Chronic infections (e.g., recurrent parotitis, tuberculosis).

• Sialolithiasis (chronic obstruction due to salivary stones).

• Autoimmune diseases (Sjogren’s syndrome, sarcoidosis).

• Post-traumatic salivary fistula or sialocele.

2. Types of Parotidectomy

Type	Extent of Surgery	Indications
Superficial Parotidectomy	Removal of superficial lobe (above facial nerve)	Most benign tumors
Total Parotidectomy	Removal of entire gland	Malignant tumors or extensive involvement
Radical Parotidectomy	Total removal + Sacrificing facial nerve	High-grade malignancies with nerve invasion
Extracapsular Dissection	Enucleation of small tumors	Selected benign cases

⚠️ Facial nerve preservation is a key consideration in all parotid surgeries except in radical parotidectomy.

3. Preoperative Considerations

A. Airway Assessment

✅ Assess for airway obstruction if there is a large tumor compressing surrounding structures.

✅ Evaluate trismus, difficulty swallowing, and signs of facial nerve palsy (CN VII dysfunction).

✅ Consider indirect laryngoscopy if malignancy extends to the deep lobe.

B. Neurological Assessment

✅ Preoperative facial nerve examination (assess for existing weakness).

✅ Document baseline function of all five branches of the facial nerve:• Temporal• Zygomatic• Buccal• Mandibular• Cervical

✅ History of previous surgeries or radiation therapy (may increase the risk of nerve damage).

C. Laboratory Investigations

✅ Complete Blood Count (CBC) – to check for anemia or infection.

✅ Coagulation Profile – parotid surgery has a high risk of hematoma formation.

✅ Electrolytes & Renal Function – if prolonged surgery is anticipated.

D. Imaging

✅ Ultrasound / MRI / CT Scan – to assess tumor location, size, and nerve involvement.

✅ Fine Needle Aspiration Cytology (FNAC) – to determine benign vs. malignant nature.

4. Anesthetic Management

A. Pre-Induction Considerations

✅ Standard ASA monitoring: ECG, NIBP, SpO₂, EtCO₂.

✅ Secure IV access: 18G or 16G cannula for fluid administration.

✅ Ensure availability of blood products (risk of major bleeding).

B. Induction of Anesthesia

✅ Airway Management:

• Standard IV induction (Propofol 2-3 mg/kg ± fentanyl 1-2 mcg/kg).

• Endotracheal intubation is preferred over LMA due to the risk of bleeding and longer surgical duration.

• Muscle relaxation with rocuronium (0.6-1 mg/kg) or atracurium (0.5 mg/kg).

✅ Facial Nerve Monitoring Considerations:

• If neuromonitoring is used, avoid long-acting neuromuscular blockers (use a single intubating dose only).

• Facial nerve stimulator may be used intraoperatively, so complete paralysis should be avoided.

✅ Maintenance of Anesthesia:

• TIVA (Total Intravenous Anesthesia) with Propofol + Remifentanil is preferred for neuromonitoring.

• Alternatively, Sevoflurane or Desflurane-based anesthesia.

• Dexmedetomidine infusion (0.3-0.7 mcg/kg/hr) for hemodynamic stability.

✅ Analgesia:

• Multimodal analgesia: IV paracetamol, fentanyl, and local infiltration with bupivacaine.

• Superficial cervical plexus block may be considered postoperatively.

5. Intraoperative Considerations

✅ Facial Nerve Monitoring:

• Avoid deep paralysis (use TOF monitoring).

• Monitor electromyographic (EMG) responses to nerve stimulation.

✅ Airway and Ventilation:

• Maintain mild hypotension (MAP 60-70 mmHg) to minimize blood loss.

• Ensure no excessive neck extension, which can reduce venous drainage and increase bleeding.

✅ Surgical Bleeding Control:

• Risk of external carotid artery and retromandibular vein injury.

• Meticulous hemostasis with bipolar cautery.

• Pack the wound if significant oozing occurs.

✅ Risk of Venous Air Embolism (VAE):

• Maintain adequate venous pressure to reduce air entrainment risk.

• End-tidal CO₂ monitoring for sudden drops in ETCO₂.

✅ Nerve Preservation:

• If nerve damage occurs, surgeon may perform grafting (sural nerve or hypoglossal-facial anastomosis).

6. Postoperative Care

✅ Immediate Priorities:

• Airway protection – monitor for hematoma formation or airway edema.

• Head elevation (30-45°) to reduce swelling.

• Suction drain (Redivac drain) placement to prevent hematoma.

• Avoid NSAIDs initially (risk of bleeding).

✅ Pain Management:

• IV paracetamol + opioids (avoid NSAIDs if recent bleeding concerns).

• Superficial cervical plexus block if not performed intraoperatively.

✅ Facial Nerve Dysfunction Monitoring:

• Assess all five branches of the facial nerve.

• Monitor for transient vs. permanent nerve injury.

✅ Complications to Watch For:

• Hematoma formation (most common) → May require emergency drainage.

• Facial nerve injury (5-20% risk):

• Temporary paresis → Resolves within weeks to months.

• Permanent damage → May need physiotherapy or nerve grafting.

• Frey’s Syndrome (gustatory sweating) → Treat with botulinum toxin injections.

• Salivary fistula formation.

MCQs on Parotidectomy

1. The most common tumor requiring parotidectomy is:

A) Warthin’s tumor

B) Pleomorphic adenoma

C) Mucoepidermoid carcinoma

D) Adenoid cystic carcinoma

✅ Answer: B (Pleomorphic adenoma is the most common benign tumor).

2. Which nerve is most commonly at risk during parotidectomy?

A) Vagus nerve

B) Hypoglossal nerve

C) Facial nerve

D) Glossopharyngeal nerve

✅ Answer: C (Facial nerve is the most critical structure at risk).