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Adenotonsillectomy (Adenoid Tonsillectomy)

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Anatomy

• Palatine tonsils: Paired lymphoid masses in the oropharynx, between the anterior (palatoglossal) and posterior (palatopharyngeal) pillars
• Adenoids (pharyngeal tonsil): Single lymphoid mass on the posterior nasopharyngeal wall; forms part of Waldeyer's ring along with the lingual tonsil and tubal tonsils
• Both have peak size in childhood (ages 4-7) and undergo physiological involution after puberty

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Indications

Tonsillectomy Indications

• ≥7 documented episodes in the preceding year, OR
• ≥5 episodes per year for 2 consecutive years, OR
• ≥3 episodes per year for 3 consecutive years
• Each episode should include one or more: fever (>38.3°C), cervical lymphadenopathy, tonsillar exudate, or positive Group A strep culture

Adenoidectomy Indications

• Adenoid hypertrophy causing nasal obstruction
• Recurrent/chronic otitis media with effusion (especially for OME-related hearing loss and grommets)
• Chronic rhinosinusitis
• Obstructive sleep-disordered breathing
• Recurrent acute otitis media

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Contraindications

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Surgical Techniques

Tonsillectomy Techniques

• Tonsil grasped, anterior pillar incised
• Capsule dissected off pharyngeal constrictors using blunt and sharp dissection
• Hemostasis by suture ligation or cautery
• Gold standard for minimizing thermal injury; higher intraoperative bleeding risk

• Most popular technique over the past 2-3 decades
• Affords greater hemostasis during dissection
• Associated with increased postoperative pain and longer healing times

• More precise coagulation, less surrounding tissue injury
• Can be performed with operating microscope using bipolar bayonet forceps or bipolar scissors

• Radiofrequency energy conducted through saline creates plasma field of active protons that break molecular bonds
• Removes tonsillar tissue en bloc while avoiding the capsule
• Lower temperatures (~60°C vs 400°C with electrocautery) - theoretically less thermal injury
• Data on pain reduction are mixed - some studies show benefit vs. cold/electrocautery, while a Cochrane review of 9 trials found no significant differences in pain and recovery speed

• Uses ultrasonic vibration to transfer mechanical energy to break hydrogen bonds
• Conflicting results on pain outcomes vs. standard techniques

• Removes bulk of tonsil while preserving the tonsillar capsule as a "biologic dressing" over the pharyngeal constrictors
• Decreased thermal injury, less postoperative pain, reduced hemorrhage risk
• Two large retrospective studies (4776 and 2943 patients) found significant reductions in delayed postoperative bleeding and readmission for dehydration
• Disadvantage: potential tonsil regrowth (~6% in one study) requiring completion tonsillectomy in rare cases

Adenoidectomy Techniques

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Anesthesia Considerations

• Airway: Endotracheal tube (ETT) vs. laryngeal mask airway (LMA). ETT is more secure and easier for the surgeon to place a Boyle Davis gag; LMA is quicker to insert. Safety of airway always takes precedence
• Positioning: Supine with neck extended (Rose position); Boyle Davis gag placed to retract tongue and provide exposure
• Antiemetics: Dexamethasone and/or ondansetron significantly reduce postoperative nausea and vomiting (PONV); combination is superior to either alone
• Analgesia: Regular NSAIDs (ibuprofen) + paracetamol; opioids are now limited given FDA warnings regarding codeine in children post-tonsillectomy (CYP2D6 ultra-metabolizers risk)

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Outcomes: OSA

• At 7-month follow-up, 79% of surgery patients had AHI <2 vs. 46% watchful waiting (p<0.001)
• Meta-analysis by Friedman et al. (23 studies, 1079 patients) found overall "cure rate" of 66.3% (AHI <1-5 per protocol); drops to 59.8% when cure = AHI <1
• Risk factors for residual SDB: age >7 years, obesity, severe OSA, chronic asthma

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Postoperative Complications

Intraoperative

• Bleeding
• Laryngospasm
• Aspiration of tooth, gauze, or lymphoid tissue
• Trauma to anterior/posterior pillars

Early (< 24 hours)

• Primary hemorrhage (within 24 h) - most feared; requires return to OR if significant
• PONV
• Pulmonary edema (especially in OSA patients - relief of chronic obstruction)
• Pain, odynophagia, referred otalgia
• Respiratory complications in OSA children: 16-27% rate vs. 0-1.3% general pediatric population

Late (> 24 hours)

• Secondary hemorrhage (days 5-10, peak risk) - due to sloughing of tonsillar fossa eschar
• Dehydration from poor oral intake
• Velopharyngeal insufficiency / hypernasal speech (adenoidectomy - esp. if submucous cleft present)
• Grisel's syndrome (atlantoaxial subluxation from ligamentous laxity)
• Nasopharyngeal stenosis
• Taste impairment
• Rare: Eagle syndrome, Horner's syndrome, mediastinitis, necrotizing fasciitis

Post-op Respiratory Risk Factors (OSA children)

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Post-Operative Care

• Analgesia: Regular NSAIDs ± paracetamol; soft diet; adequate oral hydration
• No aspirin (Reye's syndrome risk in children)
• Diet: Cool soft foods for 1-2 weeks; avoid hot, spicy, crunchy foods
• Activity restriction for 2 weeks
• Return precautions: Any bright red bleeding from mouth requires immediate ER evaluation
• Typical return to normal activity: 10-14 days

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Special Considerations

• Obese children: Higher rates of residual OSA (33-76%) vs. non-obese (15-37%) - often require post-operative sleep study
• Submucous cleft palate: Adenoidectomy is contraindicated due to risk of velopharyngeal insufficiency
• Adults: Higher complication rates (especially bleeding) compared to children; indications are similar but the "watchful waiting" benefit is less well-established

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Anesthetic Considerations for Adenotonsillectomy in a 15-Year-Old

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Pathophysiology - Why It Matters for Anesthesia

• Increased airway resistance → hypoxemia + hypercarbia → pulmonary arteriolar constriction → pulmonary hypertension → right ventricular hypertrophy → cor pulmonale
• During apneic episodes: intrapleural pressure can drop as low as -30 cm H₂O (vs. normal -2.5 to -10 cm H₂O), disrupting pulmonary capillary walls - this sets the stage for post-obstructive pulmonary edema once the airway is surgically relieved
• ECG changes (RVH) and cardiomegaly may be present in severe OSA - these are often reversible after adenotonsillectomy

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1. PREOPERATIVE EVALUATION

History

• Sleep-disordered breathing: snoring, witnessed apneas, excessive daytime somnolence, mouth breathing, inattention, hyperactivity
• Use STOP-BANG (adult patients) or STBUR questionnaire (pediatric) - STBUR evaluates Snoring, Trouble Breathing, and Un-Refreshed sleep as a reliable predictor of perioperative respiratory events
• Ask about recent URIs - a fever or productive cough may be grounds for postponement
• Medication history: NSAIDs, aspirin-containing cold medications, or antihistamines - aspirin affects platelet function and must be stopped 7-10 days pre-op

Physical Examination

• Audible respirations, obligate mouth breathing
• Elongated face, retrognathic mandible, high-arched palate - signs of chronic nasopharyngeal obstruction
• Tonsillar size assessment (Mallampati + tonsillar grading) - directly predicts ease of mask ventilation and intubation
• Chest: wheezing, rales, stridor, prolonged expiration - may indicate lower respiratory infection or partial obstruction

Tonsillar Size Classification

Investigations

• Hematocrit and coagulation profile (PT, APTT, platelet count) - routine given bleeding risk
• ECG if history suggests cor pulmonale or cardiac abnormality
• CXR only if recent pneumonia, bronchitis, or URI history
• Echocardiogram if cardiac abnormalities suspected
• Polysomnography (PSG) in complex cases: recommended by AAP when OSAS is not straightforward; assess AHI severity - guides intensity of post-op monitoring

Postpone Surgery If:

• Active acute infection / fever
• Productive cough (lower respiratory infection)
• Uncontrolled bleeding diathesis
• Incomplete workup for suspected cor pulmonale

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2. PREMEDICATION

Avoid sedative premedication (benzodiazepines, opioids) in patients with OSA, very large tonsils, or intermittent obstruction - risk of respiratory depression and complete airway collapse.

• Antisialagogue (glycopyrrolate 4-6 mcg/kg IM/IV): reduces secretions in the operative field, decreases risk of laryngospasm - use this
• Anticholinergic agents may also reduce pharyngeal secretions
• If premedication is deemed essential: use minimal doses only in a monitored setting where rescue airway support is immediately available

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3. AIRWAY MANAGEMENT

Airway Device

• Endotracheal tube (ETT) - preferred over LMA for adenotonsillectomy
  • More secure; easier for surgeon to position with Boyle-Davis mouth gag
  • Protects against blood and secretion aspiration
  • LMA: quicker to insert but less secure; may be acceptable for adenoidectomy alone in select cases - never compromise the airway for convenience
• Oral RAE tube or wire-reinforced (armored) tube - specifically recommended in both Miller's and Barash:
  • Preformed oral RAE is taped in midline to the mandible
  • Wire-reinforced tubes are less likely to kink after the mouth gag is placed

Tube Size (15-year-old)

• Near-adult sizing: typically 6.5-7.0 mm cuffed ETT (age/4 + 4 formula not applicable at 15 - use body habitus)
• Confirm correct placement and check for bilateral breath sounds after Boyle-Davis gag placement (gag can displace or kink the tube)

Difficult Airway Preparation

• Prepare video laryngoscope, multiple blade sizes, smaller tube sizes, suction
• If peritonsillar abscess is present: awake fiberoptic intubation is standard - avoid blind manipulation of friable, tense tonsillar tissue to prevent abscess rupture and purulent aspiration
• History of apnea: consider inhalational induction without paralysis until ability to ventilate is confirmed

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4. INDUCTION

• Sevoflurane is standard volatile agent for inhalational induction - pleasant odor, rapid onset
• Glycopyrrolate given after IV placement to reduce secretions
• Muscle relaxant: short-acting non-depolarizing agent (rocuronium, mivacurium) or suxamethonium preferred - allows rapid return of neuromuscular function
• Many clinicians eliminate NMB in favor of deep inhalational anesthesia alone to maintain spontaneous ventilation during intubation

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5. MAINTENANCE

• Volatile agent (sevoflurane or desflurane) in O₂
• Lower FiO₂ (avoid high-concentration O₂) - reduces risk of airway fire during surgical use of electrocautery (shared airway with ignition source)
• N₂O: used by some; avoid if significant bleeding anticipated
• TIVA (Propofol infusion): an alternative, especially in OSA - avoids volatile agent respiratory depression, faster clear-headed emergence
• Surgical position: Rose position - supine with neck extended, slight head-up tilt

Throat Pack

• Surgeon may place a moist throat pack to prevent blood from entering the trachea
• Critical: must be removed and accounted for before extubation - wrong-site retention is a sentinel event

Intraoperative Monitoring

• Standard: SpO₂, ETCO₂, ECG, NIBP, temperature
• Capnography - essential; confirms tube placement and monitors ventilation during shared-airway surgery
• Watch for sudden ETCO₂ changes - may indicate tube displacement or kinking from gag

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6. ANALGESIA

Multimodal Approach (Avoid or Minimize Opioids)

• No aspirin post-operatively - platelet dysfunction increases secondary hemorrhage risk + Reye's syndrome risk

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7. EMERGENCE

Steps Before Extubation

1. Surgeon confirms complete hemostasis
2. Remove throat pack (if placed) and document removal
3. Turn patient lateral (tonsil position / recovery position) or head-down
4. Gentle pharyngeal suctioning under direct vision - remove blood clots and secretions
5. Gastric suctioning with orogastric tube - blood swallowed during surgery causes nausea/vomiting

Awake vs. Deep Extubation

• Awake extubation is generally preferred for adenotonsillectomy to protect against aspiration of blood
• Deep extubation reduces laryngospasm and avoids dislodging blood clots with coughing - but aspiration risk is higher
• Attenuate coughing/bucking with: IV lidocaine 1.5 mg/kg (given 90s before extubation) or light remifentanil infusion during emergence (Miller's recommendation)
• Extubate in lateral/semi-prone position - gravity keeps blood away from larynx

Laryngospasm Risk

• Adenotonsillectomy has an increased incidence of laryngospasm - blood and secretions in pharynx are the primary trigger
• Treatment: jaw thrust + CPAP, deepening anesthesia (propofol 0.5-1 mg/kg), suxamethonium 0.1-0.5 mg/kg IV (or 4 mg/kg IM if no IV access)

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8. POST-OPERATIVE CONSIDERATIONS

Respiratory Monitoring

• 16-27% rate of post-op respiratory complications in OSA children vs. 0-1.3% in the general pediatric surgical population
• Risk factors for post-op respiratory complications:
  • Age <8 years (less relevant here at 15)
  • Severe OSA (AHI >10 or >5 with significant desaturations)
  • Pulmonary hypertension or cardiac abnormalities
  • Craniofacial syndromes
  • Failure to thrive, obesity

Post-Obstructive Pulmonary Edema

• Occurs when chronic upper airway obstruction is suddenly relieved
• Mechanism: large negative intrapleural pressure (-30 cm H₂O) during obstructed breathing disrupts pulmonary capillary walls; on relief of obstruction, fluid floods into alveoli
• Treat with: supplemental O₂, CPAP/BiPAP, diuretics (furosemide), occasionally intubation

PONV Prophylaxis

• Post-op vomiting is common (blood swallowing, opioids, volatile agents)
• Dexamethasone 0.15 mg/kg IV + ondansetron 0.1 mg/kg IV - combination superior to either alone (systematic reviews confirm this)
• Avoid N₂O if PONV risk is high

Discharge and Admission Criteria

• At 15, day-case discharge is acceptable if:
  • Mild or no OSA
  • No intraoperative complications
  • Tolerating oral fluids, pain controlled, no bleeding
• Overnight admission (or HDU) indicated if:
  • Moderate-severe OSA
  • Sleep apnea history
  • Cardiac complications (cor pulmonale)
  • Intraoperative difficulties
  • Post-op desaturations in recovery

Pain Management Post-Op

• Regular oral ibuprofen + paracetamol as first line
• No oral opioids as take-home drugs (contact surgical team if breakthrough pain uncontrolled)
• Soft cool diet for 1-2 weeks

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9. RE-OPERATION FOR POST-TONSILLECTOMY HEMORRHAGE

1. Resuscitate first - restore intravascular volume before induction (unless imminent airway obstruction)
2. Assume full stomach - patient has swallowed significant blood
3. Rapid sequence induction (RSI) with cricoid pressure - use suxamethonium or high-dose rocuronium
4. Vigorous suctioning during laryngoscopy - copious oropharyngeal blood obscures view
5. Reduce induction drug doses if hypovolemic - consider etomidate for hemodynamically unstable patients
6. Have multiple laryngoscope sizes + video laryngoscope + smaller ETT sizes ready - previously easy intubation can become difficult with swelling and active bleeding
7. A nasogastric tube to empty stomach before induction where time permits

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Summary Table

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General Anesthesia Drug Dosages (Per kg Body Weight)

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INDUCTION AGENTS

For a 15-year-old (~50 kg average):

• Propofol induction: 100-150 mg (up to 250 mg)
• Ketamine: 50-100 mg IV
• Etomidate: 10-15 mg IV

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INHALATIONAL AGENTS (MAINTENANCE + INDUCTION)

Note on FiO₂: In adenotonsillectomy, keep FiO₂ as low as safely possible (typically 30-40%) - surgical electrocautery creates an airway fire risk in an O₂-enriched environment.

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NEUROMUSCULAR BLOCKING AGENTS (NMBAs)

Depolarising

Non-Depolarising

For adenotonsillectomy at 15 years (~50 kg):

• Rocuronium intubation: 30 mg (standard) or 60 mg (RSI)
• Suxamethonium: 75 mg IV

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REVERSAL AGENTS

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OPIOID ANALGESICS

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NON-OPIOID ANALGESICS

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ANTIEMETICS

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ANTICHOLINERGICS / ANTISIALAGOGUES

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EMERGENCY / RESCUE DRUGS

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QUICK REFERENCE FOR A 50 kg (15-YEAR-OLD)

⚠️ Always verify doses against current local formulary and clinical context. Doses vary based on ASA status, comorbidities, concurrent medications, depth of block (for reversal agents), and clinical response. Obese patients: use ideal/lean body weight for most drugs. The above doses are from Morgan & Mikhail's Clinical Anesthesiology 7e, Miller's Anesthesia 10e, and Barash, Cullen & Stoelting's Clinical Anesthesia 9e.