Preoperative

Preoperative evaluation should focus on age group, associated comorbidities (such as Downs syndrome), OSA, and upper respiratory tract infection. These are the main factors in strati­fying perioperative complications, including post­extubation laryngospasm and bronchospasm. Important points of consideration are listed below:

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  Polysomnography (PSG) is the gold standard to diagnose OSAS in children, but it is not possible in all children.

  
  
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  Electrocardiogram (ECG) in patients with OSA (to exclude right heart involve­ment secondary to pulmonary artery hypertension).

  
  
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  Hemoglobin and hematocrit should be done to rule out anemia and polycythemia (in patients with OSA), respectively.

  
  
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  Total leucocyte counts and a chest X-ray if respiratory tract infection is present.

  
  
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  Coagulopathy should be excluded, as adenoidectomy/tonsillectomy may lead to massive bleeding during the perioperative period.

  
  
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  Cautious use of premedication because of risk of upper airway obstruction.

Intraoperative

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  The choice of anesthetic technique matters mainly in the presence of upper respiratory tract infections (URTI). Even though the laryngeal mask airway (LMA) is not used frequently for adenotonsillectomy, the evidence suggests that it may have advantages over the tracheal tube.

  
  
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  The endotracheal tube (ETT) is the gold standard of airway management. A pre­formed south pole-facing tube (oral Ring–Adair–Elwyn [RAE]) is preferable. LMA, especially reinforced one, can be used for airway management but with adequate training and experience.

  
  
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  End-tidal CO₂ monitoring is vital to detect early ETT tube kinking, due to placement of mouth gag as well as displacement.

  
  
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  The eye should be well taped and protected from direct pressure and corneal injury. After positioning and Boyle–Davis gag placement, ETT should be examined for obvious kinking and any airway pressure.

  
  
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  Anesthetic medications with lower potency of airway irritation such as propofol, sevoflurane, and halothane are preferred over thiopental and desflurane, which cause airway irritation.

  
  
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  The choice for the neuromuscular blocking agent for intubation is suxamethonium, if not contraindicated.

  
  
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  In a child with URTI, deep extubation is preferable.

  
  
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  Patients must be extubated in lateral and head low position (posttonsillectomy position) after the surgery, and it should also be maintained in the postoperative period.

  
  
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  Before extubation hemostasis, throat free of any secretion or any gauze must be established.

  
  
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  Patients must be shifted to the recovery room in the lateral position and monitored for bleeding as well as any decrease of consciousness.

Coroner’s Clot

It is an occult clot of blood left behind the nasopharynx posterior till the soft palate. It usu­ally occurs in surgeries in areas of nasopharynx or trauma, mainly due to adenotonsillectomy. It has the potential to cause fatal airway obstruction following extubation.

Postoperative Management

The following should be taken into consideration while managing the patient postoperatively:

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  Keep the child in the recovery position.

  
  
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  Constant monitoring for bleeding.

  
  
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  Pain control with multimodal analgesia.

  
  
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  Postoperative nausea and vomiting (PONV) prophylaxis with dexamethasone and ondansetron.

Anesthetic Considerations

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  The preoperative examination should be focused to elicit features of URTI and OSA secondary to adenotonsillar enlargement. Due to URTI, the airway becomes hyper­reactive, which leads to perioperative airway complications like laryngospasm and bronchospasm.

  
  
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  Anesthesia for myringotomy can be given through facemask or LMA by maintaining spontaneous breathing and with the head rotated to one side.

  
  
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  For analgesia, paracetamol and nonster­oidal anti-inflammatory drug (NSAID) can be given preoperatively.

Anesthetic Considerations

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  The important anesthetic concerns are the usage of nitrous oxide in middle-ear surgery. The solubility of nitrous oxide in the blood is around 34 times higher than nitrogen. It easily diffuses in the middle-ear cavity, which leads to very high pressure within 30 minutes of use. The raised middle-ear pressures can lead to:

  
  
  
  
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    Dislodgment of tympanoplasty grafts.

    
    
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    Deterioration of deafness and rupture of the tympanic membrane.

    
    
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    High incidence of PONV.

  
  
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  During discontinuation, the rapid reab­sorption of nitrous oxide gas can result in negative pressure in the middle ear, which can cause dislodgment of the underlay tympanic membrane graft.

  
  
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  For the bloodless surgical field, various methods can be used, such as head-up elevation of around 10 to 15° to reduce venous ooze, vasoconstrictor-like adre­naline infiltration, and maintaining low blood pressure (up to 20% of mean arterial pressure [MAP]).

  
  
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  The use of muscle relaxants should be properly timed if facial nerve monitoring is used.

  
  
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  Total intravenous (IV) anesthesia is an attractive substitute for general anesthesia (GA) with a lesser incidence of PONV.

  
  
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  Anesthesia can be maintained with pro­pofol, short-acting opioids, and inhalational agent like sevoflurane. It also allows maintenance of anesthesia without muscle relaxant and unobstructed facial nerve monitoring.

  
  
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  For airway, ETT and reinforced LMA can be used. The reinforced LMA is a good option for airway management due to less airway stimulation and smooth emergence.

Analgesia and Antiemesis

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  Multimodal analgesia should be given to minimize opioid dose. Analgesia with paracetamol and NSAIDs can be given through oral, IV, and rectally in the peri­operative period.

  
  
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  Opioids like remifentanil, fentanyl, and morphine, providing adequate analgesia, should be given in a low dose with strict postoperative monitoring. A greater auri­cular nerve block has shown to reduce the postoperative opioid requirement.

  
  
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  For PONV, measures like prevention of long preoperative fasting, good hydration with IV fluids, no nitrous oxide, the practice of total intravenous anesthesia (TIVA), and multimodal analgesia to reduce opioid dose are very helpful.

Preoperative

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  Rule out OSA by history, examination, and PSG (if needed).

  
  
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  Exclude systemic illness, especially coro­nary artery disease (CAD) and cardiac arrhythmia; in that case, surgeon should cautiously use local vasoconstriction.

  
  
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  If the patient has a history of chronic use of steroids, they should receive daily maintenance dose perioperatively.

  
  
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  History of the use of anticoagulant and recent nasal bleeding is also important.

Intraoperative

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  For minor procedures or in a patient who cannot tolerate GA, it can be done under local anesthesia (LA).

  
  
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  For complicated surgical procedures, GA is the anesthesia of choice.

  
  
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  ETT seems to be the prime option for endoscopic sinus surgeries, because of its superior protection against aspiration compared to supraglottic airway (SGA) devices. Blood can still sip through the outer surface of the ETT to vocal cord and trachea. Therefore, throat pack is necessary in case of ETT too, in order to prevent blood aspiration.

  
  
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  The oral RAE tube is better due to its pre­formed shape, and due to that, less kinking intraoperatively. Fixation of ETT should be done in midline.

  
  
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  Patient head (airway) is away from anesthesiologists; hence, EtCO₂ and airway pressure monitoring is prudent to diagnose any kinking or disconnection.

  
  
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  Throat pack should be removed before extubation, and for that, checklist should be followed, because if left, then catastrophic consequences can occur.

  
  
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  Throat pack removal should be followed by a careful examination of the oral cavity and nasopharynx for any clot.

  
  
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  For maintenance, TIVA is an ideal anesthetic technique. It has certain advantages like less bleeding due to low blood pressure, better surgical field, and reduction in the incidence of PONV.

  
  
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  The position of the patient in reverse Trendelenburg with 15° head up helps in decreasing blood loss. This posi­tioning should be done slowly to avoid hypotension.

  
  
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  The patients who are on steroids pre­operatively should continue perioperatively to reduce edema and inflammation.

  
  
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  Vasoconstrictor (epinephrine, pheny­lephrine) topical and injection applied on nasal mucosa helps to decrease congestion and hemostasis. Vasoconstrictor should be used with caution, especially in a patient with a history of CAD, cardiac arrhythmia, or myocardial infarction (MI).

  
  
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  There are certain advantages of awake extubation like less chance of aspiration of blood or secretion due to the full return of laryngeal reflex. Drawbacks of this technique are coughing, bucking, and laryngospasm.

  
  
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  Additional suctioning and laryngoscopy should be done to reduce chances of aspiration of blood or secretions during deep extubation.

Postoperative Care

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  Multimodal analgesia for pain control.

  
  
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  PONV can be prevented by:

  
  
  
  
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    Use of TIVA.

    
    
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    Liberal IV fluid.

    
    
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    Use of dexamethasone, ondansetron.

    
    
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    Judicious use of opioid.

Preoperative

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  A proper evaluation of pathology and its impact on ventilation, intubation, and cricothyroid access is essential.

  
  
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  The surgeon’s preference for airway man­agement should be given consideration.

  
  
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  The cardiovascular and pulmonary comor­bidities must be evaluated and optimized before the surgery.

  
  
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  Reflux history and potential for aspiration should be noted carefully.

Intraoperative

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  Prior detailed discussion and close com­munication with the surgeon and sharing the airway during the procedure.

  
  
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  The eyes should be covered and well-padded. Upper dentition should be pro­tected with a mouth guard or folded gauze.

  
  
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  The regular ETT, which is used for GA, is not suitable for this procedure as it will compromise vision due to its bigger size. LMA/tubeless technique/microlaryngeal sur­gery (MLS) tube is used to secure the airway for this procedure.

  
  
  
  
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    LMA: It is used at the beginning of the procedure and also at the end to secure the airway for sedated patients and for smooth emergence.

    
    
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    Tubeless technique: The technique involves either apnea bag-mask venti­la­tion or ventilation through rigid bronchoscope.

  
  
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  For known or suspected difficult airway, the procedure can be done either by awake intubation, prophylactic placement of a cricothyroid cannula, or awake tracheostomy. A discussion with the ENT surgeon and a preoperative nasal endo­scopic examination of the upper airway may aid in the decision-making.

  
  
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  For maintenance, TIVA is useful in this procedure and decrease the chances of OT pollution.

  
  
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  The emergence phase can be managed by many techniques. At the completion of panendoscopy, the muscle relaxation is reversed if nondepolarizing agents are used, and the IV or volatile anesthetic is stopped. The patient management can be done with bag/mask ventilation or by insertion of a SGA device until spontaneous ventilation is resumed.