UBP 5.6 (Long Form): Pediatrics – Laryngeal Papillomatosis

Question 1

Intra-operative Management:

Do you need intravenous access prior to induction for this case? How would you obtain it?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 1

Considering the risk for airway obstruction and bronchospasm during the induction and intubation of this asthmatic patient with airway papillomas,

I would prefer to obtain prior IV access.

Moreover, this patient’s potential susceptibility to MH further complicates an induction without intravenous access, since volatile agents must be avoided.

However, if the patient remained uncooperative, despite my reassurances, I would –

• proceed to the OR,
• prepare for a difficult intubation and possible surgical airway (i.e. difficult airway cart, rigid bronchoscope, tracheostomy/cricothyrotomy sets available, and a surgeon in the room),
• place the standard ASA monitors,
• administer a B2-agonist,
• provide supplemental oxygen,
• give a small dose of intramuscular ketamine (1-2 mg/kg), and
• attempt IV placement.

My goal would be to provide adequate sedation to obtain intravenous access while, at the same time, maintaining spontaneous respirations and airway patency.

Once access was established, I would perform an intravenous induction with the goals of achieving an adequate depth of anesthesia to avoid bronchospasm, while maintaining spontaneous respirations.

Following induction, I would perform direct laryngoscopy and secure the airway with a laser-resistant endotracheal tube, keeping in mind that no endotracheal tube completely eliminates the risk of airway fire.

Question 2

Intra-operative Management:

During induction the patient develops laryngospasm and you are unable to ventilate.
The oxygen saturation falls to 80%. What would you do?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 2

I would –

• immediately call for assistance,
• administer 100% oxygen,
• place an oral airway,
• perform bimanual jaw thrust, and
• provide positive pressure ventilation by facemask.

If possible, I would avoid the administration of succinylcholine, a triggering agent for MH, in this potentially MH-susceptible patient.

Question 3

Intra-operative Management:

None of these interventions break the laryngospasm and her oxygen saturation is now 68%.

Will you give succinylcholine?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 3

If alternative measures were unsuccessful and her condition continued to deteriorate, I would give a small dose of succinylcholine (5-10 mg), recognizing that the administration of this triggering agent places the patient at risk for developing a MH reaction.

While I could administer a non-triggering muscle relaxant, like rocuronium, I believe that the increased reliability and faster onset of action provided by succinylcholine is required in this emergent situation.

Given the risk, however, I would closely monitor the patient for signs of MH, such as tachycardia, hypercarbia, muscle rigidity, or metabolic acidosis, for at least 12-24 hours.

Question 4

Intra-operative Management:

The surgeon complains that the endotracheal tube is in his way.

What options do you have for improving the surgeon’s view?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 4

Given this patient’s preoperative stridor and the significant risk of airway obstruction,

my best option would be to maintain spontaneous respirations and exchange the current endotracheal tube for one of a smaller diameter.

This may provide better visualization while, at the same time, maintaining a secure airway.

If the surgeon was still having difficulty operating around the ETT, and assuming intubation and ventilation following induction had not been difficult, I would consider utilizing a technique that involved a less secure airway, such as – intermittent apnea, spontaneous ventilation without an endotracheal tube, or intermittent jet ventilation through the operating laryngoscope.

Since the ability to fully exhale between jet ventilations is very important, the latter technique may not be the best option for patients with significant lung disease.

However, it would probably be acceptable for this patient with mild anesthesia.

Clinical Notes:

• Intermittent extubation while maintaining spontaneous ventilation not only provides the surgeon with uninterrupted and unobstructed access to the airway, but also reduces the risk of airway fire, since there is no combustible airway device in the field during surgical ablation.
  
  • However, there are limitations to this technique, including movement of the surgical field with spontaneous respiration, the potential for inadequate ventilation, and an unreliable depth of anesthesia when volatile agents are used.
• When utilizing intermittent extubation without spontaneous ventilation (intermittent apnea technique), periods of ventilation with 100% oxygen via an endotracheal tube or mask ventilation are interspersed with periods of apnea, during which the surgeon is allowed to work without an airway device obstructing his view (usually 1-3 minutes of apnea is tolerated). In addition to an unobstructed surgical view and reduced risk of airway fire, this technique provides a motionless surgical field.
  
  • However, like intermittent extubation with spontaneous ventilation, this technique is limited by the risk for inadequate ventilation and an unreliable depth of anesthesia with the use of volatile agents.
• Finally, supraglottic jet ventilation is often utilized to allow adequate oxygenation while maintaining a relatively motionless field (eliminates significant movement of the diaphragm) and reducing the risk of airway fire (again, there is no combustible airway device in the surgical field).
  
  • However, this method of ventilation is not recommended for those with decreased chest wall compliance (i.e. obesity, restrictive lung disease, and gastric distention) or any condition that may inhibit full exhalation (i.e. severe COPD, laryngospasm, glottic lesions, and interarytenoid scarring).
  • Other potential limitations of this technique include:
    
    1. misalignment of the gas jet to the glottic inlet leading to poor ventilation and/or gastric distension;
    2. transmission of blood, smoke, and debris into the distal airways (in this case, active virus could be transmitted to the distal airways);
    3. excessive vocal cord vibration; and
    4. barotrauma (i.e. pneumomediastinum, subcutaneous emphysema, pneumothorax).

Question 5

Intra-operative Management:

In a discussion with the surgeon, you determine that jet ventilation through the suspension laryngoscope is the best option for this case.

How would you deliver jet ventilation?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 5

For this already intubated patient, I would ensure the difficult airway equipment was still in the room;

ventilate with 100% oxygen until the surgeon was ready to position the suspension laryngoscope with an attached jet injector needle;

ensure adequate muscle relaxation and depth of anesthesia to prevent bronchospasm or laryngospasm;

remove the endotracheal tube and position the suspension laryngoscope; and

initiate jet ventilation with a pressure of 5-10 psi, adjusting the pressure upward until adequate chest rise and fall are noted (I would start with 15-20 psi for an adult patient).

Given this patient’s susceptibility to MH and the unreliable delivery of volatile agents with jet ventilation, I would maintain anesthesia with an intravenous technique, using propofol and a short-acting opioid.

Moreover, I would continuously monitor the adequacy of ventilation using pulse-oximetry combined with auscultation and observation of the chest (good chest excursion), keeping in mind the potential complications associated with jet ventilation, such as – pneumothorax, pneumomediastinum, subcutaneous emphysema, gastric distention, and aspiration of resected debris.

Question 6

Intra-operative Management:

During jet ventilation the oxygen saturation decreases to 82%.

What do you think might be going on?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 6

Desaturation during jet ventilation is most commonly caused by –

inadequate ventilation pressures or a malpositioned jet injector.

However, I would also consider other potential causes, such as – pneumothorax, pneumomediastinum, subcutaneous emphysema, significant gastric distention, aspiration, airway obstruction, bronchospasm, laryngospasm, and decreased lung compliance.

In managing this hypoxia, I would inform the surgeon, confirm the position of the injector, ventilate with 100% oxygen, and auscultate breath sounds over all lung fields.

If the cause were not immediately identified, I would intubate the patient, provide positive pressure ventilation, suction the trachea, deepen the anesthetic, administer a B2-agonist, and consider a chest x-ray.

Question 7

Intra-operative Management:

After you intubate the trachea and increase the Fio2 to 100%, the oxygen saturation improves and the case continues.

Suddenly the endotracheal tube ignites.

What would you do?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 7

I would –

• immediately alert the operating room personnel,
• disconnect the oxygen supply from the airway (disconnect the circuit),
• remove the endotracheal tube, and,
• if the flame persisted, flood the surgical field with saline.

Once the fire was extinguished, I would –

• ventilate with 100% oxygen and
• perform direct laryngoscopy and rigid bronchoscopy to evaluate the airway for damage and remove any debris.

If the fire had reached the interior of the endotracheal tube (exposing it to relatively oxygen rich gas), resulting in a “blowtorch” affect, I would consider –

• bronchial lavage and a fiberoptic assessment of the more distal airways.

Given the risk of delayed airway edema formation with resultant airway obstruction, I would –

• reintubate the patient and delay extubation for a minimum of 24 hours.

Finally, I would –

• examine the oropharynx and face for additional change,
• order a chest radiograph,
• consider a brief course of high-dose steroids,
• consider a pulmonary consult (depending on the extent of the damage… i.e. a “blowtorch” type of fire), and
• monitor the patient carefully.

Question 8

Intra-operative Management:

What measures can be taken to reduce the risk of airway fire during laser surgery?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 8

Steps that can be taken to reduce the risk of airway fire include:

1. removal of flammable materials from the airway by utilizing intermittent extubation with or without apnea, or supraglottic jet ventilation with a metallic jet needle;
2. reducing the flammability of the endotracheal tube by using a laser resistant ETT, a rubber ETT, or wrapping the ETT with reflective foil;
3. minimizing the availability of oxidizing agent by reducing the Fio2 to < 40%, avoiding nitrous oxide, using air to dilute the inspired oxygen concentration, and protecting the ETT cuff so oxygen-rich gas does not flow into the surgical field with inadvertent cuff rupture;
4. minimizing the intensity and duration of laser treatment; and
5. filling the ETT cuff with colored saline (methylene blue) to rapidly identify a cuff puncture and, potentially, quench a small fire.

Question 9

Post-operative Management:

Assuming there were no clinical or bronchoscopic evidence of injury resulting from the airway fire, would you extubate this patient at the end of this case?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 9

Since inhalational injury can potentially progress from a lucid period with mild symptoms and minimal evidence of mucosal injury, to life threatening airway obstruction secondary to rapidly developing airway edema,

I would NOT extubate this patient after an airway fire, regardless of the extent of injury evident by bronchoscopy.

Rather, I would –

• keep this patient intubated,
• administer steroids to reduce airway edema,
• provide humidified oxygen, and
• monitor her for a minimum of 24 hours with continuous pulse oximetry and serial chest X-rays.

Question 10

Post-operative Management:

When would you consider it safe to extubate someone following an airway fire?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 10

Assuming there were no evidence of acute lung injury by chest X-ray, I would –

consider extubation when the patient demonstrated adequate oxygenation and ventilation, minimal ventilatory support, normal lung compliance, stable hemodynamics, and no evidence of airway edema by bronchoscopy or laryngoscopy 24 hours following an airway fire.

Prior to extubation, I would make sure there was an appropriate leak around a properly sized ETT, and make preparations for emergent re-intubation should it be required.

Question 11

Post-operative Management:

After transfer to the ICU and initiation of mechanical ventilation, the patient becomes hypoxic with increased airway pressures.

What is your differential diagnosis?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 11

Hypoxia with increased airway pressures in an intubated patient is consistent with –

airway obstruction or decreased lung compliance.

Given this patient’s asthma, the surgical procedure, and the recent airway fire, I would be concerned that her condition was the result of –

bronchospasm, pleural effusion, pulmonary edema, or acute lung injury.

However, I would also consider the possibility of –

a plugged or kinked ETT, right mainstem intubation, or a pneumothorax.

In managing this patient, I would hand ventilate the patient with 100% oxygen, suction the ETT, auscultate all lung fields, consider obtaining a chest X-ray and/or ABG, and treat accordingly.

Question 12

Post-operative Management:

Two hours following surgery the patient becomes tachycardic and hypercapnic despite appropriate ventilator management.

What do you think might be the cause?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 12

Given this patient’s potential MH susceptibility and the decision to administer succinylcholine, and assuming appropriate ventilator settings, my primary concern would be that this tachycardia and persistent hypercapnia represent a MH reaction.

Therefore, I would look for additional signs and symptoms consistent with this diagnosis, such as – tachypnea, hyperthermia (late finding), a mixed respiratory and metabolic acidosis, generalized rigidity, changes in blood pressure, arrhythmias, peripheral mottling, rhabdomyolysis (tea colored urine), hyperkalemia, elevated serum creatine kinase, sweating, and cyanosis.

If after a brief investigation I was still concerned that this may be MH, I would administer –

2.5 mg/kg of dantrolene and continue to monitor her closely.

Question 13

Post-operative Management:

After further investigation, you believe this represents a MH reaction.

How will you treat the patient?

• (A 5-year-old female is scheduled for laser ablation of laryngeal papillomatosis. Her mother states that she has noticed a change in the child’s voice over the last two weeks.*
• PMH: Asthma - mild / Paternal uncle that died from “anesthetic fever”*
• Meds: Bronchodilator*
• Allergies: NKDA*
• PE: Vital Signs: HR = 120, Temp = 37.1ºC*
• General: well developed, crying, uncooperative, exhibiting inspiratory stridor and intercostal retractions.)*

Answer 13

If I felt this were an episode of malignant hyperthermia, I would –

• alert the ICU staff,
• call for assistance and the MH cart,
• administer 2.5 mg/kg of Dantrolene
  
  • (repeating doses every 5-10 minutes as necessary to control symptomatology),
• hyperventilate the patient with 100% oxygen,
• initiate active cooling measures
  
  • (cold intravenous fluids; ice packs over major arteries (groin and axilla);
  • gastric, bladder, rectal, and wound lavage;
  • cold peritoneal dialysis; and even
  • cardiopulmonary bypass), and
• maintain urine output with intravenous fluids, mannitol, and lasix.

Ongoing treatment would include –

• monitoring urine output, potassium, calcium, arterial blood gases, serum creatine kinase, liver enzymes, and coagulation;
• treating hyperkalemia (dextrose and regular insulin), acidosis (bicarbonate), hyperthermia (reduce temperature to 38.0-38.5ºC), rhabdomyolysis (mannitol), and dysrhythmias (lidocaine) as necessary;
• continuing intravenous dantrolene, 1 mg/kg every 6 hours, for 24-48 hours to prevent relapse; and
• monitoring the patient for up to 72 hours in the ICU for signs of disseminated intravascular coagulation, myoglobinuric renal failure, and recrudescence (relapse).