UBP 5.6 (Short Form): Pediatrics – Laryngeal Papillomatosis Flashcards
Secondary Subject -- Parental Presence at Induction/MH/LASER/ Intravenous Access in the Pediatric Patient/ Laryngospasm/Jet Ventilation/Airway Fire/Increased Airway Pressures Differential
Would you allow the parents to accompany this child to the OR?
(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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
There is some evidence that parental presence during induction may reduce preoperative anxiety, minimize the need for preoperative sedatives, and improve patient cooperation in older children (> 4 years old), with a relatively calm baseline demeanor, and with parents who also have a calm baseline demeanor.
However, since there is evidence that the presence of anxious parents during induction results in increased patient anxiety,
I would NOT allow these parents to accompany their child into the OR.
Moreover, given the many issues that may complicate this anesthetic induction, such as obtaining intravenous access, possible difficult airway management, susceptibility to malignant hyperthermia, and history of asthma, – I would want to be able to focus all of my attention on the patient and prepare to treat possible complications without the distraction and emotional involvement of parental presence during induction.
However, recognizing that the reduction of this patient and her parent’s anxiety is important, I would attempt to reassure them during the pre-operative interview.
While pre-operative sedative medications would, in some cases, be a good alternative to reduce the patient’s anxiety, I would NOT administer any potential respiratory depressants to this patient who is already in respiratory distress, and potentially at risk for complete airway obstruction.
What are your concerns with providing anesthesia for 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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
I am concerned about several issues related to this patient’s history and clinical disease process, such as –
- the severity of airway obstruction,
- difficulty of intubation,
- control of her reactive airway disease, and
- susceptibility to malignant hyperthermia.
I would also be concerned about potential complications associated with the surgical procedure and the use of laser cauterization, such as –
- airway fire,
- viral transmission to the operating room staff,
- tissue injury, and
-
eye injury
- (the limited tissue penetration of the CO2 laser and result in corneal injury, while the KTP, Nd:YAG, or ruby lasers can result in retinal injury).
Another concern would be – determining the optimal mode of ventilation to provide adequate surgical visualization, while at the same time, maintaining oxygenation.
Finally, I would be concerned with the general issues associated with the pediatric patient, such as –
- patient cooperation,
- IV access,
- fluid management,
- intra-operative heat loss, and
- postoperative pain management.
How would you evaluate this child’s airway?
(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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
Because lesions in or near the airway can result in life threatening airway obstruction during the induction of anesthesia, I would perform a thorough history and physical, focusing on the severity and progression of any airway obstruction.
Specifically I would ask about periods of apnea and assess the patient for noisy breathing, stridor, dyspnea, tachypnea, use of accessory muscles of respiration, or nasal flaring.
I would also examine the airway anatomy including the size of the tongue, mouth opening, dentition, Mallampati score, cervical range of motion, and thyromental distance.
Finally, I would optimize the patient’s asthma and administer an anticholinergic to minimize oral secretions.
What is the cause of respiratory papillomatosis?
How is it treated?
(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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
Respiratory papillomatosis is a benign laryngeal neoplasm caused by the human papillomavirus (HPV), a DNA virus that is also responsible for condyloma acuminatum.
It is a self-limited condition (spontaneous regression usually occurs at puberty) associated with the growth of papillomas in the larynx that, if untreated, can lead to progressive airway obstruction (hoarseness, stridor, respiratory distress), aphonia, right ventricular hypertrophy, and cor pulmonale.
The mechanism of transmission to the child is unclear, but may occur with the vaginal delivery of an infant to a mother with genital warts.
Treatment consists of debulking or surgical removal of the papillomatous tissue using a CO2 laser or ultrasonic microdebrider as required (due to the recurrent nature of the condition, multiple surgical ablations are often required) until spontaneous regression occurs.
As many as 10% of patients require some form of adjuvant therapy in addition to surgery, such as – alpha-interferon, indole 3-carbinol, ribavirin, or acyclovir.
Is this patient susceptible to malignant hyperthermia (MH) ?
(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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
Given her paternal uncle’s history of “anesthetic fever”, she may be susceptible to MH.
Therefore, I would try to elicit additional information about the incident, including – the type of surgery, administered agents, perioperative treatment, and any post-mortem or family testing for MH susceptibility.
Based on an autosomal dominant pattern of expression (the most common form of expression), this patient has about a 25% chance of being susceptible to MH (her father has a 50% chance).
How can you test for MH susceptibility?
(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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
Susceptibility to malignant hyperthermia may be determined by skeletal muscle biopsies with in-vitro contracture testing, where the tissue is separately exposed to both halothane and caffeine.
The skeletal muscle of malignant hyperthermia susceptible patients contracts at much lower caffeine and halothane concentrations than does that of non-susceptible patients.
Other tests, which may indicate MH susceptibility, but are not diagnostic, include – an elevated resting plasma creatine kinase concentration, electromyography, and genetic testing for a DNA ryanodine mutation.
The decision to undergo muscle contracture testing (the most specific and sensitive test) must weigh the difficulty of testing (only a few centers in the United States offer this type of testing, obtaining muscle biopsies requires surgery, and the entire process is costly) against the advantages of a more definitive diagnosis, such as greater future anesthetic choices (assuming a negative result) or helping to identify affected family members (assuming a positive result).
In this particular care, the child is too young to undergo muscle biopsy (at least 7 years of age); but testing the patient’s father could be considered.
What is the genetic mode of inheritance of malignant hyperthermia?
(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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
MH has been suggested to be polygenic in origin, with over 30 mutations to the ryanodine receptor identified to date.
This makes the genetic mode of inheritance unknown, but in general the most common mutations are thought to be autosomal dominant with reduced penetrance and variable expression.
Would you order any additional labs or studies prior to 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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
The decision to order additional labs or imaging studies would depend on information obtained by history and physical exam.
If her degree of airway obstruction, respiratory distress, or reactive airway disease could not be adequately determined by history and physical exam, I could consider – ordering a chest X-ray, airway films, arterial blood gases, or pulmonary function tests.
However, since the information is unlikely to significantly alter my anesthetic plan, I would probably not pursue further testing of this young, anxious, and uncooperative patient.
Rather, I would assume her airway obstruction was significant (voice change and stridor), determine a plan for induction and intubation, prepare for a possible surgical airway, and treat acute bronchospasm as required.
Finally, if she were being treated with alpha-interferon, I would consider ordering a hematocrit, since this drug can cause myelosuppression.
Would you pre-medicate this child?
(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. Her history includes asthma and a paternal uncle that died from “anesthetic fever.” The child is crying, uncooperative, and has an audible stridor. After several unsuccessful attempts at intravenous access the patient’s parents are upset and asking to accompany their child to the OR suite.)
As I mentioned before, reducing this patient’s anxiety is important since continued crying and lack of cooperation may further complicate airway management.
However, considering the risk of additional respiratory compromise or complete airway obstruction with sedation, I would be very reluctant to administer any preoperative sedatives
[preoperative sedative medications should only be administered if the benefits (i.e. improved cooperation and improved airway conditions with the cessation of crying) outweight the risks (i.e. respiratory depression and airway obstruction), and then with great caution and appropriate monitoring].
Therefore, I would try to talk with the patient and her parents, relate to the child on her level, address any specific concerns they may have, and reassure them that the anesthetic and surgery would be done as safely as possible.
I would also consider administering a B2-agonist to optimize her asthmatic condition, and atropine (???) to reduce oral secretions.
