UBP 6.3 (Short Form): Pediatrics – Strabismus Surgery

Question 1

During the examination you hear expiratory wheezing when auscultating the lungs. The child is active, but does appear to be congested. Would you cancel the case?

(A 7-year-old male presents for strabismus surgery. His mother says that he has asthma and, for the past week, a cough and runny nose. She also admits to occasionally smoking in the house. VS: BP = 105/65 mmHg; P = 102; R = 14; T = 100.5ºF (axillary).)

Answer 1

While this patient’s cough and expiratory wheezing may simply be the result of his asthma, the presence of fever raises the concern that his symptoms are secondary to a respiratory tract infection.

Therefore, given his cough and runny nose, history of asthma, potential pulmonary involvement, significant fever, and exposure to second hand smoke,

I would delay this elective case for 4-6 weeks to allow pulmonary function to return to normal.

Proceeding with the case today would place the patient at increased risk of laryngospasm, bronchospasm, and oxygen desaturation events.

A reasonable strategy for managing a child with a respiratory infection is to:

1. delay surgery for 4-6 weeks whenever severe symptoms such as fever > 38.5ºC, productive cough, mucopurulent secretions, malaise, and pulmonary involvement are present (an example of the latter would be wheezing that does not clear with coughing);
2. delay surgery for 2-4 weeks when patients with mild symptoms (i.e. sneezing, mild nasal congestion, and nonproductive cough) require ETT placement and have additional risk factors, such as second-hand smoke exposure and/or underlying pulmonary disease (i.e. asthma); and
3. proceed with surgery when patients with mild symptoms do not require ETT placement (i.e. regional anesthesia, general anesthesia with mask or LMA).

Question 2

Would you get a chest x-ray prior to making a decision?

(A 7-year-old male presents for strabismus surgery. His mother says that he has asthma and, for the past week, a cough and runny nose. She also admits to occasionally smoking in the house. VS: BP = 105/65 mmHg; P = 102; R = 14; T = 100.5ºF (axillary).)

Answer 2

A chest x-ray would of little value since radiographic changes often lag behind clinical symptoms.

A normal chest x-ray would not change my decision to delay this elective case for at least four weeks.

Question 3

What are the risks of proceeding with the case when the child has an upper respiratory tract infection (URI)?

(A 7-year-old male presents for strabismus surgery. His mother says that he has asthma and, for the past week, a cough and runny nose. She also admits to occasionally smoking in the house. VS: BP = 105/65 mmHg; P = 102; R = 14; T = 100.5ºF (axillary).)

Answer 3

Patient’s with an acute or recent respiratory tract infection are at increased risk of experiencing perioperative respiratory complications such as – laryngospasm, bronchospasm, and oxygen desaturation.

The risk is even greater in patients who have severe symptoms (fever > 38.5ºC, productive cough, mucopurulent secretions, malaise, and pulmonary involvement), have high risk factors (i.e. reactive airway disease), require general anesthesia, and/or require endotracheal intubation.

Question 4

The mother begs you not to delay the case because they drove 2 hours to get to the surgery center, her insurance deductible is going to reset in another week, the surgery has already been canceled once for an URI, and she is not sure if she would be able to get another day off work. What would you do?

(A 7-year-old male presents for strabismus surgery. His mother says that he has asthma and, for the past week, a cough and runny nose. She also admits to occasionally smoking in the house. VS: BP = 105/65 mmHg; P = 102; R = 14; T = 100.5ºF (axillary).)

Answer 4

I would explain to her that I understand her concerns, and if her son were afebrile, otherwise healthy, and exhibited signs of an uncomplicated respiratory tract infection, I would consider proceeding with the case using an LMA

(LMA use is associated with reduced risk of bronchospasm and desaturation events when compared to ETT placement).

However, the fact that her son is asthmatic and exhibiting signs of acute and severe respiratory infection makes the risk of proceeding with an elective procedure under general anesthesia unacceptable.

Question 5

How long would you delay the case?

(A 7-year-old male presents for strabismus surgery. His mother says that he has asthma and, for the past week, a cough and runny nose. She also admits to occasionally smoking in the house. VS: BP = 105/65 mmHg; P = 102; R = 14; T = 100.5ºF (axillary).)

Answer 5

Given his asthma and the severe nature of his symptoms, I would delay the case for 4-6 weeks following the resolution of his current respiratory infection, to allow a significant reduction in airway hyperreactivity.

Although complete resolution of airway hyperreactivity may take up to 8 weeks, the longer the case is delayed, the greater the risk that the child will develop another respiratory infection before returning for surgery.

Question 6

The child comes back in four weeks. Would you use an ETT or LMA? Does it matter?

(A 7-year-old male presents for strabismus surgery. His mother says that he has asthma and, for the past week, a cough and runny nose. She also admits to occasionally smoking in the house. VS: BP = 105/65 mmHg; P = 102; R = 14; T = 100.5ºF (axillary).)

Answer 6

Assuming the child’s condition had improved significantly, there was minimal risk of aspiration, and the surgical procedure did not require the use of an endotracheal tube,

I would utilize a laryngeal mask airway (LMA).

Using a LMA in patients with an acute or recent respiratory tract infection is associated with fewer perioperative respiratory complications when compared to endotracheal intubation (i.e. reduced risk of bronchospasm and desaturation events).

Other measures I would consider to reduce the risk of respiratory complications include – administering preoperative anticholinergic (decreases airway hyperresponsiveness), ensuring an adequate depth of anesthesia during LMA placement, and carefully suctioning the oropharynx under deep anesthesia prior to removal of the LMA.

Question 7

Are there any preoperative medications you would administer?

(A 7-year-old male presents for strabismus surgery. His mother says that he has asthma and, for the past week, a cough and runny nose. She also admits to occasionally smoking in the house. VS: BP = 105/65 mmHg; P = 102; R = 14; T = 100.5ºF (axillary).)

Answer 7

Since strabismus surgery is associated with an increased risk for dysrhythmias secondary to oculocardiac reflex,

I would consider administering 20 µg/kg of atropine or 10-20 µg/kg of glycopyrrolate to decrease the magnitude and duration of bradycardic events (these drugs do not reliably prevent the occurrence of bradycardia).

Moreover, given the very high incidence of post-operative nausea and vomiting associated with this procedure (45-85% incidence – while often attributed to an oculogastric reflex mediated by the vagus nerve, there is evidence that would suggest this is unlikely),

I would administer oral midazolam, ondansetron, dexamethasone, ketorolac (to reduce narcotic requirements), and provide a fluid bolus (replacing 50-100% of the child’s fluid deficit has been demonstrated to reduce PONV).

Finally, if I believed that his asthmatic condition could be further optimized, I would consider administering a bronchodilator.

Question 8

Would you give atropine, pre-operatively, to optimize his asthmatic condition?

(A 7-year-old male presents for strabismus surgery. His mother says that he has asthma and, for the past week, a cough and runny nose. She also admits to occasionally smoking in the house. VS: BP = 105/65 mmHg; P = 102; R = 14; T = 100.5ºF (axillary).)

Answer 8

Anticholinergic medications may be beneficial for asthmatic patients secondary to reduced mucous gland secretions (possibly improving inflammation) and airway hyperreactivity (secondary to reduced vagal tone and inhibition of muscarinic cholinergic receptors).

However, their preoperative administration is controversial, since they could result in increased inspissation (increased viscosity and thickening of airway secretions), potentially leading to airway plugging and the initiation of an asthmatic attack.

Therefore, considering these potential complications, and recognizing that the intramuscular doses of anticholinergic medications typically used for pre-anesthetic medication are unlikely to significantly decrease her airway resistance (they would be sufficient to reduce airway secretions), I would NOT administer this medication pre-operatively, to optimize a patient’s asthmatic condition.

An inhaled medication, such as ipratropium, may be more appropriate for that purpose.

However, in this case, I would administer atropine, preoperatively, in order to reduce the magnitude and duration of the bradycardic events associated with strabismus surgery.