Pediatric Examination and Board Review (26 page)

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These medications may predispose to another syndrome.

8.
(C)
In general, amphetamines increase release of serotonin at neuronal synapses in the CNS, but they also cause inhibition of serotonin reuptake and breakdown at these synapses. The resultant excess serotonin concentration in the CNS results in a constellation of symptoms that have come to be recognized as CSS.

9.
(C)
Complicating serotonin physiology in this child is the presence of a MAO inhibitor that the patient takes regularly for depression. MAO inhibitors also prevent the breakdown of serotonin, producing excess CNS serotonin.

10.
(D)
The neurotransmitter responsible for NMS is dopamine. Blockade of dopamine receptors within the basal ganglia is believed to precipitate symptoms. More than 25 agents have been incriminated in the precipitation of NMS. The most commonly implicated are neuroleptic agents such as haloperidol, the withdrawal of dopamine agonists (eg, Ldopa), other antipsychotic agents such as chlorpromazine and fluphenazine, and the narcotic agonist meperidine.

11.
(D)
NMS is another drug-induced hyperthermic state that can be confused with CSS. When compared with CSS, patients with NMS are likely to have had gradual onset of symptoms and are less likely to have myoclonus and hyperreflexia. Rigidity found in NMS is more severe than in CSS, but the remainder of the clinical scenario may look much the same.

12.
(D)
Other agents have been reported to precipitate CSS that include cocaine, L-dopa, lithium, LSD, dextromethorphan, tricyclic antidepressants, serotonin reuptake inhibitors (SRIs), and SSRIs. SRIs are commonly prescribed in pediatric depression making CSS a syndrome that should be well understood by pediatric practitioners. See answer 9.

13.
(A)
The mortality should be less than 20% assuming the patient arrives at a hospital and receives appropriate intervention.

14.
(D)
Although producing overlapping syndromes, treatment for these 3 disorders differs. For CSS, symptomatic treatment is appropriate. Dantrolene has been used only in isolated cases. It also may be appropriate to consider the administration of an anti-serotonin medication. Both propranolol and cyproheptadine block serotonin activity at the postsynaptic receptor. It is possible that these drugs may be useful, but their benefit is supported only by case reports.

In both CSS and NMS, it is important to identify the offending agent and eliminate it from the patient’s medication regimen. With respect to MH, the anesthetic will have been discontinued before your involvement in the case and your participation will be to help provide supportive care. Although all of these syndromes pose a threat to life, the mortality of each should be well under 20% when appropriately treated. The key to successful intervention in life-threatening drug-induced hyperthermia is the prompt recognition and elimination of the drug that might have triggered such a response and careful supportive care.

15.
(C)
Therapy for MH relies heavily on the medication dantrolene, whereas treatment of NMS is largely symptomatic; however, it also can improve with dantrolene and bromocriptine.

S
UGGESTED
R
EADING

Arnold DH. The central serotonin syndrome: paradigm for psychotherapeutic misadventure.
Pediatr Rev.
2002. 23(12):427-432.

Rosenberg MR, Green M. Neuroleptic malignant syndrome. Review of response to therapy.
Arch Intern Med.
1989;149: 1927-1931.

CASE 13: A 4-YEAR-OLD GIRL WITH SNORING

A 4-year-old girl is brought in for a routine physical examination. Her family recently moved, and this is their first visit. She has had regular health care and her immunizations are up to date. She snores and her mother allows her to sleep with her so she can “listen to her breathe.” The mother reports she worries because her daughter’s breathing is often irregular with sleep and seems to pause. She is the youngest of 5 siblings, and none of her other children breathes as this child does. Other than 2 episodes of “strep throat,” she has not really been ill.

On physical examination, she appears small for her age. She is less than the 5th percentile for height and weight. Her head circumference is 50th percentile for age. Her entire physical examination, absent the growth parameters, is normal with the exception of moderate tonsillar hypertrophy. Her developmental assessment is normal.

SELECT THE ONE BEST ANSWER

1.
It is likely that the following symptom is also prominent

(A) encopresis

(B) poor attention span

(C) echolalia

(D) dysphagia

(E) sleepiness

2.
Which is not true about sleep in children?

(A) functional residual capacity falls

(B) upper airway resistance doubles

(C) breathing is not erratic during rapid eye movement (REM) sleep but is erratic during non-REM periods

(D) ventilatory drive is decreased from the awake state

(E) none of the above

3.
Spontaneous arousal is a potent defense against sleep-disordered breathing. Which of the following is true about sleep arousals in children?

(A) children have a lower threshold for arousal than adults

(B) moderate hypoxia is the most potent stimulus for arousal in infants during sleep

(C) hypercapnia and increased upper airway resistance are more potent than hypoxemia at stimulating sleep arousals in preschool children

(D) the sleep arousal index in infants is the same as it is in adolescents

(E) all of the above

4.
Central apnea in preschool children is significant if it exceeds

(A) 10 seconds

(B) 15 seconds

(C) 20 seconds

(D) 30 seconds

(E) 60 seconds

5.
Which is true about central apnea in children?

(A) central apnea is more common than obstructive apnea in children

(B) central apnea is significant only if it is associated with bradycardia

(C) obstructive apnea is more common than central apnea in normal children

(D) apnea associated with transient desaturation is always pathologic in children

(E) obstructive apnea does not occur in children

6.
Children with obstructive sleep apnea (OSA) differ from adults in that

(A) children with OSA are more likely to be obese

(B) children with OSA are more likely to have sleep arousal and therefore have more daytime sleepiness than adults

(C) children with OSA are more likely to have REM sleep apnea, whereas adults have apnea with non-REM sleep

(D) children with OSA do not suffer the cardiopulmonary insult that adults do

(E) none of the above

7.
Complications of OSA in children include

(A) neurocognitive defects

(B) systemic hypertension

(C) congestive heart failure

(D) failure to thrive

(E) all of the above

8.
What is the next diagnostic procedure indicated?

(A) the next step is a strep screen

(B) the next step is polysomnography

(C) the next step is an ultrasound of the neck

(D) the next step is a nasopharyngeal aspirate for viral DFA studies

(E) the next step is a CT scan of the head and neck

9.
The treatment of OSA in children usually begins in children with

(A) nighttime oxygen supplementation

(B) nighttime mechanical ventilation

(C) tonsillectomy and adenoidectomy

(D) calorie reduction diet aimed at 15% reduction in body weight

(E) watchful waiting

10.
The child with snoring

(A) is always at risk for OSA

(B) rarely has OSA

(C) always requires surgical intervention with tonsillectomy

(D) should always be evaluated by polysomnography

(E) none of the above

11.
A tonsillectomy in a patient with OSA is characterized by

(A) increased risk of postoperative respiratory failure as compared with a tonsillectomy in the same age patient with no OSA

(B) immediate improvement of airway symptoms

(C) decreased risk of postoperative bleeding as compared with a tonsillectomy in the same age patient with no OSA

(D) no risk of postoperative respiratory failure as compared with a tonsillectomy in the same age patient with no OSA

(E) all of the above