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A 2-year-old patient with Down syndrome, who has had an atrioventricular canal repair and a pull-through procedure for Hirschsprung’s disease, presents with a recent diagnosis of acute lymphoblastic leukemia. The patient is scheduled for lumbar puncture with chemotherapy, bone marrow aspiration and biopsy, and flexible bronchoscopy. The patient has been having fevers, has a chronic cough, and has multiple pulmonary nodules on chest CT.
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PREOPERATIVE CONSIDERATIONS
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Down syndrome (trisomy 21) is the most widely recognized chromosomal abnormality, with an incidence of about 1 in 700 live births. Airway management can be difficult as a result of macroglossia, macrognathia, and a narrow hypopharynx. Macroglossia and pharyngeal muscle hypotonia tend to cause upper airway obstruction. The nares and the trachea may be smaller than in normal children. There is also an increased incidence of subglottic stenosis. Disordered breathing during sleep, including upper airway obstruction and obstructive sleep apnea, is seen in 30%-60% of children with Down syndrome. These patients are at risk for congenital cardiac disease (mostly endocardial cushion defects, but also mitral valve abnormalities recognized at a later age). Pulmonary hypertension can result from cardiac disease or chronic obstructive sleep apnea. Patients with Down syndrome have an increased incidence of duodenal atresia, Hirschsprung’s disease, hypothyroidism, and leukemia. They are also at increased risk for atlantoaxial instability. The American Academy of Pediatrics recommends getting an anteroposterior/lateral x-ray of the neck once between the ages of 3 and 5 years old. One should inquire about it, but it is not required prior to the patient’s receiving general anesthesia. It is not a perfect screening tool, and we should always consider these patients at risk and use precautions when manipulating their cervical spines. To screen for pain or abnormal movement in an uncooperative patient, you can use keys, a light, a toy, or something else interesting that they will want to follow with their eyes and move it around them. Also, parents may describe regression in certain milestones, even regression in toilet training, or less tolerance for walking. These kinds of symptoms should prompt a neurologic evaluation. Ensure that you have a recent cardiovascular evaluation, and evaluate for any residual defects or pulmonary hypertension.
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Remember that the degree of intellectual impairment varies widely in patients with trisomy 21.
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ANESTHETIC MANAGEMENT
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Expect obstruction or difficult mask ventilation because of a small mouth, large tongue, and large tonsils, but intubation is generally easy.
Consider moderate continuous positive airway pressure with jaw thrust during mask induction to prevent pharyngeal airway collapse.
Avoid manipulating the cervical spine during direct laryngoscopy.
These patients can present with profound bradycardia upon induction with sevoflurane, presumably because of a predominant parasympathetic response or abnormal sympathetic response. They sometimes do not respond ...