Down Syndrome

Down syndrome (trisomy 21) occurs once in 1000 live births. It is associated with congenital cardiac lesions such as endocardial cushion defects (40%), ventricular septal defects (27%), patent ductus arteriosus (12%), and tetralogy of Fallot (8%), and prophylactic antibiotics should be used before predictable bacteremic events. Down syndrome is also associated with upper respiratory infections, with atlanto-occipital instability (in about 15% of patients,^{[675] [676] [677] [678]} in whom it is asymptomatic in most cases, but it is recommended that all patients be treated as though they have atlanto-occipital instability) and laxity of other joints, with thyroid hypofunction (50%), with an increased incidence of subglottic stenosis, and with enlargement of the tongue (or a decreased oral cavity size for a normal-sized tongue).^{[677] [679]} No abnormal responses to anesthetics or anesthetic adjuvants have been substantiated. A reported sensitivity to atropine has been disproved, although administration of atropine to any patient given digoxin for atrial fibrillation should be done with extreme care.^[679] Examination for the conditions associated with Down syndrome should precede surgery.