| Condition/disease | Comments |
| Age <2 years | The risk for perioperative respiratory complications is increased compared with older children. The clinical examination may not accurately predict the presence of OSA. |
| Obesity (BMI ≥95th percentile) | Risk for OSA generally increases with the severity of obesity. |
| Down syndrome | Evaluate for hypothyroidism prior to surgery. In addition, there is an increased risk for atlantoaxial instability for children with Down syndrome. These patients are likely to require adjuvant surgical procedures or therapy to manage residual sleep apnea after adenotonsillectomy, due to multiple sites of obstruction. |
| Craniofacial anomalies | Severity and sites of airway obstruction vary depending on the anomaly. These patients are likely to require adjuvant procedures or therapy to manage sleep apnea, due to multiple sites of obstruction. |
| Neuromuscular disorders | These children also may have significant hypoventilation, in addition to obstructive symptoms. |
| Mucopolysaccharidosis | Pulmonary and cardiac dysfunction may also be present. |
| Sickle cell disease | These children have increased adenoid and tonsil size compared with normal volunteers. They are also at increased risk for complications in the immediate perioperative period, including acute chest syndrome. |
