Trisomy 21
Stem
A 6-year-old girl with trisomy 21, 20 kg, is scheduled for dental rehabilitation under general anesthesia. She had an atrioventricular septal defect repaired at 5 months, snores loudly with witnessed pauses, and has been intubated three times before. Her mother says she has had no neck pain, no change in her walking and no new weakness. She is anxious, nonverbal with strangers, and has no IV.
Question
What are your anesthetic concerns, and how will you induce and secure her airway?
Ideal answer
HeadlineAirway, heart, neck and induction. I expect a difficult mask airway and plan a sevoflurane induction with her mother present, ready for bradycardia.
- Plan for a hard mask. Large tongue, midface hypoplasia, hypotonia and sleep-disordered breathing, which affects up to 65%;1 an oral airway and jaw thrust usually open it.
- Tubes one, two sizes smaller; leak at 20 cm H2O. After three intubations I expect subglottic narrowing.1
- Latest echo; neck kept neutral. Residual shunt, AV valve regurgitation, pulmonary hypertension worsened by obstruction;1 no films for an asymptomatic neck; video laryngoscope to limit extension.1
- Oral midazolam, then sevoflurane by mask, because an awake IV would be a fight;1 bradycardia affects over half,2 so a modest concentration, atropine and epinephrine drawn up, an assistant ready for the IV.
- Nasal tube for the dental work; monitored recovery. Obstruction and postintubation croup expected; continuous oximetry and capnography.1
Breaking down the answer
- Why mask ventilation fails — lingual tonsils add to macroglossia and hypotonia to cause unexpected difficulty, and obesity adds to it.1 Listing the risks in order with matching equipment shows organization.
- Why smaller tubes — subglottic stenosis is relatively common, especially after prior intubations; the downsized tube and leak test avoid mucosal injury.1
- Neck by symptoms, not routine films — up to 30% have radiographic atlantoaxial laxity, but routine radiographs are not recommended in asymptomatic children; new weakness, neck pain or gait change triggers a workup and precautions.1
- The heart is half the story — about half have a cardiac defect, most often an endocardial cushion defect (43%), then VSD (32%) and ASD (10%); pulmonary hypertension changes how I ventilate and what I give.1
- Expect the bradycardia — profound bradycardia after sevoflurane occurred in 57% versus 12% of other children in one study and is not caused by stimulation.1 Prospective data link it to sympathetic failure.2
- Pain and the postoperative airway — these children express pain later and less precisely, and opioids are limited by obstruction, so regional and multimodal analgesia matter; ICU care is a case-by-case decision.1
Follow-up question
During the mask induction, before an IV is placed, her heart rate drops from 115 to 50 and the pulse oximeter waveform flattens. Saturation is 98%.
What do you do?
Follow-up answer
HeadlineSevoflurane bradycardia typical of trisomy 21, with poor perfusion. I confirm she is oxygenating with an open airway and tell the team.
I ask for the atropine and epinephrine and turn the sevoflurane down at once, which often works by itself.1 An anticholinergic goes in intramuscularly while my assistant places an IV or an intraosseous needle. If the rate does not respond, epinephrine, intravenously once I have access.1 If her heart rate stays below 60 with poor perfusion, I start chest compressions. I reassess heart rate, blood pressure and end-tidal CO2, and continue only once she is stable at a lighter depth.
Pitfalls that cost points
- Ordering flexion-extension radiographs in an asymptomatic child instead of asking about symptoms.
- Treating bradycardia only as a vagal response to stimulation.
- Sending her to a ward bed without continuous monitoring after opioids.
Rapid-fire
Q: When does postintubation croup appear, and how do you treat it? A: Usually 20–30 minutes after extubation; racemic epinephrine and IV dexamethasone.1
Q: Which GI anomalies are associated? A: Duodenal atresia (the double bubble), tracheoesophageal fistula and Hirschsprung disease.1
Q: Which endocrine problem do you screen for? A: Hypothyroidism, which is common.1
Q: What hematologic risk matters later? A: Leukemia is 10 to 15 times more common than in other children.1
Q: How do you get an older, uncooperative patient to the OR? A: Intramuscular ketamine works, at the cost of secretions that an antisialagogue offsets.1
Numbers to know
| Item | Value |
|---|---|
| Incidence | ~1 in 700 live births1 |
| Cardiac defect | ~50%; AVSD 43%, VSD 32%, ASD 10% of lesions1 |
| Sleep-disordered breathing | Up to 65%1 |
| Radiographic atlantoaxial laxity | Up to 30%1 |
| Bradycardia with sevoflurane | 57% vs 12%1; 58% vs 22%2 |
| Leak test | 20 cm H2O1 |
Links
- Pediatric airway anatomy and equipment, Obstructive sleep apnea, Congenital heart disease: shunts and bubble precautions, Airway management with cervical spine injury, Pulmonary hypertension and right ventricular failure, The child with an upper respiratory infection
- AAP clinical report: Health Supervision for Children and Adolescents With Down Syndrome
Sources
- 1.Down Syndrome · OpenAnesthesia · openanesthesia.orgComorbidities, cervical spine guidance, sevoflurane bradycardia (57% vs 12%), airway sizing, postintubation croup timing.
- 2.Prospective Observational Study of Sympathetic Failure as a Mechanism Associated with Bradycardia During Induction of General Anesthesia in Children with Down Syndrome · Journal of Pediatric Research, 2024 · ebi.ac.ukSinton JW et al.; bradycardia within 300 s of sevoflurane induction in 58% of 93 children with Down syndrome vs 22% of 102 typically developing children.
Facts on this page were checked against these sources on Oct 16, 2026. Guidelines change; confirm doses against current institutional protocols.