Congenital High Airway Obstruction (CHAOS)

Step-by-step decision

Choose step by step as prompted; reaching an endpoint gives the management recommendation. You can go back a step or restart anytime.

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Full pathway

1. [Decision] Typical signs + hydrops + associated/genetic
   Typical signs + hydrops + associated/genetic? (CHAOS = complete/near-complete upper airway obstruction (laryngeal atresia most common, tracheal atresia/stenosis). Mechanism: lung fluid cannot drain → enlarged lungs compress the heart → reduced venous return → ascites/hydrops. Typical (US + fetal MRI): bilateral enlarged echogenic lungs, fluid-filled dilated tracheobronchial tree (abrupt cutoff at the obstruction), inverted diaphragm, small compressed central heart, ascites/hydrops, polyhydramnios. Differentiate bilateral CPAM.)
   • Typical signs, isolated, no hydrops, normal genetics, laryngeal membrane/cyst seen → Isolated CHAOS → localize/EXIT
   • With hydrops or associated anomalies (Fraser/VACTERL/TACRD) → With hydrops/syndrome · mostly lethal
2. [End] Isolated CHAOS → localize/EXIT
   Isolated CHAOS, no hydrops, normal genetics, visible laryngeal membrane/cyst: fetal MRI to localize the obstruction level + exclude associated anomalies; selectively, intrauterine fetoscopic decompression (puncturing the laryngeal membrane to release lung fluid) or planned EXIT (tracheostomy distal to the obstruction); multidisciplinary + delivery at a capable center.
3. [End] With hydrops/syndrome · mostly lethal
   CHAOS with hydrops or associated anomalies/syndromes (Fraser, VACTERL, TACRD): mostly lethal (especially with hydrops); karyotype/microarray + genetic counselling + detailed survey for associated anomalies; poor prognosis, full informed consent; occasional response to intrauterine decompression/EXIT.

Source guidelines & references

• Congenital high airway obstruction syndrome CHAOS imaging and management (laryngeal atresia; EXIT)

This pathway is our own synthesis of the decision logic in the guidelines above (not the guideline verbatim); thresholds and workflows change as guidelines update — in practice follow the latest guideline, your institution's protocol and the individual patient.

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