DOPES — Sudden deterioration on a vented patient

Differential for the vented patient who suddenly desats / drops EtCO2

Mnemonic device

DOPES — work top-down before changing the vent

Mapping

D — Displacement

ETT migrated (mainstem or extubated); auscultate bilaterally, recheck depth at lip

O — Obstruction

Mucus plug, kink, biting; suction, pass catheter, check bite block

P — Pneumothorax

Tension PTX after recent CVC, trauma, barotrauma; needle decompress + chest tube

E — Equipment

Disconnect, leak, kinked circuit, depleted O₂, vent malfunction; bag manually with backup O₂

S — Stomach / Stacked breaths

Gastric distension splinting diaphragm OR auto-PEEP from breath-stacking; disconnect to allow exhalation

Clinical note: First move on a vent emergency: DISCONNECT and bag manually with 100% O₂. That diagnostically tests both circuit (E) and stacked-breaths (S) while you systematically work through D-O-P.