Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Airway or cerebral compromise from SVCO
Stridor, laryngeal oedema, severe respiratory distress, syncope, confusion, reduced consciousness or rapidly progressive head and neck swelling indicates high-risk superior vena cava obstruction.
Action: Sit the patient upright, use ABCDE assessment and monitoring, secure senior airway, acute-oncology and interventional-radiology help, obtain urgent contrast-enhanced imaging if physiology permits and prioritise endovascular decompression when life-threatening obstruction cannot wait for tissue-directed therapy.
Synopsis
Recognise impaired upper-body venous drainage, distinguish airway or cerebral danger from stable obstruction, define malignant and thrombotic anatomy, obtain tissue safely and select stenting, anticoagulation or tumour-directed treatment.
SVCO causes facial, neck and arm swelling, venous distension, breathlessness, cough and head pressure that often worsens when lying flat or bending forward.
Airway oedema, stridor, severe respiratory distress, confusion or reduced consciousness defines a decompression emergency; sit upright and involve airway and interventional teams immediately.
First-line anatomical investigation in a stable patient is contrast-enhanced CT of chest and central veins, which shows level, length, collaterals, thrombus, tumour and a tissue target.
Key red flags
Stridor, voice change, drooling, severe orthopnoea or facial and tongue oedema raises impending upper-airway compromise.
Airway danger
Voice change, dysphagia, stridor, tongue swelling, orthopnoea or rapidly increasing neck oedema requires senior airway and decompression planning.
Investigation priorities
01
First-line contrast-enhanced CT chest and central veinsFirst stepFirst line
Map obstruction, thrombus, collaterals and tumour and identify a biopsy route and other thoracic emergencies.
Management branches
TriageIdentify airway and cerebral danger
Facial or upper-limb swelling and venous distension suggest central thoracic venous obstruction.
Sit the patient upright, assess airway voice and stridor, breathing, circulation and cognition and establish monitoring and intravenous access outside a severely congested limb where possible.
Call acute oncology and interventional radiology urgently; involve anaesthesia or critical care immediately for airway swelling, severe orthopnoea, syncope or neurological change.
Stable undiagnosedSecure tissue before tumour therapy
The patient is physiologically stable and imaging shows a mediastinal tumour without established histology.
Key medicines
Therapeutic anticoagulationUse the current cancer-associated thrombosis regimen at treatment dose, such as weight-based low-molecular-weight heparin or an appropriate direct oral anticoagulant, adjusted for renal function, platelets, bleeding site, interactions and planned biopsy or stenting.
Dexamethasone in selected oedema or steroid-responsive tumourUse only the acute-oncology or lymphoma-specific specialist regimen when associated airway or cerebral oedema or a confirmed steroid-responsive tumour justifies it; there is no routine dose for all mechanical SVCO.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.