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, seizure or falling consciousness indicates critical venous obstruction or associated airway disease. Waiting for routine biopsy can be dangerous.
Action: Use ABCDE assessment, sit the patient upright, give oxygen for hypoxaemia and summon anaesthetic, respiratory, acute-oncology and interventional help. Obtain urgent contrast CT if stable enough, secure appropriate venous access and prioritise endovascular decompression or another immediately effective intervention while maintaining symptom relief.
Synopsis
Recognise impaired upper-body venous return, stabilise airway or cerebral compromise, define tumour and thrombus anatomy, preserve tissue diagnosis when safe and coordinate stenting, anticoagulation, radiotherapy, systemic treatment and symptom relief.
Superior vena cava obstruction causes facial, neck and arm swelling, venous distension, plethora, breathlessness, cough and headache that often worsen when lying flat or bending forward.
Stridor, laryngeal oedema, severe hypoxia, syncope, confusion or reduced consciousness indicates airway, cerebral or haemodynamic compromise and needs immediate senior intervention.
Cancer is the commonest cause, especially lung cancer and lymphoma, but central venous catheters and thrombosis increasingly cause benign or mixed obstruction.
Key red flags
Stridor, drooling, rapidly worsening hoarseness or inability to lie back suggests threatened upper airway.
Critical SVCO
Stridor, severe hypoxaemia, syncope, confusion, reduced consciousness or haemodynamic compromise requires immediate acute-oncology and airway or interventional support.
Investigation priorities
01
Immediate severity and airway assessmentFirst step
Record posture tolerance, oxygenation, stridor, voice, facial and limb swelling, venous pattern, cognition, syncope and haemodynamic state.
Management branches
Critical obstructionStabilise and decompress without delay
SVCO causes stridor, severe respiratory compromise, cerebral dysfunction or haemodynamic instability.
Sit upright, use ABCDE care, give oxygen for hypoxaemia and involve airway, respiratory, acute-oncology and interventional specialists immediately.
Obtain urgent contrast CT when safe and plan venous access and rescue around both caval and possible central-airway obstruction.
Stable malignant SVCOSecure diagnosis then match tumour treatment
Symptoms are significant but there is no airway, cerebral or circulatory emergency and malignancy is suspected.
Key medicines
Anticoagulation for confirmed thrombotic obstructionChoose and dose low-molecular-weight heparin or another anticoagulant according to active cancer, renal and hepatic function, platelet count, bleeding risk, interactions and planned biopsy or stenting under the local cancer-associated thrombosis pathway.
Selective dexamethasone for oedematous tumourWhen acute oncology recommends treatment for steroid-sensitive lymphoma, marked tumour oedema or airway compromise, use the locally specified dexamethasone regimen and set an early response and taper review.
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.