Case Presentation: A 68 year-old-woman with right upper lobe non-small cell lung cancer on chemotherapy presented with shortness of breath. A CT scan of the chest prior to admission revealed a right hilar mass encasing and narrowing the distal superior vena cava (SVC). Her exam was notable for distended neck veins and diminished breath sounds on the right. Labs revealed severe neutropenia and thrombocytopenia. She was intubated for impending respiratory failure and developed a shock. Transthoracic echocardiogram showed preserved ventricular function. There was no pericardial effusion however SVC was severely dilated. Central venous pressure was 50 mmHg while mean arterial pressure was less than 65mmHg. She was empirically treated for sepsis as a differential diagnosis of her shock. Acute pulmonary embolism was hypothetically ruled out with normal DVT doppler studies and normal right ventricular parameters. Hemodialysis was started for renal failure, severe metabolic acidosis and volume removal to release the SVC pressure. Despite all the aggressive management patient did poorly and died.
Discussion: Affecting 15000 patients per year in the US, superior vena cava syndrome (SVCS) is caused in majority by compression effect from malignancy with subsequent increase in venous pressure causing facial and arm swelling, engorgement of the hypopharynx, compromised airway, cerebral edema, and obstructive shock. This case demonstrates the potentially lethal respiratory, neurologic, and hemodynamic sequelae of SVC, as manifested by the progressive mixed obstructive and vasodilatory shock. A refractory obstructive shock related to SVCS has been described in the literature in cases such as embolic event from arteriovenous fistula revascularization or pericardial hematoma causing extrinsic compression on the heart. The hemodynamic instability in this case was unique as it was associated by a tumor-related SVCS causing venous hypervolemia with elevated venous pressure and arterial hypovolemia with low arterial pressure, worsened by vasodilatory effect of severe metabolic acidosis due to perfusion compromise and multiple organ failure. Her unstable hemodynamics contradicted transport to radiation. She was not a candidate for stenting due to severe thrombocytopenia. The vicious cycle of obstructive and vasodilatory shock prevailed until she died.
Conclusions: Early recognition of SVCS is essential for internal medicine physicians as potentially lethal complications of increased venous pressure may include compromised airway, cerebral edema, and obstructive shock.