Responsabile UAS “Trombosi Venosa Profonda ed Embolia Polmonare”
Responsabile CDF BLSD IRC “Emersan Lateranum”
SC Medicina Interna I° per l'Urgenza
SUPERIOR VENA CAVA SYNDROME
KEY-WORDS: Superior vena cava syndrome
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INTRODUCTION
CLINICAL
WORKUP
TREATMENT
MEDICATION
FOLLOW-UP
MISCELLANEOUS
BIBLIOGRAPHY
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Background: Superior vena cava syndrome is characterized by gradual, insidious compression/obstruction of the superior vena cava (SVC). Although the syndrome can be life-threatening, its presentation often is associated with a gradual increase in symptomatology.
Pathophysiology: Extrinsic compression of the SVC is possible because it has a thin wall, coupled with a low intravascular pressure. As the SVC is surrounded by rigid structures, it is relatively easy to compress. The low intravascular pressure also allows for the possibility of thrombus formation, such as, in the case of catheter-induced thrombus.
The subsequent obstruction to flow causes an increased venous pressure, resulting in interstitial edema and retrograde collateral flow.
Frequency:
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In the US : In the United States , SVC syndrome is seen chiefly associated with malignancy. Currently, over 90% of SVC syndrome patients have an associated malignancy as the cause. This contrasts with studies in the early 1950s, in which large proportions of cases were nonmalignant. Infectious causes (e.g., syphilis, tuberculosis, etc.) have decreased due to the improvements in antibiotic therapy.
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Internationally: In underdeveloped countries, nonmalignant causes of SVC syndrome continue to constitute a significant percentage. Still, SVC syndrome occurs infrequently in the overall general population.
Mortality/Morbidity: Bronchogenic carcinoma accounts for over 80% of SVC syndrome patients. Even when treated with radiation, only 10% of these patients will be alive at 30 months. However, patients with SVC syndrome due to a malignant cause will survive only 30 days without radiation.
Race: SVC syndrome has no racial predilection. However, due to lesser access to adequate health care, some socioeconomic groups would have a disproportionately greater representation.
Age:
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As the majority of SVC syndrome patients have bronchogenic carcinoma as the cause, the age distribution is strongly skewed towards the elderly.
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Nonmalignant causes, as well as, lymphoma tends to affect younger ages than malignancy-associated SVC syndrome.
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The age range reported in the Chen study was 18-76 years, with a mean age of 54 years.
History:
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In the early clinical course, few if any signs or symptoms of SVC syndrome may be manifest.
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Typically, symptoms accelerate as the underlying malignancy increases in size and/or invasiveness.
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Dyspnea is the most common complaint, followed by trunk or extremity swelling.
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Facial swelling
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Cough
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Orthopnea
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Headache
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Nasal stuffiness
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Light-headedness
Physical:
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Physical examination often reveals facial or upper extremity edema. The degree of facial edema has been described as facial engorgement.
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The degree of jugular venous distention is variable.
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Other markers of lung malignancy, such as, Horner's syndrome, paralysis of the vocal cords and paralysis of the phrenic nerve are rarely present.
Causes:
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Today, the most common etiology of SVC syndrome is related to malignancy.
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Prior to modern antibiotics, infectious causes including syphilis, tuberculosis and fungal causes occurred with almost equal frequency.
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The most common cause of malignancy-related SVC syndrome is bronchogenic carcinoma, which accounts for nearly 80%.
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Lymphoma accounts for approximately 15% and the rest have a variety of causes, including infectious and catheter-related etiologies.
Lab Studies:
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The diagnosis of SVCS is often made on clinical grounds alone, combining clinical presentation with an often-obtained history of thoracic malignancy.
Imaging Studies:
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Plain x-rays are often helpful, showing a mediastinal mass in the majority.
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When in doubt, venography can make the diagnosis, but this is usually not necessary.
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Thoracic CT scan is helpful, but it is important to remember that the histologic diagnosis is important in initiating therapy.
Prehospital Care:
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The diagnosis of SVC Syndrome is only occasionally known to prehospital caregivers.
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The usual attention to airway, breathing and circulation applies.
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SVC syndrome only rarely presents as a life-threatening entity; therefore, other cause for the symptomatology must be sought.
Emergency Department Care:
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SVC syndrome only rarely presents as an acute emergency.
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Attention to the ABCs is essential.
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If the patient is allowed to sit upright, there may be some relief of the usual dyspnea.
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Stabilize the airway, as needed, and consider steroids.
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If cerebral/airway edema is present, consider diuretics.
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In the ED, these treatments have not consistently shown benefit.
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Endovascular shunts are being increasingly used, as is the use of thrombolytics if a thrombotic cause is present.
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After a tissue diagnosis, radiation and chemotherapy may be initiated.
Consultations:
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Emergent consultation with radiation therapy may be necessary, depending upon the acuteness of the presentation.
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As most causes of SVC syndrome are related to lung cancer, a pulmonary consultation is essential.
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Generally, it is important to consider the diagnosis in the ED.
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If the diagnosis is made de novo in the ED, only rarely is emergent consultation necessary.
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Exceptions include sudden airway compromise or acute SVC thrombosis, as may occur from an indwelling catheter.
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Steroids and diuretics have been the mainstays of ED management. However, it is useful to remember that SVC syndrome rarely presents as an acute life-threatening emergency. As such, it may be more important to consider the diagnosis than the actual definitive care when making therapeutic decisions.
Drug Category: Glucocorticoids - Decrease the inflammatory response to tumor invasion and edema surrounding tumor mass. They have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli.
Drug Name |
Methylprednisolone - It is one of several steroids that may be given in the ED. It decreases inflammation by suppressing the migration of polymorphonuclear leukocytes and reversing increased capillary permeability. |
Adult Dose |
Loading dose: Administer 125-250 mg Maintenance dose: Administer 0.5-1 mg/kg/dose q6h for up to 5 d |
Pediatric Dose |
Loading dose: Administer 2 mg/kg IV Maintenance dose: Administer 0.5-1 mg/kg/dose q6h for up to 5 d |
Contraindications |
Avoid use in patients with documented hypersensitivity to this drug and patients diagnosed with viral, fungal or tubercular skin infections. |
Interactions |
Methylprednisolone clearance may decrease when used concurrently with estrogens. In addition, when used with digoxin, it may increase digitalis toxicity secondary to hypokalemia. Phenobarbital, phenytoin, and rifampin may also increase the metabolism of glucocorticoids and should consider increasing the maintenance dose. Monitor patients for hypokalemia when taking this medication concurrently with diuretics. |
Pregnancy |
C - Safety for use during pregnancy has not been established. |
Precautions |
Hyperglycemia, edema, osteonecrosis, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, growth suppression, myopathy, and infections are possible complications of glucocorticoid use. |
Drug Name |
Prednisone - It is useful in the treatment of inflammatory and autoimmune reactions. By reversing increased capillary permeability and suppressing PMN activity, it may decrease inflammation. |
Adult Dose |
Administer to 5-60 mg/d qd or divided bid-qid Taper over 2 wk as symptoms resolve. |
Pediatric Dose |
Administer 4-5 mg/m 2 /d Alternatively, administer 1.0-2.0 mg/kg po qd Taper over 2 wk as symptoms resolve. |
Contraindications |
Avoid use in patients with documented hypersensitivity to this drug and those with viral, peptic ulcer disease, hepatic dysfunction, connective tissue infections, and fungal or tubercular skin infections. |
Interactions |
Prednisone clearance may decrease when used concurrently with estrogens. In addition, when used with digoxin, it may increase digitalis toxicity secondary to hypokalemia. Phenobarbital, phenytoin and rifampin may also increase the metabolism of glucocorticoids and should consider increasing the maintenance dose. Monitor patients for hypokalemia when taking this medication concurrently with diuretics. |
Pregnancy |
B - Usually safe but benefits must outweigh the risks. |
Precautions |
Patients receiving glucocorticoids are at risk for multiple complications including severe infections. The abrupt discontinuation of glucocorticoids may cause an adrenal crisis. Hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression, and infections are possible complications of glucocorticoid use. |
Drug Category: Diuretics - These agents may decrease venous return to the heart by decreasing preload, relieving the increased pressure in the SVC.
Drug Name |
Furosemide - It increases the excretion of water by interfering with the chloride-binding cotransport system which in turn results in the inhibition of sodium and chloride reabsorption in the ascending loop of Henle and distal renal tubule. The dose must be individualized to the patient. Depending on the response, administer at increments of 20-40 mg, no sooner than 6-8 h after the previous dose, until the desired diuresis occurs. When treating infants, titrate with 1 mg/kg/dose increments until a satisfactory effect is achieved. |
Adult Dose |
Administer 20-80 mg po once, and repeat in 6-8 h prn Alternatively, increase the dose by 20-40 mg and do not give sooner than 6-8 h after the previous dose. |
Pediatric Dose |
Administer 1-2 mg/kg po once Do not exceed 6 mg/kg/dose and do not administer more frequently than q6h |
Contraindications |
Avoid use in patients with documented hypersensitivity to this drug, sulfonylureas, or related products and those diagnosed with hepatic coma, anuria, or are in a state of severe electrolyte depletion. |
Interactions |
Metformin decreases furosemide concentrations. Conversely, furosemide interferes with the hypoglycemic effect of antidiabetic agents. It also antagonizes the muscle relaxing effect of tubocurarine. Auditory toxicity appears to be increased with the concurrent use of aminoglycosides and furosemide. Hearing loss of varying degrees may occur. The anticoagulant activity of warfarin may be enhanced, when taken concurrently with this medication. Increased plasma lithium levels and toxicity are possible when taken concurrently with this medication. |
Pregnancy |
C - Safety for use during pregnancy has not been established. |
Precautions |
Observe for blood dyscrasias and liver or kidney damage. Loop diuretics may increase the urinary excretion of magnesium and calcium. |
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Complications:
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Total SVC Obstruction:
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Fortunately this is rare.
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Potential causes of this include indwelling catheters.
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Thrombolysis must be considered.
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Airway compromise is unusual, but may result from extrinsic compression by tumor mass to the SVC or the trachea.
Prognosis:
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SVC Syndrome associated with malignancy:
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The prognosis for relief of SVC syndrome symptoms is good with radiation therapy.
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Symptoms usually decrease within one month of the onset of radiation therapy.
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However, the ultimate prognosis is associated with the underlying malignancy itself.
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The prognosis for SVC syndrome, not associated with malignancy, is excellent in that most of these causes are infectious and respond to appropriate antibiotic therapy.
Medical/Legal Pitfalls:
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Potential medical/legal pitfalls include not considering this diagnosis in the patient with known lung cancer. Their symptoms of increasing shortness of breath may be from SVC Syndrome. They may be relieved with radiation therapy.
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In the patient in whom the diagnosis of lung cancer is not known, there may be a tendency to discount a patient's sensation of arms swelling, facial fullness, etc. This may represent an excellent opportunity to positively impact a patient's prognosis if the diagnosis of SVC Syndrome is entertained and the underlying cause of cancer is considered.
Special Concerns:
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Special concerns include the need to be sensitive to the patient's probable diagnosis of lung cancer.
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In the patient in whom the diagnosis has not been made, this represents a very unique occasion for the clinician to approach the patient with care.
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Special care must be taken to ensure that the explanation of the patient's symptoms is not rushed.
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Abner A : Approach to the Patient with Superior Vena Cava Obstruction. Chest 1993; 103: 394S-397S.
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Armstrong BA, Perez CA, Simpson JR: Role of Irradiation in the Management of Superior Vena Cava Syndrome. Int J Radiat Oncol Biol Phys 1987; 13: 531-539.
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Baker GL, Barnes HJ: Superior Vena Cava Syndrome: Etiology, Diagnosis, and Treatment. Am J Cr Care 1992; 1: 54-64.
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Chen JC, Klein SR: A Contemporary Perspective on Superior Vena Cava Syndrome. Am J Surg 1990; 160: 207-211.