Pearl of the Day: Superior Vena Cava Syndrome

Superior Vena Cava Syndrome Background - effect of elevated venous pressure in upper body that results from obstruction of venous blood flow through SVC - usually caused by external compression of SVC from mass, intravascular thrombosis - most common malignancies: lung, lymphoma - if compression occurs slowly, collateral vessels dilate to compensate for impaired flow - may cause neurological abnormalities from increased intracranial pressure

Signs/Symptoms - usually start 1 - 2 weeks after diagnosis - more common: facial swelling, dyspnea, cough, arm swelling - less common: hoarse voice, syncope, headache, dizziness - rare: visual changes, dizziness, confusion, seizures, obtundation

Diagnosis - chest X-ray -> mediastinal mass - CT chest with IV contrast to assess patency of SVC - MRI if patients cannot receive IV contrast

Management - head elevation to decrease venous pressure - supplemental oxygen to reduce work of breathing - indwelling central venous catheter -> remove - lymphoma suspected -> corticosteroids (very limited evidence in other cases) - cerebral/airway edema present -> loop diuretics, though also very limited evidence - treatment: radiation therapy (can improve symptoms within 3 days), intravascular stents, chemotherapy, catheter-directed fibrinolytics (if secondary to intravascular thrombosis)

Resources Tintinalli's Emergency Medicine, 8th Edition Lepper PM, Ott SR, Hoppe H, et al. Superior Vena Cava Syndrome in Thoracic Malignancies. American Association for Respiratory Care. http://rc.rcjournal.com/content/56/5/653.full. Published May 1, 2011. Accessed April 27, 2018.

Pearl of the Day: Clavicle Fractures

Clavicle Fractures - clavicle articulates with sternum proximally and acromion distally - protects adjacent lung, brachial plexus, subclavian and brachial blood vessels - mid-portion of clavicle is thinnest and does not contain ligamentous or muscular attachments - signs/symptoms: swelling, deformity, tenderness overlying clavicle; arm is slumped inward and downward; limited ROM at shoulder - diagnosis: usually standard shoulder and clavicle X-rays, but may require 45-degree cephalad tilt view or CT - management: emergent orthopedic consult for open fractures, fractures with neurovascular injuries, fractures with persistent skin tenting

Middle Third Clavicle Fractures - most common - usually managed nonoperatively - risk factors for nonunion: initial shortening > 2 cm, comminuted fracture, displaced fracture > 100%, significant trauma, female, elderly - management: immobilization with either sling or figure-of-eight brace for 4 - 8 weeks - orthopedic follow up in 2 - 3 days: high risk of malunion, severely comminuted or displaced fractures, athletes, professional impact, cosmetic concerns - orthopedic follow up in 1 - 2 weeks for conservative treatment

Distal Clavicle Fractures - type I: fracture is distal to coracoclavicular ligaments with ligaments intact - type II: fracture is distal to coracoclavicular ligaments with disruption of ligaments -> causes upward displacement of proximal aspect of clavicle - type III: intra-articular fractures through acromioclavicular joint - management: types I and III can be managed conservatively with sling immobilization and follow up in 1 - 2 weeks; type II may require operative intervention

Proximal Third Clavicle Fractures - associated with high-mechanism injuries and associated with intrathoracic trauma - diagnosis: CT (also to identify additional injuries) - management: emergent consultation for posteriorly displaced fractures that compromise mediastinal structures; immobilization for all other proximal third fractures - orthopedic follow up in 1 - 2 weeks for conservative treatment

Resources Tintinalli's Emergency Medicine, 8th Edition

Pearl of the Day: Complications of Vascular Access for Hemodialysis

Complications of Vascular Access for Hemodialysis- more frequent with autologous vein, polytetrafluorethylene, or bovine carotid artery graft (as opposed to native artery or vein) - account for more inpatient hospital days than any other complication of hemodialysis

Thrombosis and Stenosis - most common causes of inadequate dialysis flow (<300 mL/min) - grafts have higher rate of stenosis than fistulas - signs: loss of bruit or thrill over access - treatment: angiographic clot removal or angioplasty within 24 hours; direct injection of alteplase can be considered for thrombosis

Vascular Access Infections - 2 - 5% of AV fistulas, 10% of grafts - etiology: Staphylococcus aureus (most common), Gram-negative bacteria - signs/symptoms: hypotension, fever, leukocytosis - may not have pain, erythema, swelling, or discharge from access site - after 6 months, approximately 1/2 of patients with dialysis catheter develop bacteremia - diagnosis: peripheral and catheter blood cultures drawn simultaneously -> catheter is confirmed source if colony count is 4 times higher in catheter culture than peripheral culture - treatment: vancomycin IV (drug of choice) +/- gentamicin (if Gram-negative organisms suspected); consider access removal if fever for > 2 - 3 days

Hemorrhage - rare - causes: aneurysms, anastosmosis rupture, overanticoagulation

Management of Hemorrhage 1. manual pressure to puncture sites for 5 - 10 min and observe for 1 - 2 hours if ceased 2. apply pressure for 10 min using absorbable gelatin sponges soaked in reconstituted thrombin or chemical thrombotic (e.g., transexamic acid) 3. protamine 0.01 mg per unit of heparin dispensed during dialysis - if dose is unknown, protamine 10 - 20 mg is sufficient to reverse typical dose of heparin (usually 1000 to 2000 U) 4. desmopressin acetate 0.3 mcg/kg IV can be used as adjunct in consultation with nephrologist or vascular surgeon 5. consider placing figure-8 suture 6. tourniquet proximal to vascular access while awaiting urgent vascular surgery consultation

Vascular Access Aneurysms - caused by repeated punctures - usually asymptomatic, possibly occasional pain or impingement neuropathy - rarely rupture

Vascular Access Pseudoaneurysms - from subcutaneous extravasation of blood from puncture sites - signs: bleeding, infection at access site - diagnosis: arterial Dopper ultrasound studies - treatment: surgery

Vascular Insufficiency - usually occurs in extremity distal to vascular access - due to shunting of arterial blood to venous side of access - "steal syndrome" - signs/symptoms: exercise pain, nonhealing ulcers, cool/pulseless digits - diagnosis: Doppler ultrasound or angiography - treatment: surgery

High-output Heart Failure - occurs when >20% of cardiac output is diverted through access - signs/symptoms: Branham sign (drop in heart rate after temporary access occlusion) - diagnosis: Doppler ultrasound to measure flow rate - treatment: surgical banding of access

Resources Tintinalli's Emergency Medicine, 8th Edition