Rosen & Barkin's 5-Minute Emergency Medicine Consult (192 page)

In cases of phlegmasia cerulean, or alba dolens:

• IV access
  
• Supplemental oxygen
  
• Surgical or vascular consultation
  

• Systemic anticoagulation:
  
  • In patients without contraindications as PE will occur in ∼50% of untreated DVT
    
  • Use either unfractionated heparin or low-molecular-weight heparin (LMWH), fondaparinux or adjusted dose subcutaneous heparin
    
  • Carefully selected patients can be primarily treated with as outpatients
    
• Warfarin:
  
  • Started shortly after a heparin has been administered
    
  • Not before heparin because of the theoretic risk for inducing a transient hypercoagulable state
    
  • Insufficient evidence exists to safely recommend other oral anticoagulants (e.g., dabigatran, rivaroxaban, apixaban)
    
• Vena cava filters:
  
  • Two main indications:
    
    • Contraindications to systemic anticoagulation
      
    • New thromboembolic event while on adequate anticoagulation
      
  • Vena cava filters can be placed transcutaneously, usually by a vascular or trauma surgeon or radiologist.
    
  • Empiric filter placement may be useful in certain settings:
    
    • Ongoing risk such as cancer, polytrauma.
      
    • Risk for a recurrent PE could be fatal because of poor cardiopulmonary reserve or a recent PE.
      
  • Randomized data suggest that filter placement is no more effective than anticoagulation.
    
  • Filters can also be deployed in the superior vena cava in the setting of upper-extremity DVT.
    
• Thrombolysis:
  
  • Rarely indicated
    
  • Roughly a 3-fold increase in bleeding complications
    
  • Catheter-administered lytic therapy is used more commonly in upper-extremity DVT
    
• Thrombectomy (surgical or percutaneous):
  
  • Occasionally recommended for patients with extensive disease
    
  • Consult a vascular surgeon
    
• Septic thrombophlebitis:
  
  • Surgical excision of the vein or IV antibiotics
    

• Maintain treatment with IV or SQ therapy until INR has been therapeutic for 2 consecutive days.
  
• Warfarin: 5 mg/d starting dose with a prothrombin time being checked on the 3rd day.
  
• Heparin (unfractionated): 80 U/kg bolus followed by an 18 U/kg/h drip, with the activated partial thromboplastin time (aPTT) titrated 1.5–2.5 times normal.
  
• LWMH (enoxaparin): 1 mg/kg SC BID for outpatients (alternative: 1.5 mg/kg SCQD).
  
• Tinzaparin: 175 U/kg/d SC.
  
• Dosing regimens are based on total body weight; however, in obese patients alternative dosing should be considered.
  
• Treatment usually maintained for at least 3 mo, total length is individualized.
  

FOLLOW-UP

• Patients with DVT unable to receive LMWH as an outpatient or poor follow-up
  
• Patients with concomitant PE or other serious diseases (i.e., renal failure)
  
• Patients thought to be at especially high bleeding risk
  
• Patients with phlegmasia
  

• Outpatient treatment with an LMWH:
  
  • No serious concomitant disease that requires hospitalization.
    
  • Patient has means of communication and transportation to return to the hospital if needed, as well as appropriate follow-up.
    
  • Patient (or family member) is willing and able to inject the medication.
    
  • aPTT does not need to be checked.
    
  • Heparin-induced thrombocytopenia is less common with the LMWH but still occurs.
    
• Patients with superficial or distal thrombophlebitis can be discharged with close follow-up.
  

• Consult vascular surgery if there is any question about arterial insufficiency.
  
• Consider need for inferior vena cava filter in patients who have contraindications to full anticoagulation or form new clots on adequate anticoagulation.
  

Outpatient treatment with an LMWH:

• Patient needs hematocrit, platelet count, and INR checked in 2–3 days.
  
• INR needs to be checked at about day 3.
  

• Do not use a negative Homans sign to exclude the diagnosis of DVT.
  
• Use some measure (whether clinical gestalt or a formal scoring system such as the Wells score) to determine pretest probability for DVT.
  
• In high pretest probability patients, do not rely on
  D
  -dimer testing; instead, perform venous imaging, generally compression US.
  
• In medium-risk patients with a negative
  D
  -dimer or negative US, arrange or recommend a repeat study in 1 wk.
  

• Cushman M, Tsai AW, White RH, et al. Deep vein thrombosis and pulmonary embolism in two cohorts: The longitudinal investigation of thromboembolism etiology.
  Am J Med.
  2004;117:19–25.
  
• Goodacre S, Sutton AJ, Sampson FC. Meta-analysis: The value of clinical assessment in the diagnosis of deep vein thrombosis.
  Ann Intern Med.
  2005;143:129–139.
  
• Kearon C, Akl EA, Comerota AJ, et al. Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.
  Chest
  . 2012;141:e419S–494S.
  
• Kyrle PA, Eichinger S. Deep vein thrombosis.
  Lancet
  . 2005;365(9465):1163–1174.
  
• Lawall H, Hoffmanns W, Hoffmanns P, et al. Prevalence of deep vein thrombosis (DVT) in non-surgical patients at hospital admission.
  Thromb Haemost
  . 2007;98(4):765–770.
  
• Tracy JA, Edlow JA. Ultrasound diagnosis of deep venous thrombosis.
  Emerg Med Clin North Am
  . 2004;22:775–796.
  

CODES

• 453.40 Acute venous embolism and thrombosis of unspecified deep vessels of lower extremity
  
• 453.41 Acute venous embolism and thrombosis of deep vessels of proximal lower extremity
  
• 453.82 Acute venous embolism and thrombosis of deep veins of upper extremity
  

BASICS

• An implantable cardiac device (ICD) is a small battery-powered electrical impulse generator implanted SC in patients at risk of cardiac arrest from cardiac arrhythmias.
  
• Lead(s) are positioned via venous return to heart and are endocardial (RA and RV) or epicardial (LV via coronary sinus).
  
• The device is able to detect and convert ventricular and atrial arrhythmias to sinus rhythm with electric shocks delivered between the ICD can and coil(s) in the RV (single coil) and the SVC/RA juncture (dual coil).
  
• Similar method of implantation as a pacemaker
  
• Newly released devices (S-ICD) no longer have endocardial leads reducing the risk of blood infection.
  
• 450,000 individuals experience sudden cardiac death yearly in US:
  
  • >100,000 devices implanted in US each year
    
  • ICDs have been shown to reduce mortality more effectively than antiarrhythmic drug therapy in patients with left ventricular dysfunction:
    
    • Absolute risk reduction of mortality of 7% in the 1st 2 yr
      
    • Benefit over antiarrhythmic drug therapy is limited to patients with ejection fractions of <35%
      
  • Effective in reducing mortality in hypertrophic cardiomyopathy
    
  • Both ischemic and nonischemic dilated cardiomyopathy patients show survival benefit with ICD
    
• Immediate postimplant complications:
  
  • Pneumothorax
    
  • Vascular perforation
    
  • Acute lead dislodgement
    
• Appropriate shocks:
  
  • 5% a year for primary prevention
    
  • 20% a year for secondary prevention
    
• Electrical storm:
  
  • ≥2 appropriate shocks delivered within a 24-hr period
    
• Inappropriate shocks:
  
  • 10–20% of ICD recipients
    
  • Oversensing
    
  • Inappropriate classification of rapid supraventricular tachycardia
    
• Device infection:
  
  • 1–12% of patients
    
  • Acute 1–30 days—think staph
    
  • Subacute >30 days—think
    Staphylococcus epidermidis
    or gram negatives
    
  • 31–66% mortality if the device is left in place
    
  • Infection may involve the skin, the generator, the defibrillation pocket, or the leads.
    
  • Coagulase-negative staphylococci (42%)
    
  • Methicillin-sensitive staphylococci (25%)
    
  • MRSA (4%)
    
  • Gram-negative bacilli (9%)
    
• Pocket hematoma do not aspirate
  
• Vascular occlusion
  

• Electrical storm: (≥2 appropriate shocks delivered within a 24-hr period)
  
  • Unknown
    
  • Decompensated heart failure
    
  • Acute ischemia
    
  • Metabolic disturbances
    
  • Drug proarrhythmia
    
  • Thyrotoxicosis
    
  • Fever with dilated cardiomyopathy
    
  • Genetic channelopathies, Brugada syndrome, Long QT, catacholaminergic polymorphic VT, arrhythmogenic RV cardiomyopathy
    
  • Postcardiac surgery
    
  • ICD induced from left ventricular or T-wave pacing
    
• Inappropriate shocks:
  
  • Oversensing:
    
    • QRS, T-wave, P-wave, myopotential, electromagnetic interference (EMI)
      
    • Frequent nonsustained ventricular dysrhythmias
      
    • Lead fracture
      
    • Loose setscrew
      
    • Chatter between leads
      
    • Header (device circuitry) problem
      
  • Inappropriate classification of rapid supraventricular tachycardia:
    
    • Atrial fibrillation
      
    • Sinus tachycardia
      
    • Atrial flutter
      
    • Other supraventricular tachycardias (SVT)
      
• Device/site-related:
  
  • Wound infection:
    
    • Staphylococcus aureus
      (most aggressive and seen early)
      
    • S. epidermidis
      (more indolent and later)
      
    • Escherichia coli, Pseudomonas
      species, and
      Streptococcal
      species (less common)
      
  • Pocket hematomas
    
  • Vascular (venous thrombosis/embolism secondary to impedance of venous flow as a result of the ICD lead[s])