Tag Archives: dvt

Upper Extremity Veins

Deep Veins:


1. paired ulnar, radial and interosseous veins in forearm
2. paired brachial veins of upper arm
3. axillary vein (continues as subclavian vein)


Superficial Veins:



  1. cephalic vein
  2. basilic vein



“Deep Veins Of The Upper Extremity.” Uptodate.com. Web. 27 July 2017.

“Primary (Spontaneous) Upper Extremity Deep Vein Thrombosis.” Uptodate.com. 27 July 2017.


Anticoagulation in Patients with Brain Metastases


  • Anticoagulate in patients with brain tumors and VTE except if risk of ICH is high: i.e.
    • melanoma mets
    • renal cell carcinoma mets
    • choriocarcinoma mets
    • thyroid carcinoma mets
  • treat x 3-6 months; long term if malignant gliomas
  • LMWH recommended versus warfarin
  • If risk of ICH high:
    • IVC filter if significant residual brain mets
    • if mets already removed / treated effectively and medical condition too unstable – anticoagulate

DVT Prophylaxis:

  • do not anticoagulate except in post-operative period
  • use SCDs with post-op LMWH or UFH 12-24 hours after surgery
  • cotninue prophylaxis until ambulation resumed



Uptodate. “Anticoagulant and antiplatelet therapy in patients with brain tumors.” Accessed 08/12/2016.

Lyman GH, Khorana AA, Falanga A, et al. American Society of Clinical Oncology guideline: recommendations for venous thromboembolism prophylaxis and treatment in patients with cancer. J Clin Oncol 2007; 25:5490.


Anti-factor Xa Levels (Enoxaparin)

*Standard dosing (enoxaparin 30 q12h) may be inadequate in high risk trauma; lead to inc rates of DVT

Monitor antifactor Xa level

  • Normal value = <0.1
  • >0.5 considered therapeutically anticoagulated
  • 0.2 to 0.5 considered target level for prophylaxis

–Send trough before 4th dose

  • If normal –>increase to 40mg q12h; then 50 sq q12h or even 60 q12h

–With this approach, majority of patients require enoxaparin in 40 q12h dose



Patients with morbid obesity or renal failure may require monitoring of Anti-Xa levels.

  • anti-Xa levels in plasma should be measured 4 hours after LMWH administration
  • desired anti-Xa level = 0.6-1.0 units/mL for BID dosing and >1 unit/mL for OD dosing


Early RCTs on LMWS excluded the following patients:

1. BMI>50 kg//m2

2. Pregnant

3. Renally impaired (Cr clearance <30 ml/min)


UFH affects Factor II and Factor Xa, LMWH affects predominantly Factor Xa.

Peak anti-factor Xa level is reached 3-5 hours after administration.


Suggested peak anti-factor Xa levels for enoxaparin (therapeutic):

1. BID dosing – 0.6 to 1.0 IU/mL

2. OD dosing – 1.0-2.0 IU/mL


Table. Target anti-factor Xa ranges for therapeutic anticoagulation with LMWH.


Target range for prophylactic doses of LMWH not well defined.

Table. Target anti-factor Xa ranges for prophylactic doses of LMWH.


Limited evidence available, but guidelines by ACCP suggests use of increased doses of LMWH perioperative for bariatric patients. Anti-factor Xa monitoring is recommended in patients with high-risk trauma and burns. Critically ill patients on inotropes may also be subtherapeutic on LMWH due to impaired peripheral circulation.


Table.  Target anti-factor Xa ranges for thromboprophylaxis in bariatric patients.


BOTTOM LINE:  Reasonable anti-factor Xa target range is 0.2-0.5 IU/mL. Prospective studies are required to validate this recommendation.


Marino, P. and Sutin, K. (2007). The ICU book. Philadelphia: Lippincott Williams & Wilkins.

Wei, M. and Ward, S. (2015). The anti-factor Xa range for low molecular weight heparin thromboprophylaxis. Hematology Reports, 7(4).

Caprini Risk Assessment Model for DVT

Caprini Risk Score

  • a tool to assess risk of VTE among surgical patients
  • includes 20 variables
  • derived from a prospective study of 538 general surgery patients