Consider The Evidence: Med/Peds Journal Roundup

August 24, 2006

Can UF Heparin replace LMWH as subcu anticoagulation?

Filed under: JAMA, VTE — medblog @ 8:30 pm

JAMA 8/23 – Will Lovenox and Fragmin share the same fate as New Coke? A study by Kearon et al. investigated the use of Classic unfractionated heparin as a subcutaneous treatment without APTT monitoring. The study protocol treated DVT and PE with a twice daily subQ injection of UFH in much the same way Low Molecular Weigh Heparin is used currently, except for a weight adjustment. The results essentially show that UFH was equally effective as LMWH in preventing recurrent thromboembolism. Appparently the crazy unpredictable pharmacokinetics are not a big issue with the subcutaneous route. And the fact that UFH is about 50 times cheaper is a big plus.
The study was an open-label RCT and the outcome analysis was done by blinded investigators. About 70% of subjects were treated as outpatients. Apparently there were some problems with recruitment but the power was adequate to provide reliable results.


March 14, 2006

Flight Risk: Air Travel and DVT

Filed under: lancet, VTE — medblog @ 5:43 pm

Lancet 3/11 – Shreijer et al present an interesting discovery about the increased risk of venous thrombosis during airplane travel. They wondered whether in addition to immobilization as a risk factor, passengers were also prone to hypercoagualibility during flight.

In the crossover controlled study, 71 subjects were tested during 8 hours in flight, 8 hours seated while watching movies, and during 8 hours of daily activities. Several markers of coagulation including Thrombin-Antithrombin complex (TAT), D-dimer, and prothrombin fragment 1 and 2 were measured before and after the the test conditions.

The researchers found that the levels of TAT, D-dimer, and the combination of the three factors were significantly increased after the flight in comparison to the other situations. They conclude that there are other mechanisms beyond immobilization to account for the 2 to 4 fold increased risk of DVT during flight. Whether this is related to pressure, oxygen content, or something else, will requre further research. (more…)

February 1, 2006

PE scoring Ad Nauseam

Filed under: annals of internal medicine, pulmonary, VTE — medblog @ 2:29 am

AnnalsIM 2/7 – This weeks Annals has 2 more articles on PE, didnt they read last weeks Archives? I’ll make this a 2 for 1…
Roy et al. find that ER diagnostic managment of suspected PE was incorrect in 43% of cases. Incorrect management occurred in 57% of those who ruled out and 8% percent of those that had PE.

Le Gal et al. propose a revised Geneva score to stratify pre-test risk for suspected PE. This is different than the old Geneva score in that it does not require an ABG. And unlike the Wells score – there is no need to assess the probablility of alternative diagnoses.

January 31, 2006

D-dimer Value in Recurrent VTE

Filed under: archives of internal medicine, VTE — medblog @ 8:27 pm

ArchIM 1/23 – This weeks Archives features 3 articles focusing on PE/ VTE.
D-dimer can help us rule out PE due to its high sensitivity, but will the presence of prior VTE result in too many false-positives to make it useful? In Le Gal, et al report that PE was ruled out by negative D-dimer in about 16% of pts with previous VTE, vs about 32% of of those without previous VTE. (more…)

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