Low molecular weight heparin (Innohep) as thromboprophylaxis in outpatients with a plaster cast: a venografic controlled study.
BACKGROUND
The aim of this study was to investigate the incidence of deep vein thrombosis (DVT) in patients immobilized in plaster cast and the possible efficacy of prophylaxis with low molecular weight heparin (LMWH).


METHODS
The study was a randomized, assessor-blinded, open multicenter (three centers) study. All patients over 18 years of age with planned plaster cast on a lower extremity of at least 3 weeks were eligible for participation. Written informed consent was obtained from 300 patients and they were randomized to either 3.500 IU anti-Xa of tinzaparin (Innohep) subcutaneously once daily or no prophylaxis. On the day the cast was removed, ascending unilateral venography was performed. Two experienced radiologists, unaware of treatment, assessed the pictures independently. The radiologist had to obtain consensus as to whether DVT was present or not.


RESULTS
300 patients were included (148 in the treatment group and 152 in the control group). Ninety-five were subsequently withdrawn. DVT was diagnosed in 10/99 patients in the treatment group and in 18/106 patients in the control group. This difference is not significant (P=.15, chi(2) test) and the odds ratio was 0.55 (95% confidence interval=0.34-1.26).


CONCLUSIONS
DVT in legs after plaster casting is a big problem, with an incidence of almost 20%. An effective prophylactic regime is required. Once-daily dose of 3.500 IU anti-Xa of tinzaparin was not sufficient.
Jørgensen
Per Seest
PS
Gentofte Hospital University of Copenhagen, Copenhagen, Denmark. per.seest@dadlnet.dk
Warming
Torsten
T
Hansen
Kim
K
Paltved
Charlotte
C
Vibeke Berg
Helle
H
Jensen
René
R
Kirchhoff-Jensen
René
R
Kjaer
Lasse
L
Kerbouche
Nina
N
Leth-Espensen
Per
P
Narvestad
Eva
E
Rasmussen
Søren Wistisen
SW
Sloth
Carsten
C
Tørholm
Carsten
C
Wille-Jørgensen
Peer
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002370:Casts, Surgical / Q000009:adverse effects*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage*; D006801:Humans; D015994:Incidence; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010045:Outpatients; D010690:Phlebography; D000078222:Tinzaparin; D017211:Treatment Failure; D020246:Venous Thrombosis / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control*
D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D000078222:Tinzaparin