Læknablaðið - 15.09.1994, Page 11
LÆKNABLAÐIÐ 1994; 80
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Table I. Post-operative risk ofvenous thromboembolism.
DVT’ Prox + distal
Risk group (Proximal) % PE % Death % Patients
Low <10 <1 <0.01 Age <40, generally healthy, operation <30 minutes
Moderate 20-30** 1-5 0.1-0.7 Age >40, comorbid conditions,
(2-10%) abdominal/thoracic surgery, operation >30 minutes, neurosurgery
High 40-70*** 5-10 1-5 Total hip replacement,
(8-14) total knee replacement, fractured pelvis, hip or
lower extremity,
open prostatectomy,
extensive gynecological or intraabdominal
cancer surgery, prior history venous thromboem-
bolism
The table is based on references 9-13. DVT = deep vein thrombosis. PE = pulmonary embolism.
*About 20% of distal clots will extend proximally and approximately 50% of these will cause embolism.
"Studies using radiolabeled fibrinogen uptake test (RFUT) artd/or venography.
***Studies using venography only.
Table II. Post-operative deep vein tlirombosis incidence in moderate risk patients.
Author Placebo Low-dose heparin 500x2/d Dextran 5000 x3/d* Enoxaparin 20 mg/d Logiparin 50 U/kg/d Fragmin 5000 U/d Fraxiparin 7500 U/d Sandoz LMWH APTT units 1500 U/d 2500 U* /d Org 10172 750 Ux2/d
Cade 89 (15) 30/228 19/222
Kakkar 89 (16) 8/88 10/91
Adolf 89 (17) 14/202 16/202
Schm.-Hubner 85 (18) 0/39 3/40*
Welzel 88 (19) 14/103 4/98*
Koppenhagen 92 (20) 26/330* 24/323
Kakkar 85 (21) 14/199 5/196
EFSG 88 (22) 42/936* 27/960
Dahan 89 (23) 0/41 0/46
Bergqvist 86 (24) 9/217 13/215
Bergqvist 88 (25) 41/497 28/505
Fricker 88 (26) 0/40* 0/40
Onarheim 86 (27) 0/27 1/25
Boissel 89 (28) 13/429 10/434
Leizorovicz 91 (29) 13/429 10/430
Samama 88 (30) 12/158* 6/159
Pooled total DVT 236/ 3963 6/159 20/864 42/785 321202 57/754 19/222
DVT % 6.0 3.8 2.3 5.4 2.7 7.6 8.6
Metaanalysis 22.4% 9.0%
Collins 88 (12)
Metaanalysis 25.1% 16.6% 8.7%
Clagett 88 (31)
Comment: Data are shown as total DVT (deep vein thrombosis) diagnosed/number of patients screened with phlebography or RFUT (radiolabeléd fibrinogen
uptake test) confirmed with phlebography. LMWH = low molecular weight heparin. UFH = unfractionated heparin.
The comþined DVT incidence with LMWH was 154/3764 = 4.1%. UFH 5000 U x3 gave a DVT incidence of 80/1464 = 5.5% vs.
156/2499 = 6.2% with 5000 U x 2. Only one acceptable study with eách of enoxaparin or Org 10172 exist in general surgery. Placebo controlled or dextran
controlled studies are not performed since low dose unfractionated heparin is generally accepted as effective and safe standard prophylactic treatment (see
Collins12 and Clagett31).