Prophylactic anticoagulation to prevent venous thromboembolism in traumatic intracranial hemorrhage: a decision analysis.
BACKGROUND
Patients with intracranial hemorrhage due to traumatic brain injury are at high risk of developing venous thromboembolism including deep vein thrombosis (DVT) and pulmonary embolism (PE). Thus, there is a trade-off between the risks of progression of intracranial hemorrhage (ICH) versus reduction of DVT/PE with the use of prophylactic anticoagulation. Using decision analysis modeling techniques, we developed a model for examining this trade-off for trauma patients with documented ICH.


METHODS
The decision node involved the choice to administer or to withhold low molecular weight heparin (LMWH) anticoagulation prophylaxis at 24 hours. Advantages of withholding therapy were decreased risk of ICH progression (death, disabling neurologic deficit, non-disabling neurologic deficit), and decreased risk of systemic bleeding complications (death, massive bleed). The associated disadvantage was greater risk of developing DVT/PE or death. Probabilities for each outcome were derived from natural history studies and randomized controlled trials when available. Utilities were obtained from accepted databases and previous studies.


RESULTS
The expected value associated with withholding anticoagulation prophylaxis was similar (0.90) to that associated with the LMWH strategy (0.89). Only two threshold values were encountered in one-way sensitivity analyses. If the effectiveness of LMWH at preventing DVT exceeded 80% (range from literature 33% to 82%) our model favoured this therapy. Similarly, our model favoured use of LMWH if this therapy increased the risk of ICH progression by no more than 5% above the baseline risk.


CONCLUSIONS
Our model showed no clear advantage to providing or withholding anticoagulant prophylaxis for DVT/PE prevention at 24 hours after traumatic brain injury associated with ICH. Therefore randomized controlled trials are justifiable and needed to guide clinicians.
Scales
Damon C
DC
Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Room D108, Toronto, ON, Canada. damon.scales@utoronto.ca
Riva-Cambrin
Jay
J
Wells
Dave
D
Athaide
Valerie
V
Granton
John T
JT
Detsky
Allan S
AS
D000925:Anticoagulants / Q000008:administration & dosage / Q000627:therapeutic use*; D003661:Decision Support Techniques; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D020198:Intracranial Hemorrhage, Traumatic / Q000150:complications* / Q000503:physiopathology; D056990:Post-Exposure Prophylaxis; D054556:Venous Thromboembolism / Q000517:prevention & control*
D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight
J Neurosurg. 1981 May;54(5):652-4
7229704
N Engl J Med. 1994 Dec 15;331(24):1601-6
7969340
Chest. 2008 Aug;134(2):237-249
18641095
Anaesth Intensive Care. 1995 Jun;23(3):322-31
7573919
Surg Neurol. 2001 Aug;56(2):82-8
11580939
J Trauma. 2007 Mar;62(3):557-62; discussion 562-3
17414328
Crit Care Med. 2000 Mar;28(3):840-4
10752839
Ann Intern Med. 1997 Mar 1;126(5):337-46
9054277
Lancet. 2009 Jun 6;373(9679):1958-65
19477503
Arch Surg. 2002 Jun;137(6):696-701; discussion 701-2
12049541
Neurosurgery. 1998 Nov;43(5):1074-81
9802851
Chest. 2008 Jun;133(6 Suppl):110S-112S
18574260
J Neurosurg. 2002 Jan;96(1):86-9
11794609
Surg Neurol. 2003 May;59(5):363-72; discussion 372-4
12765806
N Engl J Med. 1998 Jul 9;339(2):80-5
9654538
J Gen Intern Med. 1993 Sep;8(9):476-86
8410419
World J Surg. 2004 Aug;28(8):807-11
15457363
Med Decis Making. 1995 Oct-Dec;15(4):297-310
8544674
Am J Surg. 2007 Mar;193(3):380-3; discussion 383-4
17320539
Stroke. 1991 May;22(5):571-6
2028484
Stroke. 1991 Jan;22(1):1-6
1987664
Neurosurgery. 2002 Feb;50(2):261-7; discussion 267-9
11844260
Crit Care. 2001 Dec;5(6):368-75
11737927
J Neurosurg. 1975 Feb;42(2):201-3
1113155
Lancet. 1999 Apr 24;353(9162):1386-9
10227218
Crit Care Med. 2001 Sep;29(9):1659-65
11546959
JAMA. 1995 Dec 20;274(23):1839-45
7500532
Health Serv Res. 1988 Jun;23(2):203-35
3384669
Med Decis Making. 1993 Apr-Jun;13(2):89-102
8483408
J Health Econ. 1986 Mar;5(1):1-30
10311607
Stroke. 2001 Apr;32(4):964-72
11283398
J Chronic Dis. 1987;40(6):593-603
3298297
Med Decis Making. 1997 Apr-Jun;17(2):136-41
9107608
J Crit Care. 2009 Jun;24(2):176-84
19501306
Neurosurgery. 1980 Feb;6(2):138-41
7366805
Ann Surg. 2004 Sep;240(3):490-6; discussion 496-8
15319720
J Head Trauma Rehabil. 2006 Nov-Dec;21(6):544-8
17122685
Med Decis Making. 1997 Apr-Jun;17(2):142-51
9107609
J Trauma. 2000 Mar;48(3):367-74; discussion 374-5
10744271
J Trauma. 1993 Oct;35(4):637-41; discussion 641-2
8411290
Chest. 1992 Sep;102(3):677-81
1516386
J Neurosurg. 2002 Jan;96(1):109-16
11794591
Neurosurgery. 1993 Jan;32(1):25-30; discussion 30-1
8421553
Stroke. 1988 May;19(5):604-7
3363593
N Engl J Med. 1996 Sep 5;335(10):701-7
8703169
Med Decis Making. 1997 Apr-Jun;17(2):126-35
9107607
N Engl J Med. 1996 Dec 12;335(24):1816-28
8943165
Anaesthesia. 2001 Aug;56(8):780-85
11493245
J Surg Res. 1997 Jan;67(1):72-8
9070185
Ann Surg. 2001 Mar;233(3):438-44
11224634
Radiology. 1979 Dec;133(3 Pt 1):645-9
504644
N Engl J Med. 1988 May 5;318(18):1162-73
3283548
Neurosurgery. 1979 Sep;5(3):309-13
503290
Neurosurgery. 2005 Jun;56(6):1286-92; discussion 1292-4
15918945