Transcript Document
Prevention of Venous Thromboembolism
in Nonorthopedic Surgical Patients
----Antithrombotic Therapy and Prevention of
Thrombosis, 9th ed: American College of
Chest Physicians Evidence-Based Clinical
Practice Guidelines
Copyright: American College of Chest Physicians 2012©
Learning Objectives
• Describe a formal methodology for the evidencebased development of clinical practice guidelines
• Review select studies of venous thromboembolism
(VTE) prevention in surgical patients, as well as the
limitations of the studies
• Summarize recommendations for VTE prevention in
specific surgical populations
VTE
• Thrombosis: the formation or presence of a blood
clot within a blood vessel
Merriam-Webster’s Medical Dictionary
• Embolism: obstruction or occlusion of a vessel by
a transported clot or vegetation, a mass of bacteria,
or other … material
Stedman’s Medical Dictionary
Deep Vein Thrombosis (DVT)
Pulmonary Embolism (PE)
Goldhaber SZ. N Engl J Med. 1998;339(2):93-104.
Pulmonary Angiography
Bliss et al. N Engl J Med. 2002;347(23):1876-1881.
CT Pulmonary Angiography
Goldhaber SZ. N Engl J Med. 1998;339(2):93-104.
Kearon SF. CMAJ. 2003;168:183-194.
Risk Factors: Virchow’s Triad
• Stasis
– Immobility
– Congestive heart failure
• Injury
– Surgery (especially major orthopedic and pelvic)
– Trauma
• Thrombophilia
– Cancer
– Oral contraceptives
– Hereditary states (factor V Leiden, PT mutations)
VTE Epidemiology
• Most common cause of preventable death in
hospitalized patients
• Risk of fatal perioperative PE ~0.8%
International Multicentre Trial. Lancet. 1975
• 150,000 to 200,000 deaths per year; ~1/3 in
perioperative patients
Horlander et al. Arch Intern Med. 2003;163:1711-1717.
• AHRQ: VTE prevention is number 1 priority to
improve safety in hospitals
Many Surgical Patients At-Risk
• 2003 Nationwide Inpatient Sample
• Adult surgical patients, LOS ≥2 days
• 7.8 million surgical discharges
•
•
•
•
44% low risk
15% moderate risk
24% high risk
17% very high risk
• 4.4 million at risk for VTE
Anderson et al. Am J Hematol. 2007;82:777-782.
Million Women Study
• Population-based, prospective cohort study
• 947,454 middle-aged women in U.K. enrolled
between 1996-2001
• Mean follow-up 6.2 years
• 239,614 underwent surgery
– 5,419 readmitted for VTE within 12 weeks of inpatient
surgery
– 270 deaths from fatal PE
Sweetland et al. BMJ. 2009;339:b4583.
VTE Consequences
•
•
•
•
•
•
•
Leg swelling, discomfort (DVT)
Dyspnea, chest pain, hemoptysis, hypoxemia (PE)
Extended hospital LOS
Fatal PE (RV failure)
≥3 months of anticoagulant treatment
Postphlebitic syndrome
Chronic thromboembolic pulmonary HTN (~4%)
Pengo et al. N Engl J Med. 2004;350:2257-2264.
VTE Prevention
• Targets one or two legs of Virchow’s triad:
– Mechanical prophylaxis (stasis)
• Elastic compression stockings
• Intermittent pneumatic compression devices
VTE Prevention
• Targets one or two legs of Virchow’s triad:
– Mechanical prophylaxis (stasis)
• Elastic compression stockings
• Intermittent pneumatic compression devices
– Pharmacological prophylaxis (hypercoagulability)
•
•
•
•
Unfractionated heparin
Low-molecular-weight heparins
Fondaparinux
Aspirin (?)
Guidelines Defined
“Systematically developed statements to assist
practitioners and patient decisions about
appropriate health care for specific
circumstances.”
Field MJ, Lohr KN (eds). Clinical Practice Guidelines: Directions for a New
Program. Institute of Medicine, Washington, DC: National Academy Press,
1990.
Guidelines and
Performance Measures
• Public reporting
– Cardiac surgery outcomes in New York State
• Pay for performance
– Reward “good” behavior
– CMS: several VTE prevention P4P measures
• Registries
– Accreditation
– Facilitate quality improvement
Case Scenario
• 50 year-old woman scheduled to undergo elective
laparoscopic cholecystectomy
–
–
–
–
PMH notable for moderate emphysema
No personal or family history of VTE
Medications: Spiriva®, albuterol
Stopped smoking 1 year ago
• What should we recommend for perioperative
VTE prophylaxis in this patient?
BMJ. 1999;318:593-596.
Conceptual Framework
• VTE pharmacoprophylaxis involves a tradeoff
between preventing thrombosis and causing bleeding
• When making tradeoffs, need to compare absolute
risks of thrombosis and bleeding
• In order to determine absolute risks (eg, number of
symptomatic DVTs prevented), need to know the
following:
– Baseline risk in control/comparison group
– Relative risk for intervention vs control
• When making tradeoffs, also need to assign values to
events being compared
Calculating Absolute Effects
Scenario
Any surgical
patient
Baseline
Risk of
sVTE
(%)
Baseline
Risk of
Major
Bleeding
(%)
?
?
RR VTE RR Bleed Number
Number
(UFH vs (UFH vs
of VTEs
of Bleeds
no
no
Prevented
Caused
Prophy) Prophy) (per 1000) (per 1000)
0.50
2.0
?
?
Calculating Absolute Effects
Scenario
Baseline
Risk of
sVTE
(%)
Baseline
Risk of
Major
Bleeding
(%)
RR VTE
(UFH vs
no
Prophy)
Moderate VTE/
Average Bleed
2
1
10
10
Moderate VTE/
High bleed
2
2
10
20
High VTE/
average bleed
4
1
20
10
High VTE/
high bleed
4
2
20
20
0.50
RR Bleed
(UFH vs
no
Prophy)
2.0
Number of
VTEs
Prevented
(per 1000)
Number of
Bleeds
Caused
(per 1000)
PICO Question
• Among patients undergoing elective abdominal
surgery, should LDUH vs no prophylaxis be used
for VTE prevention?
• Are we confident that the benefits of reducing
fatal and nonfatal VTE exceed the harms of
increasing fatal and nonfatal major bleeding?
Evidence Synthesis
• Systematic Review for each PICO!
–
–
–
–
Literature search
Assessment for eligibility
Assessment of study quality
Data abstraction and synthesis
• Expensive, time-consuming, and labor-intensive
– AHRQ Evidence-Based Practice Centers
Assessment of Baseline Risk
Ideal study
• Large, population-based
• Prospective (?)
• Few exclusions or losses to
follow-up
• Well-defined endpoints
Most studies
• Single center
• Referral center bias
• Prospective
• Employ surveillance
methods to identify
asymptomatic DVT
– Important to patients
– Objectively confirmed
• Short time horizon
• Sufficiently long time horizon
• No description or
• No prophylaxis or controlled for
adjustment for
prophylaxis
prophylaxis
Estimating Baseline Risk
Ann Surg. 2010;251:344-350.
Estimating Baseline Risk
• Retrospective, observational study
• Large sample (n=8,216) of consecutively admitted
“general” surgical inpatients
• Tertiary center
• Measured clinically suspected, objectively
confirmed VTE over 30 days
• Risk stratification according to patient-specific
and procedure-specific characteristics
• Prophylaxis nonuniform but reported
Baseline Risk of VTE
Case Scenario
• 50-year-old woman scheduled to undergo elective
laparoscopic cholecystectomy
–
–
–
–
PMH notable for moderate COPD
No personal or family history of VTE
Medications: Spiriva®, albuterol
Stopped smoking 1 year ago
• What should we recommend for perioperative
VTE prophylaxis in this patient?
Baseline Risk of VTE
4
Baseline Risk of VTE
Bahl et al. Ann Surg. 2010;251:344-350.
Baseline Risk of VTE
52%
0.1%
10%
37%
Bahl et al. Ann Surg. 2010;251:344-350.
Prophylaxis Received
Risk
Category
% Receiving Prophylaxis
Pharm
Mechanical
Both
Neither
0
0.55
0.08
0.37
Low
0.02
0.66
0.13
0.19
Moderate
0.05
0.55
0.21
0.2
High
0.05
0.52
0.27
0.16
All
0.05
0.55
0.23
0.18
Very low
VTE
Risk
Patient Population
Risk categories from AT7 Patients undergoing general surgery, including
gastrointestinal, urological, vascular, breast and
thyroid procedures
Estimated risk (%)
Proximal
PE
Caprini score Observed risk of Adjusted risk of
DVT
sVTE (%)
sVTE (%)
Very
low
Low
0.4
0.2
0
0
0
2-4
1-2
1-2
0.7
1.7
Mod
4-8
2-4
3-4
1.0
2.6
High
>10
4-10
≥5
1.9
5.7
Estimated Baseline Risk
• Caprini score = 4
• Unadjusted risk = 1.0%
• Crude adjusted risk = 2.6%
• Observed, unadjusted risk in observational study
of 2,274 discharges following lap chole in
California, 1992-1996 was 0.9%
White RH et al. Thromb Haemost. 2003;90:446-455.
Calculating Absolute Effects
Scenario
Moderate VTErisk patient
Baseline
Risk of
sVTE
(%)
Baseline
Risk of
Major
Bleeding
(%)
2.6
1.2
RR VTE RR Bleed Number
Number
(UFH vs (UFH vs
of VTEs
of Bleeds
no
no
Prevented
Caused
Prophy) Prophy) (per 1000) (per 1000)
?
?
?
?
Assessment of Safety/Effectiveness
Ideal study
• Large, multicenter RCT
• Blinding of patients, treating
physicians, adjudicators
• Well-defined endpoints
– Important to patients
– Objectively confirmed
• Few exclusions or losses to
follow-up
• Sufficiently long time horizon
Most studies
• Small, single center
• Referral center bias
• Incomplete blinding
• Surrogate outcome,
asymptomatic DVT
• Large percent excluded
from efficacy evaluation
• Short time horizon
Effectiveness of LDUH: IMT
IMT Design
• Unblinded, randomized, controlled trial
• Patients: adults age > 40 years undergoing major
elective surgery (GA, >30 min, LOS ≥ 7 days) at
28 centers in Europe, Australia and South Africa
• Intervention: UFH 5,000 units tid for 7 days, 1st
dose 2 hours pre-op
• Comparator: no prophylaxis
• Outcomes: fatal PE, fatal bleed, nonfatal PE,
nonfatal bleed, clinical DVT, DVT by FUT
IMT Outcomes
• PE: clinically suspected with confirmatory evidence
recorded (chest radioraph and ECG)
• Fatal PE: confirmed by autopsy
• DVT:
– Clinically suspected and confirmed by venography
– Continuous surveillance by fibrinogen uptake test (10 centers)
• Excessive operative bleeding (surgeon’s judgment)
• Wound hematoma, transfusion, fall in Hgb
IMT Results: VTE
Outcome
LDUH
N=2045
No Prophylaxis
N=2076
RR
Death any cause
80
100
0.81 (0.61 to 1.1)
Fatal PE
2
16
0.13 (0.02 to 0.55)
Death with PE
3
6
0.51 (0.13 to 2.0)
Suspected DVT
39
81
0.49 (0.33 to 0.71)
Confirmed DVT
11
32
0.35 (0.18 to 0.69)
DVT by FUT
48/625
164/667
0.31 (0.23 to 0.42)
Proximal DVT
5/625
49/667
0.11 (0.04 to 0.27)
IMT Results: Bleeding
Outcome
LDUH
N=2045
No Prophylaxis
N=2076
RR
4
5
0.81 (0.21 to 3.0)
Excessive intra-op
182
126
1.47 (1.18 to 1.82)
Wound hematoma
158
117
1.37 (1.09 to 1.73)
202/731
202/744
1.02 (0.86 to 1.20)
Fatal bleed
Transfusion
Collins Meta-analysis
N Engl J Med. 1988;318:1162-1173.
Collins Meta-analysis
• 69 studies of LDUH prophylaxis
–
–
–
–
•
•
•
•
General surgery (45)
Urology (7)
Elective orthopedic (12)
Trauma (7)
About half open label
Most measured surrogate outcome for VTE
Many used suboptimal test (FUT)
Bleeding outcome: excessive intraoperative
bleeding or need from transfusion
Results: Meta-analysis
Outcome
Studies
With at
Least 1
Event
Baseline
Risk in
Control
Groups
Pooled OR
(REM)
Death from any cause
32
3.5%
0.82 (0.69 to 0.99)
Fatal PE
20
0.8%
0.53 (0.31 to 0.91)
Nonfatal PE
32
2.1%
0.59 (0.41 to 0.84)
Fatal bleeding
7
0.1%
1.14 (0.41 to 3.15)
Nonfatal bleeding
44
3.8%
1.57 (1.32 to 1.87)
Sensitivity Analysis
• Frequency
– Q8h 72 +/- 5
– Q12h 63 +/-5
Calculating Absolute Effects
Scenario
Moderate
VTE-Risk
Patient
Baseline
Risk of
sVTE
RR VTE
(UFH vs
no
Prophy)
(%)
Baseline
Risk of
Major
Bleeding
(%)
RR
Bleed
(UFH vs
no
Prophy)
2.6
1.2
0.59
1.57
Number
Number
of VTEs
of Bleeds
Prevented Caused
(per 1000) (per 1000)
11
7
Evidence Synthesis:
Tradeoffs between desirable and
undesirable outcomes
Summary of Findings
Absolute Risks
Effect
Relative
Absolute
(95% CI)
Nonfatal symptomatic VTE, inferred from no-fatal PE (clinical diagnosis)
LDUH
No Prophylaxis
1.7%
118/8216 (1.4%)
Importance
7 fewer per 1000
OR 0.59
2.6%
5.7%
(0.41 to 0.84)
11 fewer per 1000
CRITICAL
23 fewer per 1000
Non-fatal major bleeding, inferred from excessive intraoperative bleeding or need for
transfusion (clinical diagnosis)
1.2%
7 more per 1000
OR 1.57
388/6524 (5.9%)
CRITICAL
2.2%
12
more
per
1000
(1.32 to 1.87)
Summary of Findings
Absolute Risks
LDUH
No Prophylaxis
Effect
Relative
(95% CI)
Importance
Absolute
Fatal PE (autopsy)
0.3%
19/6809 (0.3%)
0.5%
1 fewer per 1000
OR 0.53
(0.31 to 0.91)
1.1%
2 fewer per 1000
CRITICAL
5 fewer per 1000
Fatal bleeding (autopsy)
0.09%
7/6703 (0.1%)
0.17%
OR 1.14
0 more per 1000
(0.41 to 3.15)
0 more per 1000
CRITICAL
GRADE: Quality of Evidence
Limitations
Inconsistency
Indirectness
Imprecision
Other
Threats to
validity, risk of
bias:
concealment of
allocation
sequence,
blinding, losses
to follow-up,
selective
reporting, early
stopping
Unexplained
heterogeneity in
results across
studies
Indirect
evidence from
different
population,
intervention,
comparator or
outcome
Confidence
interval around
effect includes
both no effect
and either
important
benefit or
important harm
(or both)
Potential for
publication bias
OR
Indirect
comparison:
Use studies of
A vs B and B vs
C to compare A
vs C
Quality Assessment
No. of Studies
Fatal PE
20
Fatal bleeding
7
Design
Limitations
Inconsistency
Indirectness
Imprecision
Quality
randomised
trials
no serious
limitations
+/-
no serious
indirectness
no serious
imprecision
Moderate to
High
randomised
trials
no serious
limitations
no serious
inconsistency
no serious
indirectness
serious
Moderate
no serious
indirectness
no serious
imprecision
Moderate
No-fatal symptomatic VTE, inferred from nonfatal PE
32
randomised
serious
mild
trials
Nonfatal major bleeding, inferred from excessive intraoperative bleeding or need for transfusion
44
randomised
trials
serious
no serious
inconsistency
no serious
indirectness
no serious
imprecision
Moderate
Guyatt et al. BMJ. 2008;336:1049-1051.
GRADE: Strength of Recommendation
BMJ. 2008;336:1049-1051.
Recommendation
For general surgical patients at moderate risk for
venous thromboembolism who are not at high risk
for perioperative bleeding, we suggest low-dose
unfractionated heparin (Grade 2B) over no
prophylaxis.
Recommendation
For general surgical patients at high risk for
venous thromboembolism who are not at high risk
for perioperative bleeding, we recommend use of
low-dose unfractionated heparin (Grade 1B) over
no prophylaxis.
Major Challenges
• Multiple sources of heterogeneity
• Indirectness
– When should one apply indirect evidence from studies
performed in a mixed (surgical) or different patient
population?
• Surrogate outcome: asymptomatic DVT
• Poorly standardized outcome: major bleeding
• Limited information about baseline risk of VTE in
absence of prophylaxis
Biases Introduced by Surveillance for
Asymptomatic DVT
• Downward: identification and treatment of
asymptomatic DVT prevents unknown number of
events that would have become symptomatic
• Upward: more likely to label a finding (eg, leg
swelling) as a symptomatic if event is detected by
surveillance
• Difficult to estimate the ratio of asymptomatic to
symptomatic events
Additional Challenges
• Numerous comparisons
– LDUH, LMWH, fondaparinux, low-dose ASA, high-dose
ASA, ES and IPC vs no prophy
– Mechanical vs pharmacologic
– Add mechanical to pharmacologic
– 16 unique evidence profiles and still counting!
• Numerous surgical populations
–
–
–
–
Abdomen and pelvis (vascular, bariatric)
Neurosurgery (craniotomy, spine)
Trauma (TBI, SCI, other major trauma)
Cardiac, thoracic, other…
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For general and abdominal-pelvic surgery patients at very low
risk for VTE (< 0.5%; Rogers score, < 7; Caprini score, 0), we
recommend that no specific pharmacologic (Grade 1B) or
mechanical (Grade 2C) prophylaxis be used other than early
ambulation.
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For general and abdominal-pelvic surgery patients at low risk
for VTE (~ 1.5%; Rogers score, 7-10; Caprini score, 1-2), we
suggest mechanical prophylaxis, preferably with intermittent
pneumatic compression (IPC), over no prophylaxis (Grade 2C).
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For general and abdominal-pelvic surgery patients at moderate
risk for VTE (~ 3.0%; Rogers score, > 10; Caprini score, 3-4)
who are not at high risk for major bleeding complications, we
suggest LMWH (Grade 2B), LDUH (Grade 2B), or mechanical
prophylaxis, preferably with IPC (Grade 2C), over no
prophylaxis.
Remarks: Three of the seven authors favored a strong (Grade 1B)
recommendation in favor of LMWH or LDUH over no prophylaxis
in this group.
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For general and abdominal-pelvic surgery patients at moderate
risk for VTE (3.0%; Rogers score, > 10; Caprini score, 3-4)
who are at high risk for major bleeding complications or those
in whom the consequences of bleeding are thought to be
particularly severe, we suggest mechanical prophylaxis,
preferably with IPC, over no prophylaxis (Grade 2C).
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For general and abdominal-pelvic surgery patients at high risk
for VTE (~ 6.0%; Caprini score, ≥ 5) who are not at high risk
for major bleeding complications, we recommend
pharmacologic prophylaxis with LMWH (Grade 1B) or LDUH
(Grade 1B) over no prophylaxis. We suggest that mechanical
prophylaxis with elastic stockings or IPC should be added to
pharmacologic prophylaxis (Grade 2C).
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For high-VTE-risk patients undergoing abdominal or pelvic
surgery for cancer who are not otherwise at high risk for major
bleeding complications, we recommend extended-duration
pharmacologic prophylaxis (4 weeks) with LMWH
over limited-duration prophylaxis (Grade 1B).
Remarks: Patients who place a high value on minimizing out-ofpocket health-care costs might prefer limited-duration over
extended-duration prophylaxis in settings where the cost of
extended-duration prophylaxis is borne by the patient.
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For high-VTE-risk general and abdominal-pelvic surgery
patients who are at high risk for major bleeding complications
or those in whom the consequences of bleeding are thought to
be particularly severe, we suggest use of mechanical
prophylaxis, preferably with IPC, over no prophylaxis until the
risk of bleeding diminishes and pharmacologic prophylaxis
may be initiated (Grade 2C).
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For general and abdominal-pelvic surgery patients at high risk
for VTE (6%; Caprini score, ≥ 5) in whom both LMWH and
unfractionated heparin are contraindicated or unavailable and
who are not at high risk for major bleeding complications, we
suggest low-dose aspirin (Grade 2C), fondaparinux (Grade 2C),
or mechanical prophylaxis, preferably with IPC (Grade 2C),
over no prophylaxis.
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For general and abdominal-pelvic surgery patients, we suggest
that an inferior vena cava (IVC) filter should not be used for
primary VTE prevention (Grade 2C).
Patients Undergoing General, GI, Urologic, Gynecologic, Bariatric, Vascular,
Plastic, or Reconstructive Surgery
For general and abdominal-pelvic surgery patients, we suggest
that periodic surveillance with venous compression ultrasound
(VCU) should not be performed (Grade 2C).
Patients Undergoing Cardiac Surgery
For cardiac surgery patients with an uncomplicated
postoperative course, we suggest use of mechanical
prophylaxis, preferably with optimally applied IPC, over either
no prophylaxis (Grade 2C) or pharmacologic prophylaxis
(Grade 2C).
Patients Undergoing Cardiac Surgery
For cardiac surgery patients whose hospital course is prolonged
by one or more nonhemorrhagic surgical complications, we
suggest adding pharmacologic prophylaxis with LDUH
or LMWH to mechanical prophylaxis (Grade 2C).
Patients Undergoing Thoracic Surgery
For thoracic surgery patients at moderate risk for VTE who
are not at high risk for perioperative bleeding, we suggest
LDUH (Grade 2B), LMWH (Grade 2B), or mechanical
prophylaxis with optimally applied IPC (Grade 2C) over no
prophylaxis.
Remarks: Three of the seven authors favored a strong (Grade 1B)
recommendation in favor of LMWH or LDUH over no prophylaxis
in this group.
Patients Undergoing Thoracic Surgery
For thoracic surgery patients at high risk for VTE who are not
at high risk for perioperative bleeding, we suggest LDUH
(Grade 1B) or LMWH (Grade 1B) over no prophylaxis. In
addition, we suggest that mechanical prophylaxis with ES or
IPC should be added to pharmacologic prophylaxis (Grade 2C).
Patients Undergoing Thoracic Surgery
For thoracic surgery patients who are at high risk for major
bleeding, we suggest use of mechanical prophylaxis, preferably
with optimally applied IPC, over no prophylaxis until the risk
of bleeding diminishes and pharmacologic prophylaxis may be
initiated (Grade 2C).
Patients Undergoing Craniotomy
For craniotomy patients, we suggest that mechanical
prophylaxis, preferably with IPC, be used over no prophylaxis
(Grade 2C) or pharmacologic prophylaxis (Grade 2C).
Patients Undergoing Craniotomy
For craniotomy patients at very high risk for VTE (eg, those
undergoing craniotomy for malignant disease), we suggest
adding pharmacologic prophylaxis to mechanical prophylaxis
once adequate hemostasis is established and the risk of bleeding
decreases (Grade 2C).
Patients Undergoing Spinal Surgery
For patients undergoing spinal surgery, we suggest mechanical
prophylaxis, preferably with IPC, over no prophylaxis (Grade
2C), unfractionated heparin (Grade 2C), or LMWH (Grade
2C).
Patients Undergoing Spinal Surgery
For patients undergoing spinal surgery at high risk for VTE
(including those with malignant disease or those undergoing
surgery with a combined anterior-posterior approach), we
suggest adding pharmacologic prophylaxis to mechanical
prophylaxis once adequate hemostasis is established and the
risk of bleeding decreases (Grade 2C).
Major Trauma
For major trauma patients, we suggest use of LDUH (Grade
2C), LMWH (Grade 2C), or mechanical prophylaxis, preferably
with IPC (Grade 2C), over no prophylaxis.
Major Trauma
For major trauma patients in whom LMWH and LDUH are
contraindicated, we suggest mechanical prophylaxis, preferably
with IPC, over no prophylaxis (Grade 2C) when not
contraindicated by lower-extremity injury. We suggest adding
pharmacologic prophylaxis with either LMWH or LDUH when
the risk of bleeding diminishes or the contraindication to
heparin resolves (Grade 2C).
Major Trauma
For major trauma patients, we suggest that an IVC filter
should not be used for primary VTE prevention (Grade 2C).
Patients With Major Trauma: Traumatic Brain Injury, Acute Spinal Injury,
and Traumatic Spine Injury
For major trauma patients at high risk for VTE (including
those with acute spinal cord injury, traumatic brain injury, and
spinal surgery for trauma), we suggest adding mechanical
prophylaxis to pharmacologic prophylaxis (Grade 2C) when not
contraindicated by lower extremity injury.
Patients With Major Trauma: Traumatic Brain Injury, Acute Spinal Injury,
and Traumatic Spine Injury
For major trauma patients, we suggest that periodic
surveillance with VCU should not be performed (Grade 2C).
Endorsing Organizations
This guideline has received the endorsement of the
following organizations:
•
•
•
•
•
American Association for Clinical Chemistry
American College of Clinical Pharmacy
American Society of Health-System Pharmacists
American Society of Hematology
International Society of Thrombosis and Hemostasis
Acknowledgement of Support
The ACCP appreciates the support of the following organizations
for some part of the guideline development process:
Bayer Schering Pharma AG
National Heart, Lung, and Blood Institute (Grant No.R13 HL104758)
With educational grants from
Bristol-Myers Squibb and Pfizer, Inc.
Canyon Pharmaceuticals, and
sanofi-aventis U.S.
Although these organizations supported some portion of the development
of the guidelines, they did not participate in any manner with the scope,
panel selection, evidence review, development, manuscript writing,
recommendation drafting or grading, voting, or review. Supporters did not
see the guidelines until they were published.