Nghiên cứu nguy cơ xuất hiện huyết khối tĩnh mạch sâu chi dưới lần đầu và kết quả dự phòng bằng heparin trọng lượng phân tử thấp ở bệnh nhân hồi sức cấp cứu tt tiếng anh

MINISTRY OF
MINISTRY
EDUCATION & TRAINING
OF HEALTH
HANOI MEDICAL UNIVERSITY

MAI DUC THAO

STUDY THE RISK FACTORS FOR LOWER EXTREMITY
DEEP VEIN THROMBOSIS IN THE FIRST TIME AND THE
RESULTS OF PREVENTION BY LOW MOLECULAR
WEIGHT HEPARIN IN THE EMERGENCY RESUSCIATION
PATEINT
Subject

: Emergency - Intensive Care Medicine

Code

: 62720122

SUMMARY OF THESIS OF PHILOSOPHY DOCTOR IN MEDICINE

HANOI – 2020


Research completed in:
HA NOI MEDICAL UNIVERSITY

Scientific supervisors:
1. Assoc. Prof.PhD Dang Quoc Tuan

Scientific reviewer 1:
Scientific reviewer2:
Scientific reviewer3:

The Thesis will be defended in front of The Council for Philosophy
Doctor in Mediccine at Hanoi Medical University
At

on

/

/ 2020

The Thesis can be founf at:
- The National Libary
- Hanoi Medical University Libary


1
INTRODUCTION
Venous thromboembolism (VT) is a common clinical vascular
disease, only after acute myocardial infarction and stroke. Clinically,
VT presents two forms: deep vein thrombosis (DVT) and pulmonary
embolism (PE). Clinical symptoms of PE are usually atypical, may
be asymptomatic due to other obscure diseases, easily confused with
other special diseases in patients receiving emergency - intensive care
internal medicine (ICU).
Patients in ICU have many risk factors for VT, pre-admission
risks such as immobility, infections, cancer, advanced age, heart

failure, respiratory failure and a history of ICU. There are risks when
entering the department such as lying motionless, mechanical
ventilation, sedatives, central venous catheters, hemodialysis,
infections, and vasopressors. Diagnosis and treatment of VT in ICU
patients is very difficult so diagnosis is late and easy to miss. Even
when diagnosed, there is no chance of treatment or difficulty because
of serious illness, multiple organ failure, hemostatic disorders and
unpredictability. Fortunately, VT is preventable, but currently the
prophylaxis of VT in ICU patients has not been given adequate
attention, is not consistent, and the prevention rate is not high. So far,
there have been many studies on DVT in the world and in Vietnam,
but research on DVT in emergency resuscitation patients is still
limited. On that basis, this research project is conducted with 2
objectives:
1- Understanding some risk factors for lower extremity DVT in
the first time in patients treated at the intensive care unit of the Bach
Mai hospital and the Friendship hospital.
2- Review the results of lower extremity DVT prevention by low
molecular weight heparin (Enoxaparin) in the above patient groups.
URGENCY OF THE SUBJECT
DVT is a common condition, with atypical symptoms, which
makes it difficult to diagnose, treat complexities and dangerous
complications but this disease can be prevented. In the world and in
Vietnam, there have been many studies on VT: risk factors, diagnosis,
treatment and prevention but mainly in surgical patients,


2
cardiovascular patients, internal medicine patients and obstetric.
Studies of VT in ICU patients are few. What are the risk factors for

DVT in medical ICU patients? Will the use of prophylactic medicine
on Vietnamese people reduce the rate of DVT? In particular, the
patient with medical ICU often has many serious illnesses attached.
Therefore, this research is essential and has high practical
significance.
NEW CONTRIBUTIONS OF THE THESIS
1. The study has identified Padua cut off point ≥ 4 to predict the
risk of lower extremity DVT in patients with ICU. Smoking, heart
failure are independent risk factors for lower extremity DVT in ICU
patients.
2. The study has identified the incidence of lower extremity DVT
in the prophylactic and non-prophylactic groups, proving the
effectiveness of lower extremity DVT prophylaxis by Enoxaparin in
internal ICU patients in the Bach Mai hospital and the Friendship
hospital.
THE LAYOUT OF THE THESIS
The thesis consists of 129 pages. In addition to the introduction,
aims, conclusions and recommendations, there are 4 chapters
including: Literature review (38 pages), Subjects and Methods (20
pages), Results (34 pages), Discussion (32 pages), Conclusions (1
page), Recommendations (1 page). There are 52 tables, 7 pictures, 1
diagram, 4 charts, and 160 references (Vietnamese and English).
Including 26 documents in the past 5 years.
Chapter 1
LITERATURE REVIEW
1.1. Deep vein thrombosis (DVT)
1.1.1. Some concepts and formation of DVT
- Thrombosis is a pathological condition that leads to the formation of
a blood clot in the lumen (semi-occlusive or completely embolized).
- Venous thromboembolism: A common term for two clinical

forms: pulmonary artery occlusion and DVT.


3
- The formation of thrombosis is usually due to many coordinating
factors. Virchow describes it as hypercoagulation, endothelial
damage and circulatory stagnation.
1.1.2. The natural progress of lower extremity DVT( LEDVT)
- Usually proceeds silently, 20-40% of patients have symptoms.
- About 50% of LEDVT untreated, it will lead to pulmonary
embolism, large embolism can be fatal, small arterial occlusion
may increase pulmonary artery pressure.
- Prolonged obstruction of lower extremity venous thrombosis
by thrombosis leads to venous valve failure and increases chronic
venous pressure.
1.1.3. Complication of VT
- Acute pulmonary embolism
- Pulmonary hypertension due to chronic embolism
- Post-thrombotic syndrome
1.2. Epidemiology of DVT in the world and in Vietnam
- Every year in the world, the rate of new DVT infection ranges
from 0.5/1000-2/1000 people. VT increases with age and male:
female ratio = 1.2:1. In Vietnam, there are no statistical studies on
VT rates in the national population.
- The rate of VT in ICU patients who do not have VT
prophylaxis is the rate of DVT from 13-31%, in patients on DVT
prophylaxis, the rate of DVT is from 5.4-23.6% depending on the
different disease groups attached.
1.3. Risk factors of DVT in ICU patients
ICU patients are serious patients who need to be supported by

means of machinery, drugs ... high risk of death if not diagnosed,
treated and often the last line of all other departments, so the patients
with all risk factors for DVT in general such as age, inactivity,
obesity, personal or family history of VT ... When entering the
emergency department, patients may have additional risks: sedation,
sedation, central venous catheter, artificial kidney, mechanical
ventilation, infection..


4
1.4. The combination of risk factors
The DVT ratio is correlated with the number of risk factors. In
patients without risk factors, the rate of DVT is 11%, in patients with
suspicion, the rate of DVT is 20-30% and in patients with 3 risk
factors, this rate increases to 50%.
1.5. Diagnosis of lower extremity DVT
- Based on clinical symptoms, risk stratification (Well's score
indicates lower extremity DVT), low-risk patients (Well's score <2)
have a negative DVT diagnostic value of 96% (99% if D dimer also
negative). Positive diagnosis in high-risk patients (Well’s score ≥ 2)
is less than 75%, other tests are needed to diagnose acute DVT.
- D-Dimer test for DVT: D-Dimer is a fibrin degradation product
during blood coagulation, has high sensitivity, low specificity, so it
has a diagnostic value to exclude DVT when D-Dimer is negative,
when positive D-Dimer does not necessarily mean blood clots.
- Pressed venous Doppler ultrasound is a non-invasive, less
expensive, portable, made in bed, repetitive and non-toxic method for
both physicians and patients more than other methods. Symptomatic
patients, Doppler ultrasound diagnoses DVT have 95% sensitivity
and 98% specificity. Asymptomatic patients had a sensitivity of 54%,

specificity 91%, positive predictive value 83%, negative predictive
value 69%.
1.6. Prophylaxis of DVT in patients with ER
Venous thrombosis prophylaxis has been proven effectively,
prophylaxis reduces morbidity, reduces costs and reduces mortality.
As recommended by ACCP (2012), in 2017, the Vietnam National
Association of Emergency, Intensive Care Medicine provided
guidelines for uniform treatment of VT prophylaxis in ICU patients
by following these steps:
Step 1: Assess the risk of VT in patients with hospitalization based
on the underlying risk factors and the patient's medical condition.


5
Step 2: Assess the risk of bleeding, the contraindications of
anticoagulant treatment.
Step 3: Summarize the risks, weigh the benefits of prevention and
the risk of bleeding when using anticoagulants, paying special
attention to renal function, elderly patients.
Step 4: Select the appropriate backup method and time. The risk
of VT and the risk of bleeding may vary daily for each patient.
 Follow a unified regimen
- Name of medicine: Low TLH heparin, brand-name drug:
Lovenox of Sanofi-Aventis Vietnam Company.
- Dosage: 40mg (4,000 anti-Xa units, 0.4 ml), 1 time / day
- Administration: Subcutaneous injection once daily, starting
within 24 hours after the patient is admitted to the hospital and is
indicated for prophylaxis.
Duration of use: 10 ± 4 days
Chapter 2

SUBJECTS AND METHODS
2.1. Subjects
2.1.1. Inclusion criteria: when the patient meets the following criteria:
- Over 18 year - old, eligible for treatment at ICU
- APACHE II score> 18
- Expected treatment ≥ 6 days (maximum 30 days)
- Patient or family member agrees to participate in the study
2.1.2. Exclusion criteria:
• The patient is having DVT
• The patient is being treated for anticoagulant
• Patients with coagulation disorders or blood diseases
• Patients with contraindications to taking anticoagulants
• Patient or family member do not agrees to continue the research
• The patient lost data.


6
2.2. Methods: In cohort studies, all patients who met the criteria
were conducted according to the agreed steps.
2.2.1. Setting:
Patients who were eligible for inclusion in the study, noted the
risk factors, risk stratification according to Padua Prediction Score, deep
vein Doppler ultrasound with posterior compression at 7 days posthospitalization, if DVT, discontinue study and treat DVT by regimen.
Patients without DVT continued to monitor and record risk factors,
Doppler ultrasound deep vein in the lower extremities was hospitalized
for 14 days, 21 days and ended the study after 30 days. At the end of the
study conducted analysis according to the objectives.

Figure 2.1. Research scheme

7
2.2.2. Study sample size:
Based on the formula for calculating sample size with comparison
between prophylactic and non-prophylactic treatment (calculating
sample size for 2 rates), currently there has been no announcement of
DVT prophylaxis in medical ICU patients. MEDENOX study has many
similarities with this study, so we based on the proportion of DVT in the
non-prophylactic and preventive treatment group in the MEDENOX
study was 14.9% and 5.5 %, estimated sample size (N) is:
=

=

Inside:
- p1 is the incidence of DVT in the non-prophylactic group = 14.9%
- p2 is the incidence of DVT in the preventive treatment group = 5.5%
- n1 is the sample size of the group without preventive treatment
- n2 is the sample size of prophylactic treatment group
Sample size needed for each group: n1 = n2 = 162 patients
The total sample size of the 2 groups at least is: N = 324 patients
2.2.3. Procedures and techniques in research
- Identify common VT risk factors
- Determining history of acute medical diseases and diseases
- Identify VT risk factors in ICU
- Diagnosis of lower extremity DVT: by an ultrasound Doppler
ultrasound procedure of the lower extremity is performed by a
qualified diagnostic imaging doctor. During the follow-up process, in
case of suspected postgraduate students, the image diagnosis doctor
will check again.

- Tests, image diagnostics
- Prophylaxis of lower extremity DVT by low molecular weight
heparin according to the uniform regimen
Table 1.1. Padua Prediction Score
Risk factors
Sco
re
Active cancer
3
Previous VTE(except superficial thrombosis)
3
Bedrest> = 3 days


8
Thrombophilia
Recent trauma and / or surgery (<= 1 month)
Elderly age > = 70
Heart failure and / or respiratory failure
Acute myocardial infarction or ischemic stroke
Acute infection and / or rheumatologic disorder
Obesity (BMI> = 30 kg/m2)
Ongoing hormonal treatment

3
3
2
1
1
1

1
1
1
* Patients with metastases near or far and / or undergoing
chemotherapy or radiation within 6 months
** Defect antithrombin, S protein, C protein, V Leiden factor,
prothrombin mutation G20210A, antiphospholipid syndrome
Total score <4: Low risk of VT → No need for prophylaxis
Total score ≥ 4: High risk of VT → Need preventive treatment
2.2.4. Research indicators
2.2.4.1. Target research objective 1
- Some risk factors for lower extremity DVT in internal ICU patients
- Incidence of lower extremity DVT in internal ICU patients
2.2.4.2. Target research objective 2
- Prophylaxis of DVT prophylaxis with Enoxaparin in ICU
patients in the Bach Mai hospital and the Friendship hospital.
2.2.5. Data processing
- Information collected from research records is entered into computers
and analyzed and processed on SPSS software version 21.0.
- Research risk factors of lower extremity DVT by logistic
regression model. First, univariate analysis processed by groups of
patients with or without DVT in the sample of the study population,
then multivariate regression analysis by Cox regression method.
2.2.6. Medical ethics
- The study was approved and approved by the Board of Research
Approving Council of Hanoi Medical University in 2014.


9
- This is a descriptive observational study, not affecting patients. The

research process did not delay or affect the patient's treatment process.
- Tests and diagnostic measures are carried out exactly as directed
and for the benefit of the patient. Participants in the study did not
have to pay for ultrasound of DVT screening and testing costs during
the hospital stay
- Research is only for the protection and improvement of patient
health care, not for any other purpose.
Chapter 3
RESULTS
Through study of 354 patients, we recorded the following
characteristics:
3.1. Characteristics of researched patient group
3.1.1 Characteristics of research group with qualitative variables
Table 3.1. Characteristics of research group with qualitative variables
Characteristics
Gender

Male
Female

Cancer
Exacerbation of
COPD
Heart failure
Infection
Pancreatitis
Comatose
Respiratory failure
High blood pressure
Diabetes

Acute cerebral
infarction
Use sedatives
Use vasomotor

Samples
N (%)

PREVENTION
Yes
No
n1 (%)
n2 (%)

p

266 (75.1)
88 (24.9)

122 (45.9)
49 (55.7)

144 (54.1)
39 (44.3)

0.11

38 (10.7)

13 (34.2)

25 (65.8)

0.066

40 (11.3)

19 (47.5)

21 (52.5)

0.914

86 (24.3)
284 (80.2)
26 (7.3)
34 (9.6)
220 (62.1)
187 (52.8)
80 (22.6)

33 (38.4)
135 (47.5)
11 (48.3)
11 (32.4)
104 (47.3)
82 (43.8)
40 (50.0)

53 (61.6)

149 (52.5)
15 (57.7)
23 (67.6)
116 (52.7)
105 (56.2)
40 (50.0)

0.034
0.559
0.525
0.050
0.618
0.076
0.730

39 (11.0)

19 (48.7)

20 (51.3)

0.830

59 (16.7)
107 (30.2)

28 (47.5)
43 (40.2)

31 (52.5)

64 (59.8)

0.887
0.044


10
medication
Breathing machine

155 (43.8)

78 (50.3)

77 (19.7)

0.549

3.1.2 Characteristics of patients group studied with quantitative
variables
Table 3.2. Characteristics of patients group studied with quantitative
variables
Characteristics
Average age of patient
Friendship hospital
(years)
Average age of patient
Bach Mai hospital
(years)

80.2 ± 8.8
(35 - 99)

PREVENTION
Yes
No
n1 (%)
n2 (%)
79.5 ± 8.5
80.5 ± 9.0
(50 - 94)
(35 - 99)

57.9 ± 17.9
(18 - 97)

59.4 ± 18.6
(18 - 97)

Samples
N (%)

55.1 ± 16.4
(19 - 83)

p

0.34

0.14

163.7 ± 5.1
(144.0 - 175.0)
55.5 ± 6.8
(37.0 - 88.0)

163.9 ± 5.4
163.6 ± 4.8
0.700
(144.0 - 175.0) (146.0 - 175.0)
56.2 ± 7.5
54.9 ± 6.1
0.074
(37.0 - 88.0) (39.0 - 78.0)

20.7 ± 2.3
(13.5 - 30.5)

20.9 ± 2.4
(13.6 - 30.4)

20.5 ± 2.2
(15.4 - 30.5)

0.108

Leukocytes (G/l)

14.14 ± 8.66

14.33 ± 10.20 13.96 ± 6.92

0.695

Platelets (G/l)
PT (giây)

210.9±146.76
16.97 ± 11.68

204.3 ± 113.9 217.1 ± 172.2 0.418
16.13 ± 7.49 17.76 ± 14.53 0.206

PT% (%)
INR

74.57 ± 24.39
1.66 ± 7.29

74.11 ± 24.84 74.99 ± 24.03 0.744
2.05 ± 10.47 1.30 ± 0.44 0.347

aPTT (giây)
Fibrinogen (g/l)

35.85 ± 23.33
4.7 ± 4.3

36.26 ± 30.07 35.42 ± 13.15 0.763
5.05 ± 5.97

4.37 ± 1.56 0.159

Hight (cm)
Weight (kg)
BMI (kg/m2)
± SD

D-dimer

BMH
Median
5% - 95%
FH
Median

74.77 ± 597.37 61.15 ± 545.67 99.44 ± 686.10 0.709
3.77
3.94
3.46
0.942
0.62 - 14.67
0.56 - 14.22
0.94 - 15.56
289.88 ± 956.63 438.46 ± 1333.0 216.40 ± 698.23 0.204
3.12
3.52
2.5
0.012

11
5% - 95%

0.75 - 2030

0.96 - 5000

0.73 - 1750

3.2. Risk factors for lower extremity DVT in the study population
3.2.1. Risk factors are exposed
Table 3.3. The proportion of risk factors being exposed
Number of
patients

Rate
(%)

Acute cerebral infarction

39

11.02

Exacerbation of COPD

40

11.3

Respiratory failure

220

62.15

Infection

284

80.23

Digestive diseases

26

7.34

Motionless before entering the ICU

111

31.36

Central venous catheter

269

75.99

Use sedatives

59

16.67

Use vasomotor medication

107

30.23

Breathing machine

155

43.79

Total

354

100.0

Risk factors are exposed

3.2.2. Risk factors
Table 3.4. The rate of risk factors
Number of
patients

Rate
(%)

Cancer

38

10.7

Nephrotic syndrome

30

8.5

High blood pressure

187

52.8

Diabetes

80

22.6

Smoking

184

52.0

Age> 60

252

71.2

BMI> 23

43

12.1

Risk factors


12
Pregnant

14

3.9

History of DVT
1
0.3
3.2.3. Percentage of patients following the predicted risk DVT

according PADUA Prediction Score
Table 3.5. Percentage of patients following the predicted risk DVT
according Padua Prediction Score
Number of patients
Number of risk
factors
n
%
0
4
1.1
1
46
13.0
2
110
31.1
3
124
35.0
4
64
18.1
≥5
6
1.7
Total
354
100.0
3.2.4. Padua cutoff point in the research

Table 3.6. Padua cut off point in the research
PADU
DVT
None DVT
OR(95%
p
A score
n(%)
n(%)
CI)
≥3
71 (33.2)
143 (66.8)
0.
1,68
037
(1,03-2,73)
<3
32 (22.9)
108 (77.1)
Sensitivity = 68.9;
Specificity = 43.
≥4
54 (37.2)
91 (62.8)
0.
1,94
005
(1,22-3,08)
<4

49 (23.4)
160 (76.6)
Sensitivity = 52.4;
Specificity = 63.7
≥5
47 (38.5)
75 (61.5)
0.
1,97
005
(1,23-3,16)
<5
56 (24.1)
176 (75.9)
Sensitivity = 45.6;
Specificity = 70.1


13
- The cut-off point of Padua <4 & ≥ 4 is suitable for the
sensitivity of 52.4%, specificity 63.7%, p = 0.005
3.2.5. Multivariate regression analysis of risk factors and lower
extremity DVT
3.2.5.1. Univariate regression analysis
Table 3.7. Univariate regression analysis of risk factors and lower
extremity DVT
Factors
> 60
≤ 60
Male

Gender
Female
Yes
Smoking
No
Yes
Heart
failure
No
Yes
Respiratory
failure
No
Yes
Cancer
No
≥4
Padua
<4
Yes
Ventilator
No
Age

LEDVT
None LEDVT
n
%
n
%

85
33.7
167
66.3
15
17.6
84
82.4
87
32.7
179
67.3
16
18.2
72
81.8
72
39.1
112
60.9
1
18.2
139
81.8
40
46.5
46
53.5
63
23.1

205
76.5
70
33.2
147
66.8
30
22.4
104
77.6
17
44.7
21
55.3
86
27.2
230
72.8
54
37.24
91
62.76
49
23.44 160 76.56
73
33.2
147
66.8
30
22.4

104
77,6

OR(95%CI)
2.37
(1.33 - 4.24)
2.2
(1.2 - 4.0)
2.88
(1.7 - 4.8)
2.82
(1.68 - 4.77)
1.7
(1.1-2.8)

p
0.003
0.009
<0.001
<0.001
0.03

2.2
0.025
(1.1-4.3)
1.94
0.005
(1.21-3.10)
1.72
0.03

(1.04 - 2.83)

3.2.5.2. Multivariate regression analysis
Table 3.8. Multivariate regression analysis of risk factors and lower
extremity DVT
Factors
OR (95% CI)
p
Age > 60
1.64 (0.85 - 3.18)
0.141
Gender
1.02 (0.46 - 2.26)
0.957
Smoking
2.57 (1.32 - 5.01)
0.006
Heart failure
2.92 (1.63 - 5.23)
<0.001
Respiratory failure
1.43 (0.71 - 2.86)
0.315
Cancer
1.37 (0.58 - 3.27)
0.474


14
Pardua (≥ 4)

2.72 (1.13 - 6.58)
0.026
Ventilator
1.31 (0.69 - 2.51)
0.411
Table 3.9. Multivariate regression analysis of risk factors over time
7th day
Factors

HR(95%CI)

1.868
(0.97-3.61)
1.551
Gender
(0.70-3.43)
1.262
Smoking
(0.69-2.31)
Heart
0.527
failure
(0.25-1.12)
Respiratory
1.294
failure
(0.70-2.41)
1.148
Cancer
(0.60-2.19)

Pardua (≥
1.751
4)
(1.07-2.86)
1.036
Ventilator
(0.58-1.84)
Age> 60

p
0.063
0.279
0.451
0.094
0.416
0.674
0.025
0.904

14th day
HR
p
(95%CI)
1.934
0.025
(1.09-3.45)
1.062
0.863
(0.54-2.09)
1.578

0.114
(0.90-2.78)
0.429
0.018
(0.21-0.86)
1.350
0.289
(0.78-2.35)
1.129
0.689
(0.62-2.04)
1.575
0.041
(1.02-2.44)
0.994
0.982
(0.60-1.66)

21 th day
HR
p
(95%CI)
1.902
0.029
(1.07-3.39)
1.061
0.864
(0.54-2.09)
1.614
0.097

(0.92-2.84)
0.480
0.032
(0.25-0.94)
1.287
0.368
(0.74-2.23)
1.212
0.513
(0.68-2.16)
1.598
0.035
(1.03-2.47)
1.004
0.989
(0.60-1.67)

Table 3.9. Multivariate regression analysis of risk factors in the
prophylaxis group and no prophylaxis group.
Factors

OR (95% CI)
Prophylaxis

No prophylaxis

p1*

p2**

Age> 60

2,82 (0,75 - 10,62)

2,50 (0,98 - 6,38)

0,125

0,045

Gender

0,97 (0,31 - 3,08)

1,35 (0,42 - 4,40)

0,96

0,613

Smoking

0,48 (0,14 - 1,61)

5,33 (2,07 - 13,75)

0,235

0,001

Heart failure

0,3 (0,07 - 1,24)

0,23 (0,08 - 0,62)

0,097

0,004

Respiratory
failure

2,29 (0,54 - 9,78)

1,14 (0,47 - 2,72)

0,26

0,773

Cancer

0,48 (0,07 - 3,30)

1,40 (0,48 - 4,10)

0,456

0,535

Pardua ≥ 4

6,31 (1,20 - 33,08)

4,09 (1,18 - 14,21)

0,029

0,026

Motionless

0,71 (0,15 - 3,43)

0,23 (0,06 - 0,85)

0,676

0,028


15
Ventilator

0,63 (0,16 - 2,48)

1,92 (0,81 - 4,57)

0,510

0,138

p1*: prophylaxis group; p2**: No prophylaxis group

3.3. Efficacy of prophylaxis of lower extremity DVT
with Enoxaparin
3.3.1. Incidence lower extremity DVT rate
Table 3.10. Incidence lower extremity DVT rate and prevention
Prevention
Yes
No
Total

Number of
patients
N (%)
171 (48.3)
183 (51.7)
354 (100.0)

LEDVT
n(%)
23 (13.4)
80 (43.7)
103 (29.1)

None
LEDVT
p

n(%)
148 (86.6)
< 0.001
103 (56.3)
251 (70.9)

RR (95%CI)
0.38
(0.26 - 0.55)

The incidence of LEDVT newly acquired in the prophylactic
group is lower than the non-prophylactic group, the difference is
statistically significant.
3.3.2. Time detection and prevention LEDVT
Table 3.11. Time detection and prevention LEDVT
Prevention
Patient
Time detection
LEDVT
p
Yes
No
LEDVT
(n=103)
n(%)
n(%)
After 7th days
83
18 (21.7)
65 (78.3)

<0.001
After 14 days
19
4 (21.1)
15 (78.9) <0.001
After 21 days
1
0 (0.0)
1 (100.0)
After 28 days
0
0 (0.0)
0 (0.0)
3.3.3 Mortality from all causes and prevention of
lower extremity DVT
Table 3.12. The relationship between mortality and prevention
Prevention
Yes

Number of
patients
N(%)
171 (48.3)

Death
n (%)

No death
n (%)

p

OR (95%CI)

10 (5.9)

161 (94.1)

0.00

0.49


16
No

183 (51.7)

30
(16.4)

Total

354
(100.0)

40 (11.3)

153 (83.6)

2

(0.28-0.84)

314 (8.7)

- Mortality rate in the prophylactic group is lower than the nonprophylactic group, the difference is statistically significant.
Table 3.13. Mortality rate in patients with LEDVT and non-LEDVT
patients
Mortality
Patient
p
OR
Yes n (%)
No n (%)
LEDVT
17 (16.5)
86 (83.5)
1.96
0.048
Non-LEDVT
23 (9.16)
228 (90.84)
(0.93 - 4.03)
Total
40 (11.3)
314 (88.70)
- Mortality rate in the group with LEDVT is higher than the group
without LEDVT, the difference is statistically significant.
3.3.4. Safety of prophylactic LEDVT by Enoxaparin

Table 3.14. Proportion of patients with thrombocytopenia and
prophylaxis
Preventio
n
Yes
No
Total

Number
No
Thrombocytopeni
OR
of
thrombocytopenia p
a
(95%CI)
patients
n (%)
n (%)
171
13 (7.6)
158 (92.4)
0.96
(48.3)
0.83
(0.63 6
183
1.45)
15 (8.2)
168 (91.8)

(51.7)
354
28 (7.9)
326 (92.1)
(100.0)

- The rate of thrombocytopenia in the prophylactic group is lower
than the non-prophylactic group, the difference is not statistically
significant.
- There were no cases of severe hemorrhage in the study
Table 3.15. Proportion of patients changing creatinine with
prophylaxis
Prevention
Patients
Creatinin Creatinin
p RR (95%CI)
N (%)
(≥ 120)
(<120)


17
n (%)
n (%)
Yes
171 (48.3) 12 (7.0) 159 (93.0)
1.14
0.54
(0.77-1.69)
No

183 (51.7)
10(5.5)
173 (94.5)
Total
354 (100.0) 21 (5.9) 333 (94.1)
- The proportion of patients with creatinine blood > 120 in the
prophylactic group is higher than the non-prophylactic group, the
difference is not statistically significant.
Chapter 4
DISCUSSION
During the study of DVT prophylaxis in ICU patients was uneven
and unified. Only in July 2017, the Vietnam National Associated
Emergency, Intensive Care Medicine and Clinical Toxicology guidelines
for prophylaxis of DVT in patients with intensive care. Therefore, out of
354 patients eligible for inclusion in the study, there was a group of
patients with DVT prophylaxis (171 patients, 48.3%) and a group of
patients who did not prevent DVT (183 patients, 51.7 %).
4.1. Characteristics of researched patient group
4.1.1. Characteristics of patients group studied with qualitative
variables
The ratio of qualitative variables between the prophylactic and
non-prophylactic groups was similar (p> 0.05). The group of infected
patient accounts for a high proportion (80.2%), respiratory failure
62.1%, and hypertension 52.8%, and mechanical ventilation 43.8%.
This result is equivalent to the authors in the country, higher than
foreign authors.
4.1.2. Characteristics of patients group studied with quantitative
variables
There was no statistically significant difference in the mean of
quantitative variables between the prophylactic and non-prophylactic

groups (p > 0.05). The average age of patients in the study was 69.1 ±


18
17.9 years, equivalent to the age in the studies of domestic and
foreign authors. The average age of patients studied at the Bach Mai
hospital was 57.9 ± 17.9 years, lower than the average age of patients
studied at the Friendship hospital was 80.2 ± 8.8 years, due to almost
patients at the Friendship Hospital are older people.
The average body mass index of the sample is 20.7 ± 2.3 kg/m 2,
which is consistent with the average body mass index of hospitalized
patients in Vietnam. According to the World Health Organization, a
nutrition classification for Asians, this study included 12.15% of
obese patients. The proportion of obese patients had no difference
between the prophylactic and non-prophylaxis groups. The
proportion of obese patients in the study is lower than other domestic
and foreign studies. It is possible that the age of patients in the
sample is elderly Vietnamese people, due to race. Domestically, the
obesity rate in the study of Pham Anh Tuan is 22.4%. In Western
countries, the rate of obesity in the study of the author Samama M:
19.6%, the author Lazoroviz: 30.6%.
4.2. Risk factors for LEDVT in the study population
4.2.1. Risk factors for LEDVT
- The proportion of patients with LEDVT in the infection group
(30.28%) was higher than the non-infected group (24.28%), but there
was no difference.
- The proportion of patients with LEDVT in the respiratory failure
group is higher than the non-respiratory group and this difference is
statistically significant with p = 0.03.
- The rate of patients with heart failure in the group of LEDVT

was higher than that of the group without the LEDVT, this difference
was statistically significant with p = 0.001.
- The percentage of patients with LEDVT in the cancer group is
significantly higher than the non-cancer group with p = 0.025.


19
- In the study, the number of mechanical ventilation patients in the
group of patients with LEDVT was higher than the number of
patients without LEDVT, the difference was statistically significant
with p = 0.003.
- Patients with LEDVT in patients with COPD exacerbations were
higher than in patients without COPD exacerbations, but this
difference was not statistically significant.
- The proportion of patients with LEDVT in the catheter group is
higher than the number of patients in the non-catheter group, but this
difference is not statistically significant.
- The rate of patients with LEDVT in the sedative group was 1.3
times higher than the group in the non-sedative group, but this
difference was not statistically significant.
-The proportion of patients with LEDVT in the group that used
vasopressors was 1.36 times higher than the group without vasomotor
drugs, but the difference was not statistically significant.
- The percentage of patients with LEDVT in the 2 groups of
cerebral infarction and non-cerebral infarction was no difference.
- In the study, we did not recognize the relationship between
hematological parameters, basic blood coagulation function and LEDVT.
4.2.2. Relationship between PADUA prediction core and LEDVT
The percentage of patients with LEDVT in the group with Padua
prediction score ≥4 is higher than the group with the Padua prediction

score <4, the difference is statistically significant with p = 0.005
When analyzing 3 cutting points with Padua score (≥3 and < 3), (≥4
and <4), (≥5 and <5) the difference in the prevalence of LEDVT is
significant, but with the Padua score cut (≥4 and <4) it showed that
the sensitivity and specificity are relatively similar.
4.2.3. Multivariate regression analysis of the risk of LEDVT


20
Through multivariate regression analysis, the univariate risk in the
study showed that the Padua prediction score ≥ 4 has significant
predictive of LEDVT, smokers, patients with heart failure are
independent risk factors for LEDVT in patients with ICU.
Through multivariate regression analysis over time, we found that
the Padua prediction score ≥ 4 has significant predictive of LEDVT
at all 3 points, age of patients > 60 years, heart failure is the
independent risk factors for LEDVT after 14 days and after 21 days
in ICU.
Through multivariate regression analysis in the prophylaxis group
and no prophylaxis group, we found that the Padua prediction score ≥
4 has significant predictive of LEDVT for both of them, age of
patients > 60 years, heart failure. smoking anh motionless is the
independent risk factors for LEDVT in no prophylaxis group in ICU.
4.3. Efficacy of preventive treatment of LEDVT with Enoxaparin
4.3.1. The neww incidence LEDVT rate
The prevalence of LEDVT in prevention group was 13.4% and in
non-preventive groups was 43.7%, this difference was statistically
significant (p <0.001). This rate is higher than the results of Western
studies such as MEDENOX 5.5, PREVENT 2.8, ARTEMIS 5.6%,
lower than Kaplan (2015), 113 In severe infections and septic shock

patients at the Department of Gastroenterology, all prophylactic
treatment showed a 37.2% prevalence of MS. Fraisse (2000) studied
223 patients with COPD exacerbations in France that showed the
incidence in patients with prophylaxis was 15.5%. Thus, the
prophylaxis of the LEDVT in patients with LEDVT reduces the
incidence of newly acquired DVT compared to no prophylaxis. The
results of our study are similar to those of prophylactic studies in


21
patients in the West, with prophylaxis reducing the incidence of new
infections compared with no prophylaxis. The incidence of LEDVT
varies due to different patients, patients with many different diseases,
different study time.
4.3.2. Time detection and prevention LEDVT
The prevalence of LEDVT primarily occurred in the first 7 days
of hospital admission, 83/103 patients (80.58%), the rate of LEDVT
in the prophylactic group was lower than the non-prophylactic group
with statistically significant (p <0.001). After 14 days of admission,
there were 19/103 more patients with LEDVT (18.45%), prophylactic
patients had a lower incidence of LEDVT than non-prophylaxis (p
<0.001). Only 1 case was detected by LEDVT at T3 and in nonprophylactic patients. Thus, the risk assessment and prevention of
LEDVT must be as soon as the patient is admitted to the hospital.
4.3.3. Characteristics of patients with DVD in the
prophylactic group
Despite the preventive care of DVT, there are still 18 new DVT
cases. Survey results show that: all 18 cases had multiple risk factors
for DVT at the same time, 15/18 (83.33%) cases belonged to the
group "> 60 years old", and infection of 15/18 (83.33) %), men have
12/18 (66.67%), Padua prediction scores ≥ 4 12/18 (66.67%),

respiratory failure 11/18 (61.11%), 7/18 (38.89) %) smoking. As
such, ICU patients have many risk factors for DVT, in addition to
drug prophylaxis, it is necessary to coordinate with non-drug
prophylaxis and screening ultrasound to detect DVT early.
4.3.4. Mortality from all causes and due to LEDVT


22
- Through the study of 354 ICU patients, there were 10 deaths in
the preventive group (accounting for 6.67%), there were 30 deaths in
the non-preventive group (accounting for 14.71%). The mortality rate
in the prophylactic group is lower than the non-prophylactic group,
the difference is statistically significant (p = 0.018). The mortality
rate in the prophylactic group is lower than the non-prophylactic
group, this result is similar to the results of studies such as Samama
M (4.9% and 6.2%), Cohen AT (3.3% and 6.0%).
- Among patients with LEDVT, 16.5% (10/173) of the patients
died higher than the mortality rate in the non-LEDVT group, 10.16%
(23/251) of the patients, the difference was statistically significant
with p = 0.048. Similar to the results of Lyman (2018), the mortality
rate in the group without VT is 5.5%, the mortality rate in the group
with VT increased to 15.0%.
4.3.5. Safety of prophylactic DVT prophylaxis with Enoxaparin
in ICU patients
- Hemorrhage and prophylaxis: no cases of severe hemorrhage
during hospitalization, 9 cases of minor bleeding in the
prophylactic group (6%) and 5 cases of non-severe bleeding in the
non-prophylactic group (2.45%), the difference is not statistically
significant, the results of this study are similar to the results of
studies in the West.

- Thrombocytopenia and prophylaxis: There are 2 cases of
thrombocytopenia in the prophylactic group (1.3%) and 4 cases in the
non-prophylactic group (1.9%). The difference is not statistically
significant. The percentage of prophylactic studies of Samama M is
2.2% and 3.6%, Lazoroviz's studies are 0.3% and 0.5%.


23
- Changes in blood creatinine levels and prophylaxis: In the
prophylactic group, there was 8% (12/150) of patients with an
increase in blood creatinine > 120 mmol / l, in the non-prophylactic
group less than 4.4% (9/204). The difference is not statistically
significant with p = 0.158.
CONCLUSION
Through a study of 354 patients enrolled in the Department of
Ememgency- Resuscitation Internal Medicine (ICU), comparing the
two groups with deep lower venous thromboembolism and no lower
deep vein thrombosis, we reached the following conclusions:
1. Independent risk factor for the appearance of lower
extremity deep vein thrombosis in ICU patients is: Smoking (OR
2.57; 95% CI 1.32 - 5.01 p = 0.006), Heart failure (OR 2.92, 95%CI 1.63 5.23; p <0.001). The transcript of the risk factors for predicting LEDVT
Padua prediction scores with cut points (< 4, ≥ 4) is significant in the
prediction of the LEDVT (OR 2.72; 95% CI 1.13 - 6.58; p = 0.026).
- Some other factors such as: Age > 60, BMI ≥ 23 kg/m 2, gender,
respiratory failure, cancer, infection, mechanical ventilation in the
study are significant in univariate analysis but when multivariate
analysis did not see the difference with statistical significance.
2. Reviews preventive results lower extremity
deep vein thrombosis with Enoxaparin:
- Enoxaparin prophylactic group of patients had a lower incidence of new

deep vein thrombosis than the non-prophylactic group, with a statistically
significant difference (The incidence of DVT in the prophylactic group:
13.7%, in the non-prophylactic group: 43.7%, p <0.001).
- The prevalence of LEDVT primarily occurred in the first 7 days
of hospital admission, 83/103 patients (80.58%), the rate of LEDVT