Incidence and Nature of Lower-Limb Deep Vein Thrombosis in Patients with Polytrauma on Thromboprophylaxis: A Prospective Cohort Study

Figures & data

Figure 1 VTE risk assessment and prophylaxis.

Table 1 The Demographics, Mechanism of Injuries, Baseline Characteristics on Presentation to the Emergency Department, Associated Risk Factors, Comorbidities, Surgeries, ISS, ICU Admission, Hospital Length of Stay, VTE Incidence, and Deaths for the Moderate- to High-Risk and the Highest-Risk Groups

Variables	Total (n=169)	Moderate- to High Risk for VTE (n=100)	The Highest-Risk for VTE (n=69)	p-value
Age (mean years, SD)	38.1 (14.7)	34.7 (10.9)	42.9 (17.8)	p=0.000*
Sex				p=0.936
Male sex (%)	149 (88.2%)	88 (88%)	61 (88.4%)
Female sex (%)	20 (11.8%)	12 (12%)	8 (11.6%)
Nationality:				p=0.128
Saudi (%)	101 (59.8%)	55 (55%)	46 (66.7%)
Non-Saudi (%)	68 (40.2%)	45 (45%)	23 (33.3%)
Mechanism of injury:				p=0.800
Motor vehicle accident (%)	146 (86.4%)	85 (85%)	61 (88.3%)
Low fall (<1meter, %)	3 (1.8%)	2 (2%)	1 (1.5%)
High fall (>1 meter, %)	12 (7.1%)	7 (7%)	5 (7.2%)
Assault (%)	2 (1.2%)	1 (1%)	1 (1.5%)
Penetrating (%)	6 (3.5%)	5 (5%)	1 (1.5%)
GCS (median, IQR)	14 (8–15)	15 (9–15)	10 (7–15)	p=0.002*
SBP (mean mmHg, SD)	119.5 (20.5)	119.3 (18.4)	119.8 (23.8)	p=0.431
HR (mean beat/min)	95.1 (19)	92.4 (18.8)	99 (18.7)	p=0.013*
Shock Index (HR/SBP)	1.2 (5.0)	1.4 (6.5)	0.9 (0.3)	p=0.242
Hemoglobin (mean g/dL, SD)	11.5 (2.5)	11.9 (2.3)	10.9 (2.7)	p=0.007*
Lactate (mean mmol/L, SD)	2.6 (1.6)	2.5 (1.4)	2.8 (1.9)	p=0.136
INR (mean, SD)	1.1 (0.2)	1.03 (0.23)	1.09 (0.24)	p=0.089
PH (mean, SD)	7.35 (0.08)	7.36 (0.08)	7.34 (0.09)	p=0.112
HCO3 (mean, SD)	21.8 (3.7)	22.1 (3.2)	21.3 (4.3)	p=0.096
Base deficit (mean, SD)	−1.9 (3.5)	−1.8 (3.6)	−2.1 (3.4)	p=0.273
Red cell transfusion in ED (%)	29 (17.2%)	10 (10%)	19 (27.5%)	p=0.003*
Intubated (%)	78 (46.2%)	39 (39%)	39 (56.5)	p=0.025*
BMI >24 (%)	29 (17.2%)	13 (13%)	16 (23.2%)	p=0.084
History of antiplatelet therapy (%)	6 (3.6%)	2 (2%)	4 (5.8%)	P=0.190
Comorbidities:
Hypertension (%)	16 (9.5%)	10 (10%)	6 (8.7%)	p=0.775
Diabetes (%)	12 (7.1%)	6 (6%)	6 (8.7%)	p=0.502
Ischemic heart disease (%)	6 (3.6%)	2 (2%)	4 (5.8%)	p=0.190
Previous stroke (%)	0	0	0	Invalid
Cancer (%)	0	0	0	Invalid
Surgeries:
Number of patients (%)	92 (54.4%)	49 ((49%)	43 (62.3%)	p=0.087
Types of surgeries^†:
Craniotomy/Craniectomy (%)	15 (8.9%)	8 (8%)	7 (10.1%)	p=0.232
Facial (%)	14 (8.3%)	8 (8%)	6 (8.7%)	p=0.872
Neck exploration (%)	1 (0.6%)	1 (1%)	0 (0%)	Invalid
Thoracotomy (%)	5 (3%)	3 (3%)	2 (2.9%)	p=0.969
Laparotomy (%)	13 (7.7%)	6 (6%)	7 (10.1%)	p=0.320
Vascular (%)	4 (2.4%)	2 (2%)	2 (2.9%)	p=0.706
Pelvic fixation (%)	8 (4.7%)	3 (3%)	5 (7.2%)	p=0.201
Upper limb (%)	16 (9.5%)	10 (10%)	6 (8.7%)	p=0.776
Lower limb (%)	32 (18.9%)	16 (16%)	16 (23.2%)	p=0.241
Vertebral Column (%)	19 (11.2%)	9 (9%)	10 (14.5%)	p=0.267
ISS:				P<0.000*
<16 (%)	76 (45%)	54 (54%)	22 (31.9%)
16–25 (%)	62 (36.7%)	40 (40%)	22 (31.9%)
>25 (%)	31 (18.3%)	6 (6%)	25 (36.2%)
ICU admissions (%)	87 (51.5%)	41 (41%)	46 (66.7%)	p=0.001*
Hospital length of stay (mean days, SD)	25.9 (22.3)	20.8 (18.2)	33.2 (25.5)	p=0.000*
VTE (%):	7 (4.2%)	2 (2%)	5 (7.2%)	p=0.092
DVT (%)	3 (1.8%)	1 (1%)	2 (2.9%)	p=0.358
PE (%)	4 (2.4%)	1 (1%)	3 (4.3%)	p=0.159
Death^‡ (%)	9 (5.33%)	4 (4%)	5 (7.2%)	p=0.356

Notes: *Significant p-values, ^†Same patient had single or multiple surgeries. ^‡No deaths were related to VTE.

Abbreviations: ISS, injury severity score; ICU, intensive care unit; VTE, venous thromboembolism; SD, standard deviation; GCS, Glasgow coma scale; IQR, interquartile range; SBP, systolic blood pressure; HR, heart rate; INR, international normalized ratio; BMI, body mass index; DVT, deep vein thrombosis; PE, pulmonary embolism.

Table 2 VTE Prophylaxis on Admission

VTE Prophylaxis	Total (n=169)	Moderate- to High-Risk for VTE (n=100)	The Highest-Risk for VTE (n=69)	p-value
Pharmacological agents (Enoxaparin^† or UFH^‡)	115 (68%)	72 (72%)	43 (62.3%)	p=0.185 (Chi-squared 1.76)
IPC*	54 (32%)	28 (28%)	26 (37.7%)

Notes: ^†Enoxaparin: Patients with moderate- to high-risk received enoxaparin 40 mg subcutaneously daily. Patients in the highest-risk group received enoxaparin doses of 30 mg twice daily in addition to IPC. ^‡UFH: When the patient’s creatinine clearance was < 30 mL/min or when enoxaparin was contraindicated (eg, pregnancy), the patient received 5000 IU of UFH subcutaneously three times daily in both groups. *IPC: If pharmacologic prophylaxis was not possible on admission because of bleeding risk or active bleeding. The pharmacologic agent was commenced when bleeding risk was minimized within 72 h of admission. The IPC was discontinued for patients with moderate- to high-risk group but continued in the highest-risk group.

Abbreviations: VTE, venous thromboembolism; UFH, unfractionated heparin; IPC, intermittent pneumatic compressor.

Table 3 Characteristics of Positive DVT and PE Patients

Sl. No.	Patient	Risk Category	ICU	ISS	Extremities Fractures	Associated Injuries	Site & Type of DVT	Associated DVT and/or PE	Day of Diagnosis
1	DVT	Moderate- to High	Yes	17	Right tib/fib fractures	Severe TBI, C2 fracture, and bilateral lung contusions	Right above knee (occlusive)	No PE	7
2	DVT	Highest	Yes	38	Right tib/fib fractures	Severe TBI, bilateral lung contusions and haemothoraces	Left above and below knee (occlusive)	No PE	7
3	DVT	Highest	Yes	27	No	Severe TBI and facial fractures	Bilateral above Knee (non-occlusive)	No PE	21
4	PE	Moderate- to High	Yes	17	No	Severe TBI, facial fractures, Bilateral lung contusions, and T6-11 fractures	Bilateral segmental	No DVT	9
5	PE	Moderate- to High	No	22	Left femur	Bilateral lung contusions, multiple rib fractures, and L1-4 fractures	Bilateral lobar and segmental	No DVT	3
6	PE	Highest	Yes	33	No	TBI, facial fractures, bilateral lung contusions, right 3rd rib fracture, and L1 compression fracture	Right segmental	No DVT	5
7	PE	Highest	Yes	26	No	Facial fractures, left hemopneumothorax, left pubic rami fractures.	Bilateral segmental	No DVT	13

Abbreviations: DVT, deep vein thrombosis; PE, pulmonary embolism; ICU, intensive care unit; ISS, injury severity score; TBI, traumatic brain injuries; C2, second cervical vertebra; T6-11, sixth to eleventh thoracic vertebrae; L1-4, first to fourth lumbar vertebrae; L1, first lumbar vertebra.