Patients and methods
Study design & Settings
Prospective cohort study was conducted from August 2014 to July 2015 (eleven months) at Baghdad Medical city complex (Ghazi Al-Hariri hospital).
Population of study:
Young patients with lower limbs long bones compound fractures.
Inclusion criteria:
1. Acute trauma
2. Compound fracture(s) lower limb long bone(s)
3. Admitted & managed in our ward for at least 10 days
4. Pure orthopedic injuries (no other system injuries)
5. No associated diagnosed comorbidities prior to injury
Exclusion criteria:
1. Associated contralateral lower limb injuries and / or spine injury.
2. Closed fractures.
Sampling & data collection:
The study sample included 33 trauma victims, who had compound fractures of lower limb long bones including femur, tibia or ipsilateral both bones. The data were collected by the researcher by direct interview and filling a prepared questionnaire . The patients’ age ranged from 16 to 48 years. All of them were male patients All of them had been admitted to our emergency ward were evaluated and assessed by ATLS protocol and secondary survey show that was a solitary orthopedic injury, at that time patients received antibiotics , analgesics ,fluid resuscitation and routine laboratory investigation with radiological assessment.
. After emergency intervention has been done, the patients were admitted to our orthopedic ward, where further assessment and follow up continued, those patients had urgent initial intervention in the form of wound debridement, fixation by external fixator. All patients were classified according to Gustilo classification of compound fractures. We choose only the patients with type IIIA or IIIB. External fixation was either for femur, tibia, both bones & sometimes spanning type depending on the type of injury. External fixation was either part of initial stabilization for later conversion to internal fixation, or as a definitive treatment.
All patients received one or more units of blood transfusion during the course of their stay. Blood tests done on admission at the 2nd day of admission and another set done at 10 day of hospital stay that included complete blood picture (CBP), random blood sugar, Renal Function Tests (RFT), bleeding profile (PT, PTT, INR) . Patients were under the care of multiple surgeons representing different orthopedic units in our department with single / multiple sessions of debridement with reevaluation.
According to the guideline followed by the treating surgeon(s) regarding the intervention, Patients were divided into two groups; those were receiving chemoprophylaxis and those without. Chemoprophylaxis was in the form of subcutaneous enoxaparin 4000 IU per day(18), starting after 12 to 24 hours of urgent operation (because some of them fit within the 12 hours but others were not due to the system of drug giving . All patients should have a baseline platelet count prior to starting treatment. Other baseline monitoring should include: patient weight, INR, urea and CBP. (18)
Patient clinical assessment for DVT sign and symptom done on daily basis., which include leg swelling ,redness , hot ness and tenderness.in addition to that the assessment of chemoprophylaxis done by determine bleeding from injury site or other site.
At 10 – 14 day of admission the patient send for Doppler ultrasound for detection of venous thrombosis of the lower limb as screening test.
Then the data collected during the patients’ stay which ranged from 10 – 14 days. For assessment of Outcome measures which include:
1. Evidence of DVT (clinical and Screening Doppler study result)
2. Evidence of bleeding tendency (clinical and laboratory bleeding profile changes)
The patients after that were either transferred to plastic surgery unite for complete their management or discharged to their home and follow up accordingly ,some patients referred to nearby hospital for their with management
Ethical considerations
Patients’ consent & responsible surgeons` permission and institute written agreement were obtained.
The relatively small sample size was mainly due to:
1. Because of the patient load, most patients were discharged to other cities’ hospitals to complete their treatment as soon as they are stable & they are willing to go to their cities.
2. Not all treating surgeons accept to add enoxaparin to his patients.
3. Doppler study was not available all the time.
In this way many eligible patients were excluded from our study.
Statistical analysis
All patients’ data entered using computerized statistical software .descriptive statistics presented as mean and standard deviation. Appropriate statistical tests were performed including student t test for parametric data and Fischer exact test for categorical data.in all statistical analysis, level of significance (p value) was set at < 0.05 and the results were presented as tables and or graphs.
DISCUSSION
There is a great increase in the incidence of trauma in the last decade. Many of these injuries result in compound fractures. The impact of these compound fractures is great. Every effort is directed towards improvement of care of this group of patients.
Guidelines for VTE prophylaxis have been created for elective orthopedic surgery procedures but little cohesive evidence exists to guide VTE prophylaxis for trauma patients. Many national organizations prioritizing VTE prevention as critical patient safety initiative, there has been little consensus on the development of effective and safe risk assessment strategies not mention policy supported, evidence-substantiated VTE prophylaxis protocols for trauma patients (1) .
Despite decades of research, the optimal method of prophylaxis against venous thromboembolism (VTE) after trauma is not known. The complexity of the body’s response to injury is in part to blame for our failure to understand how to prevent life-threatening venous clots from forming. Cessation of bleeding depends on the induction of a prothrombotic stage after injury, clearly an evolutionary characteristic with major survival benefits. Its downside is VTE. Preventing deep venous thrombosis (DVT) and pulmonary embolism (PE) without interrupting the ability to seal bleeding vessels presents a formidable challenge to trauma surgeons. (19)
There is currently insufficient research to be able to inform trauma surgeons as to the optimal method of thromboprophylaxis for patients following major skeletal trauma. (20)
By recognizing that lower limb’s compound fractures possess the three limbs of Virchow’s triad (8) starting from
1. Immobilization: patients with lower limbs fractures, usually suffer from decreased mobility or complete immobilization.
2. Endothelial injury: either direct endothelial injury by the causative trauma or indirectly by the following sequences like increased intra compartmental pressure, superadded infection and iatrogenic by surgical debridement session (s)
3. Hypercoagulability: multiple transfusions , consumption coagulopathy and certain bacterial induced thrombosis (MRSA associated deep venous thrombosis)
In a study done by Knudson(21) , Significant risk factors associated with the development of thromboembolism included immobilization > 3 days, age 30 years or older, and the presence of pelvic or lower extremity fractures.
We designed our work so that our patients are characterized by having an acute unilateral compound lower limb fracture(S) as the only variable risk factor for DVT.
So patients had the following inclusion criteria:
1. Acute trauma
2. Compound fracture(s) lower limb long bone(s)
3. Admitted & managed in our ward for at least 10 days
4. Pure orthopedic injuries (no other system injuries)
5. No associated diagnosed comorbidities prior to injury
Exclusion criteria was
1. Associated contralateral lower limb injuries and / or spine injury
2. Closed fractures
The study sample included 33 trauma victims, who had compound fractures of lower limb long bones including femur, tibia or ipsilateral both bones. The data were collected by the researcher by direct interview and filling a prepared questionnaire . The patients’ age ranged from 16 to 48 years. All of them were male patients All of them had been admitted to our emergency ward were evaluated and assessed by ATLS protocol and secondary survey show that was a solitary orthopedic injury, at that time patients received antibiotics , analgesics ,fluid resuscitation and routine laboratory investigation with radiological assessment.
After emergency intervention has been done, the patients were admitted to our orthopedic ward, where further assessment and follow up continued, those patients had urgent initial intervention in the form of wound debridement, fixation by external fixator. All patients were classified according to Gustilo classification (3) of compound fractures. We choose only the patients with type IIIA or IIIB. External fixation was either for femur, tibia, both bones & sometimes spanning type depending on the type of injury. External fixation was either part of initial stabilization for later conversion to internal fixation, or as a definitive treatment.
All patients received one or more units of blood transfusion during the course of their stay. Blood tests done on admission at the 2nd day of admission and another set done at 10 day of hospital stay that included complete blood picture (CBP), random blood sugar, Renal Function Tests (RFT), bleeding profile (PT, PTT, INR) . Patients were under the care of multiple surgeons representing different orthopedic units in our department with single / multiple sessions of debridement with reevaluation.
External mechanical devices such as graded compression devices or intermittent pneumatic compression (IPC) have been shown to be effective in preventing DVT, but they cannot be used in patients with lower extremity trauma. (16)
According to the guideline followed by the treating surgeon(s) regarding the intervention, Patients were divided into two groups; 15 patients in group A were receiving chemoprophylaxis and group B without. Chemoprophylaxis was in the form of subcutaneous enoxaparin 4000 IU per day, starting after 12 to 24 hours of urgent operation (because some of them fit within the 12 hours but others were not due to the system of drug giving. All patients have a base line platelet count prior to starting treatment. Other baseline monitoring should include: patient weight, INR, blood urea s.creatinin and CBP (18) .
The use of LMWH has gained popularity in medical land general surgical patients for reducing the risk of VTE in the past 20 years. (22)
Patient clinical assessment for DVT sign and symptom done on daily basis., which include leg swelling ,redness , hotness and tenderness.in addition to that the assessment of chemoprophylaxis done by determine bleeding from injury site or other site.
The diagnosis of venous thromboembolism on the basis of clinical signs and symptoms is notoriously inaccurate and, therefore, mandates confirmatory diagnostic testing. (23)
By recognizing that two thirds of patients with DVT asymptomatic. (24)
We looked for screening tests which include:
1. D dimer study
2. Doppler us
3. Venography
Since 1990, the diagnosis of DVT has been obtained noninvasively by means of (still expensive) sonographic examination. (10)
In previous 16 randomized control trials, Doppler ultrasound (Duplex) was used to diagnose DVT. (16)
We chose the Doppler us study as a screening test for the following reasons:
1. Safe
2. Sensitive
3. Available in our hospital
By realizing that Thrombus found within 24 hours of injury and may involve both injured/uninjured extremity. (24)
The Doppler study was done once for each patient after 10 to 14 days from his injury. This variation in timing was related to that Doppler ultrasound is not available at weekends.
Then the data collected during the patients’ stay which ranged from 10 – 14 days. For assessment of Outcome measures which include:
1. Evidence of DVT (clinical and Screening Doppler study result)
2. Evidence of bleeding tendency (clinical and laboratory bleeding profile changes)
The Final results showed presence of 2 asymptomatic DVT in group B, both cases were unilateral compound fracture shaft femur Gustilo 3B while no positive findings in group A.
This means that incidence of DVT in group B was 11% while the incidence in two samples together was 7%
We compare this result to the study of Geerts et al, NEJM 1994 (25), in which 349 injured patients were not receiving prophylaxis and had DVT rate of 18%.
Four trials involving 997 people compared the effect of any type (mechanical and/or pharmacological) of prophylaxis versus no prophylaxis. Prophylaxis reduced the risk of DVT in trauma patients. There was no evidence of statistical heterogeneity between trials. There was no evidence for an effect on PE or mortality. Three trials reported the effect on bleeding, no events were observed in any trial. (16)
Another study done by Knudson MM. In this prospective study, 113 trauma patients were assigned on admission to receive either low-dose heparin (LDH), (5,000 U subcutaneously every 12 hours) or to wear sequential compression devices (SCDs) as prophylaxis against the development of deep venous thrombosis (DVT). Both groups of patients were serially studied with Doppler venous ultrasound imaging to detect thrombus in the veins of the thigh. There were 12 patients who had thromboembolic complications, including 9 of 76 in the SCD group (12%) and 3 of 37 in the LDH group (8%). (26)
Our work hypothesis assumes that the early administration of chemoprophylaxis in the form of subcutaneous low molecular weight heparin will reduce the incidence of DVT in patients with acute lower limbs long bones compound fractures during the . The null hypothesis states that there is no relation.
the statistical analysis for categorical contingency 2 by 2 table of small sample sizes using Fischer exact test, the p value of using chemo prophylaxis was 0.48 which is higher than 0.05 .
We will accept the null hypothesis. So the early administration of chemoprophylaxis in the form of subcutaneous enoxaparin will not decrease the incidence of DVT in patients with acute lower limbs long bones compound fractures in the first 2 weeks following injury.
Chapter five
Conclusion and Recommendations
Conclusion
The use of chemoprophylaxis in the form of subcutaneous enoxaparin in patients with unilateral lower limbs long bones compound fractures despite being safe regarding bleeding complications, it didn’t achieve a statistically significant decrease in incidence of DVT in the early post injury period.
Recommendations
1. Larger sample size to evaluate effect of chemoprophylaxis.
2. Extending the study for longer time (more than 14 days) although the risk of DVT after this period is decreasing as the patient’s external fixation is exchanged into internal fixation and the patient starts mobilization.
Evaluating the cost effectiveness of chemoprophylaxis if further studies show statistically significant difference