Effect of thromboembolic complications prophylaxis on the course of the postoperative period in gerontological patients with polytrauma

It is known that about 75% of patients in older age groups in the postoperative period have disorders of the coagulation-anticoagulation systems of the blood of varying degrees, and their nature is determined by the volume of blood loss, the extent of tissue damage and the type of treatment. Ignoring the factors that provoke the formation of thrombosis, or simply not following the algorithms for its prevention are often the cause of a fatal course of the postoperative period, especially in gerontological patients, which is due to their age-related anatomical and physiological changes. It has been established that the frequency of thromboembolic complications correlates with the severity of the condition, assessed by the APACHE II scale. At the same time, the probability and timing of thrombosis directly depend on the methods of treating existing injuries. The most common hemocoagulation disorder in gerontological patients in the postoperative period is hypercoagulation, which is usually observed with the prevalence of endogenous toxicosis and is a condition in which, as a result of certain pathological changes, there is inadequate accumulation of platelets or fibrin, which can ultimately lead to vascular thrombosis. This is aggravated by such unfavorable factors as forced hypodynamia, the absence of a suction effect of the chest during mechanical ventilation against the background of the introduction of muscle relaxants, and an unphysiological position (excessive rotation) of the limb in a state of muscle relaxation.

In recent years, preference has been given in clinical practice to low-molecular-weight heparins (LMWH), which have a pronounced antithrombotic and weak anticoagulant effect and whose safety has been confirmed by numerous studies. However, it is relevant to search for pathogenetically determined methods of prevention and treatment of hemocoagulation complications in elderly patients, aimed at the possibility of stepwise monotherapy, which is necessary in the presence of concomitant somatic pathology that aggravates the course of the postoperative period. That is why, in the differentiated approach to the prevention of thromboembolic complications, the pharmacological profile of the drugs included in our comparative analysis was taken into account.

In turn, pentosan polysulfate SP 54, which we also consider as a variant of a prophylactic anticoagulant agent in gerontological patients, inhibits the formation of factor Xa in the endogenous coagulation system, preventing the formation of excess thrombin. The main difference from LMWH and UFH is its AT-III-independent mechanism of action on factor X. This allows using pentosan polysulfate for the prevention of thromboembolic complications for a longer period (up to 25 days in injection form) in contrast to unfractionated heparin and LMWH. The presence of ampoule and tablet forms of release allows transfer to the enteral form according to the principle of stepwise prevention of possible thromboembolic complications. The drug activates endogenous fibrinolysis by releasing tissue plasminogen activator from the endothelium into the blood. In addition, pentosan polysulfate activates kallikrein and coagulation factor XII, which is another pathway for activating fibrinolysis; inhibits activation of plasma factor VIII, preventing its transition to the active form and participation in the activation of plasma factor X; reduces the activity of plasma factor V by more than 50%; inhibits intravascular aggregation of erythrocytes, thereby preventing erythrocyte stasis; helps reduce blood viscosity and improves microcirculation. Pentosan polysulfate reduces collagen-induced platelet aggregation, but less than unfractionated heparin, which causes less bleeding from the wound surface. It reduces erythrocyte aggregation in terminal vessels by improving the elasticity of their membranes.

We conducted a study aimed at studying the effectiveness of specific prevention of thrombotic complications in gerontological patients with polytrauma using differentiated use of drugs with anticoagulant properties.

The study included an analysis of comprehensive laboratory and instrumental examination and intensive care of 62 gerontological patients with polytrauma who were hospitalized in the Department of Anesthesiology and Intensive Care for Polytrauma of the Kharkiv City Clinical Hospital of Emergency and Urgent Medical Care named after prof. A. I. Meshchaninov in 2006-2011. All patients aged 65.19±4.74 years were stratified based on the nature and severity of injuries (APACHE II 17.5±3.2 points) and the anticoagulant used. Surgical correction was performed within 12 hours of admission to hospital. The assessment of risk factors for thromboembolic complications according to Tibiana Duprarc (1961) and the degree of risk of postoperative venous thromboembolic complications according to S. Samama and M. Samama in the modification (1999) showed that all patients belonged to the high-risk group. In accordance with the drug received, the patients were divided into 4 groups. In group I (n = 18), enoxaparin was used to prevent thromboembolic complications, in group II (n = 14) - dalteparin, in group III (n = 16) - nadroparin, in group IV (n = 14) - pentosan polysulfate. According to the scheme, prophylactic administration of direct anticoagulants was started 4 hours after surgery in the following dosages: enoxaparin - 40 mg, dalteparin - 5000 IU, nadroparin - 0.6 ml, pentosan polysulfate - at a dose of 100 mg intramuscularly 2 times a day for the first 5 days after surgery, then from the 5th to the 10th day, 100 mg once a day with a transition to taking pentosan polysulfate tablets at 50 mg of the drug 2 times a day for 20 days, then a transition to 50 mg once a day. Along with general clinical and biochemical studies, the hemostasis system was studied by determining the number of platelets and their aggregation properties, activated partial thromboplastin time, and prothrombin index. The studies were conducted on the 1st, 3rd, 5th, 7th and 10th days after the injury. Statistical calculations were performed using the Statistica 6.O software package. The reliability of differences between groups was assessed using the parametric Student t-test with Bonferroni correction for multiple comparisons.

The study revealed that the highest number of thrombotic complications in the form of proximal thrombosis of the veins of the lower extremities (according to ultrasound data) was determined in the group where nadroparin was used - 9 (19.6%). And only in this group, thromboembolism of small branches of the pulmonary artery was diagnosed in the early postoperative period in 3 (6.5%) patients. In the groups where enoxaparin, dalteparin and pentosan polysulfate were used, thrombotic complications were detected in 5 (17.2%), 6 (17.2%) and 2 (6.7%) cases, respectively.

An analysis of the number of hemorrhagic complications, which were manifested by bleeding of the postoperative wound, showed that in Group I it was maximum - 10.3% (3 cases). In Groups II, III and IV it was 5.7% (2 cases), 6.5% (3 cases) and 4% (1 case), respectively.

Thus, based on clinical observations, it can be said that the greatest antithrombotic properties in the prevention of thromboembolic complications in gerontological patients with polytrauma were found in pentosan polysulfate. At the same time, against the background of its use, the number of hemorrhagic complications did not differ significantly. The dynamics of blood coagulation properties when using LMWH reflected a moderate increase in activated partial thromboplastin time and a decrease in the prothrombin index, which were more pronounced in the enoxaparin group, but were not statistically significant.

The results obtained in our studies once again confirmed the opinion of other authors that due to the insignificant effect on the coagulogram parameters, the use of LMWH does not require constant laboratory monitoring. In turn, the analysis of the parameters of vascular-platelet hemostasis showed that LMWH in gerontological victims with acute surgical pathology can cause moderately expressed transient thrombocytopenia, accompanied by a decrease in the aggregation capacity of platelets (differences in the parameters of the number of platelets and their aggregation properties between the groups are unreliable).

Summarizing the results of specific prevention of thrombotic complications in gerontological patients with acute surgical pathology, the following conclusions can be made.

The postoperative period in gerontological patients with polytrauma is characterized by a high risk of thromboembolic complications, which can be fatal. This is due not only to the volume of surgical intervention and concomitant pathology, but also to hypercoagulation syndrome.

Considering the difference in the antithrombotic spectrum of direct anticoagulants and the potential likelihood of hemorrhagic complications, the use of low molecular weight heparins in patients with combined trauma requires a differentiated approach and laboratory monitoring of all links of hemostasis.

In gerontological patients with polytrauma, the use of the injectable form of pentosan polysulfate sodium salt for the prevention of thromboembolic complications in the postoperative period with subsequent transition to the tablet form is pathogenetically justified.

Pentosan polysulfate is the only direct anticoagulant, a drug for the prevention of thromboembolic complications, which has two forms of release, which determines the most effective step-by-step long-term therapy of postoperative complications associated with disturbances in the rheological properties of the blood.

According to generally accepted standards for the prevention of thromboembolic complications, a group of direct anticoagulants is mandatory for administration in the postoperative period of patient management. The emergence of new injection and tablet preparations for the prevention of thromboembolic complications in the physician's arsenal allows for the expansion of the possibilities for conducting the necessary therapy.

Assoc. Prof. Yu. V. Volkova. The impact of prevention of thromboembolic complications on the course of the postoperative period in gerontological patients with polytrauma // International Medical Journal - No. 4 - 2012

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