The nature of the main pathophysiological disorders of the postoperative period.

Extended and extended combined pulmonary resections are operations of choice in surgery for advanced stages of lung cancer. In this case, the most traumatic and, consequently, the most severely tolerated patients are combined operations.

Studies of the duration of surgical interventions and the volume of operative blood loss in two arbitrarily taken groups of patients, 100 people each, who underwent expanded and expanded combined lung resections showed that the amount of blood loss and the duration of the operation when performing extended combined resections is much longer. So, if the average duration of the operation in group 1 patients was 2.1 ± 0.7 hours, then in group 2, it was -2.7 ± 0.5 hours (p <0.001). The volume of operative blood loss among patients of the 1st group was equal to 0.7 ± 0.23 l, 2nd —1.1 ± 0.44 l, (p <0.001).

In addition to these circumstances, the severity and originality of the postoperative period in patients who have undergone advanced combined lung resections is largely determined by the nature and extent of intervention in the extrapulmonary formations and organs of the thoracic cavity. Extensive resections of the pericardium, large nerve trunks and extrapulmonary vessels, diaphragm, chest wall, esophagus, trachea, along with extensive removal of lymph nodes and mediastinal cellulose, “skeletization” of mediastinal organs, significantly aggravate the trauma of the intervention and conceal a number of possibilities of developing dangerous complications in the postoperative period.

Pathological dysfunctions of vital organs and body systems of patients after surgical interventions for advanced stages of lung cancer are characterized by the development of respiratory failure, normochromic anemia and hypovolemia, impaired blood flow in microvessels, circulatory disorders with reduced myocardial performance and metabolic disorders (sodium retention and water, hypokalemia, metabolic alkalosis, hypoproteosis). The function of the endocrine organs , especially the adrenal cortex, undergoes serious changes . The degree of severity of these disorders depends on the initial state of the patient, the volume and nature of the surgical intervention, the complex of the therapeutic measures being conducted.

Inevitably, all operated patients develop respiratory failure, the causes of which are well known . In the postoperative period, gas exchange in the lungs either does not correspond to the body’s increasing oxygen demand, or is provided by the hard work of both the external respiratory system and other systems, primarily the blood circulation.

To clarify the characteristics of the reactions of the circulatory and respiratory systems in patients in the postoperative period for operative trauma, two groups of patients were examined who underwent extended combined (1 group; n = 138) and extended (2 group; n = 204) pneumonectomies. Patients of both groups were matched for age, nature of disorders associated with the underlying disease, and initial functional status. Relationships between executed law and

left-sided pneumonectomy in both groups were almost identical. Thus, in patients of the first group, 91 operations were performed on the right (66%) and 47 — on the left (34%), in the second group 124 — right (61%) and 80 — on the left (39%).

The initial assessment of the reactions of blood circulation and respiration in the postoperative period was carried out immediately after the end of the operation and placement of the patient in the ward of the intensive care unit and intensive care. The rating system was similar to the preoperative examination and the results are fully comparable with baseline data.

The results of studies of central hemodynamic parameters in patients of both groups in the immediate and early and late postoperative periods are given in Tables 20 and 21.

As can be seen from the above data, patients after advanced pneumonectomy (group 2) already in the first hour after surgery, moderate relative hyperdynamia developed with an increase in CR from 1.12 ± 0.11 to 1.21 ± 0.10. At the same time, this blood circulation mode was achieved exclusively by increasing the heart rate from 74.4 ± 3.2 to 101.4 ± 4.8 beats. in 1 min., while reducing one-time performance of the heart (UI = 33.6 ± 3.3 ml . m – ).

A compensatory tonic reaction appears to be a decrease in systemic arterial tone with an increase in temperature gradient (CIT decreased from 78.3 ± 2.8 to 74.4 ± 2.2, while increasing T pv from 5.3 ± 0.4 to 6.4 ± 0 , 40 o C).

At the same time, with practically unchanged, respiration rate, compared to the background data, the CDI increased significantly (from 1.40 ± 0.12 to 1.60 ± 0.19). In the first group of patients, after extended combined pneumonectomies, the response of the first hour was similar, unidirectional, but the amplitude of changes was less pronounced.

Later, in both groups, there was a tendency to a decrease in tachycardia, restoration of quantitative characteristics of a single cardiac performance, relative stabilization of tonic reactions, with an increase in hemodynamic manifestations of respiratory failure. However, if in the second group, patients remained moderate relative hyperdynamic blood circulation during the entire observation period, patients of the first group showed no hyperdynamic, and in some cases, the hypodynamic regime was observed in the second half of the first day of the postoperative period. (So, after 8 hours, the CR was equal to 0.93 ± 0.11, and by the end of the first day — 0.93 ± 0.12). At a later date, this group of patients noted a tendency to restore one-time cardiac performance.

Operational aggression caused significant, pronounced and reversible changes in the mode of functioning of the circulatory system in patients of both groups. They were characterized by: a decrease in one-time performance of the heart, which was manifested in a decrease in MD from 36.8 ± 3.2 ml . m – up to 30.0 ± 2.6 ml . m – in the first group and from 41.3 ± 2.6 ml . m – up to 32.2 ± 2.8 ml . m – in the second group. Maintaining blood circulation was provided only by transferring the system to an energetically unfavorable way — by increasing the heart rate. At the same time, if in the second group the circulatory reserve ratio showed a tendency to an insignificant increase, in the first group of patients even tachycardia did not ensure the maintenance of blood circulation at the same level. This was manifested by a decrease in CU to 0.93 ± 0.12 on the first day. The tonic reactions observed in both groups are adequate and are aimed at reducing the resistance to the work of the heart, while centralization of the blood circulation is tightened. Hemodynamic manifestations of respiratory failure are critically increasing, but they are also reversible.

Thus, it was not possible to detect significant and fundamental differences in the response of the cardiovascular and respiratory systems in patients of both groups. There was only a tendency to more severe tolerance to operative trauma in patients after combined extended pneumonectomy. This was manifested either by the absence of an increase in the minute volume of blood circulation in response to an operative injury, or by its insignificant increase, solely due to an increase in tachycardia in the immediate postoperative period, with a longer recovery of one-time cardiac performance. Despite the fact that the hemodynamic manifestations of respiratory failure were expressed in both groups, this reaction was found in patients after combined pneumonectomy and more prolonged and with a large output beyond the limits of the stress-norm.

The state of the respiratory and circulatory systems is crucial for the outcome of treatment. Studies conducted in the clinic showed that the postoperative period is most favorable if the minute volume of blood circulation increases by an average of 20% on the first day after surgery. At the same time, the compliance of oxygen delivery to the tissues with the requirements for it is preserved only if the increase in the volumetric flow rate of the blood flow is not accompanied by an increase in peripheral vascular resistance.

The risk of postoperative complications increases significantly if the immediate postoperative period runs on the background of hypodynamic circulation. Reduced blood flow velocity is most likely in patients with initially low reserves of the respiratory and circulatory systems, and also if the operation is accompanied by massive blood loss, episodes of hypovolemia or hypoxia of any etiology.

In addition to hypovolemia, anemia and impaired myocardial contractility in the pathogenesis of postoperative circulatory hypodynamia, changes in the rheological properties of blood play a role.

As the researches of the clinic employee OV Solovyova (1977) showed, in lung cancer there is hypercoagulation of the blood associated with the presence of a tumor, and, in part, with the elderly age of patients. In the postoperative period, hypercoagulation aggravates, which is manifested by an increase in fibrinogen concentration, the appearance of fibrinogen B and a decrease in fibrinolytic activity due to inhibition of profibrinolysis activity. These changes are most pronounced in patients who have undergone traumatic surgery with large blood loss. Hypercoagulation of blood can contribute to the development of postoperative thrombosis and thromboembolism, which naturally leads to impaired pulmonary gas exchange and progression of hemodynamic disturbances.

However, in addition to plasma hemostasis in oncological patients in the postoperative period, no less important for the entire hemostasis system as a whole, changes in the structure and properties of platelets and erythrocytes occur.

The dynamics of changes in erythrocyte aggregation and platelet functional properties was studied in 42 patients who underwent advanced combined pneumonectomy for lung cancer. In 24 patients (group 1) the postoperative period proceeded safely, without complications, in 18 patients (group 2) with various purulent-infectious and thrombo-hemorrhagic complications. As a rule, in the second group of patients, surgery was more traumatic in nature and was accompanied by large blood loss. The average volume of operative blood loss in the first group of patients was 1.2 ± 0.18 l, in the second group — 1.8 ± 0.21 l (p <0.05).

The dynamics of changes in the aggregation properties of erythrocytes is presented in table 22. From the data presented in it it is clear that the initial indicators of aggregation

properties of erythrocytes in patients of both groups practically did not differ from each other, but significantly differed from normal ones. This was expressed in increased aggregation activity of red blood cells and a decrease in their suspension stability. For the first time three days after surgery in both groups of patients, erythrocyte hyperaggregation significantly decreased, moreover, with an uncomplicated postoperative course, this tendency was more pronounced (Fig. 55). In patients of this group, although by the end of the first week after surgery some deterioration in the aggregation properties of erythrocytes differed, however, it was not sharply pronounced and differed significantly from the background data. Subsequent periods they observed a gradual normalization of the main indicators of the aggregation properties of red blood cells. With a complicated postoperative period after some improvement in circulating blood erythrocyte indices, which we observed in the early periods after surgery, the progression of the erythrocyte hyperagregation and the decrease in their suspension stability steadily increased.

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