Sepsis: diagnosis
Last reviewed: 23.04.2024
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The diagnosis of "sepsis" is suggested to be established in the presence of two or more symptoms of a systemic inflammatory reaction in a proven infectious process (this includes verified bacteremia).
The diagnosis of "severe sepsis" is suggested to be established in the presence of organ failure in a patient with sepsis.
The diagnosis of sepsis is made on the basis of agreed criteria, which formed the basis of the SOFA (Sepsis oriented failure assessment) scale. 23-3.
Under septic shock it is accepted to understand the decrease in blood pressure below 90 mm Hg. In a patient with clinical signs of sepsis, despite adequate replenishment of the volume of circulating blood and plasma. Decisions of the Conciliation Conference recommended not to use terms that do not have a specific meaning, such as "septicemia", "sepsis syndrome", "refractory septic shock."
In some cases, when there is no confidence in the presence of an infectious focus (pancreatic necrosis, intra-abdominal abscess, necrotizing soft tissue infections, etc.), a procalcitonin test can be of significant help in diagnosing sepsis. According to a number of studies, today it is characterized by the highest sensitivity and specificity, significantly exceeding in the latter parameter such a widespread indicator as the C-reactive protein. The use of a semi-quantitative method for determining the level of procalcitonin should, in the opinion of a number of specialists, become routine research in clinical practice in those cases when there are doubts about the presence of a focus of the infectious process.
The quality of the survey plays a decisive role in the choice of an adequate volume of surgical intervention and the outcome of the disease.
The main clinical symptoms of sepsis in gynecological patients is the presence of a purulent focus in combination with the following symptoms: hyperthermia, chills, skin discoloration, rashes and trophic changes, severe weakness, changes in the functions of the nervous system, impaired gastrointestinal function, the presence of multiple organ dysfunction , cardiovascular, renal and hepatic).
There are no laboratory-specific criteria for sepsis. The laboratory diagnosis of sepsis is based on data. Which reflect the fact of severe inflammation and the degree of multiple organ failure.
The production of erythrocytes with sepsis is reduced. Anemia in sepsis is observed in all cases, and in 45% of patients the hemoglobin content is below 80 g / l.
Sepsis is characterized by neutrophilic leukocytosis with a shift to the left, in some cases a leukemoid reaction with a white blood cell count of up to 50-100 thousand and more can be noted. Morphological changes in neutrophils in sepsis include toxic granularity, the appearance of the Dole bodies and vacuolization. Thrombocytopenia occurs in sepsis in 56% of cases, lymphopenia - in 81.2%.
The degree of intoxication reflects the leukocyte intoxication index (LII), which is calculated by the formula:
LII = (С + 2П + 3Ю + 4Ми) (Пл-1) / (Мо + Ли) (Э + 1)
Where C - segmented neutrophils, P - bacillary leukocytes, Yu - young leukocytes, M - melocytes, Pl - plasma cells, Mo - monocytes, Li - lymphocytes, E - eosinophils.
LII is normally about 1. The increase in the index to 2-3 indicates a limitation of the inflammatory process, an increase to 4-9 - of a significant bacterial component of endogenous intoxication.
Leukopenia with high LII is a poor prognostic sign for patients with septic shock.
Determination of the parameters of the acid-base state (CBS), and especially the level of lactate, allows to determine the stage and severity of septic shock. It is believed that for patients in the early stages of septic shock, compensated or subcompensated metabolic acidosis is characterized by hypocapnia and high lactate levels (1.5-2 mmol / L and higher). In the later stages of shock, metabolic acidosis becomes uncompensated and can exceed 10 mmol / l for deficiency of bases. The level of lactacidemia reaches critical limits (3-4 mmol / l) and is a criterion for the reversibility of septic shock. The severity of acidosis largely correlates with the prognosis.
Although the disruption of aggregation properties of blood to some extent develops in all patients with sepsis, the incidence of disseminated intravascular coagulation syndrome is only 11%. Hemostasiological indices in patients with septic shock indicate the presence, as a rule, of a chronic, subacute or acute form of DIC syndrome. Subacute and acute forms of it in patients with septic shock are characterized by severe thrombocytopenia (less than 50-10 9 g / l), hypofibrinogenemia (less than 1.5 t / l), increased consumption of antithrombin and plasminogen, a sharp increase in the content of fibrin and fibrinogen derivatives, an increase in chronometric the index of thromboelastogram, the time of blood clotting, the reduction of the structural index of thromboelastogram.
In chronic DVS-syndrome, moderate thrombocytopenia (less than 150-10 9 g / L), hyperfibrinogenemia, increased consumption of antithrombin III, as well as hyperactivity of the hemostatic system (decrease in the chronometric index and an increase in the structural index on the thromboelastogram) were noted.
Determination of the concentration of serum electrolytes, protein, urea, creatinine, liver function helps to clarify the function of the most important parenchymal organs - the liver and kidneys.
For patients with sepsis, pronounced hypoproteinemia is characteristic. Thus, hypoproteinemia less than 60 g / l is observed in 81.2-85% of patients).
Although the lack of positive blood culture data does not remove the diagnosis in patients with a clinical sepsis picture, patients with sepsis need a microbiological study. Blood, urine separated from the cervical canal, separated from wounds or fistulas, as well as material obtained intraoperatively directly from the purulent focus, are subject to investigation. Not only the identification of detected microorganisms (virulence) is important, but also their quantitative assessment (the degree of dissemination), although the results of such studies are often evaluated retrospectively because of the duration of their testing.
Bacteriological confirmation of bacteremia is difficult and requires certain conditions. To detect bacteremia, blood culture is preferably performed either as early as possible after the onset of body temperature or chill, or 1 hour before the expected rise in temperature, preferably before antibiotic therapy begins. It is advisable to produce from 2 to 4 blood samples with an interval of at least 20 minutes, since an increase in the frequency of crops increases the probability of excretory excretion. Blood sampling is carried out from the peripheral vein (not from the subclavian catheter). As a rule, it is recommended to take 10-20 ml of blood in 2 vials for aerobic and anaerobic incubation for 7 days at each fence, in children under 12 years - 1-5 ml.
Instrumental diagnosis of sepsis (ultrasound, X-ray, including CT, NMR) is aimed at clarifying the severity and extent of purulent lesions in the primary focus, as well as on the identification of possible secondary purulent (metastatic) foci.
At present, the APACHE II scale is used for an objective assessment of the severity of the condition of patients with sepsis, the adequacy of the therapy, and the prognosis. The conducted studies in patients with abdominal surgical sepsis showed a practically direct dependence of lethality on the severity of the condition (the sum of points on the APACHE II scale). So, with a total of less than 10 points on this scale, there were no fatalities. With a score of 11 to 15, mortality was 25%, with a total of 16 to 20 points, the lethality was 34%; in patients with a score of 21 to 25, mortality was 41%, with a score of 26 to 33, the mortality rate reached 58.9%; with a score of more than 30 it was the highest - 82.25%.