RU2705384C1 - Diagnostic technique for gram-negative abdominal surgical infection - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine and can be used for diagnosing gram-negative abdominal surgical infection. That is ensured by analyzing biological fluids; in surgical patients with postoperative peritonitis, blood serum and peritoneal fluid concentrations of lysozyme, lactoferrin and total protein are determined, and a diagnostic coefficient of the DC is calculated by the developed formula. If DC coefficient is equal to or higher than 2.8, presence of gram-negative abdominal infection is diagnosed.

EFFECT: invention provides more effective diagnosis of gram-negative abdominal surgical infection and timely initiation of etiotropic antibacterial therapy.

1 cl, 2 tbl, 4 ex, 1 dwg

Description

The invention relates to medicine, namely to surgery and can be used for preliminary diagnosis of gram-negative abdominal surgical infection.

An analysis of the mortality structure in patients with abdominal surgical pathology shows that the main cause of death in these patients was and remains peritonitis (Abdominal surgical infection: clinic, diagnosis, antimicrobial therapy. Practical guide / Edited by BC Savelyev, B. R. Gelfand. - M .: Litterra, 2006. - 168 p.), And mortality in peritonitis ranges from 18-20%, and with a common form, it rises to 60%. Such a large percentage of mortality in this category of patients is associated with a clinically important feature of intra-abdominal infections, which largely determines the poor prognosis, consisting in the rapid development of a generalized response of the macroorganism in response to the infectious process, due to the action of bacterial endo- and exotoxins and various inflammatory mediators.

Studies conducted in Russian clinics confirm the polymicrobial nature of intra-abdominal infections involving a wide range of aerobic and anaerobic gram-negative and gram-positive bacteria (Gelfand B.R., Gologorsky V.A., Burnevich S.Z. Antibacterial therapy for certain forms of abdominal surgical infection. // Consilium medicum. - 2000. - No. 4. P.21-26; Savelyev BC, Gelfand BR Abdominal surgical infection: clinic, diagnostics. Antimicrobial therapy: a practical guide 2006. - 168 p .; Chernov V.N. Emergency surgeon I: diagnosis and treatment of acute surgical pathology M., 2007. - 350 c)...

However, in 43.62% of cases with abdominal surgical infection, monocultures of pathogenic bacteria are sown from peritoneal exudate (Volkov A.G., Zarivchatsky M.F. Microbial landscape of abdominal surgical infections in patients of a multidisciplinary hospital // Perm Medical Journal. - 2014. - Volume XXXI, No. 1. - S. 53-57).

The main causative agents of infectious diseases and complications in surgical patients are gram-negative bacteria, among which representatives of enterobacteria (E. coli, Proteus spp., Klebsiella, Enterobacter, Serfatia), pseudomonads, as well as non-spore-forming anaerobes, especially bacteroids, occupy a special place. In the general structure of purulent infection during operations on the organs of the abdominal cavity, gram-positive microorganisms make up one third.

In the microbiological structure of abdominal infectious complications that develop in the postoperative period or during the patient’s hospital stay, gram-negative microorganisms, for example Acinetobacter, resistant to most cephalosporins, ureidopenicillins and aminoglycosides (Abdominal surgical infection. Russian red. Savelyev, B.R. Gelfand. - M.: BORGES Company, 2011. - 99 p.).

The operating surgeon can sometimes indicate a number of clinical signs on the participation of certain bacteria in the development of intra-abdominal infectious processes: tissue necrosis in inflammatory foci; staining exudate in black; fetid odor of exudate, contents of an abscess or wound, associated with the formation of acidic metabolic products with the participation of anaerobes. Gas formation is most pronounced in the presence of Clostridium spp., Or may be the result of the influence of some optional aerobes; concomitant septic thrombophlebitis and septic embolism of the blood vessels of the liver are characteristic for participation in the pathological process of bacteroids.

However, such quickly received information is biased and directly related to the experience and other subjective qualities of the surgeon (Abdominal surgical infection. Russian national recommendations. / Under the editorship of BC Savelyev, BR Gelfand. - M.: BORGES company, 2011. - 99 from.).

Therefore, the only objective and reliable method for the diagnosis of gram-negative abdominal surgical infection is a bacteriological study, regulated at all stages by official instructions. Data from microbiological studies play a decisive role for the rational antibiotic therapy of abdominal infection in surgery. The final identification of pathogens and determination of their sensitivity to antibacterial drugs is carried out after obtaining a pure culture. The results of native bacterioscopy help in the appointment of primary empirical antibiotic therapy (I. Eryukhin, V. A. Khrupky, V. M. Badikov http://medbe.ru/materials/infektsii-v-khirurgii/bakteriologicheskaya -mikrobiologicheskaya-diagnostika- ranevov-infektsii).

However, specific bacteriological diagnosis of infection is time-consuming, time-consuming and accessible to few medical institutions: 24-48 hours after sowing, the cultural and morphological properties of grown colonies are evaluated visually and, as a rule, individual colonies are reseeded to specialized media. Then, strains are identified based on the biochemical detection of specific enzyme markers or typical metabolites.

In large treatment centers, accelerated methods of microvolume biochemical identification of bacteria can be used with the help of automatic bacteriological analyzers from Bio Merieux (France) or Dade AG (USA), which can reduce the time of bacteriological studies to 4-6 hours. These devices and consumables they have a high cost, which limits their application (Sivolodsky EP Systematics and identification of enterobacteria. // Pasteur Institute of Epidemiology and Microbiology. Department of New Technologies / Edition third, revised and supplemented. St. Petersburg, 2011. - 21 p.),

Clinical efficacy studies are currently underway on high-tech diagnostic methods for pathogens that dominate the microbial association, regardless of their quantitative content. Such methods include, for example, gas chromatography, which allows one to recognize the characteristic metabolites of individual microbiota, which, by their microbiological properties, can act as dominant pathogens (RF Patent No. 2235325 of 08/26/2002 “Method for determining infected abdominal effusion and a method for treating diseases, accompanied by effusion into the abdominal cavity ").

This should also include modern methods of genetic analysis using artificial polymerase chain reaction (PCR) (RF Patent No. 2509804 of 03.20.2014, “A set of differentiating and specific oligonucleotides for identifying DNA of pathogens of acute intestinal infections, a method for identifying OCI, a microchip and a diagnostic system for way ”).

The disadvantages of all these specific bacteriological methods for identifying the causative agent of surgical abdominal infection are:

- inaccessibility in the foreseeable future for most surgical departments due to the high cost of equipment, reagents and qualified personnel to service the relevant equipment.

- the duration and complexity of the study;

- the need for preliminary production of sufficient biomaterial for research;

- Clinicians question the feasibility of comprehensive microbiological monitoring in the management of patients with abdominal infections.

There are methods for serodiagnosis of the pathogen, based on the detection in the blood of patients of specific antibodies to various bacterial antigens by direct reactions (RPHA) and indirect hemagglutination (RNGA), complement fixation (CSC) and their numerous modifications (Kathanov AM, Klimova LI, Boyko N.A., Tlish M.M. Method for the diagnosis of staphylococcal infection // RF Patent No. 2144190 dated 01/13/1998; Kuznetsov A.A., Kuznetsov O.A., Biletsky S.F., Biletskaya N.I. and identification of bacterial cells // RF Patent No. 2330292 of 07.27.2008).

The main disadvantages of these methods are:

- the inefficiency of serodiagnosis in relation to rapidly developing abdominal infection, since the titer of specific antibodies in the blood increases in response to an infection that has already been transmitted;

- the impossibility of applying serodiagnostic methods in an urgent laboratory service;

- serodiagnosis is unreliable, since the level of specific antibodies to the pathogen varies widely depending on the state of the patient’s immune system and the history of infections.

Among the methods for non-bacteriological diagnosis of infection, there are methods for the biochemical diagnosis of bacterial infection or sepsis, which include blood tests and determination of high levels of marker proteins in the blood serum of patients (Belkov V.V. Complex laboratory diagnosis of systemic infections and sepsis: C-reactive protein, procalcitonin, presepsin 2015. - 117 p .; Chernov V.N., Taranov I.I., Babiev V.F. Method for the diagnosis of anaerobic surgical infection of soft tissues // RF Patent No. 2073245 of 02/10/1997).

The disadvantages of these methods are:

- inefficiency in relation to the diagnosis of the microbiological structure of abdominal surgical infection;

- diagnosis is based on the determination of a certain threshold value of a biochemical analyte in the blood and is not free from various kinds of measurement errors (including those related to hemodilution).

- to establish a diagnosis, a repeated blood test is necessary in the same patient due to the extremely wide range of individual values of biochemical marker proteins.

Closest to our proposed method is a method for diagnosing a bacterial infection in a patient with non-specific complaints, comprising the following steps: (i) providing a sample from the patient’s body, received with non-specific complaints; (ii) determining the level of procalcitonin (PCT) or a fragment thereof of at least 12 amino acids in the aforementioned sample; and (iii) determining the presence or absence of a bacterial infection in the aforementioned patient by comparing the aforementioned determined level of PCT with a predetermined threshold level (Struck J., Nickel K ., Bingisser R., Girsdorf S., Hartmann O. Procalcitonin for the diagnosis of bacterial infections and antibiotic treatment control for patients with non-specific complaints // RF Patent No. 2580278 of 04/10/2016).

The disadvantages of the prototype are:

- the ineffectiveness of the method for the differential diagnosis of gram-positive and gram-negative abdominal surgical infections, each requiring their own antibiotic therapy;

- the limitations of the method - the use of a single parameter (procalcitonin level) gives a minimum of diagnostic information (allows you to distinguish only viral and bacterial infections);

- high cost of equipment and reagents - determination of the concentration of procalcitonin on a chemiluminometer in the format of a PCT test (BRAHMS PCT LIA sensitive) with a sensitivity of 0.007 ng / ml is not available for most clinical laboratories;

- the complexity of the method - the diagnosis is based on complex preliminary calculations of threshold levels of procalcitonin for each variant of immunoassay;

- inefficiency of the method for substantiating etiotropic antibacterial chemotherapy.

The invention is aimed at increasing the efficiency of the diagnosis of gram-negative abdominal surgical infection.

The specified technical result is achieved in that in surgical patients with postoperative peritonitis, the concentrations of lysozyme, lactoferrin and total protein are simultaneously determined in blood serum and peritoneal fluid and the diagnostic coefficient of DC is calculated by the formula:

Where:

DK - diagnostic coefficient of the presence of gram-negative abdominal surgical infection;

LZTS _RV - lysozyme concentration in the peritoneal fluid (U / L);

LZZ _SK - the concentration of lysozyme in blood serum (U / L);

LF _RV - lactoferrin concentration in the peritoneal fluid (ng / ml);

LF _SC - serum lactoferrin concentration (ng / ml);

F is the dilution factor calculated by the formula:

Where:

ABOUT _SK - the concentration of total protein in blood serum (g / l);

ABOUT _RV - the concentration of total protein in the peritoneal fluid (g / l),

and if the DC coefficient is equal to or higher than 2.8, the presence of gram-negative abdominal infection is diagnosed.

In the proposed method for the preliminary diagnosis of gram-negative abdominal surgical infection, capable of predicting a developing infection in patients with postoperative peritonitis, two proteins with bactericidal activity — lactoferrin (LF) and lysozyme (LZZ) —are measured simultaneously in blood serum and peritoneal exudate.

The invention is based on our technical result, which consists in the fact that when infected with peritoneal fluid (RV), higher concentrations of specific LF and LZP proteins are found in it than in blood serum (SC).

Obtaining peritoneal fluid through lavage with saline leads to its dilution and a decrease in the true concentrations of LF and LZC, as well as the total protein in it. That is, in the clinical practice of an abdominal surgeon, for the biochemical analysis of peritoneal exudate, a diluted fluid is taken, flowing through the drains, distorting the results of the study.

To correct distortions arising from dilutions of the peritoneal fluid, it is required to standardize both studied fluids with respect to the total protein. For this purpose, the true concentration of specific proteins and LF LZTS peritoneal fluid (WBF LZTS _RV and _RV) are adjusted by multiplying them true values of the dilution factor F, which is the ratio of total serum protein (OB _SC) to total protein peritoneal fluid (OB _RV).

Parallel measurement of the concentration of LF and LZC simultaneously in two biological fluids - blood serum and peritoneal fluid allows us to calculate not only the ratio of their adjusted values in the pancreas to their true values in the SC, but also to calculate their product, which we call the diagnostic coefficient of DC. The value of the diagnostic coefficient of DC greater than one indicates infection of the abdominal effusion, and the value of DC less than or equal to 1 indicates the aseptic nature of the exudate.

The choice of two specific proteins (LF and LZZ) for the diagnosis of gram-negative abdominal surgical infection in patients with peritonitis is explained not so much by the fact that both proteins have bactericidal activity, but by the results obtained in animal experiments and in the conditions of a surgical clinic (Tables 1 and 2) .

Previously, in experiments on modeling bacterial peritonitis in laboratory rats by intraperitoneal injection of a monoculture of pathogenic bacteria, we found that, depending on the type of pathogen of abdominal surgical infection, the ratio of a specific protein in the pancreas and SC does not concern all the studied proteins, but only a strictly defined group of proteins ( Table 1).

Rat experiments to simulate an intraperitoneal infection with a monoculture of pathogenic bacteria whose blood serum and peritoneal exudate samples were tested in dynamics for levels of C-reactive protein (CRP), lactoferrin (LF), fibrinogen degradation products (PDF), and three classes of immunoglobulins (IgG, IgM, IgA) and lysozyme (LZC), and their multivariate analysis showed that the definition of minimal and sufficient for differential diagnosis of gram-negative abdominal infection from staphylococcal and streptococcal is DC for only two proteins: LF and LZZ (table 1).

That is, peritonitis in rats caused by Gram-negative bacteria (Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella oxytoca) at doses of 0,5 LD ₅₀ resulted in a significant increase in the adjusted relations only for _prostate LF / LF _IC and _RV LZTS / LZTS _SC (Table one).

Even more indicative and sensitive indicator for the diagnosis of gram negative abdominal infections (Table 1) is the product of the relationship LF _RV / LF _SC and LZTS _RV / LZTS _SC, we called diagnostic coefficient DC (DC = LF _RV F / LF _SC × LZTS _RV F / LZTS _SK ).

According presence of peritonitis caused by gram abdominal infection, peritonitis with gram positive abdominal infection by calculating the relationship LF _RV / LF _SC and LZTS _RV / LZTS _IC is the value of DC ROC-analysis threshold DC value, cut-off (cut-off), is equal to or above 2.8 (Fig. 1).

The ROC curve explaining the choice of a cut-off threshold for the diagnostic coefficient of DC, providing the maximum diagnostic sensitivity, diagnostic specificity and diagnostic efficiency of the method for diagnosing gram-negative abdominal surgical infection, is presented in FIG. one.

Similar results characterizing the effectiveness of the diagnostic coefficient of DC were obtained in cases of the diagnosis of gram-negative infection in patients with diffuse purulent peritonitis due to perforation of sigmoid colon cancer, gangrenous appendicitis and enzymatic pancreatic necrosis without effusion infection.

The essence of the invention is illustrated in tables 1 and 2 and figure 1.

The proposed method has been successfully tested in the surgical departments of the National Research Institution "Department Hospital at Astrakhan-1" of Russian Railways, State Budgetary Health Institution of Aleksandro-Mariinskaya Regional Clinical Hospital, State Public Health Institution of City Clinical Hospital No. 3 named after CM. Kirov ", at the departments of pathological physiology, and surgical diseases of the pediatric faculty of Astrakhan State Medical University during 2016-2018.

The following are test results:

Example 1

We studied the ratio of protein levels and their ratio of pancreas and SC for a group of diagnostically significant proteins in experiments on white laboratory rats. The animals were divided into 5 groups of 12 rats to which five different cultures of conditionally pathogenic bacteria were injected once intraperitoneally. In the 6th comparison group, out of 30 animals, aseptic peritonitis was reproduced by a single intraperitoneal injection of carrageenan in 1 ml of physiological saline, which was prepared by dissolving carrageenan (Tinox-Him LLC, Moscow) in a sterile isotonic sodium chloride solution at the rate of 50 mg of dry powder per ampoule ( 10 ml).

For infection of animals, daily agar cultures of aerobic gram-positive bacteria: Staphylococcus aureus, Streptococcus pyogenes (Serovar A) and aerobic gram-negative bacteria: Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella oxytoca, prepared in 0.9% sodium chloride solution were used. Intraperitoneal infection of the animal was performed by injection of pre-titrated

doses containing 0.5 ml of 1 × 10 ⁸ microbial bodies of staphylococcus and streptococcus and 1 × 10 ⁷ microbial bodies of Proteus, Klebsiella and Pseudomonas aeruginosa. The choice of these 5 bacterial strains is explained by the most frequent detection of precisely them in peritoneal exudate with diffuse purulent peritonitis. The dose selection of each bacterial culture provided 0.5 LD ₅₀ and ensured the survival of all laboratory animals for more than 3 days. In order to slow down the resorption of bacteria into the blood and prevent lethal sepsis, a solution of carrageenan was administered intraperitoneally simultaneously with infection to all animals according to the scheme and in doses of animals of the 6th comparison group. 48 hours after intraperitoneal injection under ether anesthesia, animals were euthanized by decapitation followed by sampling.

The material for the study was the blood serum of laboratory animals obtained from the jugular vein, and the whole peritoneal exudate obtained by aspiration of the abdominal cavity with a Pasteur pipette.

Quantitative determination of lactoferrin (LF) was carried out by enzyme-linked immunosorbent assay (ELISA) using a set of reagents for the ELISA of CJSC Vector-Best, Novosibirsk. Lysozyme activity (LZC) in the biological material was determined by a colorimetric micromethod by measuring the optical density in samples with a micrococcus test culture. The total protein content in rat peritoneal fluid samples and blood serum was determined spectrophotometrically at 280 and 260 nm according to Warburg.

Since the concentration of total protein in rat peritoneal fluid corresponded to its concentration in blood serum, the factor F = 1.

The average concentrations of lysozyme and lactoferrin in the peritoneal fluid (RV) and blood serum (SC), their ratio (RV / SC) and the diagnostic DC coefficient on the 2nd day after modeling in rats of peritonitis with different strains of gram-positive and gram-negative bacteria are shown in table 1.

The level of LAC in rat peritoneal fluid was significantly (P (U) <0.01) 1.5-2.1 times higher than the level of LAC in the blood serum of these rats only after intraperitoneal injection of strains of gram-negative bacteria: Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella oxytoca, and gram-positive aerobes Staphylococcus aureus and was not significantly different from levels in the blood LZTS (LZTS _RV / _SC = LZTS 1-1.2) with aseptic peritonitis and peritonitis induced by intraperitoneal injection of Streptococcus pyogenes (Table 1).

The concentration of LF in rat peritoneal fluid was significantly (P (U) <0.01) 2.0-2.1 times higher than the concentration of LF in the blood serum of the same rats after intraperitoneal injection of all three strains of gram-negative bacteria: Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella oxytoca, and another gram-positive aerobic - Streptococcus pyogenes. LF concentration in the peritoneal fluid of rats was not significantly different from the concentration in the blood LF (LF _RV / LF _SC = 1-1.2) with aseptic peritonitis caused by intraperitoneal injection of carrageenan and not increased by more than 1.5 times in case of peritonitis, caused by intraperitoneal injection of Staphylococcus aureus (Table 1).

The diagnostic coefficient of DC in rats with peritonitis after intraperitoneal infection with gram-negative bacteria was:

for Proteus vulgaris, DC = 4.2 for Pseudomonas aeruginosa and DC = 4.1 for Klebsiella oxytoca (Table 1).

On the contrary, DC after infection of rats with staphylococcal intraabdominal infection did not exceed 2.2, and with intraperitoneal infection with streptococcus, DC = 2.4 (Table 1).

Thus, with DC equal to or higher than 2.8, the presence of a gram-negative abdominal infection is diagnosed with a high degree of certainty.

Example 2

Patient K., 78 years old, was admitted to the surgical department of Clinical Hospital No. 3 on 06/15/2016 in serious condition with complaints of abdominal pain, general weakness.

On physical examination of the patient - a clinic of peritonitis. On a survey radiography, there are many small intestinal levels. At admission, the prevailing clinic was pronounced endogenous intoxication, combined with intestinal paresis, pallor of the skin, dry tongue, and tachycardia. Data from laboratory tests at admission: the level of leukocytes, red blood cells, hemoglobin is within normal limits, LII is increased to 3.52 cu, biochemical blood analysis: creatinine - 130 μmol / l, urea - up to 17.8, mol / l, total protein - 42 g / l, lactoferrin - 4650 ng / ml, lysozyme activity - 7.2 U / l.

The patient underwent a laparotomy, in which sigmoid colon cancer was detected, complicated by perforation, diffuse fibrinous-purulent peritonitis. Biochemical analysis of peritoneal effusion: total protein - 27 g / l, lactoferrin - 4860 ng / ml, lysozyme activity - 8.0 U / l.

The pancreatic dilution factor in this patient is

The adjusted concentrations of LF and LZC in the peritoneal fluid in this patient are equal to LZP _RV = 8.0 × 1.56 = 12.4 U / L and LF _RV = 4860 × 1.56 = 7560 ng / ml.

According to the diagnostic method, the determination of DC by the formula:

which indicated the presence of a gram-negative abdominal infection in the patient.

The average concentrations of lysozyme and lactoferrin in peritoneal fluid (RV) and blood serum (SC), their ratio (RV / SC) and diagnostic DC coefficients in patients with peritonitis from examples 2, 3 and 4 are presented in table 2.

The patient underwent obstructive resection of the sigmoid colon, nasointestinal intubation, rehabilitation and drainage of the abdominal cavity. The abdominal cavity is sutured tightly. By the end of the first day, intestinal motility appeared.

The later results of bacteriological inoculation of the abdominal effusion revealed the predominant number of colonies of gram-negative strains of Proteus vulgaris, Pseudomonas aeruginosa and confirmed the diagnostic result by our proposed method.

Assigned profile antibiotic therapy. The subsequent course of the disease is relatively smooth: the gastric tube was removed on the 2nd day, the intestinal tube on the 4th day. The patient was discharged on the 15th day in a satisfactory condition.

Example 3

Patient K., 57 years old. Received on December 11, 2017 at the intensive care unit and intensive care unit of City Clinical Hospital No. 3 with a direct diagnosis: acute destructive pancreatitis. Ultrasound conclusion: “Echostructural signs of diffuse enlargement of the pancreas, acute pancreatitis, omenobursitis, retroperitoneal tissue infiltration. Hepatomegaly, diffuse changes in the liver. " Operation - laparoscopic drainage of the abdominal cavity, omental bursa. Duration of the disease - three days, temperature - 38 ° C, heart rate - 88 per minute, NPV - 18 per minute. General blood test: red blood cells 4.37 × 10 ¹² / l; Hb - 121 g / l; Le - 9.8 × 10 ⁹ / l, LII = 7, ESR - 12 mm / h, blood chemistry: total protein - 56 g / l, creatinine - 256 mmol / l, urea - 9.3 mmol / l, blood glucose - 5.8 mmol / l, α-amylase - 43 g / * h, lipase - 402 g / l * h, urine diastase - 256 g / l * h. The serum level of lactoferrin is 8352 ng / ml, the activity of lysozyme is 5.5 U / L.

According to the diagnostic method, the concentration of total protein was determined in the drainage fluid: 12 g / l, lactoferrin - 2245 ng / ml and lysozyme activity - 1.4 U / l.

The pancreatic dilution factor in this patient is F = 56/12 = 4.67. The adjusted concentrations of LF and LZC in the drainage peritoneal fluid in this patient are equal to LZP _RV = 1.4 × 4.67 = 6.5 U / L and LF _RV = 2245 × 4.67 = 10484 ng / ml.

Determination of DC by the formula according to the diagnostic method:

indicates the absence of gram-negative abdominal infection.

For this patient, the possibility of conservative treatment was determined; on the third day, the patient's body temperature gradually returned to normal, signs of endogenous intoxication stopped, laboratory parameters, ultrasound data returned to normal. On day 12, drainage was removed from the stuffing bag. The patient was discharged for outpatient aftercare in satisfactory condition for 18 days.

The main diagnosis: Acute necrotizing pancreatitis. Complication of the main diagnosis: Omentobursitis. Spilled enzymatic peritonitis.

Thus, DC confirmed the absence of pancreatic necrosis infected with gram-negative microflora. Spilled enzymatic peritonitis did not become infected, which in the early stages of treatment was predicted by the diagnosis result by our proposed method.

Example 4

Patient S. fell ill on 01/07/16, did not seek medical help. The patient was delivered by ambulance on 10.01.16, in serious condition, conscious, lethargic, skin temperature of 39.4 ° C. The skin of a pale color is dry to the touch, a spasm of peripheral vessels is expressed. Heart rate 108 beats. in 1 minute, NPV 24 in 1 minute. The abdomen is swollen, painful on palpation. The symptom of Shchetkin-Blumberg is positive. Peristalsis sluggish single waves. General blood test: red blood cells 3.37 × 10 ¹² / l; Hb - 118 g / l; Le - 15.4 × 10 ⁹ / L. ESR - 8 mm / hour. Dz: Peritonitis. On the operation: acute gangrenous-perforated appendicitis. Spilled purulent peritonitis.

For treatment in the postoperative period, the patient was transferred to the intensive care unit. The patient's condition continued to be severe. The temperature of the skin kept on fibril figures: 38.0-38.9 ° C. Heart rate 100-108 bpm; NPV 28-30 breaths in 1 minute. The abdomen is swollen, peristalsis is sluggish, uneven throughout the abdomen. General blood test: red blood cells 3.37 × 10 / l; Hb - 99 g / l; Le - 10.6 × 10 ⁹ / L. ESR - 11 mm / h, biochemical analysis of blood: total protein - 48 g / l, creatinine - 154 mmol / l, urea - 12.6 mmol / l, glucose - 6.4 mmol / l, LII - 5.7 Ie, lactoferrin - 8245 ng / ml, lysozyme activity - 8.8 U / L. Biochemical analysis of peritoneal fluid: total protein: 39 g / l, lactoferrin - 5263 ng / ml, lysozyme activity - 6.2 U / l.

The pancreatic dilution factor in this patient is F = 48/39 = 1.23. The adjusted concentrations of LF and LZC in the peritoneal fluid in this patient are equal to LZP _RV = 8.8 × 1.23 = 10.8 U / L and LF _RV = 8245 × 1.23 = 10141 ng / ml.

According to the diagnostic method, the determination of DC by the formula

which indicated the presence of a gram-negative abdominal infection in the patient.

The results of a bacteriological study of peritoneal exudate, obtained three days after the operation, revealed both gram-negative strains of Proteus vulgaris, Pseudomonas aeruginosa, and the presence of gram-positive coccal microflora (Staphylococcus aureus, Streptococcus pyogenes) in the exudate, which corresponded to the diagnostic results of the proposed method.

The patient was given infusion therapy, which included crystalloid solutions, colloids, 10% glucose solution, antibacterial treatment, cardiac drugs and vitamins.

On January 13 and 14, 2016, the patient's condition remained stably moderate. The temperature of the skin was kept at subfebrile and low febrile numbers: 37.2-38.0 ° C. Heart rate of 90-92 bpm / min, respiratory rate of 24-26 breaths per 1 minute.

January 19, 2016 the patient was taken to the operating room and operated on. On the operation found interloop abscesses. Abscesses are opened, the abdominal cavity is washed and sutured tightly. In the first postoperative day, the patient continued to have severe intoxication. In the subsequent postoperative period, it went smoothly and the studied parameters gradually returned to normal. February 9, 2016 the patient was discharged from the hospital.

This example shows that the diagnostic method allows in advance to predict the possible development of gram-negative abdominal infection in the early stages of peritonitis.

The proposed method improves the diagnosis of gram-negative abdominal infections in surgical patients with suspected postoperative peritonitis, namely:

- increase in diagnostic specificity to 88% and diagnostic sensitivity to 81% (for the threshold value of DC = 2.8). The area under the curve (AUC), reflecting the diagnostic effectiveness of the method, was 0.865 (in the prototype 0.721).

- high speed enzyme-linked immunosorbent assay of proteins included in this method provides a quick result of the study;

- evidence-based administration of antibacterial agents;

- early onset of targeted antibacterial chemotherapy;

- technical simplicity, insignificant labor costs (for the practical execution of the method, only 1 laboratory assistant is enough);

- the availability of the method for the surgical department of any health care unit;

- cost-effectiveness (the method does not require exclusive and expensive equipment and reagents, auxiliary equipment and highly qualified medical staff), the analyzes performed are of low cost;

The proposed method makes it possible to predict the development of postoperative infectious complications in the abdominal cavity.

The proposed method can be implemented in any surgical department for rapid diagnosis of the presence of gram-negative abdominal surgical infection, ahead of the results of bacteriological studies, and the timely initiation of etiotropic antibacterial therapy.

Claims (13)

A method for the diagnosis of gram-negative abdominal surgical infection, consisting in the study of biological fluids, characterized in that in surgical patients with postoperative peritonitis, the concentrations of lysozyme, lactoferrin and total protein are simultaneously determined in blood serum and peritoneal fluid and the diagnostic coefficient of DC is calculated by the formula:

Where: DK - diagnostic coefficient of the presence of gram-negative abdominal surgical infection; LZTS _RV - lysozyme concentration in the peritoneal fluid (U / L); LZZ _SK - the concentration of lysozyme in blood serum (U / L); LF _RV - lactoferrin concentration in the peritoneal fluid (ng / ml); LF _SC - serum lactoferrin concentration (ng / ml); F is the dilution factor calculated by the formula:

Where: ABOUT _SK - the concentration of total protein in blood serum (g / l); ABOUT _pancreas - the concentration of total protein in the peritoneal fluid (g / l), and if the DC coefficient is equal to or higher than 2.8, the presence of gram-negative abdominal infection is diagnosed.

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