Angiogenic infection

Angiogenic infection is a primary bloodstream infection originating in blood vessels or heart cavities. Bacteremia is considered a laboratory indicator of angiogenic infection, and a clinical indicator is a symptom complex of sepsis. Angiogenic infections include infective endocarditis, septic thrombophlebitis and sepsis caused by infection of vascular prostheses, stents, shunts and other intravascular devices. In the practice of intensive care units, the overwhelming majority of cases of angiogenic infection are associated with the use of vascular catheters - arterial, peripheral venous and, first of all, CBC. Therefore, the further description will concern specifically catheter-associated bloodstream infections (CABI).

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Epidemiology

There are no domestic data on the incidence of angiogenic infection, including CAI, in intensive care units. According to the US Centers for Disease Control and Prevention, the average rate of CAI associated with CBC in the ICU is 5.3 per 1000 catheter days (the sum of days of catheter use). Each year in the US, the sum of catheter days of all ICU patients is 15 million, respectively, approximately 80,000 cases of CAI associated with CBC occur per year. The mortality rate due to cases of intravascular systemic infection remains uncertain.

If we evaluate the number of cases of CAIC not only in the ICU, but in all hospitals, 250,000 such episodes are registered annually. In these cases, the mortality rate from this complication is estimated at 12-25%, the minimum health care costs are $25,000 per case.

Most cases of intravascular systemic infection are associated with the use of CBCs. Among patients with CBCs, the proportion of bloodstream infections is significantly higher than in patients without catheters. The incidence of CBC-associated BSIs varies depending on the size and profile of the units and ranges from 2.9 (in cardiac surgery ICUs) to 11.3 (in premature infants) cases per 1000 catheter-days.

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What causes angiogenic infections?

The most common pathogens causing nosocomial BSIs in the ICU are coagulase-negative staphylococci and Staphylococcus aureus. They account for 27% and 13-16% of all BSI cases, respectively. More than 50% of Staphylococcus aureus isolates obtained from ICU patients are resistant to oxacillin. In recent years, the proportion of enterococci has increased (from 8% to 12.5%) and strains resistant to vancomycin have emerged. Candida fungi account for 8% of nosocomial BSIs. The proportion of Candida strains resistant to commonly used antifungal drugs is growing. Up to 10% of C. albicans isolates obtained from the blood of hospitalized patients are resistant to fluconazole. In 48% of cases of candidal bloodstream infection, the causative agents are C. glabrata and C. krusei, which are even more often resistant to fluconazole and itraconazole than C. albicans.

The number of cases of CAI caused by gram-negative bacteria is 14-19% of the total number of CAI. At the same time, among gram-negative pathogens, the percentage of isolates obtained from intensive care unit patients has increased. This increase was due to bacteria of the genus Enterobactenaceae producing extended-spectrum beta-lactamases, in particular Klebsiella pneumoniae. Such microorganisms are resistant not only to extended-spectrum cephalosporins, but also to broad-spectrum antibiotics.

Pathogenesis

Catheter infection can occur in three ways. The first is the migration of microorganisms from the skin through the catheter exit site along its outer surface in the direction of the distal segment. This mechanism is most relevant in the first 10 days after catheter placement. At later stages, the priority is for microorganisms to enter the bloodstream through the catheter lumen, with the main sources of infection being contaminated catheter cannulas, infusion systems, and solutions. The third way is endogenous, when microorganisms entering the bloodstream from other sources settle on the intravascular segment of the catheter. In this situation, the catheter can become a secondary source of bacteremia.

The pathogenesis of CABG is based on a complex interaction of several factors. The catheter behaves as a foreign body, in response to which the host organism produces a fibrin film that covers the surface of the intravascular segment of the catheter. This film is rich in fibrin and fibronectin, to which Staphylococcus aureus and Candida spp. have an affinity. Both species produce coagulase, gaining an advantage in the thrombogenic process occurring on the catheter surface and tightly adhering to the film. Coagulase-negative staphylococci can adhere to fibronectin. They produce a sticky substance, glycocalyx, which facilitates attachment and protects against the effects of complement, phagocytes and antibiotics. This fact may explain why coagulase-negative staphylococci predominate in CABG. Other microorganisms, such as Pseudomonas aeruginosa and Candida spp., can synthesize similar substances, especially when they grow on a glucose-rich medium. Attached microorganisms multiply, form microcolonies, secrete an extracellular polysaccharide matrix that forms the architectural structure of the biofilm. An increase in the mass of the biofilm and its fragmentation lead to the entry of microorganisms into the bloodstream (planktonic forms), which is clinically manifested by bacteremia and a symptom complex of sepsis.

Classification of angiogenic infections

Currently, the classification of catheter-associated infections developed by the US Hospital Infection Control Practice Guidelines Committee is used in world practice.

• Colonization of the catheter growth >15 CFU by semiquantitative microbiological examination or >102 CFU by quantitative examination of the distal segment of the removed catheter in the absence of concomitant clinical symptoms.
• Catheter exit site infection erythema, soreness, infiltrate, suppuration within 2 cm around the external site of the catheter, purulent discharge and the appearance of fever are often combined with bacteremia.
• Pocket infection erythema and necrosis of the skin over the reservoir of an implanted port or purulent exudate in the subcutaneous pocket containing the port may be accompanied by bacteremia.
• Tunnel infection erythema, soreness and infiltration of tissues surrounding the catheter, extending beyond 2 cm from the catheter exit site, spreading along the subcutaneous tunnel, may be accompanied by bacteremia.
• KAIK isolation of the same microorganism (i.e. the same species and antibiogram) by semiquantitative or quantitative method of studying the segment of the removed catheter and peripheral blood in a patient with concomitant symptoms of bloodstream infection and in the absence of another source of infection, in the absence of laboratory confirmation, a decrease in temperature after catheter removal may be indirect evidence of KAIK.
• Infusate-associated bloodstream infection (a rare type of infection that occurs when contaminated infusion solutions or blood components are administered intravenously through a catheter and is determined by the isolation of the same microorganism from the infusate and in a blood culture from a peripheral vein in the absence of another source of infection).

Complications of CAIC include infective endocarditis, osteomyelitis, septic arthritis, and metastatic purulent discharges from other locations.

Taking into account the different periods of catheter use, the assessment and comparison of the frequency of different variants of catheter-associated infection are carried out not only by the number of cases per 100 functioning catheter-associated infections (in %), but also by the number of cases per 1000 catheter-days (the sum of the days of catheter use).

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Diagnosis of angiogenic infections

The diagnosis of CAIC is established on the basis of clinical and microbiological tests.

Clinical symptoms of catheter-associated infection are divided into local and general. Local symptoms include pain, hyperemia, infiltration, skin necrosis, purulent discharge in the catheter exit area, subcutaneous tunnel or implanted "port", as well as pain and induration along the vein (phlebitis). General manifestations of CAI are characterized by a symptom complex of sepsis, they are classified by severity. The clinical picture of CAI depends on the degree of colonization of the catheter and the nature of the microflora and varies from subfebrile fever and mild chills after the introduction of solutions through the catheter (with colonization by coagulase-negative staphylococci, Micrococcus spp, Corynebacterium, Bacillus subtilis) to severe sepsis and septic shock (with colonization by Staphylococcus aureus and gram-negative bacteria). Fungal CAIC is characterized by a protracted course with high fever. Local infection, especially purulent, is often combined with CAIC, but its absence does not exclude infection of the distal intravascular section of the catheter.

Clinical data alone are insufficient for the diagnosis of CAI due to the low specificity of the most sensitive symptoms (such as fever, chills) or the low sensitivity of specific symptoms (such as inflammation or suppuration at the catheter site). Therefore, the appearance of symptoms of systemic infection in a patient with a vascular catheter for 72 hours or more and no other foci of infection should be considered as probable CAI. Isolation of coagulase-negative staphylococci, Staphylococcus aureus or Candida spp. from blood cultures obtained by puncture of a peripheral vein increases the probability of the diagnosis of CAI. For further more accurate diagnosis, quantitative microbiological studies should be performed.

When removing the catheter, a semi-quantitative or quantitative microbiological study of the distal (intravascular) segment of the catheter is performed. Under aseptic conditions, after treating the skin in the catheter area successively with an antiseptic solution and 70% ethyl alcohol solution, the catheter is removed, its distal end 5-6 cm long is cut off with sterile scissors and placed in a sterile Petri dish. For semi-quantitative analysis, the catheter segment is rolled over the surface of blood agar. Growth > 15 CFU indicates colonization of the catheter and a high probability of CAI. Growth < 15 CFU should be assessed as catheter contamination with a low probability that it served as a source of systemic infection (the sensitivity of the method is about 60%). This method allows identifying external colonization of the catheter and is more informative with a duration of catheterization of up to two weeks, when the external route of infection is more likely. In quantitative analysis, the segment of the removed catheter is processed in various ways (jet rinsing of the lumen, shaking or ultrasound exposure), allowing microorganisms to be washed into a liquid nutrient medium not only from the outer surface, but also from the lumen of the catheter. After dilution, the resulting wash is seeded on blood agar and incubated. Growth >102 CFU is considered diagnostically significant.

In combination with simultaneously performed blood culture from a peripheral vein, the results of the bacteriological study are interpreted as follows. In the presence of clinical symptoms of systemic infection, microorganisms isolated from the blood culture obtained by puncture of a peripheral vein and catheter colonization (>15 CFU with the semiquantitative method and >102 CFU with the quantitative method), the latter is considered the source of bacteremia. If microorganisms are isolated from the blood culture obtained by puncture of a peripheral vein and the catheter is contaminated (<15 CFU with the semiquantitative or <102 CFU with the quantitative method of culture), the catheter is most likely contaminated from the bloodstream and does not serve as the source of bacteremia. In the absence of growth in the blood culture and proven catheter colonization (>15 CFU with the semiquantitative and >102 CFU with the quantitative method), catheter-mediated bacteremia is intermittent.

For cases when catheter removal or its replacement via a guidewire is impossible or undesirable, quantitative methods that do not require catheter removal have been proposed. Equal volumes of blood are taken simultaneously from the catheter and peripheral vein, then seeded on melted blood agar and incubated for 24-48 hours, after which the number of colonies is counted. If the number of colonies in the catheter culture exceeds the number of colonies seeded from the peripheral vein by a factor of five or more, CAD is considered proven. Modern automatic diagnostic systems allow performing a similar quantitative test by comparing the time of a positive response in blood cultures obtained simultaneously from the CBC and peripheral vein. The appearance of growth of the same microorganism in the CBC sample earlier than in the peripheral blood with a difference of more than 120 minutes indicates CAD (sensitivity of the method is 91%, specificity is 94%).

If an infection associated with the presence of a catheter in the pulmonary artery is suspected, it is necessary to perform a bacteriological examination of the intravascular segment of the introducer, since it is susceptible to infection much more often than the segment of the catheter located in the pulmonary artery.

An infected peripheral venous catheter is removed with mandatory subsequent semiquantitative microbiological testing. At the same time, it is necessary to perform blood culture from an intact peripheral vein before starting antibiotic treatment.

In case of local infection, it is necessary to culture the exudate from the catheter exit site for Gram smear examination and culture on nutrient media.

Blood cultures from the catheter or from a segment of the removed catheter should be performed only if CAI is suspected. Quantitative or semiquantitative studies are appropriate, while qualitative cultures are not recommended due to their low information content. To detect bacteremia, two blood cultures should be performed, one from the CBC and one from a peripheral vein. If the culture is isolated from blood collected only from the catheter, it is difficult to determine whether catheter seeding, catheter colonization, or bacteremia is present. However, a negative catheter blood culture is highly suggestive of the absence of catheter-associated infection. If the culture from the segment of the removed catheter or blood culture collected from the catheter is negative, an additional source of infection should be sought.

In intensive care unit patients with other foci of infection (pneumonia, peritonitis, purulent wounds), CAI has its own characteristics. Systemic antibiotic treatment prevents the development of CAI or delays its development, but it promotes the selection of resistant bacterial strains (Staphylococcus aureus, Klebsiella spp, Pseudomonas aeruginosa) and increases the likelihood of fungal infection. The background infection masks the clinical manifestations of CAI, so it is necessary to have a certain alertness regarding the possibility of developing CAI and, at the slightest suspicion, perform a microbiological study. With each new episode of increasing fever, leukocytosis and other signs of systemic inflammation, in addition to assessing the state of the main foci of infection, it is necessary to repeat quantitative microbiological studies of blood from a catheter and a peripheral vein.

Persistence of fever and bacteremia after catheter removal and initiation of antibiotic therapy indicates a high probability of complications. The combination of symptoms of systemic inflammation and signs of venous insufficiency or pain along the catheterized vein indicates the development of septic thrombophlebitis, which can be confirmed by ultrasound (duplex scanning), phlebography or computed tomography with vascular contrast. If S. aureus or Candida spp. are isolated in blood cultures, transesophageal or transthoracic echocardiography should be performed to assess the condition of the mitral valve cusps and identify vegetations typical of septic endocarditis. Metastatic purulent seedings of other localizations (osteomyelitis, septic arthritis) are diagnosed based on local clinical symptoms and confirmed by radiographic methods.

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Treatment of angiogenic infections

When choosing treatment for CAI, it is necessary to take into account a number of circumstances: the severity of the clinical manifestations of the infection (subfebrile fever, febrile fever, severe sepsis, septic shock), the nature of the pathogen, the presence of local inflammation at the site of catheter insertion (infiltrate, purulent discharge, pain), the need for a CBC and the possibility of alternative venous access, the type of CBC (removable non-tunneled, tunneled, implanted "port").

Treatment of CAIC includes a number of measures:

Removal of the catheter

The catheter insertion site should be carefully examined. If pus is released from the catheter insertion site or other signs of inflammation are present, the catheter should be removed. In patients with septic shock, in the absence of another source of infection, the catheter should be removed and a new catheter inserted at another site. A tunneled CBC or an implanted "port" is removed in case of a tunnel or pocket infection. In the absence of signs of local inflammation and uncomplicated CBC, an attempt to sanitize the tunneled CBC or implanted "port" without removal may be made. If the nature of the isolated microorganism (resistant bacterial strains or fungi) and the severity of the patient's condition (septic shock, MOF) do not allow for sanitizing the catheter and coping with the infection, the catheter should be removed.

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Prescribing antibiotics

In severe infections (severe sepsis, septic shock) or decreased immunity (neutropenia, glucocorticoid use, uremia, diabetes mellitus), empirical antibiotic therapy should be started immediately and adjusted after obtaining microbiological analysis data. Empirical treatment usually includes drugs effective against Staphylococcus epidermidis or S. aureus. Antibiotics active against gram-negative microorganisms should be prescribed to patients with immunosuppression, neutropenia, or other risk factors for the development of gram-negative infection. In moderate to mild infections, antibiotic treatment should be considered, but if the symptoms of infection disappear after removal of the CBC, antibiotic therapy is not necessary.

The choice of the drug and the route of administration of the antibiotic are determined by the properties of the isolated microorganism, the severity of the clinical manifestations of the infection, and the design of the CBC. Three routes of administration of antibiotics are used:

• systemic therapy by intravenous administration is used at the first stage and in severe clinical course of infection,
• Taking antibiotics orally is advisable when the patient's condition stabilizes and there is a need to continue systemic antibiotic treatment,
• "antibacterial lock" (similar to the heparin "lock") is the introduction of small volumes of antibiotic solutions in high concentrations into the lumen of the CBC with subsequent exposure for several hours (for example, 8-12 hours at night when the CBC is not used).

The latter method is used independently or in combination with systemic antibiotic therapy in cases of intraluminal infection of the CBC, the removal of which is not entirely desirable (for example, a tunnel CBC or an implanted "port"). Vancomycin at a concentration of 1-5 mg / ml, gentamicin or amikacin at a concentration of 1-2 mg / ml, ciprofloxacin at a concentration of 1-2 mg / ml can be used as a "lock". Antibiotics are dissolved in 2-5 ml of isotonic sodium chloride solution with the addition of 50-100 U of heparin. Before subsequent use of the catheter, the antibiotic "lock" is removed.

If coagulase-negative staphylococci are detected, if the isolated strain is sensitive to methicillin, oxacillin is administered intravenously at a dose of 2 g at 4-hour intervals. Alternative drugs are first-generation cephalosporins (cefazolin at 2 g every 8 hours), vancomycin at a dose of 1 g at 12-hour intervals, or co-trimoxazole at 3-5 mg/kg every 8 hours. Vancomycin has advantages over oxacillin and first-generation cephalosporins, but the latter are preferable due to the growth of resistance to vancomycin. If methicillin-resistant strains of coagulase-negative staphylococci are detected, the drug of choice is vancomycin at a dose of 1 g every 12 hours intravenously. The second-line drug is linezolid (Zyvox) at a dose of 600 mg every 12 hours intravenously (for adults weighing <40 kg, the linezolid dose is 10 mg/kg). The duration of treatment is 7 days. If the catheter is not removed, systemic therapy is supplemented by an "antibiotic lock" for up to 10-14 days.

If methicillin-sensitive S. aureus is detected, oxacillin is administered intravenously at a dose of 2 g at 4-hour intervals. Alternative drugs include first-generation cephalosporins (cefazolin 2 g every 8 hours). If methicillin-resistant S. aureus strains are isolated, the drug of choice is vancomycin at a dose of 1 g intravenously every 12 hours. Decreased sensitivity of S. aureus to vancomycin is possible. In this case, gentamicin or rifampicin are added to the prescription. The second-line drug is linezolid, which is administered at 600 mg every 12 hours intravenously or co-trimoxazole at a dose of 3-5 mg/kg every 8 hours (in case of sensitivity). When vancomycin-resistant S. aureus strains are isolated, the drug of choice is linezolid, administered at a dose of 600 mg intravenously at 12-hour intervals (for adults weighing <40 kg, the linezolid dose is 10 mg/kg). The duration of treatment is 14 days. If the tunnel CBC or port is not removed, an "antibiotic lock" is performed. In case of endocarditis, persistent or recurrent bacteremia, the CBC is removed, and systemic antibiotic treatment is continued for 4-6 weeks.

For the treatment of CAI caused by enterococci (E. faecalis or E. faecium), if they are sensitive to ampicillin, ampicillin is prescribed at a dose of 2 g every 4-6 hours as monotherapy or in combination with gentamicin at a dose of 1 mg/kg every 8 hours. Vancomycin is not prescribed in this situation due to the possible development of resistance. If enterococci are resistant to ampicillin, treatment is carried out with vancomycin as monotherapy or in combination with gentamicin. The second-line drug is linezolid. If resistance to vancomycin is detected, the drug of choice is linezolid. The duration of treatment is 14 days. To preserve the CAI, an "antibiotic lock" is performed for up to 14 days.

For the treatment of infections caused by gram-negative bacteria, antibiotics are prescribed according to the sensitivity of the isolated microorganism. If E. coli or Klebsiella spp are detected, third-generation cephalosporins are prescribed (ceftriaxone 1-2 g per day). Alternative drugs are fluoroquinolones (ciprofloxacin, levofloxacin) or aztreonam. For CAIC caused by Enterobacter spp or S marcescens, first-line drugs are carbapenems (imipenem + cilastatin 500 mg every 6 hours or meropenem 1 g every 8 hours), second-line drugs are fluoroquinolones (ciprofloxacin, levofloxacin). For the treatment of infection caused by Acinetobacter spp., ampicillin + sulbactam at a dose of 3 g every 6 hours or carbapenems (imipenem + cilastatin at a dose of 500 mg every 6 hours or meropenem at 1 g every 8 hours) are prescribed. If S Maltophilia is detected, co-trimoxazole at a dose of 3-5 mg/kg every 8 hours is prescribed, an alternative drug is ticarcillin + clavulanic acid. To treat infection caused by P. aeruginosa, third-generation cephalosporins (ceftazidime 2 g every 8 hours) or fourth-generation (cefepime 2 g every 12 hours), carbapenems (imipenem + cilastatin 500 mg every 6 hours or meropenem 1 g every 8 hours), antipseudomonal ß-lactam antibiotics (ticarcillin + clavulanic acid at a dose of 3 g every 4 hours) in combination with aminoglycosides (amikacin 15 mg/kg every 24 hours) are used. To preserve the CBC, an "antibiotic lock" is performed for up to 14 days. If there is no effectiveness, the CBC is removed, and systemic administration of antibiotics is continued for 10-14 days.

It should be remembered that recommended antibiotic therapy regimens that have shown high efficiency in large statistical data in relation to a certain type of microorganism may be ineffective in relation to a specific isolated strain, since the sensitivity of gram-negative bacteria to antibiotics can vary widely.

In the treatment of CAI caused by fungal microflora (C albicans or Candida spp), the leading role belongs to amphotericin B (intravenously at a dose of 0.3-1 mg/kg daily). Fluconazole at a dose of 400-600 mg every 24 hours should be prescribed only in cases of proven sensitivity of the isolated fungal strain to it. In case of fungal infection, the CAI of any design must be removed due to the ineffectiveness of sanitation. Treatment with antifungal drugs should be continued for 14 days after the last positive result of blood culture.

Treatment of CBC caused by rare microorganisms should be carried out taking into account their sensitivity to antibiotics. If Corynebactenum spp or Flavobacterium spp are isolated, vancomycin should be prescribed, if B. cepacia is isolated, co-trimoxazole or carbapenems, O. anthropi - co-trimoxazole or fluoroquinolones, T. beigelii - ketoconazole, M. futfur - amphotericin B. In all cases, the CBC should be removed. If M. futfur is detected, intravenous administration of fat emulsions should be stopped.

In case of organ dysfunction (renal or liver failure), appropriate adjustment of antibiotic doses is necessary.

Complicated CAIC requires prolonged antibiotic treatment for endocarditis - up to 4-6 weeks, for osteomyelitis - up to 6-8 weeks. If antibiotic treatment is ineffective, surgical intervention is indicated.

Treatment of complications

Pathogenetic connection of coagulation and infectious processes often leads to thrombosis of the catheterized central vein. In this case, anticoagulant therapy with sodium heparin should be prescribed.

Surgical treatment

Treatment of septic thrombophlebitis includes mandatory removal of the catheter, opening and drainage or excision of the infected peripheral vein. Surgical debridement is indicated for subcutaneous phlegmon, purulent arthritis, osteomyelitis and septic lesions of other localizations.

Prevention of angiogenic infections

Prevention of catheter-associated infections is of great importance due to its high efficiency. The system of preventive measures is based on identifying risk factors and reducing their impact by using various prevention methods.

Risk factors for the development of angiogenic infection can be divided into three main groups.

• patient related factors
  • o - extreme age groups (children 1 year and younger, adults 60 years and older),
  • granulocytopenia (<1.5x10 ⁹ /l with increasing risk at <0.5x10 ⁹ /l),
  • disease- or treatment-related immunosuppression,
  • skin lesions (psoriasis, burns),
  • severity of the condition,
  • the presence of infectious diseases or complications,
• factors associated with vascular catheters
  • catheter material and design,
  • vascular access option,
  • duration of catheterization (>72 h),
• factors associated with the placement and use of catheters
  • ensuring asepsis during installation and use of the catheter,
  • variety of manipulations

The first group of factors is practically not amenable to correction, therefore recommendations for the prevention of CAIC relate to factors of the second and third groups.

The leading role in prevention is played by professional training of personnel and strict adherence to the rules of antisepsis and asepsis when installing and working with vascular catheters. For this purpose, each hospital should develop instructions that allow standardizing the work of personnel and providing a material base for work. It is necessary to conduct training with personnel and control knowledge and skills in the prevention of nosocomial infections in the ICU. The creation of specialized groups dealing only with intravenous appointments allows to reduce the frequency of KAIK by 5-8 times. Fulfillment of aseptic requirements when installing a CBC, similar to those during surgical interventions (treatment of the patient's skin in the puncture area, lining the surgical field, treatment of the doctor's hands, use of sterile gloves, gown, mask and cap) reduces the risk of infection by 4-6 times. To treat the patient's skin before catheterization and during catheter care, it is necessary to use a 10% iodopyrone solution, a 70% ethanol solution, and a 2% aqueous or alcoholic chlorhexidine solution. The latter is probably the most effective for preventing CAI.

Subclavian vein catheterization is associated with a lower incidence of CABG than internal jugular or femoral vein catheterization, which is associated with a lower number of microorganisms on the skin surface in the area of CBC placement. Polyurethane or Teflon catheters are less susceptible to infection than polyethylene or polyvinyl chloride catheters. The use of catheters with an antimicrobial coating of silver sulfadiazine and chlorhexidine reduces the risk of CABG within 14 days after catheterization in a group of patients with an increased risk of CABG development. Tunneled catheters with a Dacron or silver sleeve, which prevents infection of the outer surface of the catheter, can reduce the incidence of CABG in the first 10-14 days.

Systemic or local (“antibiotic lock” or daily treatment of the catheter exit area) prophylactic use of antibiotics or antiseptics reduces the incidence and prolongs the development of CAI, but increases the risk of the emergence of antibiotic-resistant bacteria and colonization of catheters with fungal flora.

No differences in the incidence of CAIC were found when using single-lumen or multi-lumen (two- or three-lumen) CBCs. However, for catheterization, a catheter with the minimum number of lumens that ensures the implementation of the treatment program should be used.

It is necessary to strictly adhere to the replacement periods for infusion systems, connectors, stopcocks and other parts connected to catheters. Usually, the system is replaced after 72 hours. When infusing fat emulsions, the replacement period should be reduced to 12-24 hours. When transfusing blood components, the system must be replaced every 12 hours.

Planned replacement of the CVC via a guidewire or with a change in access does not reduce the risk of CVC.

An effective measure for preventing CAI is regular inspection and assessment of the catheter condition, timely treatment of the skin and replacement of the dressing in accordance with the instructions of the medical institution and as it becomes contaminated.

Current and stage-by-stage analysis of infectious complications associated with CVC is extremely important. It allows us to establish sources of infection and the nature of nosocomial microflora in a specific department, identify and eliminate errors in the work of personnel, and improve preventive measures.