Blood poisoning – this is a specific systemic pathogenetic state of the human body, which develops as a result of the introduction of infectious agents and the subsequent development of a generalizing infectious inflammatory response against the background of a decrease in the work of the immune apparatus.
Acute general blood infection makes its debut at the time of the spread of infectious agents from the primary focus to the general bloodstream, and this primary focus of infection most often is the suppurative focus of soft tissues, joints, internal structures and even bones. Acute infection of the blood develops almost always against the background of a pronounced decrease in immunity, which occurs when the primary inflammatory focus is not detected in time, resulting in a massive spread of toxic substances into various structures of the human body along with the blood flow.
It should be borne in mind that there are various etiopathogenetic types of blood infection, each of which is not a contagious infection, that is, even an infectious blood infection is not capable of being transmitted from one person to another. The maximum severity of the flow and the extremely negative effect on the patient’s health condition are characterized by purulent general blood infection resulting from the entry of pathogenic microorganisms from the purulent focus into the blood stream. Practically all etiopathogenetic types of blood infection in 90% of cases provoke a lethal outcome, therefore, it is not possible to speak about sufficient effectiveness of therapeutic measures in this pathological condition.
The main etiological provocateurs of blood infection are various pathogens in the form of protozoa, fungi, virus particles and, of course, bacteria. The pathogenetic stages of blood infection are triggered when the first portion of toxic substances enters the general circulation.
Infection in the blood in pediatric practice belongs to the category of practically unrecoverable pathological conditions due to the development of irreversible pronounced systemic inflammatory reactions affecting all structures of the child’s body.
Regardless of the clinical and etiopathogenetic forms of blood infection, clinical symptoms are characterized by a rapid increase in the intensity of clinical manifestations and their polymorphism.
Blood contamination is categorized as extremely unfavorable with respect to predictions for the recovery of pathological conditions due to the high level of mortality due to the low efficiency of the existing treatment methods.
The development of such a heavy condition for the human body as a blood infection is largely due not to the concentration or pathogenicity of the pathogen, but to a decrease in the function of the immune apparatus. In one person, whose immune system functions reasonably well, the causative agent provokes the development of a limited inflammatory response, and in another it may be a provocateur for the development of blood poisoning. A separate nosological form is blood infection after surgery, as well as during the long-term use of immunosuppressive therapy. It is extremely difficult with regard to the influence on the state of health of a woman when blood is infected after delivery, as well as in the post-sports period, the occurrence of which is caused by the penetration of infectious agents on the wound surface of the myometrium.
The development of this pathological condition occurs gradually, therefore an indication of the pathogenetic and clinical stage of blood infection in the diagnosis is mandatory for the attending physician.
Causes of blood poisoning
Such a pathological condition as a blood infection in a person develops against the background of a massive attack of infectious agents and their toxins, which, together with an inadequate treatment regimen, creates conditions for fulminant generalization of the inflammatory process. Considering the issue of etiology and the main pathogenetic mechanisms of development of blood infection, it should be noted the indisputable role of bacterial coccal flora, Pseudomonas aeruginosa, fungi, viruses and protozoa in its development. Pathogenetic mechanisms of blood infection development have their beginning from the moment the active pathogen enters the human body, after which an active or latent inflammatory response develops, which, against the background of increased individual reactivity of the organism, is a favorable background for enhancing inflammatory reactions.
Of course, there is a definite relationship between the concentration of the pathogen and the risk of developing blood contamination, that is, the more bacteria or viruses enter through the entrance gate into the human body, the greater the chances for the development of blood contamination. And at the same time, in the pathogenesis of the development of blood infection, the main role belongs to the imbalance in the work of the human immune apparatus, as a result of which a person is not able to resist even a small concentration of infectious agents. Thus, such pathological and physiological conditions as a somatic disease, endocrine disorders, oncopathology, changes in the blood composition, chronic vitamin deficiency, psycho-emotional stress, have an inhibitory effect on the main factors of immunity, which becomes a favorable background for the development of blood poisoning.
The development of blood poisoning proceeds with some consistency and staging. Thus, the primary pathogenetic link is the spread of a large concentration of pathogens from the primary inflammatory focus through blood collectors and the further formation of secondary septic metastases, which intensify the process of inflammation. Thus, the pathological marker of blood infection is the detection of a large number of ulcers in various structures of the human body.
Polymicrobial blood infection occurs, as a rule, in the group of HIV-infected patients suffering from a pronounced decrease in the function of the immune apparatus and the rapid reproduction of various kinds of pathological microorganisms. In the category of clinically healthy individuals, staphylococcus, pneumococcus, and meningococcus are the main instigators of the development of blood poisoning.
Symptoms and signs of blood poisoning
The clinical course of blood infection is accompanied by the appearance of polymorphic and at the same time low-specific clinical symptoms, which often simulate the clinical picture of other pathological conditions and diseases. The absence of pathognomonic clinical symptoms that would help the attending physician to establish blood infection at an early stage is largely due to the fact that quite aggressive and intensive antibacterial drugs are used in medical practice by doctors. Thus, against the background of a powerful antibiotic therapy, an atypical clinical picture of blood infection develops, consisting in a low degree or complete absence of a pyretic reaction, as the main marker of an inflammatory response.
In the classical course, blood poisoning is accompanied by the development of a hectic-type fever, the attack of which ends with profuse sweating, disruption of the cardiovascular system in the form of an abrupt pulse and blood pressure, chills, malaise, vomiting and diarrhea, as well as a marked dyspeptic syndrome that provokes dehydration and rapid weight loss.
Objective signs of blood infection, which are detected by the attending physician already at the initial examination of the patient, are a decrease in elasticity and turgor of soft tissues and skin, which acquire an earthy tint, the presence of many common foci of purulent infection in the form of phlegmon and abscesses.
Pediatricians note that blood poisoning in children already at an early stage of development is accompanied by the development of pronounced psychomotor disturbances with the appearance of gross neurological changes and deep impairment of consciousness up to coma. The chronic course of blood infection is characterized by the development of slow-progressive multiorgan disorders and the appearance of a multitude of inflammatory foci in various internal organs.
In many respects, the appearance of any pathognomonic manifestations in a patient directly depends on the etiopathogenetic type of blood infection. Thus, blood infection after surgery is primarily manifested by a local reaction in the postoperative suture area in the form of inflammation, after which an increase in the general intoxication syndrome is observed.
Infection of blood after childbirth in almost 99% is fulminant due to the rapid increase in the intensity and polymorphism of clinical symptoms. In this situation, a good collection of anamnestic data is a good help in making a diagnosis of “blood poisoning”. The fulminant course of blood infection always ends in death due to the development of pathogenetic mechanisms of infectious-toxic shock.
Diagnosis of blood poisoning
The statement of the clinical diagnosis of “blood poisoning”, although difficult, is possible, provided that the patient’s clinical manifestations are adequately evaluated, as well as the typicality of her individual symptoms. Obligatory stage for verification of the diagnosis of “blood infection”, and especially determining its etiopathogenetic form, is the collection of anamnestic data that preceded the development of clinical symptoms of the disease (period after surgery, injury, delivery and severe infectious diseases).
Based on the analysis of the unfolded hemogram of the patient, in which the attending physician suspects the development of blood poisoning, in most situations pronounced leukocytosis and a clear stab-left formula are shifted to the left with a simultaneous critical decrease in platelet blood cells. The identification of the pathogen is of great importance in determining the tactics of treating patients with blood poisoning, for which various types of bacteriological blood tests, carried out three times at least one hour before taking the antibacterial drug, are successfully used.
To assess the severity of the patient’s condition, which has previously been diagnosed as “blood poisoning,” it is necessary to take into account the peculiarities of an individual “systemic inflammatory response”, which is a systemic response of the body to the introduction of any active infectious agents. The distinctive signs of blood poisoning in this situation is the development of generalization of the pathological inflammatory response and the formation of many limited inflammatory-purulent foci.
Additional instrumental techniques that allow visualization of blood contamination are various methods of radiation diagnostics such as standard fluoroscopy, ultrasound scanning, and computer-assisted spiral tomography. With the localization of the main pathological changes of blood infection in the patient’s bone tissue, the main instrumental method of investigation is radiography, which allows visualizing signs of osteomyelitis (limited or extended areas of destruction of bone structure).
With the development of multiorgan disorders caused by the development of a powerful inflammatory process, blood infection is quite effectively diagnosed on ultrasound, as well as on tomographic scans (intra-abdominal and intrathoracic abscesses, unlimited infiltrates).
Severe infection of the patient’s blood is manifested by signs of cardiovascular insufficiency, manifested by hypotension and hypoperfusion. Typical biochemical laboratory markers of blood infection appear at the terminal pathogenetic stage and act as a sign of multiple organ failure.
Blood poisoning treatment
In determining the treatment tactics of a patient suffering from blood infection, it is necessary first of all to take into account the features of the pathogenetic mechanisms of development of this pathology. Given the two main mechanisms for the development of blood poisoning in the form of the development of massive intoxication syndrome and the symptom complex of disseminated intravascular coagulation of blood, therapeutic measures should be directed to relieve these pathogenesis links. All patients for whom the development of blood poisoning was suspected are subject to immediate hospitalization in the intensive care unit of the infectious disease profile. Signs of late medical correction of blood poisoning are the development of multiple hemorrhages in the adrenal glands, gangrene of the extremities, and irreversible changes in the internal organs.
Immediately after taking blood for biochemical and other types of tests, the patient must intravenously enter the first maximum dose of the antibacterial drug. In the event of the appearance of minimal signs of DIC in the form of a hemorrhagic rash, nonspecific myalgia and muscle soreness, interstitial pulmonary edema on standard radiographs of the thoracic cavity, medical corrections are ineffective and the plasmapheresis procedure should be started immediately. To conduct it, it is necessary to remove about 1.5 liters of plasma from the patient’s body, followed by parenteral administration of 2/3 of this volume of fresh frozen plasma. Fulminant heavy course of blood infection is the basis for the expansion of the volume of fresh frozen plasma to 2 liters or more.
Often, in order to obtain a quick effect of cupping DIC in the blood of a patient, combined therapy with plasmapheresis and Heparin is used at a maximum dose of 24,000 U / day. This drug for blood infection is preferably administered continuously intravenously, especially during the first days of therapy.
In the case when blood infection is accompanied by the development of cardiovascular insufficiency in the patient in the form of arterial hypotension, it is advisable to use drugs of the sympathomimetic group, and in the absence of a pharmacological effect, therapy should be supplemented with the administration of intravenous hydrocortisone. The presence of signs of arterial hypotension in a patient suffering from blood poisoning is not considered a contraindication for plasmapheresis, however, the volume of plasma to be removed and injected should be somewhat reduced.
When selecting a drug for antibiotic therapy for blood infection should be primarily based on the expected type of pathogen. In the case of difficult early verification of the causative agent of blood infection, it is necessary to start early with empirical drug antibacterial therapy, which involves the administration of Gentamicin in a daily dose of 240 mg in combination with Zeporin at a maximum daily dose of 4 g intravenously. Reliable signs of sufficient pharmacological efficacy of antibiotic therapy for blood infection include improving the patient’s subjective well-being, stopping hemodynamic disturbances, reducing the body’s pyretic reaction, eliminating chills, and reducing the elements of the rash. Laboratory criteria for improvement are a decrease in the absolute number of stab cells in the hemogram.
Consequences of blood poisoning
The generalized course of blood infection often provokes the development of complications associated with hemodynamic and respiratory disorders due to a sharp drop in PaO2, as well as an increase in the permeability of the aerohematological barrier. As a result of these changes, when a patient is infected with blood, the blood component of the blood in the alveoli sweats, a decrease in the lung excursion and a further violation of the gas exchange function. When a patient suffering from blood poisoning is detected on the radiograph, there are increasing bilateral obstructions of the pulmonary parenchyma, a decrease in the compliance of the pulmonary parenchyma, as well as laboratory signs of hypoxemia, the development of respiratory distress syndrome, which occurs in 50% of all pathologies, should be implied. When detecting the rise of DZLA to the level of more than 18 mm Hg. Art. should be suspected development of hypervolemia and acute heart failure, rather than respiratory distress syndrome.
Another option for the complicated course of blood infection in humans is the development of septic shock, caused by a sharp drop in round focal disease, and to a greater extent by the redistribution of blood flow and a decrease in circulating blood volume. The leading mechanism for the development of septic shock during blood infection is an increase in the permeability of the vascular wall at the level of the capillary bed and the release of the liquid component of the blood into the perivascular space. The aggravating factor in septic shock is the continued decrease in circulating blood volume due to dehydration of the body, which develops in most infectious diseases. In the debut of the development of the clinical picture of blood infection, there is no violation of cardiac output, and in some situations even a compensatory increase may be observed, which allows differentiation of septic shock from cardiogenic, obstructive and hypovolemic types of shock.
The development of acute cardiovascular insufficiency in blood infection is observed after one day, as evidenced by an increase in the end-diastolic and end-systolic volumes, as well as a decrease in the ejection fraction. However, no change in cardiac output is observed, even despite the developing myocardial dysfunction and arterial hypotension. The development of a fatal outcome in this situation is due to refractory shock and multiple organ failure, and not heart failure.
Signs of impaired renal function during blood infection is the detection of signs of oliguria, azotemia, proteinuria and cylindruria in the patient. The development of renal failure during blood infection is associated with the formation of damage to the renal capillary network and acute tubular necrosis due to arterial hypotension. In addition, the development of signs of glomerulonephritis, interstitial nephritis, and cortical necrosis of the kidneys can be observed upon blood infection. The situation aggravating the course of renal failure during blood infection is the use of anti-bacterial drugs of the aminoglycoside group in case of existing arterial hypotension.
The consequences of blood poisoning also include a prolonged coagulation disorder caused by thrombocytopenia, which occurs in 30% of all cases of this pathology. With a prolonged course of blood infection, the development of severe, often irreversible neurological disorders in the form of polyneuropathy is noted. To establish these pathological changes, it is recommended to use electrophysiological studies, complete elimination of Guillain-Barre syndrome, as well as various metabolic disorders and toxic damage to the nervous system.
Prevention of blood poisoning
After suffering a blood infection, each patient requires a long-lasting immunorehabilitation in order to prevent recurrence of the disease, implying the use of various kinds of extra-immune therapy drugs (vitamin-mineral complexes, herbal immune-active drugs and adaptogens). In addition, as prophylactic measures after suffering a blood infection, patients are recommended periodic use of prolonged courses of mild immunomodulators such as timomimetics, as well as derivatives of bacterial mural dipeptides, drugs of the antioxidant group.
To prevent the development of complicated forms of blood poisoning, the duration of inpatient treatment in a highly specialized medical institution should be based on clinical and laboratory “recovery” in combination with complete sterility of blood cultures. The length of the disability certificate after the discharge of a patient who has suffered a blood infection is, on average, two months, during which he is under the dynamic supervision of a therapeutic profile specialist. During this time, the patient is obliged to carry out thermomentria at least three times a day, and a visit to the attending physician should be once every two weeks with a full blood and urine test.
Even after the patient has fully recovered and there are no complaints on his part for three years after blood infection, he should be kept at the dispensary in order to completely prevent the development of chronicity of the pathological process and the development of a recurrence of blood infection.
In some situations, with the prophylactic goal after the cessation of inpatient treatment for blood infection, the use of several courses of taking antibacterial drugs for two weeks every two months is shown.
Blood poisoning – which doctor will help? In the presence or suspicion of the development of blood poisoning, immediately consult a physician such as an infectious diseases specialist or a neurologist.