A. Common symptoms of burns
Sharp pain, burn trauma pale yellow mucous discharge, burn trauma sweet smelling mucous discharge, nausea and vomiting after burn injury, pulse rate increase after burn injury burn trauma light coffee-colored thin discharge.
Second, the risk factors of burn infection
Some studies have shown that trauma infection in burn patients is closely related to the following factors.
(1) the size of the burn and the degree of cauterization.
(2) The composition and number of germs on the trauma surface.
(3) The age of the burn patient.
(4) the strength of the patient’s own immunity.
C. Burn infection prevention
When local or systemic infection occurs, it is generally difficult to treat, so the prevention of infection is even more important, and reasonable preventive measures include the following.
1. debridement, aseptic operation and disinfection and isolation measures: Although the causative bacteria of systemic infection are not entirely from the trauma, the bacteria of the trauma have a certain relationship with the infection, so it is necessary to take antibacterial measures, commonly used are debridement and aseptic operation principles. Early in the patient’s admission, the necessary debridement should be administered without hindering anti-shock, removing contaminants and putrefied skin from the trauma, flushing the trauma with 1‰ Neosporin or 0.5% Chlorhexidine, and finally flushing the trauma with saline from 20℃ to 35℃ to reduce the bacterial count of the trauma. Asepsis and disinfection should not be neglected in the pathway of preventing infection. Although placing the patient in a sterile laminar flow room is not easy to achieve and unnecessary in general, placing the patient in a ward with sterile isolation is essential, and all factors that may cause cross-infection (such as utensils in the ward, and things carried by health care workers) should be avoided. The principle of asepsis is the key to prevent medically-derived infections.
2. Nutrition: Patients with large burns usually have malnutrition, immune deficiency and infection at the same time, and the three are mutually causal. Studies have shown that the conditioning index, total serum protein, transferrin, C3 and IgG levels in the high-protein treatment group are higher than those in the control group under adequate caloric supply of severely burned patients. Strengthening nutrition and paying attention to maintaining positive nitrogen balance can significantly reduce the incidence of invasive infections and mortality.
3.Immunotherapy: immunotherapy of burn infection is more studied than immunotherapy of Pseudomonas aeruginosa infection. Immunotherapy is divided into active immunity and passive immunity. At present, the active immunization is mainly Pseudomonas aeruginosa vaccine, and the passive immunization is Pseudomonas aeruginosa immunoglobulin or high-valent immune serum (or plasma).
(1) Active immunization: Pseudomonas aeruginosa vaccine can be divided into lipopolysaccharide antigens and endotoxin protein antigens according to antigen components. 7-valent P. aeruginosa vaccine and 16-valent P. aeruginosa vaccine (PEV-01) belong to lipopolysaccharide antigens, and the P. aeruginosa vaccine (EP) developed in China belongs to endotoxin antigens. Pseudomonas aeruginosa vaccine has good immunogenicity. After burn patients were vaccinated with PEV-01 three times on the day of admission, 7 days and 14 days, the antibody potency against 16 components increased on average from 1/4 to 1/32 on admission to 1/64 to 1/256 and was maintained for 4 weeks. The presence of lectins and hemagglutination in the serum was protective against lethal attack by P. aeruginosa. In contrast, protective antibodies were rare in patients who were not vaccinated.
Plasma levels of endotoxin were low in vaccinated patients and high in patients infected with P. aeruginosa without vaccination. Endotoxin depletes the C3 component of complement, impairs the nonspecific immune mechanism, and increases the patient’s susceptibility to infection. Inoculation with P. aeruginosa vaccine reduces the level of endotoxin in the blood and indirectly increases the patient’s resistance to its bacterial infection.
The phagocytic activity of neutrophils is increased after vaccination, and the phagocytic effect of neutrophils on latex granules, Bacillus pneumoniae and A. chimaera is enhanced. The ability of neutrophils to kill Pseudomonas aeruginosa was significantly enhanced in the presence of specific antibodies.
The appropriate dose of the vaccine produces the maximum level of antibody response, and the generally recommended dose for application is 25 μg/kg/dose for 7-valent vaccine, one adult dose (RHD) per dose for PEV-01, and 0.5 RHD for children under 12 years of age. combined intradermal and intramuscular or subcutaneous injections may be used. It usually takes 5 to 7 days to produce the appropriate level of antibodies. Therefore the earlier the vaccination, the better. The first vaccination should be given within 6 days, as the patient’s response to the vaccine is quite poor after 6 days. Active immunization generally takes 5-7 days for the level of IgG antibodies in the serum to reach a protective level and is maintained for a short period of time, so continuous immunization must be given once every 3-7 days until the threat of P. aeruginosa infection disappears.
Local redness and swelling may occur after vaccination, and body temperature may increase. The dose of vaccine should be stopped or reduced in case of serious reaction.
(2) Passive immunization: Passive immunization is the administration of P. aeruginosa immunoglobulin or high-valent immune serum (or plasma) to patients. High-valent immune plasma is prepared by injecting volunteers with the vaccine, separating the plasma when the antibody potency reaches 1:512, and preserving it by lyophilization. The dosage is 250 ml for adults and 125 ml for children, usually injected within a week. Pseudomonas aeruginosa immunoglobulin is injected on the day of admission and for 3 consecutive days, 0.5 ml for adults and 0.2 ml for children each time.
Passive immunization can compensate for the disadvantage of longer production time of active immunity. For people with low immune function, it is generally recommended to inject multivalent Pseudomonas aeruginosa vaccine and high efficiency Pseudomonas aeruginosa immunoglobulin or immune plasma immediately after the burn.
4, prophylactic application of antibiotics: the principles of prophylactic application of antibiotics are early, combined, adequate and sensitive. Although some scholars do not advocate the prophylactic application of antibiotics, we believe that the reasonable application of antibiotics can reduce the incidence of invasive infections. Early refers to the application of antibiotics to prevent infection after the admission of patients with large and deep burns or more serious contamination; combined refers to the combined application of two types of antibiotics to inhibit the proliferation of bacteria on the trauma surface and under the scab, generally using vanguardin plus hypromellose.
5, active treatment of the trauma: the necrotic tissue of the burn trauma provides a good medium for bacteria, and the trauma is the main source of infection. And the damage of immune function after burn injury also returns to normal with the healing of trauma or after covering by scab implant. Therefore, active treatment of trauma (including scab grafting and topical medication to promote trauma healing) is the key to prevent infection.