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Antisepsis - is a complex of measures oriented on removing, inhibition of growth, or killing of microorganisms which are already present in the wound.

Types of antisepsis

Mechanical antisepsis (surgical debridement etc ) Mechanical antisepsis (surgical debridement, etc.) Physical antisepsis (use of UV, HBO, laser, drains, etc.) Chemical antisepsis (chemical antiseptic agents, etc.) Biological antisepsis (antibiotics, serums, enzymes, etc.) Combined (mixed) antisepsis

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Mechanical antisepsisSurgical debridement represents the procedure of removal of all necrotized, nonviable tissues (affected parts of the skin, subcutaneous fat, muscles, or even bone). The purpose of the procedure is to remove all nonviable tissues and create best environment for healing process and prompt closure of the wound. g p p p

Mechanical antisepsis Amputation represents removal of the distal part of an extremity. It is absolutely indicated if the extremity is obviously nonviable. Relative indications represent limb conditions associated with direct thread to patient’s life. These are the severe infections, conditions which cannot be cured, etc.

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Physical antisepsisPressurized pulsatile irrigationPressurized pulsatile irrigation of the wound is necessary adjunctive of the wound is necessary adjunctive of the wound cleaning. of the wound cleaning.

Pressurized pulsatile irrigation helps to fulfil finer debridement, remove all pus, tiny particles, and foreign bodies. The procedure requires 1-7 L of fluid. Common used agents are: saline solution, furacilline, chlorhexidine, aqueous antibiotics, etc.

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Physical antisepsis Low frequency ultrasound action onto the wound cavity. The mechanism of action of the US is caused by mechanical cleaning of the wound due to disintegrating action on the necrotized areas and improvement of blood circulation. Period of action varies from 2 to 8 minutes. Procedure is effective at the first period of wound healing.

Physical antisepsis High intensity laser action onto the wound. It produces local heat leading to prompt evaporation of necrotized tissues with destruction of bacteria by high temperature. Simultaneous cauterisation of vessels minimizes blood loss.

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Physical antisepsis Managed abacterial environment (MAE). A special device is able to isolate the part of the body to create sterile environment. Special plastic chamber is placed over the affected part. The method is especially useful at treatment of suppurative wounds and burns.

Special plastic chamber is placed over the affected part. Air humidity, PaO2, etc. can be specially adjusted.

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The method is especially useful at treatment of suppurative wounds and burns. The wound does not require any covering with dressing.

Wound drains

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Physical antisepsis Drains - different appliances used to evacuate any fluid stagnating in the cavities, wounds, etc.

All draining systems are divided into open and closed: 1) Closed drains are tubes connecting a body cavity to a sealed reservoir 2) Open drains are not sealed at either end (high risk of infection).

Variants of closed drainsGravity drainage (passive draining) uses forces of gravity -posture of a patient, placement of the drain below the affected region (pleural empyema, etc.)

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Variants of closed drainsSuction drainage (active draining) applies a low level of suction to the drainage tube (very effective to evacuate fluid and close the “dead space” allowing a better approximation of tissue surfaces.

Variants of closed drains Underwater-seal drainage (passive draining) system prevent air and fluid from reentering the body. This system is used for tubes in the pleural space.

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Variants of closed drainsContinuous irrigation drainage (active draining)

Sump drains (active draining) are double-lumen catheters that allow air or irrigation fluid to enter through one lumen while suction is applied to the other lumen.Sump drain is commonly used to decrease intestinal dilation, nausea, and vomiting (paralytic ileus after GIT surgery).

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Sometime a rubber strip (passive draining) is inserted into the wound to prevent sealing of its edges. It improves outflow of collecting fluid. An insertion of the gauze strip (pledget) may limit a contact of contaminated tissues with sterile one. Also it helps to control bleeding. Improvement of outflow of drainage from the wound may be promoted by soaking the dressing with NaCl 10%.

Situations requiring drainage – indications to insertionTreatment:Chest tube to evacuate pneumothorax (tension), hemothorax, etc.

Deep cavities with poor contact with the skin (deep abscesses, such as subphrenic, subhepatic, or periappendiceal abscess, etc.)

Area where excessive dissection has been performed (to prevent collection of fluid (lymph, etc.).u d ( y p , etc.).

Diagnosis: an indicator of possible postoperative complications such as bleeding or anastomotic leak at the area of performed surgery – cholecystectomy, after pancreatic surgery, duodenal stump after gastrectomy, etc.)

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Management of drains (precautions)The reaction of the body can isolate a drain from adjacent tissues (the drain becomes “walled off”). So within 24-48 hours it may be no longer effective.Care at the drain’s exit site (particularly open drains) decreases risk of infection.Must never be used as a substitute of hemostasis.A rigid drain may erode through the wall of a blood vessel or viscus (soft drains and early removal may minimize the complication)early removal may minimize the complication).Excessive suction on a tube can also cause necrosis of nearby structures (intermittent low-level suction is safer).Drains may become detached from the skin and retract into the body (especially into the peritoneal cavity). They should be firmly attached and marked with a radiopaque marker.

RemovalWhen a drain is used for postoperative fluid collection it is removed when no further drainage occurs.When the main risk of leakage has passed, the drain is removed (after a cholecystectomy, if a leak from a bile duct injury is present, it should be evident in 1 or 2 days). Thus, drains are normally removed by the second day.

Complications of surgical drainage

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Chemical antisepsis.Antiseptics are chemicals which can be applied to living tissue to kill or inhibite the growth of microbes. Disinfection involves the killing or removal of microbes on an inanimate objects. After application of both the bacterial spores are not killed, but that growing, “vegetative” bacteria are.

1. Acids and alkalis boric acid 2-3% solution (Eusol) - broad spectrum and locally toxic;

Chemical antisepsis.

2. Halogens Chlorine and Iodine. Iodine (Lugol's solution) - broad spectrum, cheap, hypersensitivity is common; Povidone-iodine - broad spectrum, some hypersensitivity and local wound toxicity, rapidly inactivated by blood; dilute sodium hypochloride - broad spectrum and locally toxic.

3 Salts of heavy metals silver nitrate aqueous solution of silver mefenide3. Salts of heavy metals silver nitrate, aqueous solution of silver, mefenide acetate, mercuric chloride, Zn, etc.

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4. Antiseptics of phenol group first representative was carbolic acid, or phenol (significant tissue toxicity).- chlorhexidine (is referred to detergents) - non-toxic, persistent action, good activity against Gram + and moderate against Gram -; - savlon is a compound of chlorhexidine and cetrimede) is widely used in burns, wound care, etc.

h hl h i d i d d f ( ki h l i i- hexachlorophane is used in soap and powder form (on skin as prophylaxis against Staph infection.- cresols. Solution of cresols in soaps (lysol) – possesses tissue toxicity;

5. Oxidising agents H2O2 (Hydrogen peroxide) - weakly and slowly bactericidal, cheap. Ozone, potassium permanganate.

6. Dyes: brilliant green, methylene blue, acriflavin, acridine orange.

7. Surface acting agents quaternary ammonium compounds, soaps.

8. Alcohols most active in 70% concentration, broad spectrum and rapid action.

9. Derivatives of nitrofuran - aqueous furacillin. Furagin, and furasolidon are available in tablets and for i.v. injections.

10. 5-nitro-imidazole derivatives metronidazole (flagil) is available in tablets, solution, and for i.v. injections. Most effective against anaerobes; dioxidin.

Some chemical agents are used only locally (topical chemotherapy), another are administered systemically (systemic chemotherapy).

Utility of the topical chemotherapy application to operative and traumatic wounds and indwelling

devices (intravenous cannulas); treatment of established infection of wound and body cavities; clearance of colonization with pathogenic or antibiotic-resistant

organisms. Recommended antiseptics for local care

Traumatic wounds: aqueous chlorhexidine; saline. Traumatic wounds: aqueous chlorhexidine; saline. Surgical incisions: chlorhexidine; saline. Peritoneal, pleural and wound irrigation: chlorhexidine; saline;

noxythiolin Removal of slough: chlorinated lime and boric acid (Eusol)

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Biological antisepsis uses administration of antibacterial medicines.

Penicillins. Natural penicillins

- penicillin, bensil- penicillin, penicillin G (bicillin), extencillin Penicillinase-resistant penicillins (or semisynthetic)

hi illi illi f illi l illi di l illi- methicillin, oxacillin, nafcillin, cloxacillin, dicloxacillin Aminopenicillins

- ampicillin, amoxicillin (more effective) Carboxipenicillins

- carbenicillin, ticarcillin (more effective): Against G- infection especially. Ureidopenicillins

- azlocillin, piperacillin, mezlocillin: very broad spectrum of activity

General characteristic: Common rate of administration is 4 times a day, mostly are effective against G+ infection. Most of penicillins are susceptable to B-lactamase (should be used with B-lactamase inhibitors)

Adverse effects: allergic reactions (anaphylaxis, rashes), diarrhea, occasionally anemia, rarely seizures.

B-lactamase inhibitors.B-lactamase is an enzyme which alters the B-lactam ring of penicillins and cephalosporins- Clavulonate, sulbactam, tazobactam.

Amoxicillin clavulonat is used for treatment of upper Amoxicillin-clavulonat is used for treatment of upper respiratory tract infections caused by B-lactamaze producing flora.

Ticarcillin-clavulonat is used for treatment of intraabdominal, gynecologic infections where the flora commonly has B-lactamaze activity.

Piperacillin is commonly combined with any of Piperacillin is commonly combined with any of clavulonate, sulbactam, tazobactam and effective against G- B-lactamaze producing flora.

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CephalosporinsFirst generation:

- cefazolin, caphalothin. Mostly against G+ bacteria, little effect on the G-bacteria. Treatment of skin infections, osteomyelitis. They were used with aminoglycosides to provide broad-spectrum coverage. But bacterial resistance to first generation is very high.

Second generation:- cefotetan, cefoxitine, cefuroxime, cefamandole. Broader activity against G-bacteria

Third generation:- cefotaxime, ceftriaxone, cefoperazone. They have broader action against G-than against G+ bacteria. That group can be used instead of aminoglycosides. But now they are not so popular because of incomplete spectrum of activity that may be present at polimicrobial infections, unexpected toxicity, high propensity for inducing resistancy. Still the gold standard for treatment of abdominal infections includes aminoglycoside to cover enteric G- organisms andinfections includes aminoglycoside to cover enteric G organisms and clindamycin or metronidazole to cover anaerobes. If the third-generation cephalosporin is used for emperical therapy of serious intraabdominal infection it should be combined with clindamycin or metronidazole to cover anaerobes

New caphalosporins (fourth generation) : cefepime, cefpirome. Generally they are administered 2 times a day, 3 times in severe casesAdverse effects: they are relatively nontoxic. Hypersensetivity, local pain, GIT

disturbances. Reactions are usually mild and reversible.

Aminoglycosides

- Streptomycine, kanamycine, neomycine, tobramycine, gentamycine, amikacinCharacteristic: poor intestinal absorption (parenteral route is preferred), Bactericidal effect due to inhibition of protein synthesis. In anaerobic conditions it cannot penetrate the cell. So in that circumstances better penetration is achieved with inhibitor of cell wall synthesis such as B-penetration is achieved with inhibitor of cell wall synthesis, such as B-lactam AB or vancomycin. Gentamycine is commonly used for severe intraabdominal infections.Adverse effects: ototoxicity, nephrotoxicity.

Tetraciclines

- Tetracicline, doxicicline, minocicline.They are metabolized by the liver, here is the highest concentration, penetrate body tissues well crossing blood-brain barrier and placenta. Very effective for sexually transmitted diseases (STD). Adverse effects: GIT irritation, hepatotoxicity, fetus toxicity, nephrotoxicity, vestibular toxicity (dizziness, vomiting)

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Macrolides

- erythromycin and oleandomycin- metabolized by the liver, here is the highest concentration, commonly used at ambulance patients and those allergic to penicillins. Rate of administration is 4 times a day.New macrolides - azithromycin, clarithromycin: well absorbed and widely distributed. Broad spectrum. Standard oral therapy of respiratory and soft p py p ytissue infections. Can be given once a day. Adverse effects: GIT irritation

Clindamycin

Active against anaerobes and is useful at therapy of serious intraabdominal pelvic and pulmonary infections. Only few side effects.

Chloramphenicol

Has the same point of action. Single very negative side effect limiting its utility. Bone marrow supression starts usually 5-7 days after initiation of therapy - pancytopenia (reticulo, leyco-, neutro-, thrombocytopenia).

Vancomycin

Main feature is the effectiveness against resistant penicillinase-producing Staph inhibiting synthesis of cell wall peptidoglicane. Mainly administered i.v. and effective against G+. Agent of choice in treatment of methicillin-resistant Staph. aureus, useful for multiple resistant infections of CSF shunt, prosthetic valve infections. Side effects: anaphylactoid reactions (pruritis hypotension cardiac arrest)Side effects: anaphylactoid reactions (pruritis, hypotension, cardiac arrest)

Carbapenems

Extraordinary effective against anaerobes as well as G+ and G- bacteria. - Thienamycin, Imipenem- cilastatin.Cilastatin is added to prolongate action. Highly effective against most species likely to be encountered in severe intraabdominal infections. Can be used to yreplace combination therapy in mixed infections or exclude toxicity of other AB. Side effects: potentiation of seizures, diarrhea.

Monobactams

Aztreonam only inhibits aerobic G-, two-three times daily, may be useful to replace side effects of aminoglycosides.

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Quinolones

Characteristic: wide spectrum, used orally or parenterally less toxicparenterally, less toxic.- Ciprofloxacin, ofloxacin, norfloxacin, enoxacin, pefloxacin.Excellent activity against most Enterobac. including organisms resistant to aminoglycosides and cephalosporines, very effective against Staph, including methicillin-resistant isolatesmethicillin-resistant isolates. Treatment of urinary infections, prostatitis, bacterial diarrhea, skin infections, pneumonia.Side effects: CNS -headache, dizziness; GIT- diarrhea, vomiting; rushes, pruritis.

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Initial systemic antibacterial therapy

Culture may be done with most rapid test not less than 24 h. And sensetivity is obtained not less than 48-72 h. But at some patients AB should be started as soon as possible with established diagnosis. Therapy is initiated with an agent or combination of g py gagents those action is broad enough to cover all the suspected microbial pathogens. Initiation of such broad spectrum AB therapy in the absence of microbial confirmation is termed emperical therapy. Decision of emperical therapy should include knowledge of common pathogens of the site, host defense status, severity of infection, and response of the host. If chosen therapy is appropriate, the patient will get well (normalization of body temperature, clinical improvement, and normalization of labtemperature, clinical improvement, and normalization of lab picture).

Risk patients: advanced age, malnutrition, preexisting diseases.AB may be administered i.v., i.a., i.m., instillations into the body cavity or the wound.

Plan of AB therapy - considered questions:

distribution of an agent toxicity cost dosage route of administration duration:

treatment - 5-14 days (longer therapy may require change of AB), till resolution of symptoms;

prophylaxis - intraoperatively and 1-2 days after surgery)p p y p y y g y) single-agent or multi-agent therapy.

Careful evaluation of drug history, previous administration and allergy is done. Caution in pregnant women (possible toxicity to mother or fetus)

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Complications of AB therapy: - widespread resistance to AB, development of suprainfections which are more difficult to eradicate.

RememberAB are not used in treatment of viral infections.AB are not used in treatment of viral infections.During AB therapy a close observation of a patient is necessary for possible complications (anemia, leycopenia, allergy, etc.).If the purulent focus (abscess, etc.) is not drained or soiling is continued (uncontrolled peritonitis, empyema, etc.) an AB will not be effective.

After AB treatment an intestinal disbiosis is common Bificol After AB treatment an intestinal disbiosis is common. Bificol, lactobacteriin, colibacteriin, etc. may restore normal intestinal flora.

After AB treatment the fungi associations are common. Nistatin or levorin are used parallel to AB treatment to suppress growth of fungi.

Development of drug resistancy.

After exposure to AB most germs are killed. Sometime, however, there is a microbe with a mutation that makes it resistant to a drug Then a colony grows back all germs are drug resistantdrug. Then a colony grows back, all germs are drug resistant.

Drug resistance that develops in harmless bacteria may be transferred to harmful one. One microorganism attaches itself to another and a tube is opened between them in a process of conjugation.

A virus may infect a bacterial cell and incorporate bacterial genes into its own genes. Later the virus may infect another bacteria so it may transfer the deadly gene to the bacterium making the bacteria y y g gmore dangerous.

Arising of new viruses from wild environment (from animals) Often bacteria links up with another microorganism of the same

species and expose genetic material.

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Immune compoundsfor active immunity toxoids (anatoxins) and vaccines are used:

- tetanus toxoid, staph. anatoxine, etc.

for passive immunity antitoxins and serums are used: antistaph plasma, immunoglobuline, HTIG, antigangrene serum

Immune stimulators: prodigiozan, levamizole, lyzozyme, tactivine, timaline, etc.

Biological antiseptic compounds (proteolytic enzymes). They are used topically (finest debridement), or systemically p y ( ), y y(antiinflammatory action)

Classification:

Animal origin trypsin, chymotrypsin, ribonuclease, etc.

Bacterial origin streptokinase, collagenase, etc.

Plant origin papain, etc.