MINISTRY OF PUBLIC HEALTH OF UKRAINE
National Pirogov Memorial Medical University, Vinnytsya
CHAIR OF OBSTETRICS and Gynecology №1
Methodological instruction
on the practical class
“POSTNATAL INFECTIOUS COMPLICATIONS”
Module 2: Obstetrics and gynecology
I. Scientific and methodical grounds of the theme
Postnatal infections remain one of the basic reasons for maternal mortality. Postnatal infections most often take place at body temperature rise to more than 38° C and uterus painfulness even in 48—72 h after delivery. During the first 24 h after delivery normally body tempera-lure rise is not infrequent. About 80 % women with body temperature rise during the first 24 h after delivery through the natural maternal passages do not have signs of an infectious process.
II. Aim:
A student must know:
1. Etiology and pathogenesis of postnatal infectious complications.
2. Clinic symptoms of postnatal infectious complications.
3. Diagnostics methods of postnatal infectious complications.
2. Differential diagnostics of postnatal infectious complications.
3. Treatment methods of postnatal infectious complications.
A student should be able:
1. To carry out an objective obstetrics examination of a patient.
2. To make up a plan of a patient’s examination.
3. To evaluate the results of patient’s examination and to make a diagnosis.
4. To write out a prescription of medicine.
III. Recommendations to the student
POSTNATAL INFECTIOUS COMPLICATIONS
In the International Classification of Diseases of the 10th review (ICD-10,1995) the following postnatal diseases are singled out;
085 Postnatal sepsis.
Postnatal:
— endometritis;
— fever;
— peritonitis;
— septicemia.
086.0 Surgical obstetric wound infection. Infected (after delivery):
— wound of cesarean section;
— perineal suture.
086.1 Other infections of the maternal passages after delivery:
— cervicitis;
— vaginitis.
087.0 Superficial thrombophlebitis in the puerperal period.
087.1 Deep phlebothrombosis in the puerperal period.
Deep vein thrombosis in the puerperal period. Pelvithrombophlebitis in the puerperal period.
Etiopathogenetic factors of infection development:
1. Presence of an infectious agent and its characteristics (the type of the microorganism, its virulence, toxigenicity, invasiveness, and close).
2. The state of the portal of infection entry (localization, the degree of tissues damage).
3. The state of nonspecific protection factors (organism resistance) and specific mechanisms (immunity).
4. Physiological resistance of the microorganism:
- biological barriers (the skin, mucous tunics);
- reticuloendothelial system organs (the liver, spleen, lymph nudes);
- bactericidal component of biological fluids (lysozyme, complement, properdin);
- inflammation reaction and phagocytosis mechanism. Despite the great variety of agents in the majority of cases at postnatal infection the following are singled out:
— gram-positive microorganisms (25%): Staphylococcus aureus — 35 %, Enterococcus spp. — 20 %, Coagulase-negative staphylococ-cus — 15 %, Streptococcuspneumoniae -- 10 %, other — 20 % ;
— gram-negative microorganisms (25 %): Escherichia coli — 25 %., Klebsiella/Citrobacter — 20 %, Pseudomonas aeruginosa — 15 %, En-lerobacterspp. — 10 %, Proteus spp. — 5 %, other — 25 %;
— mixed infection of gram-positive and gram-negative microorganisms — 20 %;
— fungi of the Candida genus — 3'%;
— anaerobic flora — 2 %;
— unestablished flora — 25 % cases.
Microorganism virulence is, in laboratory environment, a minimal dose of microbal bodies capable of causing an infectious process or lethal outcome in experimental animals; in clinical conditions it is detected by the degree of severity and consequences of the pathological process.
Microorganism toxigenicity is the ability to produce toxic1 substances in the form of ferments and toxins, which influence the metabolic processes of the organism.
Ferments produced by pathogenic microorganisms are divided into two groups by the character of influence on the microorganism:
1. Ferments splitting high-molecular compounds of the microorganism and promoting the appearance of aggressive qualities of the agent (hyaluronidase, deoxyribonuclease, fibrinolysin, collagenase, proteinase).
2. Ferments indirectly promoting the pathogenetic action of bacteria (urease, decarboxylase, lipolytic and acid-restorative).
Toxins are divided into two groups:
— exotoxins — high-toxic, have pronounced antigenic and aller-genie properties. Outside a cell exotoxin is thermolabile and high-sensitive to acids and disinfectants. The place of their action is the vessel endothelium, leucocytes, lymphoid tissue, and vegetative nervous system;
— endotoxins are released when a bacterial cell dies; they are less toxic and more thermoresistant.
Invasiveness is the ability of bacteria to overcome protective barriers of the microorganism and spread in tissues by forming ferments (hyaluronidase, phospholipase, elastase, collagenase).
The portal of infection entry is the area of tissue or organ through which pathogenic microflora gets into the patient's organism. There may be a couple of ways of getting into the organism:
— endogenous way (autoinfection) due to microflora in the patient's organism, in case of reduction of the natural organism resistance. It may be: a) opportunistic flora, which vegetates on the skin and mucous tunic of the organism; b) "dormant" infection, which is in chronic infection foci — tonsillitis, caries, osteomyelitis. The patient's organism becomes tolerant to its own microflora — this is a characteristic feature of autoinfection;
— exogenous — infection gets into the patient's organism from the environment through the damaged skin, mucous tunics, wounds;
— iatrogenic is a purulo-infectious process conditioned by the actions of medical workers.
Infection spread in the organism may be: blood, lymphatic, intercellular, intracanalicular (through the vagina, neck, uterine cavity, and uterine fallopian tubes), by combined ways.
The mechanism of wound infection development:
1. Penetration of the agent into tissues or organs.
2. Microorganisms reproduction, toxins and ferments release.
3. Development of the local and general reaction of microorganism response.
Postnatal infection may be caused by:
1) wound infection: infected episiotomy, laparotomy wound, wound of the perineum, vagina, uterine neck;
2) endometritis, parametritis;
3) mastitis;
4) infection of the upper respiratory tract, especially at general anesthesia application;.
5) epidural tunics infection;
6) thrombophlebitis: the lower extremities, pelvis, vein catheterization sites;
7) urinary infection (asymptomatic bacteriuria, cystitis, pyelonephritis);
8) septic endocarditis;
9 appendicitis.
Predisposing factors of postnatal complications development include:
1. Ccsarean section. The presence of suture material and ischemic necrosis of infected tissues alongside with an incision on the uterus create ideal conditions for septic complications.
2. Protracted labor and preterm rupture of membranes leading to chorionamnionitis.
3. Tissue trauma at vaginal delivery: forceps application;
— episiotomy;
— manual placenta removal;
— repeated vaginal examinations during delivery;
— intrauterine manipulations (internal version);
— internal monitoring of the fetal condition and uterine contractions;
— reproductive tract infections.
4. Low social level combined with bad nutrition and unsatisfactory hygiene.
WOUND INFECTION
Wound infection appears as a result of the infection of scratches, fissures, ruptures of the neck, mucous tunic of the vagina and vulva, wounds after excision of the perineum, anterior abdominal wall after cesarean section.
Inflammatory reaction is characterized by such general clinical manifestations:
— local inflammatory reaction: pain, hyperemia, edema, local temperature rise, malfunction of the injured wound;
— generalized reaction of the organism: hyperthermia, intoxication signs (general weakness, tachycardia, ABP decrease, tachypnoe).
Diagnostics takes into account the following data:
— clinical: examination of the injured surface, assessment of the clinical presentation, complaints, anamnesis;
— laboratory: common blood analysis (leucogram), common urine analysis, bacteriological investigation of the exudate, immuno-grara;
— instrumental: US.
Clinical signs of wound infection development in the wounds healing by primary intention:
a) complaints:
— of intensive, often throbbing pain in the region of the wound;
— of body temperature rise — subfebrile or to 38—39 °C;
b) local changes:
— hyperemia around the wound without positive dynamics;
— appearance of tissue edema, which gradually increases;
— palpation detects tissue infiltration, which often increases; appearance of deep infiltrates is possible (necrotizing fasciitis, which may spread to the buttocks, anterior abdominal wall — often a fatal complication);
— serous exudate often changes to pus.
Clinical signs of wound infection development in the wounds healing by secondary intention:
— progressing edema and infiltration of the tissue around the wound;
— appearance of dense painful infiltrates without clear contours;
— signs of lymphangitis and lymphadenitis;
— wound surface is covered with continuous fibrinopurulent incrustation;
— deceleration or cessation of epithelization;
— granulations become pail or cyanotic, their hemorrhagic diathesis sharply decreases;
— exudate quantity increases, its character depends on the agent:
• staphylococcus conditions the appearance of thick yellowish pus, and some strains cause the development of local putrid infection with the formation of the foci of tissue necrosis and grayish pus with sharp smell;
• streptococcus is characterized by the appearance of liquid pus of yellow-green color, ichor;
• colibacillary and enterococcal infections condition the appearance of brown pus with characteristic smell;
• blue pus bacillus, Pseudomonas aeruginosa, leads to the appearance of green pus with specific smell.
The type of the agent also defines the clinical course of wound infection:
• staphylococcosis is characterized by the fulminant development of the local process with evident manifestations of purulo-resorptive fever;
• streptoroccosis has a tendency to diffuse spread in the form of phlegmon, with low-grade local symptoms;
• blue pus bacillus is characterized by the flaccid, protracted course of the local process after acute onset with evident manifestations of general intoxication.
Bacteriological investigation of exudate is conducted with the purpose of detecting the agent and its sensitivity to antibiotics. Material sampling is to be performed before the beginning of antibiotic therapy. Material for the investigation may be the exudate, pieces of tissue, lavage from the wound. Material is taken with sterile instruments and placed in sterile tubes or vials with standard medium. Material is to be inoculated in the course of 2 h after sampling. Simultaneously with material sampling for bacteriological investigation one should perform not less than two Gram-stained smears for express-diagnostics.
There may be used accelerated methods of identifying the wound infection agent with the help of multimicrotest systems, lasting 4— 6h.
In the absence of microbal growth in the clinical material one should exclude such reasons:
— presence of high concentrations of local or systemic antibacterial preparations in the material;
— violation of the regimen of specimen storage and transportation;
— procedural mistakes in the bacteriological laboratory; effective control over the infectious wound process with antibacterial preparations.
You will find the US technique in the chapter Fetal Condition Imaging and Assessment except for fact that the sensor is placed on the lesion area in order to image the infiltration process.
Treatment: in most cases local treatment is sufficient. The treatment includes surgical, pharmacological, and physiotherapeutic methods.
Surgical wound treatment The initial handling of the wound is performed by primary indications. Repeated initial handling is performed if the first surgical intervention was not radical for some reason and repeated intervention was necessary before the development of i nfectious complications in the wound.
Surgical treatment of wound consists in:
— removal of dead tissue -- primary necrosis substrate — from the wound;
— removal of hematomas (especially deep ones), foreign bodies;
— final arrest of bleeding;
— restoration of damaged tissues.
Secondary treatment of the wound is carried out by secondary indications, as a rule, in connection with pyoinflammatory complications of the wound. Repeated secondary treatment of the wound at severe forms of wound infection may be conducted iteratively. In most cases secondary surgical treatment of wound includes:
— removal of the focus of infectious-inflammatory alteration; wide opening of recesses, leakages;
— full-blown drainage providing exudate outflow.
The pharmacological method is antibiotic prophylaxis and antibiotic therapy.
Antibiotic prophylaxis is systemic administration of an antimicrobial preparation till the moment of microbial contamination of the wound or development of postoperative wound infection, and also if there are signs of contamination, on the condition that primary treatment is surgical
Antibacterial prophylaxis principles:
— predominately a single dose of an antimicrobial preparation, in case of long-term anhydrous period and other risk factors of infectious complications development one should resort to full-blown prophylactic doses;
— at noncomplicated cesarean section the first dose of antibiotic is introduced after clipping the umbilical cord and then twice more with an interval of 6 h;
— the same preparation may be used for antibiotic therapy in case of complications arising during surgery or infectious process signs detected;
— prolongation of antibiotic introduction after 24 h from the moment of surgery termination does not lead to any increase of the efficiency of wound infection prophylaxis;
— preterm prophylactic administration of antibiotics before surgical intervention is not expedient.
Antibiotic therapy is the usage of antibiotics for long-term treatment in case of infectious process onset. Antibiotic therapy may be:
— empirical — based on the usage of broad spectrum preparations, active relative to potential agents;
— object-orientated — preparations are used according to the results of microbiological diagnostics.
Local application of antiseptics is very important. For wound cleansing one can use 10 % solution of sodium chloride, 3 % hydrogen peroxide, 1:5,000 furacilinum solution, 0.02 % chlorhexidme solution, etc. For quicker healing one may use liners with levomecol, levosin, synthomycin or solcoseryl ointment, etc.
Physiotherapeutic procedures in the period of reconvalescence include UHF-inductotherapy, ultraviolet irradiation, electrophoresis with medicamental preparations.
Prophylaxis of wound infection consists in rational management of labor and puerperal period, observance of aseptics and antiseptics.
POSTNATAL ENDOMETRITIS
Postnatal endometritis is inflammation of the superficial layer of endometrium. Endomyoinetritis (metroendometritis) is the spread of inflammation from the basal layer of endometrium to mvometrium. Perimetritis is the spread of inflammation from the endometrium and myometrium to the serous uterine layer.
The initial stage of postnatal infectious process may have different intensity
and polymorphous presentation. One should differentiate classical, obliterated and abortive forms of endomyometritis, endornyometritis after cesarean section. The classical form usually develops on the 3rd ~5th day after delivery. This form is characterized .by fever, intoxication, psyche alteration, evident leucocytosis with leucogram shift to the left, pathological discharge from the uterus. At. the obliterated form of endomyometritis disease usually develops on the 8th-9th day after delivery, temperature is subfebrile, local rnanifestations are low-grade. The abortive form has a course similar to the classical form, but is quickly arrested at a high level of immunologic;il protection. Endomyometritis after cesarean section is often complicated with pelviperitonitis, peritonitis, which may develop during the : 1st—2nd day after the surgery.