化脓性脑膜炎60566ppt课件

Purulent Meningitis,Purpose and demand:,To familiarize the pathogeny of purulent meningitis. To understand the mechanism and pathology change. To grasp the clinical manifestation,diagnosis,differential diagnosis and treatment. To self-study the accessory examination of neural system.,Contents,Induction Etiology & pathogenesis Manifestations Complications Laboratory findings Diagnosis & differential diagnosis Treatment & prevention,Introduction,Acute infection of central nervous system(CNS). 75% of cases occur in the age of 2yr. The inflammation of meninges caused by various bacteria.Common features in clinical practices include: fever,headache,vomit, convulsions, disturbance of consciousness,increased intracranial pressure, meningeal irritation. One of the most potentially serious infections, associated with high mortality (about 10%) and morbidity.,Etiology,1. Pathogens: Main pathogens: Neissria meningitidis, streptoccus pneumoniae, Haemophilus influenzae. 2/3 of purulent meningitis are caused by these pathogens,1. Pathogens(Pathogens in special populations ) neonate & 3mo infants : Escherichia coli Streptococcus haemolyticus group B Staphlococcus aureus 3mo infants : Haemophilus influenzae group B Streptococcus pneumoniae Neisseria meningitidis 5yr children : Neisseria meningitidis Streptococcus pneumoniae,Etiology,Etiology,2. Major risk factors for meningitis Immature immunologic function and attenuated immunologic response to pathogens Low level of immunoglobulin, defects of complement Immature or impaired blood-brain-barrier (BBB) Immature BBB function: maturation at about 1yr Impaired BBB: Congenial or acquired defects across mucocutaneous barrier,Access of bacteria invasion,Typical access-hematogenous dissemination Bacteria colonizing the mucous membranes of the nasopharynx invasion into local tissue bacteremia through BBS mainly effect on arachnoid and leptomeninges Mode of transmission: Person to person contact through respiratory tract secretions or droplets,Access of bacteria invasion,Invasion from parameningeal organs:such as paranasal sinuses or middle ear Bacteria spread to the meninges directly: through anatomic defects in the skull or head trauma,Structure of meninges,Pathology,Characterized by leptomeningeal and perivascular infiltration with polymorphonuclear leukocytes and an inflammatory exudate. Exudate which may be distributed from convexity of brain to basal region of cranium. Exudate is more thickness due to streptococcus pneumoniae than other pathogens.,Clinical manifestations,Prodrome: acute onset,precede by several days of upper respiratory infections or gastrointestinal symptoms fulminant onset:epidemic cerebrospinal meningitis manifestations:progressing shock bleeding spots in the skin or ecchymosis disseminated intravascular coagulation disturbance of central nervous system.,Clinical manifestations,Common features of meningitis: signs of systemic infection : fever,headache,fatigue,weakness,anorexia,bleeding spots in the skin,ecchymosis, alteration of mental status and consciousness,Clinical manifestations,Common features of meningitis: neurological signs: meningeal irritation: nuchal rigidity,kernig sign, brudzinski sign increased intracranial pressure: headache, vomiting, herniation Seizure (20-30%) Focal or generalized Due to cerebritis, infarction, electrolyte disturbances Frequently noted with H influenzae & S pneumococcal meningitis,When flexing the hip 90 degrees and then extending the leg, the patient feels subsequent pain,When passively flexing the neck while supine, patient involuntarily flexes his knees and hips.,Clinical manifestations,Common features of meningitis: neurological signs: alteration of mental status and consciousness including:irritability,lethargy,somnolence,confusion,stuppor,coma due to increased intracranial pressure,cerebritis focal signs 、 cranial nerves in trouble,paralysis,sensory disturbance,mainly caused by vascular occlusion,Clinical manifestations,The symptoms and signs are not evident in neonates and infants younger than 3mo of age; and patients already received irregular antibiotic therapy.,Comparison of the manifestations of meningitis between different age groups,Complications and sequelae,Subdural effusion Definitive diagnosis: volume of fluid in subdural space 2ml, protein0.4g/L, Incidence: develop in 10-30% of patients, asymptomatic in 85-90% of patients; especially common in infants 4-6 month of age ( rare in children over 1yr); Causative organisms: H influenzae, S pneumoniae,Complications and sequelae,Indications: No response to a sensitive antibiotic therapy Prolonged fever or fever reoccurring after an afebrile interval with effective treatment Bulging fontanel, widening of sutures, enlarging head circumference, vomit,seizure, altered consciousness. Improved CSF profile with more serious clinical manifestations,Complications and sequelae,Diagnosis methods: Cranial translucent test B ultrasonic examination and CT Subdural space puncture,normal,subdural effusion,Complications and sequelae,2. Ventriculitis Usually occurs in neonates and infants (50x106/L, Glucose400mg/L.,Complications and sequelae,3. hydrocephalus : Communicating hydrocephalusincreasing neuropsychiatric symptoms 4.Cerebral hyponatremia: The syndrome of inappropriate secretion of antidiuretic hormone 5.others: Deafness, blindness, paralysis, epilepsy, mental retardation,Examinations,1.Blood routine examination:WBC raised protein concentration, 1g/L Finding bacteria in CSF,Examinations,2.Cerebrospinal fluid examinations: (2)special examination: Specific bacterial antigen-detection test Countercurrent immuno-electrophoresis,CIE Latex agglutination Immunofluorescent test LDH,lactic acid,CRP,TNF,Ig,NSE determinations,Examinations,3.Other examinations (1)blood culture:before antibiotic therapy (2)petechia smear:epidemic cerebrospinal meningitis (3)other secretion cultures: (4)imaging:CT&MRI,Diagnosis,Earlier diagnosis and prompt initiation of effective antibiotic treatment is critical for minimizing sequelae of purulent meningitis. Suspected cases: febrile infants with seizure, meningeal irritation, increased intracranial pressure, altered mental status Pay attention to the atypical symptoms and signs in neonate, infant and patient already received irregular antibiotic therapy,Diagnosis,Diagnosis is confirmed by analysis of cerebrospinal fluid ( CSF) Suggestion bacterial meningitis Increased pressure (90%) Appearance: slightly cloudy to purulent Raised white blood cells,consisting chiefly of polymorphonuclear leukocytes Raised protein concentration, Decreased glucose concentration (80%),Diagnosis, Confirmation of the diagnosis: isolation from the CSF of a specific bacterial pathogen by microscopy or a positive culture or rapid antigen-detection test of CSF Gram-stained smear of CSF: identify the causative organism in 70-90% of cases CSF culture: positive in about 80% of cases.definitive diagnosis, determination of antibiotic sensitivity. PCR: amplifies bacterial DNA (H influenzae, N. meningitidis),Differential diagnosis,Viral meningitis/encephalitis: Less severe systemic infectious symptoms Usually not develop after 2-3weeks CSF: normal glucose Tuberculous meningitis: Subacute onset and progress A history of close contact with known cases of tuberculosis Evidence of acute or healed tubercular infection on chest x-ray Tuberculin skin test : OT, PPD CSF,Differential diagnosis,Cryptococcal meningitis: slow onset,a long course of disease, increased intracranial pressuresevere headache CSF changes:similar with tuberculous meningitis confirmed by Indiainkstaining or culture of CSF Mollarets meningitis: etiology:unknow clinical manifestations and CSF:recurrent,similar to purulent meningitis CSF:Mollarets cells adrenocortical hormone therapy:effective,Differential diagnosis,Brain abscess: slow onset CSF:pressure ,cellnormal or ,protein further diagnosis:CT or MRI Acute toxic encephalopathy: manifestations:delirium,convulsions,coma,meningeal irritation,cerebral palsy CSF:only pressure ,Treatment,1.Antibacterial therapy Therapy principles: early treatment,antibiotics susceptible to pathogens and with high permeability through BBB, given intraveninously, enough dose, enough course of antibiotic therapy,Treatment,at the time of unknown pathogenic bacteria: First choice: Cefotaxime, Ceftriaxone (3dr generation of cephalosporins, high permeability through BBB, products of metabolism also has effect, CSF sterilization within 24h) Other choice: Penicillin, Chloramphenicol, ( side effects: gr