儿科英文化脓性脑膜炎Bacterialmeningitis.ppt

儿科英文化脓性脑膜炎BacterialmeningitisIntroductionn nAnnual incidence in the developed countries is approximately 5-10 per 100000.n n30000 infants and children develop bacterial meningitis in United States each year.n nApproximately 90 per cent of cases occur in children during the first 5 years of life.Introductionn nCases under age 2 years account for almost 75%of all cases and incidence is the highest in early childhood at age 6-12 months than in any other period of life.n nThere are significant difference in the incidence of bacterial meningitis by season.Etiologyn nCausative organisms vary with patient age,with three bacteria accounting for over three-quarters of all cases:n nNeisseria meningitidis(meningococcus)Neisseria meningitidis(meningococcus)n nHaemophilus influenzae(if very young and Haemophilus influenzae(if very young and unvaccinated)unvaccinated)n nStreptococcus pneumoniae(pneumococcus)Streptococcus pneumoniae(pneumococcus)Etiologyn nOther organisms n nNeonates and infants at age 2-3 months n nEscherichia coliEscherichia colin nB-haemolytic streptococciB-haemolytic streptococcin nStaphylococcus aureusStaphylococcus aureusn nStaphylococcusStaphylococcus epidermidisn nListeria monocytogenesListeria monocytogenesEtiologyn nElderly and immunocompromisedElderly and immunocompromisedn nListeria monocytogenesListeria monocytogenesn nGram negative bacteriaGram negative bacterian nHospital-acquired infectionsHospital-acquired infectionsn nKlebsiellaKlebsiellan nEscherichia coliEscherichia colin nPseudomonasPseudomonasn nStaphylococcus aureusStaphylococcus aureusEtiologyn nThe most common organisms n nNeonates and infants under the age of 2monthsNeonates and infants under the age of 2monthsn nEscherichia coli Escherichia coli n nPseudomonas Pseudomonas n nGroup B StreptococcusGroup B Streptococcusn nStaphylococcus aureusStaphylococcus aureus Etiologyn nChildren over 2 monthsn nHaemophilus influenzae type bHaemophilus influenzae type bn nNeisseria meningitidisNeisseria meningitidisn nStreptococcus pneumoniaeStreptococcus pneumoniaen nChildren over 12 yearsn nNeisseria meningitidisNeisseria meningitidisn nStreptococcus pneumoniaeStreptococcus pneumoniaeEtiologyn nMajor routes of leptomening infectionn nBacteria are mainly from blood.Bacteria are mainly from blood.n nUncommonly,meningitis occurs by direct Uncommonly,meningitis occurs by direct extension from nearly focus(mastoiditis,extension from nearly focus(mastoiditis,sinusitis)or by direct invasion(dermoid sinus sinusitis)or by direct invasion(dermoid sinus tract,head trauma,meningo-myelocele).tract,head trauma,meningo-myelocele).Pathogenesisn nSusceptibility of bacterial infection on CNS in the children n nImmaturity of immune systemsn nNonspecific immuneNonspecific immunen nInsufficient barrierInsufficient barrier(Blood-brain barrierBlood-brain barrier)n nInsufficient complement activityInsufficient complement activityn nInsufficient chemotaxis of neutrophilsInsufficient chemotaxis of neutrophilsn nInsufficient function of monocyte-macrophage systemInsufficient function of monocyte-macrophage systemn nBlood levels of diminished interferon(INF)-and Blood levels of diminished interferon(INF)-and interleukin-8(IL-8)interleukin-8(IL-8)Pathogenesisn nSusceptibility of bacterial infection on CNS in the childrenn nSpecific immuneSpecific immunen nImmaturity of both the cellular and humoral immune Immaturity of both the cellular and humoral immune systemssystemsn nInsufficient antibody-mediated protectionInsufficient antibody-mediated protectionn nDiminished immunologic responseDiminished immunologic responsen nBacterial virulence Bacterial virulence Pathogenesisn nA offending bacterium from blood invades the A offending bacterium from blood invades the leptomeninges.leptomeninges.n nBacterial toxics and Inflammatory mediators are Bacterial toxics and Inflammatory mediators are released.released.n nBacterial toxicsBacterial toxicsn nLipopolysaccharide,LPSLipopolysaccharide,LPSn nTeichoic acidTeichoic acidn nPeptidoglycan Peptidoglycan n nInflammatory mediatorsInflammatory mediatorsn nTumor necrosis factor,TNFTumor necrosis factor,TNFn nInterleukin-1,IL-1Interleukin-1,IL-1n nProstaglandin E2,PGE2Prostaglandin E2,PGE2Pathogenesisn nBacterial toxics and inflammatory mediators cause suppurative inflammation.n nInflammatory infiltrationInflammatory infiltrationn nVascular permeability alterVascular permeability altern nTissue edema Tissue edema n nBlood-brain barrierBlood-brain barrier detroydetroyn nThrombosis Thrombosis Pathologyn nDiffuse bacterial infections involve the leptomeninges,Diffuse bacterial infections involve the leptomeninges,arachnoid membrane and superficial cortical arachnoid membrane and superficial cortical structures,and brain parenchyma is also inflamed.structures,and brain parenchyma is also inflamed.n nMeningeal exudate of varying thickness is found.Meningeal exudate of varying thickness is found.n nThere is purulent material around veins and venous There is purulent material around veins and venous sinuses,over the convexity of the brain,in the depths of sinuses,over the convexity of the brain,in the depths of the sulci,within the basal cisterns,and around the the sulci,within the basal cisterns,and around the cerebellum,and spinal cord may be encased in pus.cerebellum,and spinal cord may be encased in pus.n nVentriculitis(purulent material within the ventricles)Ventriculitis(purulent material within the ventricles)has been observed repeatedly in children who have has been observed repeatedly in children who have died of their disease.died of their disease.Pathologyn nInvasion of the ventricular wall with perivascular Invasion of the ventricular wall with perivascular collections of purulent material,loss of ependymal collections of purulent material,loss of ependymal lining,and subependymal gliosis maylining,and subependymal gliosis may be noted.be noted.n nSubdural empyema may occur.Subdural empyema may occur.n nHydrocephalus is an common complication of Hydrocephalus is an common complication of meningitis.meningitis.n nObstructive hydrocephalus Obstructive hydrocephalus n nCommunicating hydrocephalusCommunicating hydrocephalus Pathologyn nBlood vessel walls may infiltrated by inflammatory cells.Blood vessel walls may infiltrated by inflammatory cells.n nEndothelial cell injuryEndothelial cell injuryn nVessel stenosisVessel stenosisn nSecondary ischemia and infarctionSecondary ischemia and infarctionn nVentricle dilatationVentricle dilatation which ensues may be associated with which ensues may be associated with necrosis of cerebral tissue due to the inflammatory necrosis of cerebral tissue due to the inflammatory process itself or to occlusion of cerebral veins or arteries.process itself or to occlusion of cerebral veins or arteries.Pathologyn nInflammatory process may result in cerebral Inflammatory process may result in cerebral edema and damage of the cerebral cortex.edema and damage of the cerebral cortex.n nConscious disturbanceConscious disturbancen nConvulsionConvulsionn nMotor disturbance Motor disturbance n nSensory disturbanceSensory disturbance n nMeningeal irritation sign is foundMeningeal irritation sign is found because the because the spinal nerve root is irritated.spinal nerve root is irritated.n nCranial nerve may be damagedCranial nerve may be damagedClinical manifestationn nBacterial meningitis may present acutely(symptoms Bacterial meningitis may present acutely(symptoms evolving rapidly over 1-24 hours)in most cases.evolving rapidly over 1-24 hours)in most cases.n nSymptoms and signs of upper respiratory or Symptoms and signs of upper respiratory or gastrointestinal infection are found before several days gastrointestinal infection are found before several days when the clnical manifestations of bacterial meningitis when the clnical manifestations of bacterial meningitis happen.happen.n nSome patients may access suddenly with shock and DIC.Some patients may access suddenly with shock and DIC.Clinical manifestationn nToxic symptom all over the body n nHyperpyrexiaHyperpyrexian nHeadacheHeadachen nPhotophobiaPhotophobian nPainful eye movementPainful eye movementn nFatigued and weak Fatigued and weak n nMalaise,myalgia,anorexia,Malaise,myalgia,anorexia,n nVomiting,diarrhea and abdominal painVomiting,diarrhea and abdominal painn nCutaneous rashCutaneous rashn nPetechiae,purpuraPetechiae,purpura Clinical manifestationn nClinical manifestation of CNSn nIncreased intracranial pressureIncreased intracranial pressuren nHeadacheHeadachen nProjectile vomiting Projectile vomiting n nHypertension Hypertension n nBradycardia Bradycardia n nBulging fontanel Bulging fontanel n nCranial sutures diastasisCranial sutures diastasisn nComa Coma n nDecerebrate rigidity Decerebrate rigidity n nCerebral herniaCerebral hernia Clinical manifestationn nClinical manifestation of CNSn nSeizuresn nSeizures occur in about 20%-30%of children Seizures occur in about 20%-30%of children with bacterial meningitis.with bacterial meningitis.n nSeizures is often found in haemophilus influenzae Seizures is often found in haemophilus influenzae and pneumococal infection.and pneumococal infection.n nSeizuresSeizures is correlative with the inflammation of is correlative with the inflammation of brain parenchyma,cerbral infarction and brain parenchyma,cerbral infarction and electrolyte disturbances.electrolyte disturbances.第一课件网站 Clinical manifestationn nClinical manifestation of CNSn nConscious disturbancen nDrowsinessDrowsiness n nClouding of consciousness Clouding of consciousness n nComaComan nPsychiatricPsychiatric symptomsymptom n nIrritation Irritation n nDysphoria Dysphoria n ndullnessdullness Clinical manifestationn nClinical manifestation of CNSn nMeningeal irritation signn nNeck stiffnessNeck stiffnessn nPositive KernigPositive Kernig s signs signn nPositive BrudzinskiPositive Brudzinski s signs signClinical manifestationn nClinical manifestation of CNSn nTransient or permanent paralysis of cranial nerves Transient or permanent paralysis of cranial nerves and limbs may be noted.and limbs may be noted.n nDeafness or disturbances in vestibular function Deafness or disturbances in vestibular function are relatively common.are relatively common.n nInvolvement of the optic nerve,with blindness,is Involvement of the optic nerve,with blindness,is rare.rare.n nParalysis of the 6Paralysis of the 6thth cranial nerve,usually transient,cranial nerve,usually transient,is noted frequently early in the course.is noted frequently early in the course.Clinical manifestationn nSymptom and signs of the infant under the age of 3 Symptom and signs of the infant under the age of 3 monthsmonthsn nIn some children,particularly young infants under the age In some children,particularly young infants under the age of 3 months,symptom and signs of meningeal inflammation of 3 months,symptom and signs of meningeal inflammation may be minimal.may be minimal.n nFever is generally present,but its absence or Fever is generally present,but its absence or hypothermiahypothermia in in a infant with meningeal inflammation is common.a infant with meningeal inflammation is common.n nOnly irritability,restlessness,dullnessOnly irritability,restlessness,dullness,vomiting,poor vomiting,poor feeding,cyanosis,dyspnea,jaundice,seizures,shock and feeding,cyanosis,dyspnea,jaundice,seizures,shock and coma may be a may be noted.n nBulging fontanel may be found,but there is not meningeal Bulging fontanel may be found,but there is not meningeal irritation sign.irritation sign.Complication n nSubdural effusionSubdural effusionn nSubdural effusions occur in about 10%-30%of children Subdural effusions occur in about 10%-30%of children with bacterial meningitis.with bacterial meningitis.n nSubdural effusions appear to be more frequent in the Subdural effusions appear to be more frequent in the children under the age of 1 year and inchildren under the age of 1 year and in haemophilus haemophilus influenzae and pneumococal infection.influenzae and pneumococal infection.n nClinical manifestations are enlargement in head Clinical manifestations are enlargement in head circumference,bulging fontanel,circumference,bulging fontanel,cranial sutures cranial sutures diastasis diastasis and abnormal transillumination of the skull.and abnormal transillumination of the skull.n nSubdural effusions may be diagnosed by the examination Subdural effusions may be diagnosed by the examination of CT or MRI and subdural pricking.of CT or MRI and subdural pricking.Complicationn nEpendymitis n nNeonate or infant with meningitis Neonate or infant with meningitis n nGram-negative bacterial infection Gram-negative bacterial infection n nClinical manifestationClinical manifestation n nPersistent hyperpyrexia,Persistent hyperpyrexia,n nFrequent convulsion Frequent convulsion n nAcute respiratory failure Acute respiratory failure n nBulging fontanel Bulging fontanel n nVentriculomegaly(CT)Ventriculomegaly(CT)n nCerebrospinal fluidCerebrospinal fluid by ventricular punctureby ventricular puncturen nWBC5010WBC50109 9/L/LComplicationn nCerebullar hyponatremian nSyndrem of inappropriate secretion of antidiuretic hormone(SIADH)n nHyponatremia Hyponatremia n nDegrade of blood osmotic pressureDegrade of blood osmotic pressuren nAggravatedAggravated cerebral edema cerebral edeman nFrequent convulsion Frequent convulsion n nAggravatedAggravated c conscious disturbanceonscious disturbance Complicationn nHydrocephalus Hydrocephalus n nIncreased intracranial pressureIncreased intracranial pressuren nBulging fontanelBulging fontaneln nAugmentation of head circumferenceAugmentation of head circumferencen nBrain function disorder Brain function disorder n nOther complicationOther complicationn nDeafness or blindnessDeafness or blindnessn nEpilepsyEpilepsyn nParalysis Paralysis n nMental retardationMental retardationn nBehavior disorderBehavior disorder Laboratory Findingsn nPeripheral hemogramn nTotal WBC count n n20109/L 40109/L WBCn nDecreased WBC count at severe infectionn nLeukocyte differential countn n80%90%NeutrophilsLaboratory Findingsn nRout Rout e examination of cerebrospinal fluid(CSF)xamination of cerebrospinal fluid(CSF)n nIncreased pressure of cerebrospinal fluid Increased pressure of cerebrospinal fluid n nCloudinessCloudiness n nEvident Increased total WBC count(100010Evident Increased total WBC count(1000109 9/L)/L)n nEvident Increased neutrophils in leukocyte differential Evident Increased neutrophils in leukocyte differential countcountn nEvident Decreased glucose(1.1mmol/l)Evident Decreased glucose(1.1mmol/l)n nEvident Increased protein levelEvident Increased protein level n nDecreased or normal chloridateDecreased or normal chloridaten nCSF film preparation or cultivation:positive result CSF film preparation or cultivation:positive result Laboratory Findingsn nEspecial examination of CSFn nSpecific bacterial antigen testn nCounterc