Acute Bacterial Meningitis

Acute bacterial meningitis is a rapidly progressive bacterial infection of meninges and subarachnoid space. Findings are typically headache, fever and stiff neck. The diagnosis is made by a CSF. Treatment is with antibiotics and corticosteroids, which are given as soon as possible.

Neonatal meningitis, acute bacterial meningitis in newborns.

Acute bacterial meningitis is a rapidly progressive bacterial infection of meninges and subarachnoid space. Findings are typically headache, fever and stiff neck. The diagnosis is made by a CSF. Treatment is with antibiotics and corticosteroids, which are given as soon as possible. Neonatal meningitis, acute bacterial meningitis in newborns. Pathophysiology Most get the bacteria on hematogenous spread into the subarachnoid space and the meninges. Bacteria can also reach from neighboring infected structures or through a congenital or acquired defect in the skull or spine the meninges (Acute bacterial meningitis: entryway). Since leukocytes, immunoglobulins and complement in CSF normally hardly occur or missing, the bacteria multiply at first, without causing inflammation. Later, the bacterial endotoxins, teichoic acid and other substances liberate that trigger an inflammatory response through mediators such as leukocytes and TNF. Typically, increased cerebrospinal fluid protein levels, and since the bacteria consume glucose and less glucose is added to the liquor, the glucose level decreases. Inflammation in the subarachnoid space is accompanied by a cortical encephalitis and a ventriculitis. Complications are frequent and can include hydrocephalus (in some patients) Arterial or venous infarction due to inflammation and thrombosis of arteries and veins near the surface and sometimes deep brain areas N. abducens paralysis due to inflammation of the VI. Cranial nerve deafness due to inflammation of the VIII. Cranial nerves or structures in the middle ear subdural empyema Elevated intracranial pressure (ICP) as a result of cerebral edema herniation of the brain (leading cause of death in acute stages) Systemic complications (which are sometimes fatal) such as septic shock, disseminated intravascular coagulopathy ( DIC) or hyponatremia due to a syndrome of inappropriate antidiuretic hormone secretion (SIADH) etiology Probable causes bacterial meningitis depend on patient age of entry immune status of the patient’s age in children and young adults, the most common causes of bacterial meningitis are Neisseria meningitid Streptococcus pneumoniae is a meningitis caused by N. meningitidis occasionally leads within hours of death. Sepsis caused by N. meningitidis sometimes results in a bilateral hemorrhagic infarction adrenal (Waterhouse Friderichsen syndrome). Haemophilus influenzae type B was once the most common cause of meningitis in children <6 years of age and overall; Today, the pathogen is valid in the US and in Western Europe as a rare cause, for there the vaccine against H. influenzae is generally used. In areas where it is not widespread, H. influenzae is a common cause, v. a. in children aged 2 months to 6 years. In adults, middle-aged and the elderly the most common cause of bacterial meningitis S. pneumoniae N. meningitidis caused less frequently meningitis in adults middle-aged and elderly. As the host defenses become weaker with age, patients may develop meningitis due to L. monocytogenes or gram-negative bacteria. For people of all ages Staphylococcus aureus occasionally causes meningitis. (Rarely seen in developed countries, but still in countries where the vaccine against H. influenzae type B is not used often) causes bacterial meningitis according to patient age age group bacteria children and young adults Neisseria meningitidis Streptococcus pneumoniae Staphylococcus aureus * Haemophilus influenzae Adults middle ages S. pneumoniae S. aureus * N. meningitidis Elder (in this age group less common) people S. pneumoniae S. aureus * Listeria monocytogenes Gram-negative bacteria * S. aureus occasionally causes severe meningitis in patients of all ages. The causative agent is the most common cause of meningitis, which occur after a penetrating head injury. Of entry to entry routes include the following: By hematogenous spread (most common way) Starting from infected structures in or around the head (eg, sinuses, middle ear, mastoid.), Sometimes associated with a CSF leak through a penetrating injury after a neurosurgical procedure ( z. B. when a ventricular shunt is infected) by congenital or acquired defects in the skull or spinal column with one of the above States the risk of acquiring meningitis increased. Causes bacterial meningitis according entryway entryway bacterial infection in or around the head (z. B. sinusitis, otitis, mastoiditis), sometimes associated with a CSF leak Streptococcus pneumoniae Haemophilus influenzae and anaerobic streptococci microaerophilic Bacteroides sp. Staphylococcus aureus Penetrating head injury S. aureus damaged skin (z. B. skin infections, abscesses, pressure ulcers, extensive burns) S. aureus S. epidermidis infected shunt neurosurgery Gram-negative bacteria (eg. B., Klebsiella pneumoniae, Acinetobacter calcoaceticus, Escherichia coli) immune status Overall, the most common causes of bacterial Men ingitis in immunocompromised patients S. pneumoniae L. monocytogenes, Pseudomonas aeruginosa Mycobacterium tuberculosis N. meningitidis bacteria The Gram-negative bacteria is most likely present depend on the type of immune deficiency: defects in cell-mediated immunity (eg. B. in AIDS Hodgkin's lymphoma or drug-induced immunosuppression): L. monocytogenes or Mycobacterium defects in humoral immunity or splenectomy: S. pneumoniae or, more rarely, N. meningitidis (both can lead to fulminant meningitis) neutropenia: P. aeruginosa or gram-negative enterobacteria For very young children (especially premature babies) and elderly people may be weak, the T-cell immunity; thus these age groups are at risk of meningitis by L. monocytogenes. Symptoms and signs In most cases begins bacterial meningitis with 3-5 days slowly progressive nonspecific symptoms such as malaise, fever, irritability and vomiting. However, meningitis can start faster and run brilliantly, making the bacterial meningitis to one of the few diseases where go to sleep with mild symptoms, a previously healthy young people and can wake up ever again. Typical menigealen symptoms include fever tachycardia headache photophobia mental status changes (eg. As lethargy, somnolence) neck stiffness (although not report any patient thereof) Sometimes when Staphylococcus aureus is the cause, back pain seizures occur early in up to 40% of children with acute bacterial meningitis and can occur in adults. Up to 12% of patients are initially comatose. A severe meningitis can cause papilledema, but papilledema may be absent early, even if the intracranial pressure is elevated. Concomitant systemic infection by the organism can rashes, petechiae or purpura (which indicates to meningococcemia) Pulmonary consolidation (often in meningitis due to S. pneumoniae) heart sounds (indicated on endocarditis out-z. B. often caused by S. aureus or S. pneumoniae ) Atypical forms in adults fever and neck stiffness may be absent or only present attenuated in immunocompromised or elderly and in alcoholics. Often confusion and decreased responsiveness is the only character in the elderly or in patients with pre-existing dementia. In these patients, it may make sense to start his before a cranial CT or -MRT with appropriate antibiotics. Takes the bacterial meningitis after a neurosurgical procedure, it often takes days to develop symptoms. Diagnosis GRF analysis Once a suspected. acute bacterial meningitis is, blood cultures must be recognized and a lumbar puncture for cerebrospinal fluid (if it is not contraindicated) perform. If bacterial meningitis is suspected and the patient is very ill, antibiotics and corticosteroids are given immediately before a spinal tap done. If bacterial meningitis is suspected and carried lumbar puncture to the delayed CT or MRI, should with antibiotics and corticosteroids after blood cultures, but are started before carrying out imaging procedures; the need for confirmation should not delay the treatment. Doctors should in patients with typical symptoms and signs, usually fever, out changes in mental status and neck stiffness of bacterial meningitis. However, they must be clear about the fact that the symptoms and discomfort in neonates and young children are different and may be missing or with weakened immune systems may fail at first light in the elderly, alcoholics and patients. The diagnosis can be a challenge in the following patients: those who have undergone neurosurgery because such procedures can also lead to changes in mental status and neck stiffness. In elderly people and alcoholics because mental status changes may be due to metabolic encephalopathy (which can have several causes) or falls and subdural hematomas Focal seizures or focal neurological deficits on a focal lesion such as based a brain abscess. As an untreated bacterial meningitis runs lethal tests should be carried out in the lightest probability of meningitis. Tests are particularly useful in infants, the elderly, alcoholics, immunocompromised patients and patients undergoing neurosurgery because the symptoms can be atypical. Tips and risks Perform a lumbar puncture, even if the findings are not specific to meningitis, v. a. in infants, the elderly, alcoholics, immunocompromised patients and patients after neurosurgical operation. Write the results of acute bacterial meningitis, the routine tests Liquroanalyse blood count and differential white blood include clinical chemistry with electrolytes, liver and kidney parameters CRP blood cultures plus PCR (if available) lumbar puncture they Unless contraindicated, is immediately a lumbar puncture for the production of CSF for the analysis performed; this forms the mainstay of diagnosis. Contraindications an immediate indication of a lumbar puncture are significantly increased intracranial pressure or an intracranial mass effect (e.g., due to edema, bleeding or a tumor.); typically neurological deficits is one of those characters Focal papilledema deterioration of consciousness Seizures (within a week after the Vortellung) immunodeficiency Past CNS disorders (eg Massenläsion, stroke, focal infection) In such cases, a lumbar puncture can cause impaction of the brain. It is postponed until a neuroradiological imaging (typically CT or -MRT) for Überpüfung of increased intracranial pressure or mass effect has occurred. If the lumbar puncture moved, the treatment is best to start immediately (after blood collection for Culture and before neuroradiological imaging). After a possibly increased intracranial pressure is lowered or no mass is detected, the lumbar puncture may be performed. Liquor should be sent for analysis: cell count, protein, glucose, Gram stain, culture, PCR (when available) and other tests as clinically indicated. (Editor's note: In Germany it is common to take glucose to determine the CSF lactate.) At the same time, a blood sample should be taken and sent to determine the CSF-blood glucose ratio. (Editor's note: This is not done in Germany so because the CSF lactate is determined.) The cell count should be quickly determined because the leukocytes adhere to the walls of the collection tube Koenen, giving a falsely low cell count; in extremely purulent cerebrospinal fluid leukocytes can lyse. Typical Liquorbefunden with bacterial meningitis include Increased pressure fluid that is often cloudy A high white blood cell count (predominantly PMN) Increased Protein A low Licquor: Blood sugar ratio A CSF: blood glucose levels of <50% indicates possible meningitis. A glucose levels in the cerebrospinal fluid of ? 18 mg / dl or a CSF-blood glucose ratio of <0.23 indicates clearly to bacterial meningitis. However, changes of glucose in the CSF can 30-120 min ago lag behind the changes in blood glucose. (Editor's note: In Germany it is customary to determine the CSF lactate instead of glucose.) In acute bacterial meningitis, increased protein levels shows (typically 100-500 mg / dl), a blood-brain barrier disruption on. Cell count, protein and glucose levels in the cerebrospinal fluid of patients with acute bacterial meningitis are not always typical. Atypical CSF findings may be normal in the early stages, except for the presence of bacteria predominance of lymphocytes in about 14% of patients, especially in neonates with gram-negative meningitis, patients with meningitis due to L. monocytogenes, and in some patients with partially treated bacterial meningitis normal glucose levels at about 9% of patients normal white blood cell counts in severely immunocompromised patients CSF findings in meningitis state Prevailing cell type * protein * glucose * Specific tests Normal Liquor All lymphocytes (0-5 cells / ul) <40 mg / dl> 50% of blood glucose No Bacterial meningitis leukocytes (usually PMN), often greatly increased Increases <50% in blood glucose (can be extremely low) Gram staining (the yield is high, if 105 colony forming units of bacteria / ml are present) bacterial culture PCR, be mixed if available Viral meningitis lymphocytes (can; PMN and lymphocytes during the first 24-48 h) Increases Usually normal PCR (simplex for testing enterovirus or herpes, herpes zoster, or West Nile Virus) IgM (for review of West Nile virus and other arboviruses) † tuberculous meningitis PMN and lymphocytes (typically pleocytosis) Increases <50% of the blood glucose (which may be extremely low) acid-fast staining PCR Mykobakterienkultur (ideally with a cerebrospinal fluid ? 30 ml) of interferon-? assays in serum, and (if present) Liquor fungal meningitis Usually lymphocytes Increases <50% in blood glucose (can be extremely low) cryptococcal antigen test Serological tests to the antigen against Coccidioides immitis or Histoplasma sp., V. a. if the patient has recently spent time in an endemic area fungal culture (ideally with a cerebrospinal fluid ? 30 ml) ink (at Cryptococcussp.) The changes of cell count, glucose and protein may be minimal in severely immunocompromised patients. † In tubercular meningitis the acid-resistant Liquorfärbung may be insensitive, the sensitivity of the PCR is only about 50%, and the culture takes up to 8 weeks. Positive interferon-?-CSF testing indicate a tubercular meningitis, serum interferon-? tests can only point to a previous infection. Thus, the confirmation of the diagnosis of tuberculous meningitis is difficult; if this is unconfirmed, but is strongly suspected, is treated conjectural. ‡ A small number of cells can normally present in newborns or after a seizure. PCR = polymerase chain reaction; PMN = polymorphonuclear neutrophils. An identification of the causative bacteria include Gram stain, culture, and, if available, PCR. The Gram stain quickly provides information, but the information content is limited. To detect bacteria reliably using the Gram stain, about 105 bacteria / mm3 must be present. Results may flasch-negative when the liquor is handled carelessly, if the bacteria are not well suspended after the CSF could sit down, or if Failed to bleaching or reading the slide occur. For the diagnosis of specific bacteria and determining the sensitivity to antibiotics, a bacterial culture is required. Take the clinician an anaerobic infection or other unusual bacteria, they should notify the lab before the samples for culture are plated. A previous antibiotic therapy can reduce the yield of Gram stain and culture. PCR can, if available, be a useful additional test, especially in patients who have already received antibiotics. is confirmed until the cause of meningitis, other tests with samples of CSF or blood can be performed to rule out other meningitis causes such as viruses (simplex particular herpes), fungi and cancer cells to prüfen.Andere function tests samples of other possibly infected sites ( z. B. urinary or respiratory tract) are also cultured. Prognosis In children <19 years can be as low as 3% mortality, but it is often higher; Survivors may be deaf and neuropsychological impaired. The mortality rate is about 17% for adults <60 years, but up to 37% at> 60-year-olds. Community-acquired meningitis due to S. aureus has a mortality rate of 43%. The mortality rate correlated i. Gen. with the depth of depression of consciousness or coma. Factors associated with a poor prognosis age> 60 years Enervating comorbidities Low Glasgow Coma Score on admission (see table: Glasgow Coma Scale * and d Modified Glasgow Coma Scale for Infants and Children) Focal neurological deficits Low cell count Liquor increased CSF (in particular) seizures, and a low-CSF serum glucose ratio can also mean a poor prognosis. Clinical computer: Glasgow coma scale treatment antibiotics, corticosteroids to reduce cerebral inflammation and edema antibiotics are the cornerstone of therapy. In addition to antibiotics include the treatment measures to reduce the inflammation of the brain and cranial nerves and increased intracranial pressure. Most patients are moved to an intensive care unit. Antibiotics Antibiotics have bactericidal effect on the causative bacteria, and they must be able to cross the blood-brain barrier. (: Initial antibiotics for acute bacterial meningitis see table) and corticosteroids started as soon as the blood cultures are taken and even nohc before a lumbar puncture if the patient appears ill and address the findings of meningitis, antibiotic treatment. Although the lumbar puncture is deferred because of outstanding results of neuroradiological imaging, treatment with antibiotics and corticosteroids starts before neuroradiological imaging. Tips and risks if the patient appears ill and acute meningitis is believed to treat with antibiotics and corticosteroids as soon as blood was drawn to the culture. A corresponding empirical antibiotic treatment depends on the age of the patient, his immune status and the route of infection (see table: Initial antibiotics for acute bacterial meningitis). Clinicians should i. Gen. use antibiotics that are effective against S. pneumoniae, N. meningitidis, and S. aureus. Sometimes (. Eg in newborns and some immunocompromised patients) can not be ruled out herpes simplex encephalitis; Therefore, acyclovir is added taken. It may be necessary to modify the antibiotic therapy based on the results of culture and sensitivity testing. Commonly used antibiotics are 3rd generation cephalosporins for S. pneumoniae and N. meningitidis ampicillin at L monocytogenes vancomycin for penicillin-resistant strains of S. pneumoniae and S. aureus Initial antibiotics for acute bacterial meningitis patients Suspected bacterial Preliminary antibiotics Age <3 months Streptococcus agalactiae, Escherichia coli, or other gram-negative bacteria Listeria monocytogenes Staphylococcus acid * us ampicillin plus ceftriaxone or cefotaxime 3 months-18 years Neisseria meningitidis S. pneumoniae S. aureus Haemophilus influenzae * ‡ cefotaxime or ceftriaxone plus vancomycin (Editor's note: in Germany is not recommended vancomycin!) 18-50 Years S. pneumoniae N . meningitidis S. aureus * ceftriaxone or cefotaxime plus vancomycin (Editor's note: In Germany, the recommendation of a cephalosporin plus ampicillin are due to other resistance spectra. Vancomycin is not recommended)> 50 S. pneumoniae L. monocytogenes S. aureus Gram-negative bacteria N. meningitidis (unusual) ceftriaxone or cefotaxime plus ampicillin plus vancomycin (in this age group Editor’s note: In Germany, vancomycin is not recommended) entry way! sinusitis, otitis, spinal fluid leak S. pneumoniae † H. influenzae Gram-negative bacteria, incl. Pseudomonas aeruginosa Anaerobic or microaerophilic streptococci, Bacteroides fragilis * S. aureus vancomycin plus ceftazidime or meropenem p lus metronidazole Penetrating head injuries, neuro surgery, shunt infections S. aureus S. epidermidis Gram-negative bacteria, including P. aeruginosa S. pneumoniae, vancomycin plus ceftazidime (Editor’s note:. Recommendation in Germany: vancomycin plus ceftazidime plus vancomycin or meropenem [possibly plus metronidazole in surgical access through mucous membranes]) immune status AIDS, other conditions that affect cell-mediated immunity S. pneumoniae L. monocytogenes Gram-negative bacteria, including P. aeruginosa S. aureus the editors * ampicillin plus ceftazidime plus vancomycin (Note:.. In Germany is vancomycin not recommended!) * S. aureus is a rare meningitis cause, unless the entryway is a penetrating head injury or neurosurgical intervention. However, the virus can cause meningitis in all patient groups. Thus, vancomycin or other antibiotics against staphylococci should be given if the doctors these bacteria for a possible, if unlikely keep cause. † S. pneumoniae is the most common causative bacterium in patients with CSF leakage or acute otitis. Such patients may be treated with vancomycin and ceftriaxone or cefotaxime. However, if the meningitis occurs together with a Subduralempyem or developed after neurosurgery, it is more likely that this is P. aeruginosa dealing with other bacteria, including,.; in such cases the first-line treatment of vancomycin plus ceftazidime plus metronidazole should be. ‡H. influenzaesollte be considered in children <5 years without proven conjugate vaccine against H. influenzae type B.

Health Life Media Team

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