Meningitis Risk factors: Head injury – skull #, cranial or spine surgeryCauses: Septic site – pneumonia, mastoiditis, sinusitis, OM 1. Viral Immunosuppressed – CA, AIDS, hyposplenism, sickle-cell dz, Commonest cause hypogammaglobinaemia Usually benign and self-limiting Host factor – complement or antibody deficiency Complete recovery w/o specific Rx is the norm. Foreign body – CSF shunt/ VP shunt (prone to staph. Meningitis) Common organisms: echoviruses, mumps. Less commonly HSV & zoster, coxsackie Causes of bacterial meningitis by population groups: Neonate 1. Group B strep 2. Bacterial – high mortality & morbidity 2. Gram negative bacilli (E coli, proteus) 3. Fungal 3. Listeria monocytogenes 4. Others – malignancies, drugs (NSAIDS, trimethoprim), intrathecal Pre-school 1. H. influenzae drugs, sarcoidosis, SLE 2. N. meningitides child 3. Strep. Pneumoniae 4. M. TBDDx: Older child / 1. N. Meningitidis1. Any acute infections eg malaria Adults 2. Strep. Pneumoniae2. Local infections causing neck stiffness 3. M. TB 4. L. monocytogenes3. Encephalitis 5. H. influenzae4. Subarachnoid hemorrhage Elderly / DM/ 1. Strep. Pneumoniae 2. N. Meningitidis debilitatedS/S: 3. H. influenzae 4. L. monocytogenesMeningism Headache Kernig’s sign 5. M. TB Photophobia Brudzinski’s sign (hip Immuno- 1. Strep. Pneumoniae Neck stiffness flexion on flexion of neck) compromised 2. N. Meningitidis Opisthotonus 3. H. influenzae 4. L. monocytogenes↑ ICP Headache Fits 5. C. Neoformans Vomiting Cushing’s reflex: ↑BP & 6. Toxoplasma gondii Irritability ↓pulse 7. S. aureus Drowsiness Irregular respiration Meningococcus: Spread by air-borne route. May result in meningococcaemia. ↓consciousness/coma Papilloedema ∼ Cxs of meningococcaemia: meningitis, purpuric rash, shock, Focal neuro signs DIVC, renal failure, peripheral gangrene, arthritis (rxtive or septic), pericarditis (rxtive or septic)Septicaemia Malaise DIC H. influenzae: a/w ottitis media Fever ↓BP, ↑pulse, tachypnoea Pneumococcus: a/w ottitis media and pneumonia, esp in elderly, alcoholics & Rash – petechiae/purpura Arthritis immunocompromised. suggests meningiococcus. Odd behaviour TB: chronic or acute on chronic, a/w chronic headache, isolated CN6 palsy due to ↑ICP, and S/S of TB eg fever, nightsweats.
ViralInvestigations: Supportive treatmentCT head Exclude ↑ICP (eg cerebral abscess, head injury, brain tumour) Completer recovery without specific therapy is the norm. pre-LP.LP Exclude ↑ ICP by CT head, fundoscopy & clinical signs. Bacterial Tubes IV penicillin stat on suspicion of bacterial meningitis 1. Cell count, cytospin for cell and differential count 2. Protein & glucose Modify ABx regimen according to CSF invx results 3. Microbiology – gram stain, C&S, AFB smear, TB culture, Meningococcal Benzyl penicillin (2.4g/4hr slow IV) Indian ink stain, fungal culture Pneumococcal Ceftriaxone (2g/12 hrly IV) 4. Cryptococcal antigen, bacterial antigens (S. pneumonia, N. H. influenzae Ceftriaxone meningitides, H. influenzae, GBS) GBS/ Gram negative bacilli Ceftriaxone + Gentamicin + ampicillinFBC (50mg/kg/6 hr IV) L. monocytogenes Gentamicin + ampicillinU/E/Cr M TB Pyrazinamide, isoniazid, rifampicin, ethambutolDIVC screen Especially if meningococcaemia is suspected. 6-12 mthsBlood glucose To compare with CSF C. neoformans Amphotericin + flucytosineBlood C/SUrine C/S Treatment for pyogenic meningitis of unknown cause Neonate Ampicillin + Ceftriaxone or gentamicinCXR ?Lung abscess Infant Ampicillin + Ceftriaxone Pre-school child CeftriaxoneTypical CSF in meningitis Older child / adults Penicillin G (400K units/kg/day) + Ceftriaxone Pyogenic TB Viral (‘aseptic’) Elderly (>50YO) Ampicillin + CeftriaxoneAppearance Turbid Fibrin web forms Clear Prophylaxis for close contacts--meningococcus: on standing ∼ Children: 2 days of oral rifampicin (3-12mths 5mg/kg 12 hrly;Predominant cell Neutrophils Lymphocytes Lymphocytes >1yr 10 mg/kg 12 hrly)Cell count/ mm3 90-1000+ 10-1000 50-1000 ∼ Adults: single dose of 500mg ciprofloxacin OR rifampicinGlucose ↓ (< 1/2 plasma) ↓ (< 1/2 plasma) N (> 1/2 plasma) 600mg 12 hrly for 2 days. Vaccination: available for groups A & C meningococci, but not group B.Protein (g/L) ↑ (>1.5) ↑ (1-5) N (<1)Culture / smear Positive Usually not seen Negative Complications of bacterial meningitis: 1) Hydrocephalus: pus causes adhesions which cause CSF flowTreatment: obstruction. Rx: ±surgical drainage Monitoring: BP, pulse, RR, temp, SpO2, conscious level 2) Cranial nerve damage Supplemental O2 3) Secondary cerebral infarction: due to obliterative endarteritis of the ABx if bacterial (see below) leptomeningeal arteries passing through the meningeal exudates. Antipyretics and antiemetics 4) Cerebral venous sinus thrombosis Corticosteroids for ↑ICP (controversial): 0.15mg/kg dexamethasone Digitally signed by DR WANA HLA SHWE DN: cn=DR WANA HLA SHWE, c=MY, o=UCSI University, School of Medicine, KT-Campus, Terengganu, ou=Internal Medicine Group, firstname.lastname@example.org Reason: This document is for UCSI year 4 students. Date: 2009.02.24 14:18:24 +0800