Suspected Meningitis

Presentation

1. Meningism common – headache, neck stiffness, photophobia
2. Other features may include fever, classic petechial rash, seizures, signs of shock, fluctuations in consciousness or mental state, vomiting.

Common Causes

1. Bacteria – Neisseria meningitidis, streptococcus pneumonia, haemophilus influenza, listeria monocytogenes.
2. Viruses – enteroviruses, herpes viruses esp HSV2 and VZV
3. Young adults – more likely to be viral than bacterial, particularly in 20-40 year-old women. Neisseria meningitidis infection (meningococcal meningitis) has peak incidence in childhood and in late teens to early 20s.
4. Older individuals – streptococcus pneumoniae infection (pneumococcal meningitis) more prevalent in patients >50; listeria monocytogenes is rarely the cause, but more likely in those >60.
5. Patients with fractured skull and/or CSF leakage – increased risk of pneumococcal meningitis and repeated infections.
6. Patients presenting with rash – more likely Neisseria meningitidis than streptococcus pneumonia
7. Patients with ongoing URTI – often pneumococcal meningitis
8. Patients with HIV infection – cryptococcal meningitis, TB meningitis, pneumococcal meningitis.

In All Cases of Suspected Meningitis, the Following Should be Requested

1. FBC, U&E, LFT, clotting, glucose, lactate
2. Blood culture – before antibiotic whenever possible.
3. Blood for meningococcal/pneumococcal PCR
4. Blood for storage to enable serological testing if cause not identified.
5. Nasopharyngeal swab for meningococcal culture
6. Lumbar puncture – within one hour of arriving in hospital providing safe to do so

When to Avoid or Delay LP

1. If clinical suspicion of brain shift – focal neurological signs, papilloedema, continuous or uncontrolled seizures or GCS ≤12
2. Respiratory or cardiac compromise
3. Signs of severe sepsis or a rapidly evolving rash
4. Infection at site of LP
5. Coagulopathy – see below

When to Image

1. No need for CT head unless there is clinical suspicion of brain shift ie focal neurological signs, papilloedema, continous or uncontrolled seizures or GCS ≤12
2. Note that inability to view fundus is not a contraindication to LP

When to Perform LP if on Anticoagulants

1. In patients already on prophylactic LMWH the LP should not be performed until 12 hrs after the dose.
2. Prophylactic LMWH should be delayed until 4h after LP.
3. Patients on therapeutic LMWH should not have an LP until 24 h after a dose.
4. Therapeutic intravenous unfractionated heparin can be restarted 1 h after an LP
5. In patients on warfarin LP should not be performed until INR is ≤1.4
6. Patients on aspirin and other non-steroidal anti-inflammatories do not need to have their LP delayed.
7. In patients on clopidogrel an LP should be delayed for 7 days or until a platelet transfusion or desmopressin (DDAVP) is given – these should be discussed with a haematologist and the risk benefit ratio of performing LP discussed.
8. Expert advice, from a haematologist, must be sought for those patients on newer anticoagulants such as apixaban, dabigatran and rivaroxaban.
9. In patients with known thrombocytopenia LP should not be performed if platelets <40,000 or if platelet falling rapidly
10. LP should not be delayed for the results of blood test unless there is a high clinical suspicion of coagulopathy
11. When LP is not possible immediately, this should be reviewed at 12 hrs and regularly thereafter.

In Patients in Whom LP Performed the Following Should be Requested

1. CSF opening pressure (unless performed in sitting position), glucose (with simultaneous blood glucose), protein.
2. CSF Microscopy, cell count, culture and sensitivities
3. CSF PCR for pneumococci and meningococci if LP suggests bacterial meningitis,
4. CSF PCR for enteroviruses, HSV 1 and 2, VZV if LP suggests viral meningitis.
5. CSF for storage for later tests if cause not identified

CSF Findings on Lumbar Puncture & Their Likely Diagnoses

Management Within the First Hour of Presentation

1. Follow ABCDE protocol to ensure patient is stable
2. Make early assessment as to the requirement for senior/critical care involvement
3. Record the GCS score
4. Take blood culture as soon as possible and within 1 hour of arrival
5. Perform LP within 1 hour of arrival – but see notes above
6. Give IV antibiotic immediately after LP unless patient has rash/suspected severe sepsis/ possible brain shift, or if LP cannot be performed immediately, in which case start as soon as possible after taking blood cultures
7. Start 10mg IV dexamethasone 6-hourly either shortly before or simultaneously with antibiotic. If antibiotic already started dexamethasone should still be given up until 12 hours after the first dose.
8. Start IV infusion especially if sepsis or rash, with initial bolus 500ml of crystalloids, but careful not to cause hypervolaemia.
9. Request input from consultant on call, microbiologist or Dr Jones if any of the following red flags present

When to Request Urgent Senior Help

1. Patient with rash that is rapidly evolving.
2. Signs of impaired peripheral perfusion.
   1. CRT>4 seconds.
   2. Oliguria.
   3. SBP<90mmHg.
3. RR<8 or >30 breaths/min.
4. HR<40 or >140 bpm.
5. Acidosis with H⁺ >50.
6. WCC <4000/mm3
7. Lactate >4mmol/l.
8. GCS<12 or reduced by at least 2 points from baseline.
9. Initial IV fluid resuscitation has not produced an adequate response.

Empirical Antibiotics

1. Generally give 2g of IV ceftriaxone 12-hourly, or 2g IV cefotaxime 6-hourly.
2. If patient has travelled to a country with high rates of penicillin-resistant pneumococci in the past 6 months add in 15-20mg/kg IV vancomycin 12-hourly or 600mg IV/oral rifampicin 12-hourly.
3. If patient aged 60 or older or immunocompromised, add in 2g IV amoxicillin to be given 4-hourly to cover listeria.
4. If documented/known anaphylactic responses to penicillin/cephalosporin, give 25mg/kg IV chloramphenicol 6-hourly and add 10-20mg/kg cotrimoxazole qds if 60 or older.
5. Definitive antibiotic therapy will be decided on basis of sensitivities once microbiology available

Duration of Definitive Antibiotic Therapy

1. Neisseria meningitides – 5 days.
2. Streptococcus pneumonia – 10 to 14 days depending on speed of recovery and antibiotic sensitivities.
3. Listeria monocytogenes – 21 days.
4. Haemophilus influenza – 10 days.

Consider Outpatient Antibiotic Therapy for Patients Who:

1. Feel comfortable with the decision for outpatient antibiotics.
2. Have been monitored and managed in a hospital setting for at least 5 days.
3. Are not febrile and are making a clinical recovery
4. Have good venous access
5. Do not have further acute medical issues that demand more than antibiotics
6. Can have access to continual support from an OPAT team or suitable specialists.
7. Possible therapeutic options include 4g IV ceftriaxone once daily (can switch to 4g once daily after first 24 hours) if organism sensitive.

Infection Control in Hospital Setting

1. Respiratory isolation and barrier nursing with surgical masks required until meningococcal disease ruled out, or until 24 hours of ceftriaxone has been given.
2. Health professionals working closely with meningococcal meningitis should receive prophylactic antibiotics if exposed to patient’s respiratory fluids or secretions, for instance during CPR or intubation.

Notification, Contact Tracing and Prophylactic Antibiotic

1. All cases of bacterial meningitis will be notified by microbiology to Public Health
2. Contact tracing and prophylactic therapy for meningococcal disease and H Influenzae type b infection will be initiated by Public Health and are not the responsibility of the admitting clinician.
3. Contact tracing and prophylactic therapy not required for pneumococcal infections.

Discharge, Follow-up & Support

1. All patients with meningitis should be screened for possible long-term physical and psychological complications prior to hospital discharge.
2. Note the presence of any of the following:
   1. Impaired hearing, balance, dizziness and/or tinnitus
   2. Other neurological injury e.g cognitive deficit, learning impairment, seizures, problems with vision, movement or communication
   3. Wounds or scars.
   4. Orthopaedic complications including amputation.
   5. Psychological effects
   6. Impaired kidney function.
3. All patients with likely/known bacterial meningitis should receive medical follow-up within the first 6 weeks following hospital discharge.
4. Rehabilitation services should liaise with patient as well as their family and/or carers where needed.
5. Information on meningitis support services should be provided eg www.meningitisnow.org or www.meningitis.org

Viral Meningitis

1. This is becoming increasingly important, with viral CNS infections representing around 50% or more of all cases.
2. It is the key differential diagnosis in suspected bacterial meningitis.
3. Presenting features include headache, photophobia, fever and neck stiffness
4. Conscious state and behaviour not usually affected so consider encephalitis or bacterial meningitis if this is the case.
5. Follow same initial pathway of investigations as in bacterial meningitis, since their presentations can be difficult to distinguish although bacterial meningitis is generally more severe.
6. CRP and WCC often normal in viral meningitis
7. If LP supports diagnosis of viral meningitis then send CSF for enterovirus, HSV and VZV PCR and stool for enterovirus PCR.
8. No need for CSF PCR or serological tests for other viruses e.g CMV/EBV/mumps unless clinically indicated
9. If no suggestion encephalitis stop antibiotic, give IV fluid and analgesia as required and aim for early hospital discharge
10. If encephalitis likely eg behavioural or cognitive dysfunction, or impaired consciousness, give IV aciclovir 10mg/kg tds for 10 days. See Antibiotics and the Kidney in Infectious Diseases folder for dose reductions in CKD

Flowchart for Suspected Meningitis

Links

• The UK Joint Spec. Soc. Guideline – Diagnosis & M’g’ment of Acute Meningitis & Meningococcal Sepsis in Immunocompetent Adults
• The UK Joint Spec. Soc. Guideline – Diagnosis & M’g’ment of Acute Meningitis & Meningococcal Sepsis in Immunocompetent Adults Algorithm
• Meningitis Now – Support after meningitis booklet [pdf]