Monday 13 August 2007

Meningococcus

Dear Bloggers

Sorry for the lack of new articles but I have been busy with teaching plus nursing my recent head cold which has left me feeling unwell....

A recent case was passed to me about a patient from another hospital who was admitted with an alteration in consciousness. The patient could not speak very well following a sub-arachnoid haemorrhage some years ago that left the patient with paresis and required a VP shunt to be placed in vivo.

The patient had developed a drop in consciousness and vomiting. There was no fever or other symptoms from the patient.

The salient clinical signs included a high blood pressure (systolic >200) and a disseminated haemorrhagic rash on both forearms (patient was not taking warfarin).

CSF examination revealed a high WCC, High protein and low Glucose but no visible bacteria.

These findings were consistent with a Meningococcial Meningitis and Septicaemia.

However, the high blood pressure concerned me that there may have been a blockage in the VP shunt due to infection causing a Hydrocephalus.

CT film showed an old infarction area, the VP shunt but evidence of a dilated anterior horn on the contralateral side to the shunt. There was no midline shift.

The patient was started on Vancomycin, Ampicillin and Ceftriaxone which is the standard therapy for meningitis when the organism is unknown.

Patients with meningococcus infection can develop complications including:

1) Disseminated Intravascular Coagulation (DIC)
2) Adrenal Failure (Friederichson-Waterhouse Syndrome) from DIC
3) Haemorrhagic rash (from DIC)
4) Renal Failure
5) Death

The rash may intially present a small areas of non-blanching haemorrhage around or within the white of the eye (sclera) or it may progress to diffuse ecchymosis.

Blood cultures should always be done!! Don't ever delay using the antibiotics for fear of a negative CSF gram stain / culture because the longer you wait the greater chance of death.

In fact, in the UK, GPs routinely will give Benzylpenicillin intravenously / intramuscularly if they suspect meningitis in order to start treating the disease before they reach the hospital. They will not delay treatment.

Apparently, CSF can still yield a positive culture up to 4 hours after antibiotic use (CMDT 2007, Tierney, L. Lange press). If such CSF exams reveal no bacteria and suspicion of meningococcus is high, then consider checking the CSF for meningococcal PCR. Also consider nasal and throat swabs for the organism as it is in these two places where meningococcus can be found and where it is considered to invade in the later location.

REMEMBER all close contacts e.g. family members / nursing home residents / kissing contacts / and RARELY medical staff need TREATING WITH RIFAMPICIN as prophylaxis (600mg twice daily for two days) to prevent them from developing meningitis or spreading the organism they may harbour derived from the sick patient.

This treatment can be done as an outpatient, but it should not be forgotten or delayed.

Patients with meningococcal sepsis / meningitis should ideally be treated on an ICU / HCU ward until stable.

Please consider....