May present with patient feeling non-specifically unwell. Common signs include fever, tachycardia, and postural hypotension.
If the neutrophil count is <0.5 x 109/L there is a significantly increased risk of severe or fatal sepsis. Try to identify the cause of this abnormal blood count.
Chemotherapy, radiation treatment, drug toxicity, severe sepsis, leukaemias, myelodysplastic syndromes, aplasia are a number of possible causes.
Unless the cause is obvious and temporary, investigations should include examination of the bone marrow.
Treatment
If the neutropaenia is a new feature, initial management should consist of isolation of the patient. Place the patient in a single room and institute strict hand washing for the attending staff. Restrict the number of visitors. If the neutropaenia is chronic and the patient has been out in the community with neutropaenia, then there is no need for isolation.
If the patient is febrile (fever >38.5°C or history of fever >38°C for one hour or any question of either of these) start empirical antibiotics after blood cultures (from peripheral vein and also central line if present) are taken, before doing other investigations, and seek Specialist advice.
Other appropriate investigations include MSU, swab of any lesion or pustule, sputum for Gram stain and culture, faecal culture if diarrhoea is present, CXR.
First line antibiotic therapy for the treatment of neutropaenic sepsis is:
Piperacillin/tazobactam 4.5 g IV q8h plus gentamicin 5-7 mg/kg IV in 100 mL sodium chloride 0.9% over 30 min q24h
or, if there is a history of penicillin allergy,
Meropenem 1 g IV q8h plus gentamicin 5-7 mg/kg IV in 100 mL sodium chloride 0.9% over 30 min q24h.