College Answer

a) What is the most likely cause of the abnormalities?

Acute blood loss . Hemolysis is unlikely in this setting.

b) He is due to undergo orthopaedic surgery and a laparotomy on day 2. A
coagulation profile performed prior to the procedure reveals the following.

Prothrombin ratio	0.9	INR		(0.8-1.2)
APTT	33	sec	(24-39)
Fibrinogen	6.1	g/L	(1.5-4.0)*

What is the cause of the raised fibrinogen?
Acute phase response

c) On day 10 in intensive care, he develops a new fever, A full blood count and a septic screen are performed. The results of the full blood count are provided below. The septic screen results are awaited.

Hb	76	g/L	(130-175)*
WCC	15.8	x 109/L	(4.0-11.0)
Platelets	1211	x 109/L	(150-450)
Reticulocytes	220	x 109/L	(10-80)*
Neutrophils	10.4	x 109/L	(1.8-7.5)
Lymphocytes	2.06	x 109/L	(1.5-4.0)
Monocytes	2.54	x 109/L	(0.2-0.8)
Eosinophils	0.48	x 109/L	(0.0-0.4)
Haematocrit	0.26		(0.4-0.52)*
MCV	92	fl	(82-98)
MCH	29.9	pg	(27.0-34.0)
MCHC	326	g/L	(310-360)

Film review: Moderate anisocytosis. Moderate polychromasia. Moderate number of target cells. Occasional Howell-Jolly bodies. Increased rouleaux formation. Marked thrombocytosis

c). What is the explanation  for the blood picture?

Post splenectomy

d)Based on this explanation  , what additional  therapy will you consider ?
Immunization for HIB. Meningococcus and pneumococcus.
Penicillin or other antibiotic prophylaxis

e) As a consequence of the head injury, he develops a hydrocephalus which requires a ventriculo-peritoneal shunt.  He is discharged home 4 weeks later.  Six months after discharge, he presents with fever, headache and seizures.

List the 2 most likely differential diagnoses.

a)  Shunt infection / blocked shunt
b)  Meningitis from encapsulated bacteria.
c)  Consideration should be given to other causes such as viral and bacterial meningitis, however they will carry a lesser mark.

Discussion

a) What is the most likely cause of the abnormalities?

The college presents us with an FBC which demonstrates anaemia and a vigororus reticulocyte response. This is consistent with the bone marrow of a young man trying to regenerate a hematocrit.

b) What is the cause of the raised fibrinogen?

Fibrinogen is one of the acute phase reactant proteins; trauma and blood loss are major stimuli to increased fibrinogen synthesis by the liver. One could list all the acute phase reactants here, but there are too damn many - this NEJM article has a table (Table 1). Fibrinogen syntheis si induced by interlukin-6, and it in turn induced endothelial cell proliferation, which is good if you have open wounds to heal. Fibrinogen is also one of the reasons the ESR increases during inflammatory states.

c). What is the explanation  for the blood picture?

The blood picture demonstrates a characteristic post-splenectomy scenario.

The typical abnormalities are as follows:

• Howel-Jolly bodies
• Anisocytosis
• Thrombocytosis
• Acanthocytosis
• Target cells
• Pappenheimer bodies
• Platelet aggregates

d)Based on this explanation , what additional  therapy will you consider ?

Management of the post-splenectomy patient is discussed in greather depth elsewhere. In brief summary, the management consists of the following measures:

• The asplenic patients should carry an identifying card
• They should receive the following vaccinations:
  • Pneumococcal vaccination
  •  Haemophilus influenzae type b conjugate vaccine
  • Meningococcal conjugate vaccine (B, C)
  • Influenza immunization
• There may be some role for lifelong prophylactic antibiotics
• The patient should have a supply of antibiotics for emergency use at home

e) List the 2 most likely differential diagnoses.

Fever, headache and seizures in an asplenic patient with a VP shunt simply screams "meningitis". The shunt may be infected, or simply blocked, but the smart money is on an encapsulated orgnaism of some sort, and Streptococcus pneumonia is the most likely culprit. More details can be found in the chapter on sepsis in the post-splenectomy setting.