A 72-year-old man is admitted to ICU post-operatively for multi-trauma following a motor vehicle crash. 10 days post admission he develops a new fever. Septic screen results are pending and the full blood count is as follows:
|
Parameter |
Result |
Normal Range |
|
Haemoglobin |
76 G/L* |
130 – 175 |
|
White Cell Count |
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 |
Comment on blood film: Moderate anisocytosis. Moderate polychromasia. Moderate number of target cells. Occasional Howell-Jolly bodies. Increased rouleaux formation. Marked thrombocytosis.
With this blood picture, one might safely wager that this patient has had a splenectomy. Howel-Jolly bodies are bits of lefteover DNA in the erythrocytes. The rest of the RBC morphologies commented on are essentially just cellular garbage. Normally, the spleen would view these as pollutants of the bloodstream, not to be tolerated; and they would be rapidly destroyed. The asplenic man, therefore, must put up with factory seconds of haematopoiesis.
As for protecting him from complications - one must immunise him, and protect him from the thromboembolic complications of thrombocytosis. Thrombosis after splenectomy has an incidence of about 5%, and can be managed wth either aspirin or (in extreme circumstances) with hydroxyurea.
The vaccinations prevent severe infection by encapsulated organisms - because the encapsulated organisms are poorly opsonised by complement, and the spleen was the only organ which could remove them. Thus, one must protect this patient from these bugs. There has been a 2011 revision of the guidelines for such prophylaxis. The most recent iteration of the immunisation schedule can be found here, at Spleen Australia.
Vaccines recommended for adults (>18 years) with asplenia/hyposplenism -from Spleen Australia
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