A common theme of many of the PedEM Morsels has been the need to be ever vigilant. This is not in contradistinction to the adult side of the ED. Certainly vigilance is mandatory with all patient encounters; however, the fact that the overall quantity of critical illness encountered in the PedsED is (fortunately) a lot less than that in the adult ED engenders potential complacency. Essentially, complacency is the parent of disaster and only the paranoid will survive!
A great example of vigilance / paranoia being clinically useful is with sickle cell patients. Yes, we see a lot of patients with sickle cell who are having pain crisis. We know to consider acute chest syndrome and are extremely leery of fever and serious bacterial infections. But let us not forget another significant cause of mortality in young patients with sickle cell disease: splenic sequestration.
- Sudden enlargement of the spleen associated with,
- A precipitous decline in hemoglobin concentration by at least 2 g/dL.
- Commonly there will also be increase in reticulocytes.
- Consider aplastic crisis if the reticulocyte count is low.
Why we care:
- The spleen can trap enough circulatory blood volume that the patient develops shock.
- It can have a high mortality rate (some studies report up to 12%).
- In 20% of infants with HgbSS it is the initial clinical presentation.
Who is at risk:
- Basically, any sickle cell patient with a functional spleen.
- Recall that most patients with HgbSS disease will often have autosplenectomy from repetitive infactions at an eary age; therefore, the homozygous patient will be at greatest risk for splenic sequestration before age 5yrs.
- The more mild forms of sickle cell disease (ex, SC disease) may not autoinfact the spleen and can, hence, have splenic sequestration even later in life (cases of it occurring in adults have been reported).
- Good question… it is not fully determined.
- Often they are associated with infections (particularly the dreaded parvovirus B19).
- Pallor, decreased activity
- SHOCK (put simply) – tachycardia, tachypnea, hypotension, poor perfusion
- May be so enlarged that only a distended, hard abdomen can be appreciated… this is a good reason to start palpation for spleen with your hand initially down at the pelvis and work your way cephalad.
- Here’s where the vigilance comes in… the child with sickle cell and fever may not initially present with overt splenic sequestration but can develop it during the course of clinical care… it is imperative to always document the presence or lack of splenomegaly to help you and your colleagues pick up the condition as soon as possible.
- Check CBC, Type & Screen, Retic Count
- Obtain Blood Cultures (especially if febrile)
- Check CXR if febrile or with respiratory symptoms (20% of the time there will be concurrent acute chest syndrome).
- If signs of shock, then Restore circulatory blood volume!
- Bolus 10-20ml/kg normal saline while awaiting PRBCs.
- Transfuse 10ml/kg PRBC
- Do not transfuse higher than baseline hgb!
- The sequestered blood will eventually reenter circulation, increasing risk for heart failure and for hyperviscosity and possible strokes.
- Have a low threshold for antibiotics (especially if febrile).
- Analgesics (naturally)
- Eventually, splenectomy is often recommended
- To prevent recurrence of sequestration
- Those who have had the 1st episode prior to age 2yr are at highest risk for recurrence.
So, while we will evaluate many, many more sickle cell patients with vaso-occlusive crisis or fevers than we will with splenic sequestration, we will benefit our patients best by remaining vigilant with regards to the size of the spleen. Paranoia can be beneficial.
Brousse V, et al. Acute splenic sequestration crisis in sickle cell disease: cohort study of 190 paediatric patients. Br J Haematol. 2012 Mar;156(5):643-8.
Topley JM, Rogers DW, Stevens MCG, Serjeant GR. Acute splenic sequestration and hypersplenism in the first five years in homozygous sickle cell disease. Archives of Diseass in Childhood. 1981; 56: pp. 765-769.
“Spenic Sequestration” in Textbook of Clinical Pediatrics, Volume 1. Editor elzouki AY, Harfi HA, Nazer H, Oh V, Staleton FB,Whitley RJ. Page 3008.
The Royla Children’s Hospital Melbourne Clinical Practice Guidelines – http://www.rch.org.au/clinicalguide/cpg.cfm?doc_id=5245 – ass