Sickle Cell - Presentation, Crises, Management

Question 1

Sickle cell anemia
-pathophysiology and epidemiology

Answer 1

Autosomal recessive => abnormal Hb chain (HbS)
-heterozygous only symptomatic if severely hypoxic

Sickle cells are fragile, hemolyse => block small vessels, leading to infarction

Common in African descent

Question 2

Sickle cell anemia
-acute events

Answer 2

Vaso-occlusive crisis => ischemia, severe pain in affected area

Acute chest syndrome => vaso-occlusion in pulmonary vasculature/infection
-fever, chest pain, cough, SOB, hypoxia

Splenic sequestration crisis => vaso-occlusion into spleen => hypovolemic shock
-splenomegaly

Aplastic crisis triggered by parvovirus B19 => erythropoeisis stopped
-severe anemia, reduced reticulocytes

Hemolytic crisis => accelerated destruction of RBCs
-anemia, jaundice

Priapism => vaso-occlusion from corpus cavernosa
-pain

Question 3

Sickle cell anemia
-chronic complications

Answer 3

Chronic hemolytic anemia
-pallor, fatigue, SOBOE

Infections
-recurrent splenic infarctions traps bacteria

Leg ulcers
-venous insufficiency => non healing venous ulcers

Ocular complications
-retinal vessel occlusion => vision loss

Skeletal complications
-AVN of heads
-marrow hyperplasia => osteopenia, pathologica fractures

Renal complications
-renal ischemia => nocturia, polyuria, proteinuria, CKD

Cardiopulmonary complications
-compensation for chronic anemia => increased CO
-leads to pulmonary HTN and RHF

Neurological complications
-CVAs

Growth retardation, delated puberty
-chronic hypoxia, undernutrition from increased metabolic demands

Question 4

Sickle cell anemia
-investigations

Answer 4

Definitive - Hb electrophoresis

Crisis - clinical diagnosis

Question 5

Sickle cell anemia
-long term management

Answer 5

Hydroxyurea
-increases HbF
-prophylaxis of sickle cell anemia

Pneumococcal vaccine 5yearly

Question 6

Sickle cell anemia
-crisis management

Answer 6

Analgesia - opiates
Rehydration
O2
ABx if infection

Blood transfusion
-severe/symptomatic anemia
-pregnant
-preop

Exchange transfusion => rapidly reduce HbS cells
-acute vaso-occlusive crisis

Question 7

When to admit for sickle cell crisis?
-children

Answer 7

Fever + no identified source of crisis
-needs bloods and cultures taken to look for the possible source of infection

Acute chest symptoms