Sickle Cell Disease Flashcards
Laboratory Tests to diagnose SCD
Blood smear
2. Slide sickling preparation
3. Solubility test
4. Complete Blood Count, reticulocyte count
5. Hemoglobin separation tests
6. Quantitation of hemoglobin fractions
7. Quantitation of globin chain fractions
8. DNA-based tests
9. Family studies
The Sickling Test
indicate the presence of HbS, but do not define the Hb genotype.
They use the morphology of the RBCs when subjected to low PO2;
Classically 2% sodium metabisulphite induces deoxygenation when mixed with a drop of blood on a microscopic slide, covered with a cover slip.
Only RBCs with Hb-S sickle.
Tests are not useful in the newborn period.
Can’t pick Hb-C and other Hbs
TEST results are reported as POSITIVE or NEGATIVE
Simple Screening Tests for Hb S - Solubility test and Sickle Prep
Of no use as a primary screening tests
Positive = Presence of Hb S
Negative in newborns, infants and others with high levels of Hb F; negative for Hb C
Does not distinguish sickle cell trait (AS) from types of SCD
In emergency, may help raise suspicion of SCD
Can help distinguish Hb S from other hemoglobins with similar electrophoretic migration or chromatographic retention patterns.
Assessment of Pain
FACES- faces indicating intensity of pain : 6-8 yrs
OUCHER scale- 6 photos of children indicating pain- 3-12 yrs
FLACC (Face, Legs, Activity, Cry, Consolabilty)- 2 months to 7 yrs
VISUAL ANALOGUE Scale- vertical/horizontal line with numerical anchors: ≥ 5yrs
PAIN DIARY- Numerical rating along with time: Adolescents
Management of pain crisis
Classify pain- mild, moderate, severe
Identify and treat underlying cause if any
Hydration-oral and/or IV infusion at one and a-half maintenance. Use D/S or N/S.
Analgesics- give adequate amounts and promptlyType and amount of analgesic should reflect severity of pain.
Other measures: massaging, application of heat etc.
WHO Recommendation for Pain Management
Mild pain start with simple non-opiods: P’mol
Moderate pain use NSAIDs (may combine with p’mol)
Severe pain- opiods
HYPERHAEMOLYTIC CRISIS
lifespan of HbS-RBC is about 10-20 days;
Infections, G6PD Def. worsen the chronic haemolysis.
Evidence: fall in Hb, PCV, increased retic count, hepatosplenomegaly, pallor, jaundice, dark-colored-like urine
APLASTIC CRISIS
acute failure of erythropoiesis-low Hb, PCV, low or absent retic count.
Associated with parvovirus B19 infection- Acute infection may be associated with: ACS, ASS, Pain, Stroke, AGN.
Treatment- packed RBC transfusion for heamodynamic instability
Acute sequestration crisis
Sudden progressive anaemia accompanied by painful splenic enlargement and shock (ASS). This is due to pooling of blood in the spleen.
Technically: 1. enlargement of spleen by ≥ 2cm
2. Drop in Hb ≥2gm
Sequestration can also occur in the liver- Hepatic sequestration
Megaloblastic changes
Chronic haemolysis leads to folate deficiency
Acute Chest Syndrome
chest pain,
fever,
signs of respiratory distress,
New pulmonary infiltrate on CXR.Clinically treated as INFECTION (pneumonia) or INFARCTION: -Antibiotics, analgesics, hydration, Oxygen/ventilation.Transfusion may be benificial in severe cases
Acute Chest Syndrome
chest pain,
fever,
signs of respiratory distress,
New pulmonary infiltrate on CXR.Clinically treated as INFECTION (pneumonia) or INFARCTION: -Antibiotics, analgesics, hydration, Oxygen/ventilation.Transfusion may be benificial in severe cases
Clinical Presentation of Acute Chest Syndrome - Symptoms
Fever
Cough
Chest pain
Shortness of breath / dyspnea
Chills
Wheezing
Hemoptysis
Clinical Presentation of Acute Chest Syndrome - Signs
ever
Chest tenderness
Use of Accessory muscles:-Intercostal and subcostal recessions (ICR,SCR).
Abnormal pulmonary exam
Rales
Wheezes
Dullness to percussion
Normal pulmonary exam
Risk Factors of Acute Chest Syndrome
young age, past history of ACS, recurrent pain, high WBC or 2 percentage point decrease in O2 saturation
