Sickle Cell Flashcards
Comprehensive Clinics
Nurses, NPs, doctors, social workers, counselors
Sickle Cell Disease Pathophys
substitution of valine for glutamic acid at 6th AA position on hemoglobin
- formation of polymers when hemoglobin becomes deoxygenated
- deformed (sickled) RBCs –> block blood flow in microvasculature –> local tissue hypoxia, pain, tissue damage
- hemolysis –> chronic anemia
Sickle cell traits
FA - normal
FS - both alleles are S –> sickle cell disease
FSC - one allele S, one allele C –> sickle cell disease
FAS - carrier of sickle cell
FSA - beta-thalassemia
Common procedures for SCD kids
- Tonsillectomy - lymphoidal tissue hypertrophy –> obstructive sleep apnea
- Cholecystectomy - bilirubin gallstones from hemolytic anemia
Risk of sepsis in kids with SCD
infants and kids with SCD at greater risk of sepsis
- decreased splenic function -> encapsulated organisms (s. pneumo, Hib, N. meningitidis)
- prophylactic penicillin greatly decreases risk (stop around 5-6 y.o)
Goals for comprehensive SCD appointment
- How is family doing/dealing with disease?
- Frequency of painful/vaso-occlusive episodes?
- Frequency of fevers?
- Access to healthcare?
Expected complications of SCD
- Jaundice - hemolysis of RBCs
- Anemia - can be result of recent infection, hypersplenism
- Stroke - increased risk (evaluate with doppler)
- Respiratory problems - lungs frequent site for sickling, vaso-occlusion of lung parenchyma –> acute chest syndrome (EMERGENCY = oxygen supplementation and transfusion)
Immunizations for SCD patients
Hib vaccine
Pneumococcal vaccine
Meningococcal vaccine
Influenza vaccine
Inheritance of SCD
Autosomal recessive - each parent must have 1 allele
- knowing newborn screen is important to know whether or not to start prophylactic penicillin
Prenatal testing for SCD
Can do it, some testing in development
- samples of blood obtained in utero
- extracting DNA from chorionic villi
Effects of chronic illness on growth and development
- can affect academic progress
- socialization and self-esteem
Growth in SCD
- impairment of growth in SCD is common
- chronic anemia
- poor nutrition
- painful crises
- endorine dysfunction
Important PE for SCD
- Splenic Enlargement - common in first 2 years of life (make sure it isn’t massive)
- Sclera - jaundice from RBC hemolysis
- Neuro exam - evaluate for potential stroke
Baseline CBC in SCD
common to have baseline Hgb from 6-9 range
- lower the baseline = lower threshold for acute changes
When to seek care with SCD
FEVER - emergency Splenic enlargement Slurred Speech - stroke Chest pain - EMERGENCY Rapid breathing - EMERGENCY Pallor and jaundice Priapism - permanent damage possible
Aplastic crisis
temporary inhibition of erythroid production caused by viral illness (parvovirus)
Acute Chest Syndrome
child with SCD presenting with fever, cough, difficulty breathing, low sats, chest pain
- PNA, fat embolism, intrapulmonary sickling
DDx for chest pain, tachypnea and fever in SCD
- Acute Chest Syndrome
- Pericarditis
- CHF
- Rib infarction - vaso-occlusive crisis
- Sepsis
Acute Chest Syndrome CXR
bilateral lung infiltrates
atelectasis - pain can exacerbate this by not taking good breaths
cardiomegaly - from baseline in SCD
possible effusions
CBC findings is stress response in SCD
SCD patients frequently show exaggerated leukocytosis and thrombocytosis
- don’t definitively help diagnose sepsis or ACS
Treatment for pain crises
IV fluids (vigorously rehydrate as it can contribute to sickling), NSAIDs, narcotics (remember they are a respiratory depressant --> further exacerbate atelectasis) - possible PCA
Atelectasis
partially collapsed lung due to obstruction
- serious risk for kids with ACS
- critical to do deep breathing and assist devices (incentive spirometer)
RBC transfusion for ACS
only way to directly reduce # of sickling RBCs
*exchange transfusion - best wat
Use if: fall in Hgb below baseline, increased RR, worsening chest symptoms, declining O2 sats, infiltrates on CXR
ABx in acute chest syndrome
Broad IV Abx started
- Viruses, Chlamydia, Mycoplasma, Bacteria
3rd generation ceph + macrolide
