Term
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Definition
hereditary disorder that is a chronic illness that presents with sickle cell hemoglobin (HbS) in RBCs;
substitution of valine for glutamic acid in beta chain leads to development; |
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Term
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Definition
| heterozygous inheritance of 1 normal cell & 1 sickle cell hemoglobin (HbAS) gene; usually asymptomatic; |
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Term
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Definition
| homozygous inheritance of 2 defective genes (HbSS); symptomatic |
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Term
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Definition
primary O2 transport in fetus;
only a small proportion of red cell clones remain to produce HbF in adults;
Makes up 60-90% of fetal RBCs, but only <1% in adults; |
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Term
| Sickle Hgb Polymerization |
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Definition
| allows deoxygenated Hbg to exist as semisolid gel that protrudes into cell membrane --> loss of biconcave shape --> elongated, rigid, curved at ends ("sickle" shape) |
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Term
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Definition
increases blood viscosity --> sludging --> tissue hypoxia;
cycle of sickling & unsickling --> cell membrane damage, loss of membrane flexibility --> vasoocclusion;
Damage to cell membranes --> dehydrated, dense sickle cells --> loss of K/H2O --> irreversible sickled cells (ISCs) |
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Term
| End Result of Sickle Hgb Polymerization & Viscosity & Sickle Cell Adhesion |
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Definition
| impaired circulation, RBC destruction, & stasis of blood flow |
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Term
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Definition
*PAINFUL VASOOCCLUSIVE crises (Hallmark)*;
dactylitis (hand-foot syndrome, inflammation of digits);
infarction of spleen, liver, bone marrow, kidney, brain, lungs;
gallstones;
priapism;
slow healing lower extremity ulcers;
weakness, lethargy; |
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Term
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Definition
chronic hemolytic anemia;
enlargement of spleen, heart;
scleral icterus; |
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Term
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Definition
Hbg 7-10 g/dL;
low HbF & increased reticulocytes, Plts, WBCs;
presence of sickled cells on blood smear; |
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Term
| Featured Presentations of SCA |
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Definition
| hemolysis AND vasoocclusive crises (VOC) |
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Term
| Goals of Treatment of SCA |
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Definition
reduce or eliminate pts symptoms;
decrease frequency of sickle cell crises;
prevent development of complications;
maintain or improve quality of life through decreased hospitalizations & decreased morbidity; |
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Term
| Nonpharmacological Therapy for SCA |
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Definition
*maintain adequate hydration --> decrease blood viscosity*;
avoid extreme temp. changes;
avoid physical exertion that leads to complications;
regular exams required to monitor for organ damage; |
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Term
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Definition
annual influenza vaccine, 6 months or older;
pneumococcal vaccine:
- PCV 7 (Prevnar): 6 wks - 15 months old;
- PPV 23 (Pneumovax): >2 yrs old & adults;
Meningococcal vaccine in asplenic pts; |
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Term
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Definition
prophylaxis until at least 5 yrs old to protect against pneumoccocal infections;
IM preferred due to noncompliance issues;
Use erythromycin if pts are allergic; |
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Term
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Definition
| pts have increased demand for this --> accelerated erythropoiesis; |
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Term
| hydroxyurea (Droxia, Hydrea) |
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Definition
MoA: stimulates production of HbF levels, increases # of HbF-containing reticulocytes, & intracellular HbF;
Indications:
- pts w/ >= 3 severe vasoocclusive pain crises and/or ACS per year or severe symptomatic anemia;
Adjust dose after 8-12 wks;
Administer folic acid w/ drug;
ADRs: myelosuppression, N/V, constipation, confusion, peripheral neuropathy;
Monitoring:
baseline - CBC, reticulocytes, MCV, HbF, bilirubin, ALT, pregnancy test;
Toxicity (myelosuppression): Stop drug for at least 1 wk until toxicity resolves, resume at smaller dose; |
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Term
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Definition
2nd line tx of SCA;
for pts who do not respond to hydroxyurea;
Induces HbF production;
Administer SC;
ADR: neutropenia |
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Term
| chronic transfusion therapy |
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Definition
important role in managing SCD;
Primary indication: stroke prevention, improvment of other organ damage;
Goal: achieve & maintain [HbS] <30% of total Hgb;
Administered every 3-4 wks;
Risks: alloimmunization, IRON OVERLOAD; |
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Term
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Definition
use 1st with chronic transfusion therapy;
chelating agent used for iron overload (hemosiderosis) 2ndary to multiple transfusions;
Indications: after 1 yr of chronic transfusion OR serum ferritin >1500-2000 ng/ml;
Give Orally;
DO NOT chew or swallow --> disperse in water, OJ, apple juice for oral suspension;
ADRs: SCr increase, proteinuria, fever, HA, nausea; |
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Term
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Definition
used as 2nd agent after deferasirox is tried;
IV chelating agent;
Indications: after 1 yr of chronic transfusion OR serum ferritin >1500-2000 ng/ml;
Given SC via pump;
ADRs: injection site rxns, pain, fever, HA, ocular & ototoxicities; |
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Term
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Definition
acute complication of SCA;
Most commonly caused by S. pneumoniae, influenza, and parvovirus 19;
Tx:
- may require hospitalization;
- Empirically start ANTIBIOTICS in any pt w/ fever >101 F; |
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Term
| neurologic complications of SCA |
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Definition
vasoocclusive processes --> cerebrovascular occlusion (stroke);
Diagnose w/ CT scan or MRI;
TX:
- blood transfusion reduces incidence of stroke;
- thrombolytic therapy may be considered if <3 hrs since symptom onset; |
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Term
| Acute Chest Syndrome (ACS) due to SCA |
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Definition
leading cause of death in SCD;
new pulmonary infiltrate w/ 1 or more symptoms: cough, dyspnea, chest pain, tachypnea, fever, wheezing, new onset hypoxia;
& an ambiguous response to antibiotics;
Tx:
- requires hospitalization;
- pain management;
- broad-spectrum antibiotics: macrolide, fluoroquinolone, or cephalosporin;
- O2 for respiratory distress;
- transfusions; |
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Term
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Definition
sickling in sinusoids of penis;
painful erection lasting < 2 hr (stuttering) to >2 hrs (prolonged);
Can lead to fibrosis & impotence;
Tx:
- vasoconstrictors (phenylephrine, epinephrine) - forces blood out of corpus cavernosum into venous return;
- vasodilators (terbuatline, hydralazine) - relaxes smooth muscle of vasculature, allowing blood to enter corpus cavernosum which displaces sickle cells; |
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Term
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Definition
| vasooclussive pain; aplastic crisis; acute splenic sequestration crisis; |
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Term
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Definition
acute pain; recurrent acute crises can lead to permanent damage & chronic pain;
Involves: bone, liver, spleen, brain, lungs, penis;
Precipitating factors: infection, extreme weather conditions, dehydration, stress;
S/Sx: throbbing pain, local tenderness, erythema, swelling;
Tx:
- hydration & analgesia;
Monitor:
- PhEX, CBC, reticulocyte, UA, LFTs, bilirubin, CXRY, culture; |
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Term
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Definition
transient suppression of RBC production in response to bacterial or viral infection;
- most commonly due to infection with PARVOVIRUS B19;
S/Sx: HA, fatigue, dyspnea, pallor, tachycardia, fever, upper respiratory or GI symptoms;
Tx:
- supportive care, transfusions;
Monitor:
- CBC, reticulocytes, X-ray, cultures, parvovirus titers; |
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Term
| Acute Splenic Sequestration Crisis |
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Definition
acute exacerbation of anemia;
seen in viral or bacterial infections;
Common recurrence, can be fatal;
S/Sx:
- sudden onset of fatigue, dyspnea, distended abdomen;
- rapid decrease in Hgb w/ elevated retic count;
- SPLENOMEGALY;
Tx:
- RBC transfusion;
- broad-spectrum antibiotics;
- splenectomy (severe cases);
Monitor:
- vitals, spleen size, O2 sats, CBC, retic, cultures |
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Term
| Management of Acute Pain of SCD |
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Definition
treat underlying precipitating factors;
Pick initial analgesic regimen based on SCD crises;
Schedula pain medication;
Provide rescue doses for breakthrough pain;
Frequently assess pain severity & side effects;
Treat adverse effects of opioids;
Transition to PO meds as pt improves, start pt on IV or IV PCA; |
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Term
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Definition
| nonopioid +/- weak opioid |
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Term
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Definition
| weak opioid or low dose of strong opioid +/- nonopioid |
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Term
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Definition
| strong opioid + nonopioid |
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Term
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Definition
APAP w/ codeine;
hydrocodone + APAP; |
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Term
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Definition
morphine;
hydromorphone;
methadone;
fentanyl; |
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Term
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Definition
ibuprofen;
naproxen;
ketorolac (IV);
APAP |
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Term
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Definition
respiratory depression;
itching; N/V; constipation; drowsiness; |
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Term
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Definition
hydration, heating pads, relaxation, & distraction;
stool softener and/or stimulants for constipation;
antihistamine for itching;
antiemetics for N/V; |
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