CLIPP 30 Flashcards
SCD pathology
substitution of valine for glutamic acid at the sixth amino acid position of the hemoglobin molecule. This mutation leads to the formation of polymers of hemoglobin when the hemoglobin becomes deoxygenated.
These polymers lead to deformation of the red blood cell into the characteristic “sickle” cells. Sickle cells have increased adherence and block blood flow in the microvasculature, which leads to local tissue hypoxia, pain, and tissue damage.
The abnormal hemoglobin induces hemolysis of the red blood cells leading to chronic anemia with an elevation of the reticulocyte count.
hgb nomenclature - for example, how do Hemoglobin FA vs FAS vs FSA differ
F listed first bc predominant kind at birth
FA = A is normal adult hgb
FAS = sickle trait, more hgb A than hgb S, will not have sickle sx?
FSA = sickle and beta thal w/ both sickle and beta thal but less hgb A than Sickle hgb. IS a disease.
FSA vs FSC vs FAS
FAS - sickle triat, no sx?
FSA - sickle cell and beta thal, sx
FSC sickle cell and hgb c , sx
2 common surgeries in sickle kids
tonsills - hypertrophy in waldeyers ring leads to OSA, snoring
cholecsytetomy - sickle cell dz cause bilirubin gallstones - typically do convesative management first then surgery if need, and give prbc before surgery to avoid sickle crisis. cholecystitis is serious to tx so tx if symptomatic from stones
what med to give to sickle cell kids
penicillin - until age 5-6yo bc after this, little data to support use except in kids w documents sepsis and bacteremia or if spleen removed (but what about functional asplenia in kids above 5 yo?)i
fever in sicklesr
Fever may be the only sign of sepsis in children with sickle cell disease and must be dealt with as a medical emergency, with rapid evaluation, blood cultures, and institution of broad-spectrum parenteral antibiotics while waiting for culture results to guide the therapy.
If cultures are negative and the patient is well, usually the child may be discharged in 48-72 hours. Remember that children with sickle cell disease also get “normal” colds and other viral illnesses.
acute chest syn
The lungs are a site of occasional sickling problems.
This can occur in the form of pneumonia, because of the increased tendency to infections.
It may also occur as a result of vaso-occlusion in the lung parenchyma. This process, called acute chest syndrome, is a medical emergency requiring supplemental oxygen and transfusion therapy.
two risks of chronic transfufsion
overload - tx w/ iron cheaters like deferasmionx or deferoxamine
-alloimmunzation, trranfusion rxn
TCD studies are now recommended in __ of age to determine __
2-15 year olds
risk of stroke
tx w transfusion if at risk
conjugation of vaccine
In a child under the age of 2 years, the immune system has a suboptimal response to purely polysaccharide vaccine. Conjugating the antigens to a protein allows an infant’s immune system to make antibodies.
13 vs 23 pneumococal
13 is whats given in first year of life, but 23 is given to sickle kids at 2 and 5 yo(or 5-8yo)
specifcla circmstances in which u should get meningicocal vaccine
kids w/ fx or anatomic asplenia should get this at 2yo and the booster 3-5 y later
sickle cell inheritance is
AR
sickle cell prenatal testing
One samples fetal blood obtained in utero;
Another involves extracting DNA from chorionic villi
time course of spleen in sickle cell and what is splenic sequestration crisis?
Enlargement of the spleen is common during the first few years of life in children with sickle cell disease; massive enlargement or rapid change in size can indicate splenic sequestration crisis. This is often accompanied by other symptoms, including increased pallor, fatigue, and irritability.
This life-threatening complication occurs when blood pools in the spleen and leads to severe anemia and shock.
The spleen in sickle cell disease becomes progressively fibrotic; by the time the child is 4 to 6 years old, it is no longer palpable (children with hemoglobin SC or S beta thalassemia can have splenic enlargement into adolescence).
3 key things to examine in sickle kid
spleen, neuro (look for stroke sx), sclera
kids w/ scd frequently have hemoglobins between and __ for heart size
6-9, cardiomeg
fever in scd
medical emergency - could be only or first sign of sepsis
slurred pseech in scd
could be sign of stroke- transfuse to decrease amt of hgb s to prevent progression
tacyhpnea and CP in scd
could mean acute chest
pallor in scd
could mean aplastic crisis, splenic sequestration, incr hemolysis
scd skin
baseline jaundice - but incr levels of jaundice can mean more hemolysis ad a need for transfusion, can be assoc w/ viral stuff
pripism
can happen in sickling in penile arteries and can be permanent
in scd, acute chest syn is the term for __
plum fat embolism, pna, or intrapulm sickling–>occlusion of plum vasculature - must assess pain, pulmo/resp complaints and chance of infection in these pt
spleen palp 3 vs 2 cm below left costal margin
3 means splenomeg
ACS sx (5)
Fever Cough Chest pain (this can lead to difficulty with expansion of the lower lung and result in atelectasis) Shortness of breath Decreased oxygenatio
in scd, infiltrates can happen in…
and effusions can happen in…
infiltrates - acs, chf, pericarditits
effusions - acs, rib infarct, pericarditis
wbc and plateltes in scd w/ stress
leukocytosis, thrombocytosi (vs will be lower in aplastic crisis)
faces pain scale
typically not under 4yo but sickle kids under 4 yo may understand it, can also use parent judgmeent
hallmark of scd
Painful crisis with or without fever or pulmonary event is one of the hallmarks of sickle cell disease. Intravenous fluids, NSAIDs, and intravenous narcotics (morphine or derivatives of morphine) are frequently required to control the pain. It is important to know that pain is often underdiagnosed and undertreated in the pediatric population, including patients with sickle cell disease.
Patient-controlled anesthesia (PCA) can be an excellent approach to the use of narcotics in these patients, restoring the locus of control over pain to the patient.
Patients on PCA receive a baseline continuous infusion of narcotic analgesics and can also receive small boluses on demand using a handheld button.
If narcotics are used, ensure that your patient is carefully monitored for respiratory depression.
fluid in ACS
can give bolus right away but later do maintenance to make up for tachypena/insensible loss - more than maintenance can flood them (or 1.5 maint???)
atelectasis
A collapsed or airless segment of lung due to obstruction with distal collapse of the alveoli.
Atelectasis is a serious risk in a child with chest pain. It can exacerbate acute chest syndrome, causing it even to become life-threatening.
Therefore, it is critical to encourage deep breathing, often through the use of assistive devices.
incentive spirometry
increase insrpiation efforts to lower atelectasis
trasnsfusion in ACS
An RBC transfusion is the only way to directly reduce or reverse the sickling process which is the underlying cause of the acute chest syndrome. Indications for RBC transfusion in ACS are not precise, but if a child experiences one of the following, a transfusion of packed red cells is recommended:
A fall in hemoglobin from baseline Increasing respiratory rate Worsening chest symptoms Declining O2 sats Progressive infiltrates on chest x-ray It should be noted that the vast majority of sickle cell patients with acute chest syndrome will have one or more of these findings.
Exchange transfusion (erythrocytapheresis) should be reserved for especially severe disease and/or hypoxemia not corrected by oxygen therapy. For more on erythrocytapheresis, see the Expert.
erythracytapheresis
An automated method of doing an exchange transfusion.
The best way to rapidly lower the hemoglobin S level and rapidly raise the hemoglobin.
This method would be used with severe respiratory distress, failing pulmonary function, or acute onset of stroke.
In acute chest syndrome, increasing the hemoglobin alone is usually effective to treat this life-threatening condition.
abx in acute chest
third-generation cephalosporin and a macrolide antibiotic. However, the overall rate of positive cultures was < 10%.
-hard to distinguish between cvaso occlusion or fat embolism or actual infection
most common reasons for admission in sickle cell
Osteomyelitis and painful vaso-occlusive crises represent the most common reasons for admission for sickle cell disease patients. Rib infarction may lead to a picture similar to ACS as the pain can lead to hypoventilation, which may result in atelectasis and the characteristic radiographic findings of ACS. However, no radiographic findings are present in this patient. As a result, rib infarction is the most likely etiology.
prevnar vs pneumovax
prevnar = what all kids get pneumovax = the 23 valent for sc kids (pneumococcal polysach vaccine)
