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Pediatrics Clerkship > Aquifer - Cardiovascular and Hematology (Part 1) > Flashcards

Aquifer - Cardiovascular and Hematology (Part 1) Flashcards

1
Q

List the steps in the cardiac examination.

A
  1. Assess color of skin and mucous membranes
  2. Precordial activity
  3. Heart sounds (S1 and S2, physiologic split of S2, possible gallop (S3 or S4), and clicks)
  4. Murmurs, (clicks, rubs)

(History - poor feeding, diaphoresis, FTT, family h/o CHD)
(Vitals)
(Inpsection for dysmorphism, cyanosis, clubbing)
(Distal pulses)

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2
Q

What is the most common cyanotic heart defect? What are the other cyanotic congenital heart defects?

A

Tetralogy of Fallot

Truncus arteriosus, transposition of the great arteries, tricuspid atresia, and total anomalous pulmonary venous return

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3
Q

What does a hyperactive precordium indicate?

A

Increased workload

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4
Q

True or false - gallops are uncommonly heard in infants and children.

A

True

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5
Q

What is a holosystolic murmur?

A

Begins with S1 (not after it), during isovolumic contraction

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6
Q

List 3 causes of holosystolic murmurs.

A

VSD, mitral regurgitation, and tricuspid regurgitation

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7
Q

What is an ejection murmur?

A

Systolic murmur that does not start until after S1 (delay to the onset of ejection)

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8
Q

List 2 causes of ejection murmurs.

A

Aortic and pulmonic valve stenosis

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9
Q

What type of murmur is always pathologic?

A

Diastolic murmur

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10
Q

What causes a continuous murmur?

A

PDA

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11
Q

How are murmurs graded (intensity)?

A

I - faint and easily missed
II - obvious
III - loud
IV - associated with a thrill

(III and IV are likely pathologic and should be evaluated by a cardiologist)

(1/6 - faint, not heard in all positions, no thrill)
(2/6 - soft, heard in all positions, no thrill)
(3/6 - loud, no thrill)
(4/6 - loud with palpable thrill)
(5/6 - heard with stethoscope partially off chest, thrill)
(6/6 - heard with stethoscope off the chest - thrill)

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12
Q

Define hepatomegaly in infancy. What can cause a false impression of hepatomegaly?

A

Liver edge palpated >1 cm below the right costal margin; hyperexpansion of the lungs

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13
Q

DDx - hepatomegaly in infancy?

A

CHF, congenital infections, inborn errors of metabolism, anemias, and tumors (less commonly)

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14
Q

What are the classic findings of CHF in an infant a few weeks after birth?

A 
Dyspnea with feedings
Diaphoresis
Poor growth
Active precordium
Hepatomegaly
Tachycardia
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15
Q

Describe the pathogenesis of CHF in infants.

A

Inefficient circulation, whether due to poor cardiac function, increased myocardial demand, or shunt lesions (most common in infants) leads to adrenergic activation. This increases metabolic demands that contribute to poor weight gain, as well as diaphoresis with any activity, including feeding.

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16
Q

Which signs of CHF seen in adults are not frequently seen in children?

A

Rales, JVD, and peripheral edema

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17
Q

List the 4 heart defects that can present with a murmur and signs of CHF in infancy.

A
  1. VSD
  2. Severe aortic stenosis
  3. Coarctation of the aorta
  4. Large patent ductus arteriosus

(Most cyanotic heart defects present with cyanosis rather than progressive CHF)

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18
Q

How is CHF treated in infants?

A
  1. First line/most common: Furosemide (Lasix) - diuretic that counteracts the fluid retention caused by activation of RAAS.
  2. Digoxin: some studies show improvement in infants with CHF due to VSD (mechanism is unclear, as infants with VSD do not have impaired contractlity)
  3. Enalapril (ACEIs): reduces afterload to decrease systemic vascular resistance and promote forward flow of blood from the left ventricle rather than through the VSD to the pulmonary vasculature

These medications control symptoms and help the child grow - there are no medications to encourage closure of the VSD.

Consider fortifying expressed breast milk or formula to provide greater caloric density.

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19
Q

What is the most common cause of a murmur in children? Give a specific statistic.

A

Innocent murmur; occurs in 70-80% of otherwise healthy patients as some point during childhood, particularly between 3-7 years of age. It is by definition normal and is not due to any heart abnormality.

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20
Q

What is the most commonly heard innocent murmur? Describe its quality and location.

A

Still’s murmur; Musical or vibratory, heard best at LLSB or in supine position (low-pitched and louder)

(Usually found between 3-6 years, thought to be due to turbulence in LV outflow or vibration of fibrous tituse bands crossing LV lumen)
(Typically grade II-III, midsystolic, LLSB, vibratory, decreases with standing, increases with fever, exercise, anemia)

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21
Q

List important questions to consider when deciding if a murmur is innocent.

A

Is the child otherwise well?
Is the precordial activity normal?
Is the second heart sound normally split?
Is the murmur less than or equal to grade II/VI?Is the oxygen saturation normal?

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22
Q

Which structural heart defects may present later than infancy?

A

ASD (3-5 years of age)
Coarctation of the aorta (infancy or any age, as it tends to be progressive)
Bicuspid aortic valve

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23
Q

What are the findings of an ASD?

A

Systolic ejection murmur, widely split, fixed S2 (best way to distinguish from an innocent murmur)

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24
Q

What causes the systolic ejection murmur in an ASD?

A

Increased flow across a normal pulmonary valve

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25
Q

What are the findings of coarctation of the aorta?

A

Murmur (may present medial to the left scapula), hypertension in the upper extremities, discrepancy between upper and lower extremity blood pressures (poor femoral pulses)

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26
Q

What are the findings of a VSD?

A

Holosystolic murmur beginning with S1 with a blowing quality

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27
Q

What are the findings of aortic stenosis?

A

Systolic ejection murmur, radiating to the neck (occasionally a thrill in the jugular notch), with an early systolic click

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28
Q

What are the findings of pulmonic stenosis?

A

Prominent and harsh systolic ejection murmur just after S1, radiating to the lung fields, with an early systolic click

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29
Q

What are the findings of a PDA?

A

Continuous (a bit louder in systole) machine-like murmur, bounding pulses due to a widened pulse pressure

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30
Q

What are the findings of tetralogy of fallot?

A

Systolic ejection murmur radiating to the lung fields (RVOT obstruction)

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31
Q

What are the findings of a bicuspid aortic valve?

A

No murmur if the valve is not stenotic or regurgitant

Early systolic click made by the abnormal valve when it opens (shortly after the first heart sound)

Subtle exam finding

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32
Q

Congenital heart defects occur in approximately what percent of newborns?

A

1%

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33
Q

What are the leading cause of early mortality from congenital anomalies?

A

Congenital CV malformations

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34
Q

Isolated VSD accounts for what percent of all congenital heart defects?

A

15-20%

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35
Q

What are the 4 components of Tetralogy?

A
  1. VSD
  2. RVOT obstruction
  3. Overriding aorta
  4. RVH

Causes cyanosis through obstruction of the pulmonary artery and R to L shunting through the VSD; progressive, worsens over time

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36
Q

What is the most common heart defect presenting with cyanosis in the newborn period (despite having a lower overall incidence than Tetralogy)?

A

Transposition of the great vessels (requires urgent intervention)

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37
Q

List the 3 general methods for evaluating congenital heart defects.

A
  1. EKG
  2. CXR
  3. Echo
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38
Q

What is seen on EKG with congenital heart defects?

A

Abnormal EKG demonstrating chamber enlargement; findings not specific to a gien defect

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39
Q

What are the typical EKG findings in an infant with a large VSD?

A

Prominent, biventricular forces (high voltage QRS complexes in leads V1 and V2) suggesting both LV volume overload and RV pressure overload

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40
Q

Compare the classic findings on EKG of and large, moderate, and small VSD.

A

Large -
RVH due to RV pressure overload (pulmonary hypertension) + an upright T wave in V1 (another RVH sign)

Medium - LVH due to LV overload (VSD causes left-heart dilation by increased pulmonary blood flow returning to the left heart, VSD shunt occurs in systole when the right ventricle is also contracting. The right ventricle does not fill with the extra volume and dilate, as the VSD flow is immediately ejected into the pulmonary arteries)

Small - normal

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41
Q

True or false - interpreting the EKG in children and infants is complicated by the fact that the normal voltage is very age-dependent.

A

True; in general, newborns/young infants have a more right ventricular voltage and a more rightward axis (in fetal circulation, the lungs do not contribute to ventilation and the resultant pulmonary vascular resistance is elevated, leading to thickening of the right ventricle)

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42
Q

What is seen on CXR to evaluate heart defects?

A

Heart size and prominence of pulmonary vascular markings

Hallmark of L to R shunt - cardiomegaly, increased pulmonary vascular markings, pulmonary edema

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43
Q

When should children be admitted for congenital heart disease?

A

Children in shock
Severity of illness
Tempo with which the symptoms are evolving
Respiratory effort, lethargy/decreased level of alertness, feeding difficulty, cyanosis

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44
Q

Define a VSD.

A

Any persistent communication between the ventricles occurring in isolation or as part of a more complex defect

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45
Q

The ventricular septum is composed of what three distinct structures?

A
  1. Inlet septum (embryologic endocardial cushion)
  2. Outlet septum (embryologic conotruncus)
  3. Muscular septum (embryologic trabecular septum)
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46
Q

Describe the formation of a VSD.

A

The fusion point of the three structures of the ventricular septum is the membranous septum. VSDs occur due to either a lack of tissue (endocardial cushino defect resulting in an inlet VSD) or a lack of fusion at the septum (resulting in a perimembranous defect)

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47
Q

Describe the pathophysiology of a VSD.

A

L to R shunt during ventricular systole causes increased pulmonary blood flow, increased pulmonary venous return, and resultant left ventricular volume overload

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48
Q

When does VSD typically present?

A

Several days to weeks of age (related to the magnitude of the shunt, which is determined by the size of the defect and the pulmonary vascular resistance)

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49
Q

Prognosis of VSD?

A

Tend to diminish in size with time, spontaneous closure of ~75% of small defects and 25-50% of all defects

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50
Q

Why does the VSD murmur not present right away?

A

Newborns have elevated pulmonary vascular resistance. When this is nearly equal to the systemic vascular resistance, blood does not shunt through the VSD. When the pulmonary vascular resistance drops at a few days to weeks of age, this changes.

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51
Q

What is Eisenmenger’s syndrome?

A

Outcome of a patient with unrepaired VSd due to pulmonary vascular obstruction in response to high pressure and high flow. Shunting through the VSD will shift to R to L. The patient will develop cyanosis, progressing to polycythemia, heart failure, and death. Most patients live into their 20s but with a very impaired quality of life.

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52
Q

When does Eisenmenger’s syndrome develop?

A

After 6 months of age

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53
Q

When should VSD closure be performed?

A

Large defect + pulmonary hypertension, before 6 months of age

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54
Q

Qualities of an innocent vs. pathologic murmur

A

Innocent - systolic, ejection, soft/vibratory, grade 1-2/6, normal S1/S2, no extra sounds, louder supine

Pathologic - diastolic, holosystolic, harsh, 3+/6 grade, abnormal split S2, extra sounds (click), louder with standing

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55
Q

List 5 mechanisms of petechiae and purpura.

A
  1. Trauma
  2. Platelet deficiency or dysfunction (e.g., immune-mediated thrombocytopenia, bone marrow infiltration or suppression, malignancy)
  3. Coagulation abnormalities (e.g. hereditary or acquired clotting-factor deficiencies)
  4. Vascular fragility (e.g., immune-mediated vasculitis)
  5. Combinations of the above (e.g., infection causing coagulation abnormalities, vascular fragility, platelet consumption_)
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56
Q

DDx - bruising and leg pain (9)

A
  1. Coagulation disorder
  2. Henoch-Schnolein purpura (HSP)
  3. Idiopathic thrombocytopenic purpura (ITP)
  4. Leukemia
  5. Viral infection
  6. Bacterial endocarditis
  7. Meningococcal septicemia
  8. Rocky Mountain spotted fever (RMSF)
  9. Systemic lupus erythematosus (SLE)
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57
Q

How does a coagulation disorder present?

A

May present with petechiae or superficial bruising, but more often presents with easy bruising in deep tissues or hemarthrosis (painful bleeding into joints)

Family history and/or personal history of bleeding (e.g., after trauma, immunizations, circumcision, dental work)

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58
Q

How are bleeding disorders (hemophilias, von Willebrand’s disease) characterized?

A

Easy bruising in response to minor trauma. Spontaneous superficial bruising is less common

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59
Q

What is HSP (aka anaphlyactoid purpura)?

A

Self-limited Ig-A mediated, small vessel vasculitis that typically involves the skin, GI tract, joints, and kidneys

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60
Q

How does HSP present?

A

Hallmark: non-thrombocytopenic purpura; rash tends to involve lower extremities

“Otherwise well-appearing child with bruising and leg pain)

1/3 of children have renal involvement (typically hematuria), less common <2 years

Arthritis or arthralgia due to periarticular vasculitis (mainly of knees and ankles) in 75% of children

Colicky abdominal pain in 65%, 50% may develop intestinal bleeding

Recent URI (66%)

NOT associated with splenomegaly

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61
Q

How does ITP present?

A

Often with asymptomatic, thrombocytopenic purpura and petechiae, non-specific URI preceding >50% of the time

NOT associated with splenomegaly

62
Q

How does leukemia present?

A

Constitutional symptoms such as fever, malaise, and weight loss

Bone pain is also common in children resulting from infiltration of the bone marrow by the malignant cell

Petechiae can be caused by thrombocytopenia due to bone marrow replacement by malignant cells

Splenomegaly and lymphadenopathy

63
Q

How does viral infection present when causing a petechiael rash?

A

Some viruses such as enteroviruses may present with a petechial rash

Children usually have a low-grade fever

Other constitutional complains may be present or absent

Prominent coughing and/or vomiting can also cause petechiae, generally above the nipple line

64
Q

How does bacterial endocarditis present?

A

Fever (usually present but may be low-grade), fatigue, weight loss, petechial rash

Bruising is not characteristic

65
Q

How does meningococcal septicemia present?

A

Petechiae and purpura

While the early stages may have only mild symptoms, by the time the hemorrhagic rash appears, patients are usually very ill appearing and require emergent care

Fever is usually present

66
Q

How does RMSF present?

A

Rash is often petechial, starts on the extremities before moving centrally

Fever is a hallmark

67
Q

How does SLE present?

A

Variable rash
More common in older children and in girls
Often presents with constitutional symptoms such as fever and malaise

68
Q

Lab evaluation of suspected HSP?

A
  1. Platelet count (non-thrombocytopenic [HSP] vs. thrombocytopenic [ITP or leukemia] purpura)
  2. Urinarlysis (determine if renal involvement via hematuria/proteinuria)
  3. BUN/Cr (if hematuria or proteinuria is present, needed to determine extent of renal disease)
69
Q

What is the most commonly diagnosed form of vasculitis in children? M vs. F?

A

HSP (~50% of cases)

M>F

70
Q

Hallmark of HSP?

A

Non-thrombocytopenia purpura

71
Q

Pathologic finding in HSP?

A

Leukocytoclastic vasculitis with IgA deposition

72
Q

Complications of HSP?

A

~5% progress to chronic renal failure. Fewer than 1% will develop ESRD.

Although considered a benign childhood disease, it occasionally requires hospitalization for management of severe abdominal pain, GI bleeding, intussusception, and renal involvement

73
Q

Treatment of HSP?

A

Systematic reviews have not demonstrated a consistent benefit for corticosteroids in preventing serious renal involvement

Early corticosteroids in hospitalized children may confer benefits in reducing GI manifestations

74
Q

Pathophysiology of ITP?

A

Caused by the binding of an antiplatelet antibody to the platelet surface, leading to removal and destruction of platelets in the spleen an dliver

75
Q

Most common cause of isolated thrombocytopenia in otherwise healthy children?

A

ITP

76
Q

ITP vs. HSP - epidemiology (M vs. F, peak incidence age, # annually)

A

ITP: M=F, 2-5 years (range 2-10 years), ~5/100,000

HSP: M>F (2:1), 4-6 years (range 2-17 years), ~10/100,000

77
Q

ITP vs. HSP - pathophysiology and history of URI?

A

ITP: anti-platelet antibody binds to platelet surface leading to removal and destruction of platelets in the spleen and liver; most cases follow a non-specific viral illness

HSP: underlying mechanism unknown; suspected to represent an Ig-A dominated immune response to infection or other triggers. 50% of cases follow viral/bacterial URIs

78
Q

Clinical features of ITP vs. HSP

A

ITP: superficial bleeding into the skin (petechiae and bruising), some have evidence of mucosal bleeding; other symptoms/physical findings are generally absent. No HSM on exam.

HSP: skin lesions begin as erythmatous macules or urticarial wheals that evolve into petechiae and palpable purpura. Rash is symmetrically distributed in gravity-dependent o pressure-sensitive areas (lower extremities, elbows), young patients more likely to have involvement of face/upper extremities, colicky diffuse or periumbilical abdominal pain (50-75%), arthritis/arthralgia (40-75%), renal disease (20-50%)

79
Q

ITP vs. HSP - lab findings

A

ITP - thrombocytopenia (usually <20k) with normal WBC and HgB

HSP - normal platelet count; may have hematuria/proteinuria/affected BUN/Cr, may have blood in stool, coagulation studies should be normal

80
Q

ITP vs. HSP - natural history

A

ITP: most do not have significant bleeding (3% have severe epistaxis or other mucous membrane hemorrhage), most concerning complication is intracranial hemorrhage (0.1-0.5% of cases)

HSP: all will eventually have skin findings, abdominal pain/joint involvement may precede the rash, recurrence rate is about 30% (symptoms may return weeks to many months after the first episode)

81
Q

ITP vs. HSP - Rx

A

ITP - observation, oral corticosteroids, IVIg, Rhogam

HSP - no specific therapy, supportive care for symptoms of arthralgia or stomach pain, observation for complications

82
Q

Define shock.

A

Inadequate delivery of substrates and oxygen to meet the metabolic needs of tissues.

83
Q

Describe the pathophysiology of shock.

A

As cells are starved of oxygen and substrate, they can no longer sustain metabolism. Eventually, cellular metabolism is no longer able to generate enough energy to power the components of cellular homeostasis, leading to disruption of cell-membrane ionic pumps. The cell swells, the cell membrane breaks down, and cell death occurs.

84
Q

Describe the compensatory mechanisms of shock in children.

A

Children can maintain a normal BP until they are in profound shock. They have excellent compensatory mechanisms to maintain tissue perfusion that include:

  • Tachycardia - because CO is dependent on both SV and HR, the body tries to maintain CO when SV decreases by increasing HR
  • Increased heart contractility - results in more complete emptying of ventricles
  • Increased venous tones - results in more blood return to the heart
  • Tachypnea - attempts to compensate for the metabolic acidosis caused by decreased oxygen perfusion of the tissues and cells

Therefore in early shock you will find the following: elevated HR and RR, peripheral blood vessel constriction (cool, clammy extremities and delayed capillary refill time), and decreased peripheral pulses (due to vasoconstriction and decreased SV). This can lead to difficulty obtaining a pulse ox measurement.

85
Q

Because children compensate so well in early shock ___ is a late sign of shock.

A

Hypotension

86
Q

List the 4 types of shock.

A
  1. Distributive (includes neurogenic and anaphylactic, some authors include septic in this category as well)
  2. Hypovolemic
  3. Cardiogenic
  4. Septic
87
Q

What causes distributive shock?

A

Intravascular hypovolemia from vasodilation, increased capillary permeability, and third-space fluid losses

88
Q

What is the most common type of shock worldwide?

A

Hypovolemic

89
Q

What causes hypovolemic shock?

A

Inadequate fluid intake to compensate for fluid output (e.g., vomiting, diarrhea, hemorrhage)

90
Q

What causes cardiogenic shock in children (albeit rare)?

A

Severe congenital heart disease, dysrhythmias, cardiomyopathy, and tamponade

91
Q

What causes septic shock?

A

Results when infectious organisms release toxins that affect fluid distribution and cardiac output

92
Q

How do patients in septic shock present?

A

Compensated or “warm” shock, with warm extremities, bounding pulses, tachycardia, tachypnea, adequate urination, mild metabolic acidosis

(second most common cause in children)

93
Q

What is the primary consideration in managing shock?

A

Maintaining perfusion - intravascular volume replacement is the priority

94
Q

How should fluid replacement be administered in shock?

A

Isotonic solutions, NOT hypotonic solutions, rate of infusion as fast as possible, even in patients who have a relative contraindication, such as patients with meningitis

General guidelines recommend giving repeated boluses of isotonic fluids up to a total of 60 mL/kg, then starting inotropic support (e.g. with dopamine) if perfusion remains inadequate

95
Q

What is the ideal approach to vascular access in managing a patient in shock?

A

Place the largest bore catheter possible in the largest, most accessible vein. Peripheral venous access is always the first attempt.

96
Q

In an adolescent or adult patient, placement of a ___ line would be appropriate if peripheral access cannot be established. List common options.

A

Central venous; femoral, subclavian, or internal jugular

97
Q

In shock, if a peripheral IV line cannot be placed within 90 seconds, what is the fastest way to get access?

A

Intraosseous line inserted into the marrow cavity of a long bone

98
Q

What technique is often used as a last resort if peripheral venous access, central venous access, and intraosseous access are unavailable or unsuccessful?

A

Venous cutdown technique on the saphenous vein

99
Q

Why does infusion by IO work?

A

IO infusion is possible because the veins that drain the medullary sinuses in the bone marrow do not collapse in children with shock or hypovolemia.

100
Q

Blood draining from the bone marrow of the tibia enters the general circulation via the ___ vein, and branches of the ___ vein drain the medullary sinuses of the distal femur.

A

Popliteal; femoral

101
Q

Discuss the pathophysiology of sickle cell disease.

A

Mutation: substitution of valine for glutamic acid at the 6th amino acid position of the Hgb molecule

Leads to the formation of polymers of Hgb when Hgb becomes deoxygenated

These polymers lead to deformation of the RBC into sickle cells, which have increased adherence and block blood flow in the microvasculature, which leads to local tissue hypoxia, pain, and tissue damage.

Abnormal Hgb induces hemolysis of the RBCs leading to chronic anemia with an elevation of the reticulocyte count

102
Q

Predominant hemoglobin at birth?

A

Hemoglobin F (fetal)

103
Q

What always appears first in hemoglobin nomenclature of the newborn?

A

F (predominant), followed by other Hgb in order of concentration

104
Q

What is Hgb FA?

A

Fetal + normal adult

105
Q

What is Hgb FAS?

A

Baby is a carrier of one abnormal hemoglobin gene (S) -> benign sickle cell trait

106
Q

What is Hgb FAC?

A

Baby is a carrier of one abnormal hemoglobin g (C) -> benign hemoglobin C trait

107
Q

What is Hgb FS?

A

Both of the baby’s hemoglobin genes have mutations for Hgb S

108
Q

What is the most common hemoglobin pattern causing SCD?

A

FS

109
Q

What is Hgb FSA?

A

Sickle cell beta thalassemia, meaning one of the globin genes has a mutation for S and the other has a mutation for beta thalassemia (which produces no or little hemoglobin)

110
Q

What is Hgb FSC?

A

Sickle cell hemoglobin C disease - one gene has the S mutation, one gene has the C mutation

111
Q

List 2 common procedures for young individuals with SCD.

A
  1. Tonsillectomy

2. Cholecystectomy

112
Q

Why is a tonsillectomy common in SCD?

A

Lymphoidal-tissue hypertrophy involving Waldeyer’s ring is common in children with SCD, possibly related to desaturation of hemoglobin and increased risk of sickling. Excessive snoring and OSA may be observed.

Tonsillectomy with adenoidectomy will improve OSA in most patients.

113
Q

Why is a cholecystectomy common in SCD?

A

Bilirubin gallstones occur frequently in all patients with hemolytic anemias, including SCD due to the increased release of Hgb during breakdown of abnormal RBCs.

114
Q

Who should have a cholecystectomy in the setting of SCD?

A

Patients who are symptomatic, NOT patients who have evidence of gallstones on screening U/S

115
Q

Why is penicillin given to children until ages 5-6 with SCD prophylactically?

A

To prevent infections that can lead to sepsis (decreases risk of mortality from overwhelming sepsis)

116
Q

Why are children with SCD at greatly increased risk for sepsis?

A

Decreased splenic function leads to decreased resistance to infection with encapsulated organisms (S. pneumoniae, Hib, N. meningitidis)

117
Q

List the goals for the comprehensive visit for SCD.

A
  1. How the family deals with the various complications that can occur
  2. Frequency of painful or other vaso-occulsive problems
  3. How the family accesses health care
  4. How the family is dealing with a chronic illness
118
Q

List # expected complications for children with SCD.

A
  1. Jaundice (hemolysis)
  2. Anemia (can cause some fatigue, can sometimes be more severe due to myelosuppression from infections such as parvovirus or from hypersplenism when the spleen enlarges and traps blodo cells)
  3. Stroke (increased risk, 10% by the age of 15 years)
  4. Respiratory problems (lungs are a site of occasional sickling problems, can have pneumonia because of increased tendency to infection or acute chest syndrome as a result of vaso-occlusion in the lung parenchyma)
119
Q

Rx - acute chest syndrome

A

Medical emergency requiring supplemental oxygen and transfusion therapy

120
Q

What is a useful screening tool for predicting the risk of SCD patients for stroke?

A

Transcranial doppler studies to evaluate cerebral blood flow (recommendd in children 2-15 years)

121
Q

Immunization recommendations for children with SCD?

A

Hib and 13-valent pneumococcal conjugate vaccine (Prevnar 13) - 2, 4, and 6 months

23-valent pneumococcal polysaccharide vaccine - 2 and 5 years

Meningococcal conjugate at 2 years, booster 3-5 years later

Influenza annually

122
Q

Why are vaccine conjugated for infants?

A

Children under 2 years have a suboptimal immune response to purely polysaccharide vaccines. Conjugation allows better antibody production.

123
Q

Sickle cell gene mutation gene frequency among African Americans living in the US?

A

7-10%

124
Q

Inheritance pattern of SCD?

A

AR

125
Q

Impairment of growth is common in children in SCD. Why?

A

Combination of chronic anemia, poor nutrition, painful crises, endocrine dysfunction, poor pulmonary function

126
Q

Important signs in the physical exam in a patient with SCD?

A
  1. Splenic enlargement (common during first few years of life, becomes progressively fibrotic, by 4-6 years, no longer palpable)
  2. Sclera (icterus?03
  3. Neurologic exam (signs of potential stroke)
127
Q

Massive enlargement or rapid change in size of the spleen can indicate what?

A

Splenic sequestration crisis - life-threatening complication that occurs when blood pools in the spleen, leading to severe anemia and shock

128
Q

Baseline Hgb in SCD?

A

Children with SCD frequently have baseline Hgb between 6-9 g/dL

129
Q

List reasons to seek emergency care for a patient with SCD.

A
  1. Fever (medical emergency, sometimes the only sign of serious infection)
  2. Splenic enlargement (sequestration crisis)
  3. Slurred speech (stroke, exchange transfusion may be indicated)
  4. Chest pain (+tachypnea - acute chest syndrome)
  5. Rapid breathing (ACS)
  6. Increased pallor (anemia, non-emergent unless with signs of splenic sequestration, increased hemolysis, etc.)
  7. increased jaundice (baseline jaundice is typical, marked increase indicates increased hemolysis and need for transfusion)
  8. Priapasm (sickling in penile arteries)
130
Q

What is an aplastic crisis?

A

Temporary inhibition of erythryoid production frequently associated with viral illness, particularly Parvovirus B19

131
Q

In a child with sickle cell anemia, cough and breathing difficulty may indicate?

A

Pneumonia
Intrapulmonary sickling
Pulmonary fat embolism

All = ACS

132
Q

In ACS, what three problems must be addressed rapidly and appropriately?

A

Possible infection
Pulmonary/respiratory complaints
Pain

133
Q

DDx - Fever, Respiratory Distress, and Chest Pain in a child with SCD

A
  1. ACS
  2. Pericarditis
  3. CHF
  4. Rib infarction
  5. Sepsis
134
Q

What is one of the most common causes of death in patients with SCD?

A

ACS

135
Q

Clinical features of ACS?

A

Fever, cough, chest pain (can lead to difficulty with expansion of the lower lung and result in atelectasis), SOB, decreased oxygenation

136
Q

Clinical features of pericarditis?

A

Tachypnea and fever

Uncommonly causes chest pain

137
Q

Clinical features of CHF?

A

Can occur in patients with SCD and chronic anemia

Tachypnea (common sign)
Usually does not cause chest pain on its own

138
Q

CXR findings of ACS

A

Findings may be due either to fat embolism or to vaso-occlusion of pulmonary vasculature

Include multilobular infiltrates (more commonly lower and middle), effusions, atelectasis

It is always difficult to distinguish whether an infiltrate represents an infectoius process or atelectasis from infarction/pulmonary fat embolusm

139
Q

CXR findings of pericarditis

A

Effusion and infiltrate

140
Q

CXR findings of CHF

A

Lower lobe infiltrates and cardiomegaly

141
Q

CXR findings of rib infarction

A

No pulmonary infiltrate, pleural effusion is possibe

142
Q

CXR findings of sepsis

A

Cardiomegaly only if patient in cardiogenic shock (cardiomegaly may be patient’s baseline)

143
Q

Patients with SCD frequently demonstrate what CBC findings in response to stress?

A

Exaggerated eukocytosis and thrombocytosis

144
Q

Rx - painful crises +/- fever or pulmunary event

A

IV fluids, NSAIDs, IV narcotics

145
Q

Hydration of children with SCD?

A

Vigorously hydrate children with SCD because dehydration may contribute to intracellular Hgb polymerization and RBC sickling

With ACS, however, we must be careful to avoid being too vigorous and cause pulmonary edema

146
Q

What is atelectais?

A

A collapsed or airless segment of lung due to obstruction with distal collapse of the alveoli

147
Q

What is a serious risk in a child with chest pain?

A

Atelectasis

148
Q

How can atelectasis be prevented?

A

Encourage deep breathing, often through the use of assistive devices like an incentive spirometer

149
Q

Rx ACS?

A

RBC transfusion is the only way to directly reduce or reverse the sickling process causing the ACS

150
Q

When is RBC transfusion recommended in ACS?

A 
Fall in Hgb from baseline
Increasing RR
Worsening chest symptoms
Declining O2 sats
Progressive infiltrates on CXR
151
Q

What is the only known curative therapy for SCD?

A

HSC transplantation

Pediatrics Clerkship (14 decks)

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