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SPRING16 N833 Adv Pedi > Labs (Quiz 2) > Flashcards

Flashcards in Labs (Quiz 2) Deck (43):
1

Examples of universal and selected screenings a different ages throughout childhood

Newborn:

  • ID genetic, metabolic, developmental issues via blood on filter paper (HRSA recommends 30 dos, all states do at least 21, some >30)
    • newest NBS is for critical congenital heart disease (pulse oximetry and pulse)
  • Hearing screening in 43 states + PR and DC

IDA: 12 mo Hgb screening

2

Rationale for newborn screening

Testing, Tracking, Treating

 

3

Role of APRN in newborn screening

  • Educate parents during pregnancy
  • f/u abnl results asap - locate baby
  • if +, arrange f/u w/appropriate specialists (use ACT sheets)
  • Continue f/u and support in PC
    • complete medical hx
    • Signs illness (GI, cardiac, neuro)
    • Dvptl/neuro f/u
  • Continue care w/specialists
  • Reassure; stress importance of adherence

4

Available tools for newborn screening

  • National Newborn Screening and Genetics Resource Center: comprehensive source of info
  • American College of Medical Genetics
    • Includes "ACT" sheets (ACTion) - info for providers what to do if screen +, specialists
      • immediate steps for + newborn screening: family contact, specialist, evaluation, confirmatory testing, tx, education, algorithm including BW results
  • March of Dimes: consumer friendly reading, video about screening

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5

Types of hyperbilirubinemia

Bilirubin is product of RBC breakdown.

  • unconjugated (indirect) bilirubin: 2/2 abnormality of bilirubin metabolism / excretion (physiologic jaundice of newborn) (our focus)
  • conjugated (direct) bilirubin: sugars are attached to bilirubin, 2/2 biliary obstruction/cholestasis (hepatitis, pancreatitis, biliary atresia, sepsis)

6

What are breast milk jaundice and breastfeeding failure jaundice?

How are they managed?

  • Breast milk jaundice: 
    • = physiologic jaundice > 1 week of age
    • Presents 3-5 days of life, peaks 2 weeks of age, declines 3-12 weeks
    • Usually total bili >5mg/dL, but generally mild and does not require intervention >> monitor for increases
  • Breastfeeding failure jaundice
    • sub-optimal breastfeeding >> inadequate intake >> decreased stools
    • First 7 days of life
    • Results in excessive weight and fluid loss and decreased bili elimination
    • Prevention: breastfeed 8-12x/day

**if babies have jaundice that require intervention -- phototherapy, bili blanket, blood exchange transfusion

7

Causes of unconjugated hyperbilirubinemia

  • Hemolysis: blood group incompatabilit, infection, hemoglobinopathies, RBC enzyme defects, RBC membrane DOs...
  • No hemolysis: breast milk jaundice, infant of mother w/DM, internal hemorrhage, physiologic jaundice, polycythemia, hypothyroidism, Gilbert syndrome, pyloric stenosis...

8

Clinical sx of hyperbilirubinemia 

  • Simple jaundice: bili >5-6 mg/dL, skin yellow (60% of newborns in 1st wk, cranial-caudal progression, best seen in periphery of conjunctivae and in oral mm (under tongue, hard palate))
    • may have some sleepiness, feeding difficulty
  • Acute bilirubin encephalopathy: as above+ lethargy, hypotonia, poor suck
    • may have irritability, hypertonia, high pitched cry, fever, seizures
  • Kernicterus: above + athetoid cerebral palsy, hearing loss, gase palsies, dental enamel hypoplasia 
    • TB >20 and ≤25 mg/dL  – Risk of kernicterus usually only in conjunction with a co-morbid condition
    • ●TB >25 and ≤30 mg/dL – 6 percent
    • ●TB >30 and ≤35 mg/dL  – 14 to 25 percent
    • ●TB >35 mg/dL  – Almost all infants will have signs of kernicterus

9

Bilirubin: nl range, when increased risk for kernicterus, nl peak

  • Bilirubin
    • Elevated > 2.5-3mg/dL
    • Increased risk for kernicterus > 20mg/dL
    • Bilirubin peaks at age 3-5days (5-7days if premature; also later in Asian infants)
    • Mean peak total serum bilirubin is 6mg/dL (higher in Asian infants)

10

Transcutaneous vs serum bili

  • Transcutaneous:
    • Advantages: used as screening tool in newborns; no blood lab needed
    • Disadvantages: TcB does not distinguish between conjugated + unconjugated; levels may be affected by skin pigmentation
    • Follow up with serum TB if TcB >95th percentile OR TcB > 13mg/dL
  • Serum:
    • Total and direct bilirubin levels
    • Used to confirm TcB values if questioning validity of TcB
    • Used if infant undergoing phototherapy
    • Consider cholestasis if conjugate bilirubin >1mg/dL + TB <5mg/dL

* Interpret all levels according to baby’s age in hours

11

Other labs that may be useful in assessing hyperbilirubinemia

  • CBC (for H/H)
  •  Low hemoglobin may indicate hemolysis
  • Peripheral blood smear (for RBC morphology)
  • Hemolysis can be confirmed by presence of fragmented cells in smear
  • Reticulocyte count
  • Rising reticulocyte count is consistent with RBC destruction
  • Coomb’s test
  • Comparison of mother and infant’s blood type to see if there’s a possibility of isoimmune hemolytic disease (mother’s antibodies destroy newborn’s RBC)
  • G6PD measurement
  • If either parent is Mediterranean, Nigerian or East Asian OR
  • If TB > 18/mg/dL

12

Risk factors for hyperbilirubinemia 

major, minor, reduced

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13

What tool is available to determine phototherapy needs, how is it used?

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14

When to send to the hospital for hyperbilirubinemia?

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15

Components of a CBC

16

RBC indices 

(not #s)

17

Macro / micro / normo cytic anemias

  • Microcytic anemia: MCV low
    • e.g. IDA - universal screening at 12mo but still high prevalence, 9% ado females have IDA (no universal screening). Risks: premature, BF w/o iron supp after 6mo, hispanic, lead exposure, heavy menses, cow's milk before 12mo
  • Macrocytic anemia: MCV high
  • Normocytic anemia: MCV nl

18

von Willebrand Disease (vWD): what is it?

  • most common inherited bleeding DO (1% of population)
  • autosomal inheritance (M-F equally affected)
  • VWF carries clotting protein factor VIII
  • Many types: Type 1 is most common and mildest

19

VWD: important history and exam findings?

  • History:
    • Easy bruising
    • Bruising in unusual locations
    • Abnormal menstrual bleeding
    • Bleeding in mucous membranes (gums, nose, GI tract)
    • Prolonged nose bleeds (>10 mins)
    • Excessive or prolonged bleeding at dentist, post-op
    • If severe vWD, presentation is early (i.e., circumcision)
  • On exam:
    • Large bruising on trunk and anterior chest
    • Otherwise well-appearing

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20

Initial Lab diagnostics for VWD

  • CBC w/diff: nl, no abnormality in PLTs
  • PT: nl
  • aPTT: nl

Then you try VWD screening

  • plasma von Willebrand factor antigen: Low
  • Plasma VWF activity (rostocetin cofactor activity, VWF collagen binding): both low
  • Factor VIII activity: low or nl

 

21

MGMT / referral for VWD

If none of the screenings for VWD are abnormal, refer for selected specialized VWD studies / hematological evaluation

Tx: DDAVP often effective

22

Description and function of platelets

a.k.a. thrombocytes

Role of platelets is to prevent bleeding

23

Disorder associated with decreased platelets

characteristics

Idiopathic thrombocytopenic purpura

  • Most common acquired bleeding disorder
  • Immune-mediated destruction of platelets (plt < 100K) in otherwise nl CBC
  • Slight predominance boys > girls
  • Peak incidence between 2 and 5 yo, but can present at any age
  • In about 60% of pediatric cases, there is a history of prior infection within the past month
  • In 80% of  pediatric cases, ITP resolves without treatment, usually within 6 months

24

Differentials

non-blanching rash

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  • Vascular dysfunction (vasculitis): Henoch Schonlein Purpura, Kawasaki disease
  • Blood clotting disorder: hyper/hypo coagulable states: hemophilia
  • Idiopathic thrombocytopenic  purpura
  • Long term steroid tx
  • Hemangioma
  • meningococcemia
  • Rocky mountain spotted fever
  • DIC
  • Leukemia

25

WBCs: types of cells and roles of each

  • Neutrophils ( bands)  53%: infection, bacteria
  • Lymphocytes 36%: Abs, immunity
  • Monocytes 9%: phagocytosis
  • Eosinophils 2%: parasites, allergies, neoplasms
  • Basophils: immune function, release heparin and histamine

26

What is indicated by a high or low WBC?

  • high wbcs: infection, maybe HSP (if following infxn)
  • Low wbcs: bone marrow failure or infiltration (leukemia, lymphoma, hemophagocytic lymphohistiocytosis)

27

Risk factors for lead expsure

  • Paint in homes built before 1978.
  • Water pumped through leaded pipes.
  • Imported items including clay pots.
  • Certain consumer products
  • Candies,  make -up jewelry.
  • Certain imported home remedies.
  • <6yo, living below poverty level
  • some racial and ethnic groups

28

Effects of lead exposure

  • CNS
    • Development
    • lower IQ
    • ADHD
    • Seizures
    • Headaches
    • Increased ICP
  • GI-
    • constipation
    • vomiting
    • abdominal pain
    • anorexia
  • HEME- anemia

29

Clinical Presentation of lead exposure

  • Low concentrations
    • Vomiting
    • Cognitive impairment
    • Language delay
    • Hearing loss
    • Behavior problems
  • Higher concentrations
    • Colicky abdominal pain
    • Anemia
    • Intellectual disability
    • Seizures
    • Renal insufficiency
    •  Encephalopathy

30

Recommended screening for lead exposure

  • capillary sample: Routine 12 and 24 mo
  • Continue after 2yo if RFs! 
  • Venous sample: > 5 mcg/dL is positive

31

Current values and classifications regarding lead exposure

32

MGMT/Tx of lead exposure

  • Mild: <44 mcg/dL
    • <5mcg - check at least yearly, maybe more
    • 5-14 mg - recheck in 1mo, 3 mo, education
    • 15-19 mcg - 1 mo, 2mo, educate
    • 20-44 mcg - report to public health, recheck, educate, no chelation
  • Moderate: 45-69
    • admission, chelation w/toxicologist (po or IV), check BLL until <45, Q3mo check
  • Severe: >70
    • emergency admission, signs of encephalopathy?, check until <45, Q2-3mo check

33

Components of a CMP

  • Glucose
  • BUN
  • Creatinine
  • Sodium
  • Potassium
  • Chloride
  • Carbon Dioxide
  • Calcium
  • Protein
  • Albumin
  • Bilirubin, total
  • Alk phosph
  • AST
  • ALT

34

Examples of pedi conditions for which you would order a cmp and what you might find

LIVER

 

  • To evaluate LIVER FUNCTION e.g., if jaundice, HSM, obesity, suspect hepatitis, OD, malnutrition, Wilson Dz, abd pain w/alarm findings, etc.
    • cholestasis / obstructive bile duct injury: increased alk phos, conj bili, (GGT)
    • viral or toxic insult to liver cells: increased ALT, AST, (LDH)
    • NAFLD: increased ALT, AST, Alk phos, (GGT)
    • Malnutrition: labs generally not indicated unless FTT - decreased albumin, total protein, (prealbumin)
    • Wilson's: increased total bili, ast > alt, alk phos may be low, may see damage to liver fx (decreased albumin, increased PT)

35

Examples of pedi conditions for which you would order a cmp and what you might find

kidney function

  • Usually BMP (CHEM 7) is sufficient in evaluating renal function
  • conditions
    • AKI (prerenal, intrinsic, postrenal): order cmp/bmp if s/s e.g., edema, decreased/no UO, gross and microscopic hematuria, HTN
    • CKD: often 2/2 congenital abnormalities (routine UA no longer recommended). May notice subtle signs, polyuria, poor growth, 2 positive albumin on UA

36

Examples of pedi conditions for which you would order a cmp and what you might find

  • Suspect impaired liver or kidney function
  • Abdominal/GI alarm symptoms
  • Medication monitoring

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37

How to interpret CMP changes: chart

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38

Difference between ESR and CRP

  • Both commonly used to measure inflammation - nonspecific, but simple and cost effective to distinguish from non-inflammatory
  • CRP: acute phase protein, produced by hepatocytes, triggered by cytokine production. Begins to rise 4-6h after inflammatory stimulus, peaks 48-72h, rapid decline w/tx. May indicate minor inflammation to CTD
  • ESR: rate at which RBCs sediment in 1hr. indirect measure of acute phase reactants. Dependent on ability of RBCs to aggregate. Can be affected by RBC size, shape and number, technical factors (unrelated to inflammation), less valuable in assessing acute changes - can be 2/2 events from weeks to months prior.

39

Indications for ordering ESR or CRP

  • Non-specific. Useful to distinguish between inflammatory and non-inflammatory DOs

40

What are thyroid indices?

commonly TSH, Free T4, T3

41

PE / lab findings suggestive of hyperthyroidism

  • Enlarged thyroid on exam
  • hyperactivity
  • unintentional weight loss
  • unexplained tachycardia
  • heat intolerance
  • declining school performance
  • order labs if >1 sx

Expected Labs: Low TSH, High free T4

42

PE / lab findings suggestive of hypothyroidism

  • enlarged thyroid on exam
  • new onset fatigue
  • cold intolerance
  • acquired growth failure
  • constipation, dry skin

Expected Labs: high TSH, low free T4

43

Is thyroid testing useful in obesity?

  • no - low yield unless concomitant slow linear growth
    • even severe hypothyroid causes minimal wt gain (5-10 lbs) which is mainly water not fat
  • Other low yield conditions for ordering thyroid studies: mild short stature  (3-10%ile) w/nl growth rate, infants w/FTT (poor wt gain), FH thyroid dz w/no sx in child, menstrual abnl, hyperactivity alone