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AP Exam 4 (UPenn) > Lab Values > Flashcards

Flashcards in Lab Values Deck (36):
1

TSH

1T: 0.1-4.4 (TSH production starts @ 12wk)
2T: 0.4-5.0
3T: 0.23-4.4
Term: 0.0-5.3

(TSH > ~5.3 = ABNORMAL)
*high TSH --> hypothyroidism?

2

Free T4

1T: 0.7-1.58 (T4 peaks at 12 wks)
2T: 0.4-1.4
3T: 0.3-1.3
Term: 0.3-1.3

*hyper vs. hypothyroidism,
subclinical hyperthyroidism

3

Total T4

1T: 3.6-9.0
2T: 4.0-8.9
3T: 3.6-8.6
Term: 3.9-8.3

4

Free T3

1T: 2.3-4.4
2T: 2.2-4.2
3T: 2.1-3.7
Term: 2.1-3.5

5

Total T3

1T: 71-175
2T: 84-195
3T: 97-182
Term: 84-214

6

Urine testing in pregnancy

Urine culture - dx & treat asymptomatic bacteuria

7

B-hCG normal ranges in 1st tri

- Can be detected in blood and urine 7-10 days after fertilization
- Doubles q2 days in 1T
- Peaks at 9-10 weeks
- Declines to nadir @ ~16-20 wks

1 wk: 5-50 IU/L
2 wks: 50-500
3 wks: 100-10,000
4 wks: 1,080-30,000
[discriminatory zone: ~5.5 wks, 1,500-2,000)
6-8 wks: 3,500-115,000
[9-10 wks PEAKS]
12wks: 12,000-270,000
13-16wks: up to 200,000

8

hCG patterns for multiples, ectopic, SAB

SAB
- hCG <1500 IU/mL + gestational sac

-Ectopic
- >1500-2000, absent gestational sac

SAB & ectopic
Will fall or plateau, fails to reach 50% increase in 48 hrs

Abnormally high plasma hCG
- multiples
- erythroblastosis fetalis (associated with hemolytic anemia)
- gestational trophoblastic disease
- down syndrome

9

Screening for blood type and irregular antibodies

-Type and screen
-Indirect coombs test: mixing maternal serum w/ standard reagent that carries antigens --> +/- rxn w/ clinical significant. Unbound antibodies identified. only IgG abs are concerning, as IgM abs do not cross the placenta.

10

Rh-D negative management

-Rhogam (anti-D immune globulin) @ 28 weeks and 72 hrs after delivery
- Rhogam for anyone with risk of hemorrhage/bleeding
-prevents alloimmunization, which would cause increased risk of hemolytic disease to new born, hydrops.

11

WBC ranges

WBC
1T: 3.9-13.8
2T: 4.5-14.8
3T: 5.3-16.9
Term: 4.2-22.2

*Infection? think causes: respiratory, UTI/pyelo, VS, infectious diseases, etc.

12

Hgb & Platelet

PLATELET COUNTS
1T: 149-433
2T: 135-391
3T: 121-429
Term: 121-397

HgB / HCT
1T: 11.0-14.3 / 33-41
2T: 10.5-13.7 / 32-38
3T: 11.0-13.8 / 33-40
Term: 11.0-14.6 / 33-42

*Anemia -- think MCVs, iron/ferritin, folate/B12 deficiencies, genetics for differentials

13

Iron and Ferritin normal ranges

Ferritin (ferriTEN) <10 = low

Iron <40 = low

*Iron deficiency anemia? Dx: Low hgb w/ serum ferritin <12

14

Folate and B12

Folate
1T: 2.3-39.3
2T: 2.6-15
3T: 1.6-40.2
Term 1.7-19.3

B12 LOW
1T <118
2T: <130
3T: <99

*folate deficiency? B12 deficiency? -- also see CBC for macrocytic anemia

15

Albumin

Serum albumin decreases 0.5g/dL during 1st tri and by 0.75g/dL by term

1T: 3.2-4.7
2T: 2.7-4.2
3T: 2.3-4.2
Term: 2.4-3.9

16

Uric Acid

1T: 1.3-4.2
2T: 1.6-5.4
3T: 2.0-6.3
Term: 2.4-7.2

*High --> preeclampsia?
virtually all cases of preeclampsia correlates w/ disease severity, but not used for diagnosis

17

Hep B lab values

No hep B + immunity =
- negative HBsAg
- negative IgM anti-HBc
- Pos anti-HBs (developed immunity from vaccine)

Immunity from prev infection =
- positive anti-HBs
- positive anti-HBc
- negative HBsAG

Acute infection:
- positive HBsAg and anti-HBc
- anti-HBs negative

1. HBsAg - surface marker on outside of Hep B virus, indicates acute or chronic infection and currently infectious. HBcAg - released within infected hepatocytes.
2. HBeAg - viral replication during acute and chronic infection.
3. anti-HBs - produced in response to recovery from B virus or immunity, developed in response to vaccine.
4. anti-HBc - in response to Hep B infection, positive for life.
5. anti-HBe - response to replicating HBe antigens, indicates clearance of virus or response to antiviral therapy.
6. IgM anti-HBc - acute infection with Hep B within past 6 mo.

18

Hep C testing

Negative HCV: Negative HCV antibodies

Resolved HCV infection: Anti-HCV positive (confirmed), HCV RNA negative

Active HCV infection: Anti-HCV positive (confirmed), HCV RNA positive

19

Toxoplasmosis

Maternal
IgM & IgGs

Fetal: PCR test of amniotic fluid via amnio

20

Rubella

Maternal:
IgM

Fetal:
-detection virus via CVS or amniocentesis
- detect IgM via cordocentesis

21

HSV

Cell culture: culture of specimens from lesions of recurrent disease much less sensitive
- interpret +HSV cultures in context of clinical presentation b/c HSV may rarely be shed in chronic infection in absence of overt clinical disease

Serology: serologic testing has limited value for mgmt of acute infix; may be useful in assessing past infxn or patient's risk for infxn
- Immunoblot IgG has sensitivity > 80% and specificity of 95%

Molecular dx-
NAAT techniques: may be used for detecting HSV DNA in tissue, CSF, and other specimen types
PCR = dx test of choice if CNS infxn suspected w/ sensitivity & specificity > 95%
Core labs-
pts w/ HSV encephalitis: CSF shows incr WBC count w/ mononuclear cell predominance; RBC count usually increased; CSF protein increase

22

Varicella and
Parvovirus

Serology IgG and IgM

23

Varicella
and
Parvovirus

Serology IgG and IgM

24

Initial prenatal visit labs

- CBC
- type & screen, antibodies
- Rubella
- RPR
- Hep B
- HIV
- Varicella
- UA/UC (Udip q visit)
- pap if needed
- For high risk --> GC/CT

High risk GDM:
- Hgb A1C

25

1st Trimester genetic screen

- CF, SMA, and other familial diseases
- NIPT / cell-free DNA: 9 wks GA to delivery (tests trisomies 21, 18, 13, and monosomy X)
- First trimester screen: 11-13.6 wks
-Serial sequential testing:
1. FTS 11-18 wks + US
2. Quad screen 15-21 wks


-For pt's with + screening tests, amniotic fluid and chromosome analysis on chorionic villus sampling may be performed and is diagnostic.

26

1st Trimester genetic screen

- CF, SMA, and other familial diseases
- NIPT / cell-free DNA: 9 wks GA to delivery (tests trisomies 21, 18, 13, and monosomy X)
- First trimester screen: 11-13.6 wks
-Serial sequential testing:
1. FTS 11-18 wks + US
2. Quad screen 15-21 wks


-For pt's with + screening tests, amniotic fluid and chromosome analysis on chorionic villus sampling may be performed and is diagnostic.

27

Mild Preeclampsia dx

Mild pre-eclampsia:
- BP >= 140/90 AND proteinuria

Proteinuria:
- 24-hr urine protein >= 300mg
- Protein:Creat ratio >0.3
- alternate test: >1+ by dipstick on 2 occasions >6hrs apart, but <1 week apart OR single specimen >=2+ by dipstick

In absence of proteinuria, can be HTN in association w/:
- thrombocytopenia (CBC + platelets)
- elevated ALT/AST to 2x normal concentration (LFTs)
- new renal insufficiency (Cr >1.1mg/dL or doubling of serum Cr in absence of other renal disease)

*draw HELLP labs
- uric acid almost always elevated, correlates with severity of disease

28

Severe Preeclampsia dx

- BP >160/110 on 2 occasions at least 6hrs apart
- Proteinuria of >5g/day
- Persistent visual or mental abnormalities, headache, RUQ pain, N/V, maybe edema

* draw HELLP labs to r/o

29

Mild Preeclampsia dx

Mild pre-eclampsia:
- BP >= 140/90 AND preoteinuria
- 24-hr urine protein >= 300mg
- Protein:Creat ratio >0.3
- alternate test: >1+ by dipstick on 2 occasions >6hrs apart, but <1 week apart OR single specimen >=2+ by dipstick

30

Severe Preeclampsia

-

31

gestational HTN

- Dx'd after 20 wks
- BP: 140-160 mmHg sys OR 90-110 mmHg dias AND elevated pressures on at least two occasions 4h apart but no more than 7 days apart
- no other s/s of proteinuria, cerebral sx, hemoconcentration, thrombocytopenia, hepatic dysfunction

32

chronic HTN

- dx'd before 20 wks
- BP: 140-160 mmHg sys OR 90-110 mmHg dias AND elevated pressures on at least two occasions 4h apart but no more than 7 days apart
- cerebral symptoms may or may not be present
- no other s/s of proteinuria, hemoconcentration, thrombocytopenia, hepatic dysfunction

33

GDM Screening Test

1 hr/ 50g test:
130-140 mg/dL

--> 3 hr/ 100g test:
- FBG: 95-105
- 1hr: 180-190
- 2hr: 155-165
- 3hr: 140-145

Dx of GDM is made when any 2 values are met or exceeded in a 100-g, 3-hr test

- if pt has risk factors for DM, consider drawing HgbA1c with initial labs --> if A1c >= 5.7, then consider drawing random plasma glucose, 2 hr/ 75g OGT or fasting plasma glucose

34

Dx overt DM in early pregnancy

- fasting plasma glucose > 126 mg/dL
OR
- HgbA1c > 6.5%
OR
- 2hr OGT after 75g load (need 1+ abnormal value)
OR
- random plasma glucose (>200mg/dL) in pt w/ classic symptoms

2hr/ 75g test values:
- fasting >= 92 mg/dL
- 1 hr >= 180 mg/dL
- 2 hr >= 153 mg/ dL

35

HELLP labs

HEmolytic anemia (CBC with peripheral smear, indirect and direct bilirubin)
Elevated Liver enzymes (ALT, AST)
Low Platelets - <100,000 (CBC w/ platelets)

36

Dx overt DM in Postpartum period

Dx:
- fasting plasma glucose >= 126 mg/dL
OR
- 2hr fasting plasma glucose >= 200 mg/dL

Impairment/increased risk for DM:
Impaired fasting plasma glucose: 100-125 mg/dL
Impaired glucose tolerance: 2h plasma glucose 140-199 mg/dL