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COMMON LEARNING ISSUES
PBL TEST 1 2012
ALPHA FETOPROTEIN
USED AS A SCREENING MARKER INDICATING INCREASED
RISK FOR BIRTH DEFECTS (NEURAL TUBE, BODY WALL, AND
CHROMOSOMAL)
PRODUCED BY FETAL LIVER AND YOLK SAC IF THERE IS A
BODY WALL DEFECT THE AFP WILL LEAK INTO AMNIOTIC
FLUID AND IS PICKED UP BY MATERNAL SERUM
ALSO ASSOCIATED WITH TUMOR MARKERS, HEPATOMA,
TERATOMA, HODGKINS, LYMPHOMA, AND RENAL CELL
CARCINOMA
ALPHA-FETOPROTEIN
NORMAL FINDINGS < 40 ng/mL • Child < 30 ng/mL• Ranges vary by week of gestation normally detected at 10 weeks• Peak levels at 16-18 weeks
DECREASED LEVELS:• TRISOMY 21• FETAL WASTAGE
INCREASED LEVELS:• NTD, ABDOMINAL WALL DEFECTS• MULTIPLE FETUSES• THREATENED ABORTION• FETAL DISTRESS OF CONGENITAL ANOMALIES• FETAL DEATH
ANTINUCLEAR ANTIBODY (ANA)
Used to diagnose systemic lupus erthematosus
(SLE) and other autoimmune disease
ANA is a group of protein antibodies that react
against cellular nuclear material
Normal findings negative at 1:40 dilution
ARTERIAL BLOOD GASES
Monitor patients on ventilators, monitor critically
ill nonventilator patients, establish preoperative
baseline parameters, and regulate electrolyte
therapy
pH –log[H+]• Acids normally found in blood: carbonic, dietary,
lactic and ketoacids• Elevated indicates alkalosis• Decreased indicates acidosis
BLOOD GASES
PCO2• Measure of partial pressure of carbon dioxide in the
blood• Measure of ventilation• 10% free floating in plasma, 90% carried by RBCs• Respiratory component of acid-base determination• Co2 and pH are inversely proportional
BLOOD GASES
HCO3- or CO2 content• Measure of the metabolic component of the acid-base
equilibrium• Regulated by the kidney• Directly proportional to pH• In alkalosis kidneys excrete more into the urine to lower pH
PO2• Pressure of oxygen dissolved in plasma• Indirect measure of O2 content• Determines effectiveness of oxygen therapy• Determines the force of oxygen to diffuse across the pulmonary
alveoli membrane
BLOOD GASES
Oxygen saturation• Percentage of hemoglobin saturated with oxygen• As PO2 decreases so does saturation of hemoglobin
Oxygen content• The amount of oxygen in the blood• Nearly all of it is bound to hemoglobin
Base excess/deficit• Amount of • anions in the blood, bicarbonate being the largest• Also hemoglobin, proteins, phosphates• Negative base excess indicates acidosis, positive alkalosis
BLOOD GASES
Alveolar to arterial oxygen difference• If gradient is abnormally high there is a problem in
diffusing oxygen across the alveolar membrane (thickened or edematous) or unoxygenated blood is mixing with oxygenated
• Thick walls due to edema, fibrosis, and RDS• Mixing occurs with septal defects, shunts or
underventilated alveoli still being perfused
KAROTYPE
Study an individual’s chromosome makeup to determine chromosomal
defects associated with disease or risk for developing disease
Congenital or acquired because of duplication, deletion, translocation,
reciprocation, or genetic rearrangement
Performed by a banding technique, pairing similar chromosomes
based on size, location of centromere, banding patterns
Congenital anomalies, growth and mental retardation, infertility,
delayed puberty, hypogonadism, amenorrhea, ambiguous genitalia,
CML, neoplasm recurrent miscarriage, turner, klinefelter, downs
CBC
Measures RBC
Hemoglobin
Hematocrit
RBC Indices
WBC count
Blood smear
Platelet count
Mean platelet volume
CBC
Mean corpuscular volume ( MCV)• Average volume or size of a single RBC• Divide hematocrit by total RBC count• Large: folic acid or B12 deficiency• Small: iron deficient anemia or thalassemia
RBC• # circulating RBC• Normal life span 120 days• Lysed and extracted from circulation by spleen
CBC
Mean corpuscular hemoglobin• Measure of average weight of hemoglobin within
RBC
Mean corpuscular hemoglobin concentration• Average concentration or % of hemoglobin within
RBC
RBC distribution width• Indicates variation of size of RBC• Important in classifying anemias
CBC
Blood smear• Information concerning drugs and diseases that
affect RBCs and WBCs• Examines RBC, platelet, and WBC
White count• Neutrophils, basophils, eosinophils, monocytes,
lymphocytes
CBC
Platelet count• Number of platelets formed in bone marrow of
megakaryocytes• Adult/child 150,000-400,000• Newborn/ premature infant: 100,000-300,000• Infant 200,000-475,000
Mean platelet volume• Measure volume of large number of platelets to
evaluate platelet disorders especially thrombocytopenia
CREATININE, BLOOD
. Normal Findings:
A. Elderly: Decrease in muscle mass may cause decreased values
B. Adult: Male: 0.6-1.2 mg/dL Female: 0.5-1.1 mg/dL
C. Adolescent: 0.5-1.0 mg/dL
D. Child: 0.3-0.7 mg/dL
E. Infant: 0.2-0.4 mg/dL
F. Newborn: 0.3-1.2 mg/dL
---creatinine clearance
1. used to measure the GFR of the kidneys
2. Normal Findings:
A. Adult (<40 yrs): Male: 107-139 mL/min Female: 87:107 mL/min
B. Values decrease 6.5 mL/min/decade of life after age 20 yrs with decline in GFR
C. Newborn: 40-65 mL/min
CREATININE
Catabolic product of creatine phsophate used in skeletal
muscle contraction, depends on muscle mass
Excreted by kidneys and is directely proportional to renal
excretory function; serum levels should be constant
Used to diagnose impaired renal function
Unlike BUN it is minimally affected by hepatic function
Approximation of GFR
Suggest chronic disease
CREATININE
In chronically unstable patients acute changes in
renal function can make real time evaluation of GFR
difficult
Cystatin C may be used for chronic kidney disease
Clearance: amount of filtrate made • Amount of blood to be filtered and ability of
glomeruli to filter
ERYTHROCYTE SEDIMENTATION RATE
no-n-specific test used to detect illnesses associated with acute and
chronic infection, inflammation, advanced neoplasm, and tissue necrosis or
infarction
Measure rate at which RBC settle in saline solution or plasma per unity
time
RBC will settle faster with illness
Male up to 15 mm/hr
Female up to 20 mm/hr
Child up to 10 mm/hr
New born 0-2 mm/hr
ESTROGEN FRACTION
EstradiolSerum (pg/mL)
Urine mcg/ 24 hr
Child <10 <15 0-6
Adult male 10-50 0-6
Adult female
Follicular phase
25-350 0-13
Midcycle peak 150-750 4-14
Luteal phase 30-450 4-10
postmenopausal
<20 0-4
ESTROGEN FRACTION
estriol Serum (ng/mL) Urine mcg/ 24 hr
Male, child, postmenopausal
1-11
Follicular phase 0-14
Ovulatory phase 13-54
Luteal phase 8-60
1st trimester <38 0-800
2nd trimester 38-140 800-12,000
3rd trimester 31-460 5000-12,000
ESTROGEN FRACTION
Total estrogen serum Urine mcg/ 24hr
Male or child 4-25
Female not pregnant
4-60
1st trimester 0-800
2nd trimester 800-5000
3rd trimester 5000-50,000
ESTROGEN FRACTION
Evaluate sexual maturity, menstrual problems, and fertility
problems
Evaluate males with gynecomastia or feminization
In pregnancy it indicates feto-placental health or tumor
marker
FSH and LH stimulate ovaries to make estradiol (E2)• Peaks during ovulatory phase of menstrual cycle• Menopausal status, sexual maturity, fertility problems,
gynecomastia, feminization syndromes, and tumor mark for ovarian tumors
ESTROGEN FRACTION
E1 or estrone is major circulator after menopause
E3 (estriol) major estrogen in pregnant female assess placental function
and fetal normality, produced by placenta from estrogen precursors rising
values are good declining values mean fetoplacental deterioration,
preeclampsia/eclampsia, diabetes mellitus, anencephaly, death,
dysmaturity
Increased levels liver necrosis, adrenal tumor, hepatic cirrhosis,
hyperthyroidism
Decreased: turners, failing pregnancy, hypothryoidism or pituitarism,
stein-leventhal syndrome, menopause, anorexia nervosa
MATERNAL SCREEN TESTING
Potential birth defects or serious chromosomal/genetic
abnormalities
Women over 35 for downs, NTD, or abdominal wall defects
Double test hCG and AFP
Triple AFP, hCG, and estriol
Quadruple AFP, hCG, inhibin A, and estriol
With trisomy 21 AFP levels are 25% lower than normal hCG 2x
higher
Inhibin A just like hCG
PARTIAL THROMB OPLASTIN T IME (PT T)
Assess the intrinsic system and common pathway of clot formation
and to monitor heparin therapy
First phase of reactions is intrinsic system: factor XII forms complex
on subendothelial collagen
Extrinsic factors include thromboplastin
Prothrombin becomes thrombin converts fibrinogen to fibrin
Plasmin degenerates
Evaluates fibrinogen II (prothrombin, V, VIII, IX, X, XI, and XII
If any of these exist in inadequate quantities then PTT is prolonged
PTT
Vitamin K deficiency can prolong PTT II, IX, and X are
dependent
Coag factors are made in the liver so hepatocellualr
disease will prolong
Heparin inactivates prothrombin (II) no thromoplastin
Monitor heparin whose effects are short-lived if too
much is given protamine sulfate can reverse
HCG
<5 for non-pregnant people, used to diagnose pregnancy, increases
throughout pregnancy, can be detected as early as 10 days post conception
Secreted by placental trophoblast
Immunologic test: high risk of false positive
Beta subunit characteristic of hCG
Radioimmunoassay: blood test for beta
Radioreceptor assay performed in one hour reliable
Ectopic pregnangy, hydatiform mole, and choriocarcinoma can produce
Liver cancer cells as well
PROTHROMBIN TIME
Adequacy of extrinsic system and common pathway
Activation of factor X in the presence of factor V
and phospholipid and calcium
Stimulates platelet aggregation and converst
fibrinogen to fibrin in clot stabilization
Factors I (fibrinogen) II (prothrombin), V, VII, and
X
PT
Hepatocellular liver disease (cirrhosis, hepatitis, neoplastic
invasive processes) I, II, V, VII, IX, X
Obstructive biliary disease bile necessary for fat absorption
decreases A,D,E and K are all fat soluble II, VII, IX, X all
dependent on vitamin K, differentiate from liver disease because
it responds to vitamin K
Coumarin ingestion (warfarin) interfere with vitamin K
associated factors; effects long lasting, can be fixed by vitamin K
RHEUMATOID FACTOR
Negative <60 units/mL
Used in the diagnosis of RA
RA: morning stiffness for 6 weeks, pain in at least one joint,
swelling in at least 1 joint, symmetric bilateral joint swelling,
presence of subcutaneous nodules, radiographic changes
Abnormal IgG made in synovial joints
IgG and IgM along with fc attack abnormal IgG
Immune complexes are activated and joint destruction begins
RF
Tests mainly for identification of IgM
Must be found in greater than 1:80 dilution
SLE may also give false positive
Tuberculosis, chronic hepatitis, infectious
mononucleosis and subacute bacterial endocarditis
may give false reading
Does not disappear in remission
BUN
10-20 mg/dL adult
Child and infant 5-18 mg/dL
Newborn 3-12 mg/dL
Rough and indirect measurement of renal function and GFR
also a measure of liver function
Amount of urea nitrogen in the blood
Urea is an end product of protein metabolism and digestion
Elevated bun or azotemia
BUN
Shock, dehydration, congestive heart failure, excessive
protein catabolism
GI bleeding
If kidney disease is unilateral and other kidney can take on
role then BUN won’t be affected
Ureteral and urethral obstruction
Liver disease decreased BUN
Can be normal if there is liver and kidney disease
AMNIOCENTESIS
Performed on women whose pregnancies are high
risk (diabetic, obese, older)
Indicate fetal maturity, distress, risk for RDS,
genetic and chromosomal abnormalities, sex, NTD
Lung maturity (lecithin and sphingomyelin ratio)
lecithin is a major constituent of surfactant 2:1
indicates maturity; at 35 weeks rapidly increases
AMNIO
Phosphatidyglycerol (PG) small component of
surfactant, produced by mature lung alveolar cells
appear at 35 weeks
Lamellar body count: produce by type II
pneumocytes, represent the storage of surfactant
Microviscosity: aggregates dependent on L/S ratio
and degree of saturation of fatty acid side chains,
high early decreases later
AMNIO
Rh isoimmunization: assess levels of bilirubin in amniotic fluid,
indicates severity of hemolytic anermia in Rh-sensitized
pregnancy higher bilirubin, lower fetal hemoglobin, early delivery
or blood transfusion may be indicated
Anatomic abnormalities: increased AFP neural crest
abnormality
Fetal distress: pale, straw colored fluid tinged with green,
yellow indicates blood incompatibility, yellow-brown may be
intrauterine death red is blood contamination
ECHOCARDIOGRAPHY
Normal findings: normal position, size, and
movement of cardiac valves and heart muscle wall,
normal directional flow of blood within the heart
chambers
Performed to evaluate heart wall motion and detect
valvular disease, evaluate heart during stress testing
and identify and quantify pericardial fluid
Ultrasound procedure to evaluate structure and
function of heart
ECHO
M-mode echocardiography recording of amplitude and rate of
motion in real time
Two dimensional ultrasonic beam moved within one sector of the
heart 3D gives better image of heart wall and valves
Color flow: direction and velocity of blood flow within heart and
great vessels for valve function in regards to regurgitation
Septal defects, perfusion, valvular heart disease, prolapse, stenosis,
subaortic stenosis, tumors, aneurysm
Perflutren (definity or optison) provides enhancement of borders
OXIMETRY
>95% is normal
Monitors arterial oxygen saturation in patients at risk for
hypoxemia. Surgery, cardiac stress testing, mechanical
ventilation, heavy sedation, lung function testing or trauma
Non-invasive measures home many hemoglobin have oxygen
attached to them
Fetal oxygen saturation monitoring: if heart is in distress but
saturation is fine you can avoid c-section, placed on cheek
between 30 and 70%
EATING DISORDERS
Anorexia nervosa: refusal to maintain body weight (BMI below 17.5), afraid of
appearing fat, frequently staving but in denial, lacking insight, brought in by family
members, failure to make expected weight gain as child or adolescent, amenorrhea,
loss of libido or potency in men, depressive mood, irritability, social withdrawal,
insomnia, decreased libido, self-induced vomiting or purging, excessive exercise, use of
diuretics or appetite supressants
Increased corticotropin releasing factor, cortisol, growth hormone, serotonin,
decrease diurnal cortisol fluctuation, LH, FSH, TSH
Bradycardia, hypotension, arrhythmias, cardiomyopathy
Hypokalemia, hypochloremic metabolic alkalosis, increased BUN, edema
Dry skin dental carries, delayed gastric emptying, constipation, anemia, osteoporosis
FREMITUS
Palpable vibrations transmitted through the bronchopulmonary
tree to the chest wall as the patient is speaking. To detect use ball
or ulnar surface of hand to optimize vibration in bones of hand.
Repeat 99 or one one one
Is decreased or absent when the voice is soft or when the
transmission of vibrations from larynx to chest is impeded.
Causes of faint fremitus: very thick chest walls, obstructed
bronchus, COPD, fibrosis, pleural effusion, pneumothorax or
infiltrating tumor
HYPER-RESONANCE
Very loud, lower pitch, longer duration
Generalized hyper-resonance may be heard over
the hyper-inflated lungs of COPD or asthma, but it is
not reliable
Unilateral hyper-resonance suggests a large
pneumothorax or large air filled bulla in lung
GRAVIDA-PARA
Gravida = total number of pregnancies
Para = or outcomes of pregnancies• Often after you will see notations F (full-term), P
(premature), A (abortion), L (living child)
APGAR
Key assessment of newborn immediately after birth
5 components take at 1 and 5 minutes after birth
based on 0,1, or 2, total score is 0-10, five minute
score of 8+ move on to full exam
1 minute score 8-10 normal, 5-7 some nervous
system depression 0-4 severe depression requiring
immediate resuscitation
5 minute score 8-10 normal, 0-7 high risk for
subsequent central nervous system and other organ
dysfunction
APGAR
Clinical sign
0 1 2
Heart rate absent <100 >100
Respiratory effort
Absent Slow and irregular
Good, strong
Muscle tone
Flaccid Some flexion of arms and legs
Active movement
Reflex irritability
No response
Grimace Crying vigorously, sneeze or cough
color Blue/pale Pink body, blue extremities
Pink all over
VITAL SIGNS
Doppler method detects arterial blood flow
vibrations, converts them to systolic normal for
males is 70 mmHg at birth 85 at 1 month and 90 at 6
months
Pulse is best found at femoral artery
VITAL SIGNS
age Average heart rate
Range
Birth 0-2 140 90-190
0-6 130 80-180
6-12 115 75-155
VITAL SIGNS
Fever can raise respiratory rates by 10 respirations per
minute for each degree centigrade of fever
Temperature rectal, oral and auditory canal (rectal in infants)• Usually above 99 degrees until after 3 years• May approach 101 in normal children in late afternoon after
vigorous activity• Above 100 <2-3 months may be a sign of a serious infetion
Respiratory rate 30-60 per minute• Birth – 2 months >60/minute cutoff• 2-12 months >50/ minute cutoff
VERTEX PRESENTATION
Presentation of any part of the fetal head during
birth
Head/neck in flexion so chin is pushed against
chest
May be different degrees of flexion
CONGENITAL ADRENAL HYPERPLASIA
Refers to disorders of adrenal steroid biosynthesis
that result in glucocorticoid and mineralcorticoid
deficiencies
Because of deficient cortisol biosynthesis,
increases in ACTH occurs, inducing adrenal
hyperplasia and overproduction of steroids that
precede blockage of enzyme production
21-hydroxylase (CYP21) deficiency is the most
common (95%)
CAH
Failure of CYP21 and 17 hydroxyprogesterone and
progesterone to 11 deoxycortisol and 11
deoxycorticosterone respectively with deficient
cortisol and aldosterone is to replace
Aim of treatment for class in 21 hydroxylase
deficiency is to replace glucocorticoids and
mineralcorticoids, suppress ACTH and androgen
overproduction and allow for normal growth and
sexual maturation in children
SOUTHERN BLOT
Used for identifying DNA sequences on gels
Produced when DNA on a nitrocellulose blot of an
electrophoretic gel is hybridized with a DNA probe
BMP VS. CMPBMP/Chem-7:
• Sodium• Chloride• Potassium• CO2/Bicarbonate
• BUN• Creatinine• Glucose
CMP/Chem-12:• Same as BMP plus:
• AST• ALT• Albumin• Bilirubin• Alkaline Phosphatase
SODIUM (NA)Normally 125-145 mmol/l
Collect in red top tube
Increased: Diabetes inspidius, exessive sweating,
Cushing’s syndrome
Decreased: Excess body water (CHF, renal failure,
small cell lung cancer, brain disorders),
hypothyroidism, vomiting, diarrhea, pancreatitis
CHLORIDE (CL)Normally 97-107 mEq/L
Collect in tiger top tube
Increased: Diarrhea, hyperalimentation
Decreased: Vomiting, renal disease, diabetic
ketoacidosis
POTASSIUM (K)Normally 3.5-5 mEq/L
Collect in red or tiger top tube
Hemolysis may falsely elevate level
Increased: Renal failure, Addison’s disease,
dehydration, ACE inhibitors, Spironolactone
Decreased: Diuretics, NG suctioning, vomiting,
diarrhea, metabolic alkalosis
CARBON DIXOIDE (CO2)
Normally 23-29 mmol/L
Collect in tiger tube top; don’t expose to air
CO2 excreted into blood as bicarbonate
Increased: COPD, severe vomiting
Decreased: Starvation, diabetic ketoacidosis,
diarrhea, dehydration
BLOOD UREA NITROGEN
Normally 5-20 mg/dl
Collect in tiger top tube
Increased: Renal failure, CHF, aminoglycosides
Decreased: Starvation, liver failure
BUN:Creatinine >20 suggests dehydration
BUN:Creatinine >30 suggests GI bleed
CREATININENormally <1.1 mg/dl
Collect in tiger or red top tube
Measures blood flow through kidneys
Increased: Renal failure, false positive seen in
diabetic ketoacidosis
Decreased: Muscle wasting, liver disease
GLUCOSENormally 80-140 mg/dl
Collect in red or tiger top tube
Slight increase normal with aging
Increased: DM, Cushing’s syndrome, pancreatitis,
thiazide diuretics
Decreased: Liver disease, malnutrition, sepsis,
endocrine tumors
AST/ALTAspartate Aminotransferase:
• Normally 7-42 IU/L• Increased: Liver disease,
muscle trauma, burns• Decreased: Vitamin B6
deficiency, dialysis• AST>ALT in alcoholic
hepatitis
Alanine Aminotransferase:• Normally 1-45 IU/L• Increased: Liver disease,
billary obstruction• ALT>AST in viral hepatitis
ALBUMINNormally 3.5-5 g/dl
Collect in tiger top tube
Best lab test for measuring protein
Decreased: Malnutrition, nephrotic syndrome,
alcoholic cirrhosis, inflammatory bowel disease,
metastatic cancer, leukemia, Hodgkin’s disease
BILIRUBINNormally 0.3-1 mg/dl
Collect in tiger top tube
Increased: Liver damage, hemolysis, billary
obstruction
ALKALINE PHOSPHATASENormally 25-160 IU/L
Collect in tiger top tube
Increased: Liver disease, billary obstruction, bone
tumors, healing fracture, hyperparathyroidism,
hyperthyroidism
Decreased: Malnutrition, excessive vitamin D
intake, pernicious anemia, zinc deficiency
WHITE BLOOD COUNTNormally 4500-11,000
Differential provides more clues to cause than
overall count does
Increased: Infection, inflammation, leukemia
Decreased: Bone marrow failure, vitamin B12
deficiency
CAUSE OF INCREASED DIFFERENTIALS
Basophils: Leukemia, s/p spleenectomy
Eosnophils: Allergies, asthma, parasites
Lymphocytes: Viral infections, leukemia
Monocytes: Bacterial infections, protozoan
infections, ulcerative colitis
Neutophils: Bacterial infection, noninfectious
tissue damage, metabolic disorders
H & HHematocrit: ~40-50% (lower in women, higher in
men)
The percentage of blood that is RBCs
Decreased with anemia and blood loss
Hemoglobin: ~12-16 g/dl (lower in women, higher
in men)
Does not acurately reflect acute bleeding because
plasma and RBC lost at same rate
COAGULATION STUDIES
Collect in blue top tube
PT: 11.5-13.5 second
INR: 0.8-1.4
Higher with mechanical heart valves or history of
thromboembolitic disease or atrial fibrillation
INR is now the standard measure reported
CAUSES OF POSITIVE VALUES ON UA
Bilirubin: Jaundice, hepatitis, fecal contamination
of sample
Blood: Stones, BPH, infection, Foley cath
Glucose: DM, pancreatitis, steroids
Ketones: Starvation, high fat diet, diabetic
ketoacidosis, vomiting, diarrhea, asprin overdose
CAUSES OF POSITIVE VALUES ON UA
Leukoesterase: UTI• Leukoesterase plus nitrates: 75% of UTI• Neither LE or nitrates: 92% not UTI
Protein: Renal failure, CHF