stats & ethics Flashcards
What is the equation for specificity?
True negatives / true negative + false positive
What is the formula for sensitivity?
True positives / true positives + false negatives
What is the probability that a test will produce a true negative result when used on a population without disease?
Specificity
What is the probability that a test will produce a true positive result when used on a population with the disease?
Sensitivity
What is the probability that someone who had the disease will test positive?
Positive predictive value
What is the equation for positive predictive value?
True positive / true positive + false positive
What is the probability that someone who does NOT have a disease will have a negative test result?
Negative predictive value
What is the equation for negative predictive value?
True negative / true negative + false negative
What does the P value respresent?
The chance that the null hypothesis was rejected in error
What P value is significant enough to reject the null hypothesis?
<0.05
What type of error occurs when the null hypothesis is rejected in error?
Type 1
What type of error occurs when the null hypothesis was NOT rejected but the null hypothesis is not true?
Type 2
What number is obtained by adding the sample values and dividing by the size of the sample?
Mean
What number is the middle value in which half the data is larger and the other have is smaller?
Median
What is the most frequently occurring number in a sample?
Mode
What type of study follows persons with risk factors to determine the outcomes?
Cohort study
What type of study examined those with a disease and then checks for common risk factors?
Case control study
What is an analysis of data from several studies?
Meta analysis
Is a 15 y/o who has a child and lives on her own considered an emancipated minor?, why?
No - must be older than 16
In a comatose infant, what two lab values are most important in diagnosing inborn error of metabolism ?
Ammonia and anion gap
What inborn errors of metabolism should you consider in a patient with high ammonia and no acidosis?
Urea cycle defect or transient hyperammonemia
What inborn errors of metabolism would you consider in a patient with high ammonia and metabolic acidosis?
Propionic acidemia
Methylmalonic acidemia
Fatty acid oxidation defects
What inborn error of metabolism would you consider in a child with normal serum ammonia and metabolic acidosis?
Maple syrup urine disease
What inborn errors of metabolism would you consider in a patient with normal ammonia and normal abg?
Aminoacidopathy
Galactosemia
Non Ketotic hyperglycinemia
What is the appropriate treatment in a comatose infant with high ammonia ?
If >200, reduce ammonia with benzoate and phenylacetate
If >600, dialysis
What is the normal serum ammonia value in a newborn?
<110
What is the best initial study in a 2 day old infant with acidosis, kerosine and high ammonia?
Measure urine organic acids
What should be the first study in an infant who presents with the appearance of sepsis but no fever or other signs of infection?
Serum ammonia level
What is the first step in managing a patient with organic acidemia?
Hydration
When would organic acidemias present?
First 2 days of life after introduction of protein in the diet
What are the similarities and difference between organic acidemias and brain tumors?
Both have decreased appetite, falling down and delayed milestones but brain tumors would progressively worsen
What happens to the CBC in patients with metabolic acidosis?
Suppression of bone marrow with low platelets and WBC count
What condition should you expect in an infant with poor feeding, seizure and odor that smells of sweaty feet ?
Isovaleric acidemia
What is the appropriate treatment for isovaleric acidemia?
Protein restriction
What are the symptoms of Propionic acidemia?
Tachypnea, poor feeding and lethargy
What is the treatment for methylmalonic acidemia?
Vitamin b12
How are fatty acid oxidation defects inherited ?
Autosomal recessive
What would you consider in a patient who had a brief episode of illness and decreased PO intake followed by hypoglycemia and hepatoma halt?
Fatty acid oxidation defects
What lab findings would you suspect in a child with defects in fatty acid metabolism?
Absence of reducing substances and ketones in the urine
Normal serum amino acids
What is the test for definitive diagnosis of fatty acid oxidation defects?
Plasma acylcarnitine profile
What is the treatment for urea cycle defects?
Reduce serum ammonia by reducing protein intake and increasing glucose via IV
Which metabolic disorders do NOT present with hepatomegaly?
Organic acid defects
Hyperinsulinism
Urea cycle defects
Which syndrome should you consider in a patient with hypotonia, dysmorphic features but NO high ammonia?
Zellweger syndrome
If an infant presents with signs of inborn error of metabolism but has ketonuria, what disease could you rule out?
Urea cycle defects
What should you consider in a patient with elevated ammonia, hypotonia and coma but no acidosis?
Urea cycle defect
What would you suspect in a patient who is normal at birth but then develops poor feeding, abdominal distention, hypoglycemia and gram negative sepsis?
Galactosemia
What laboratory finding would you expect in galactosemia?
Non glucose reducing substances in the urine
How is definitive diagnosis of galactosemia made?
Measuring GALT in RBCs (will be deficient)
How are children with galactosemia treated?
Galactose free diet
What complications can arise with untreated galactosemia?
cataracts, intellectual disability or liver disease
What should you suspect in a child with seizures after each meal?
Inherited fructose intolerance
What is the duarte variant?
Infants with half the normal amount of GALT…newborn screen may be positive but require more specific testing
What is the drug of choice in refractory hypoglycemia in infants?
Diazoxide
How would you know the difference between Hyperinsulinism and adrenal insufficiency?
Both have hypoglycemia but adrenal insufficiency does NOT have ketonuria
Why do children with beckwith wiedemann syndrome develop hypoglycemia?
Islet cell hyperplasia
What should you suspect in a patent with lactic acidosis, alopecia and rash as well as neurological signs?
Biotinidase deficiency
Which amino acids are elevated in maple syrup urine disease?
Valine
Isoleucine
Alloisoleucine (not normal in infants)
Leucine
What is the most useful test in an infant with hypoglycemia, seizures and hepatomegaly ?
Urine ketones and reducing substances
What should you consider in an infant with tachypnea, shallow breathing, lethargy and hypertonicity?
Maple syrup urine disease
What is the treatment of alcaptonuria?
Diet low in phenylalanine and tyrosine
What condition results in dark sclerae, cartilage, sweat, cerumen and urine?
Alcaptonuria
What causes dark urine in patients with alcaptonuria ?
Homogentisic acid in urine