NR 576 MIDTERM STUDY GUIDE QUESTIONS WITH 100%CORREC
ANSWERS
WEEK 1
Differential Diagnosis: process involves using clinical reasoning to distinguish between
two or more conditions that share similar signs or symptoms
• Begins as a list of common and uncommon diagnoses that are relevant to the
patient's chief complaint or specific symptom.
• A thorough list of potential diagnoses based on the patient's presenting
symptoms must be developed and narrowed based on subjective, objective, and
diagnostic data
• The subjective history and review of systems are the first steps in gathering data
to narrow the potential differentials, followed by the physical examination
• During the HPI, a series of directed, open-ended questions are asked to gain
information about the complaint using the OLD CARTS mnemonic
(Onset, Location, Duration, Character, Aggravating factors, Relieving
factors, Timing, and Severity).
• Findings from the focused PE are used to narrow down the list of potential
diagnoses.
• If the diagnosis cannot be finalized based on data from the subjective history and
physical examination, diagnostic testing is utilized to assist in determining the
correct diagnosis.
• ALL diagnostic tests have false-positive and false-negative results. There are NO
perfect tests.
Diseased individuals who test positive are true positives and non-diseased individuals
who test negative are true negatives.
• An individual with a false positive will likely have further testing, which may lead
to: exposure to potentially invasive tests, fear about having these tests, increased
healthcare costs, being labeled with an inaccurate diagnosis, receiving
inappropriate treatment.
Diseased individuals who test negative are false-negatives and non-diseased who test
positive are false-positives.
• An individual with a false-negative who has a potentially treatable disease may
become sicker or die because the disease is not detected and treatment is
delayed.
Positive Predictive Value is the percentage of diseased individuals out of those who test
positive. (Proportion of patients with a positive test who have the disease)
• Positive predictive value increases with prevalence; thus, low prevalence value
yields a low positive predictive value and implies a high false-positive rate
,Negative Predictive Value is the percentage of non-diseased people out of those who
tested negative
• Negative predictive value is inversely correlated with prevalence
• Negative predictive value decreases with prevalence, and sensitivity/specificity
do not vary.
Predictive values depend on the prevalence of disease in the population.
Pretest probability is the chance the patient has the disease, estimated before the
results of the test are known.
• It is based on the probability of the suspected disease given the patient's
symptoms or clinical context
• If the pretest probability is high, diagnostic testing may be warranted to clarify or
confirm a diagnosis
Specificity: proportion of ‘test negative’ of total without the disease; the number of true
negatives over all negatives.
Sensitivity is the proportion of patients with the disease that have a positive result; it is
the number of true positives divided by the total number of patients who have the
disease.
Complete Blood Count (CBC)
• Used to obtain data in evaluating a variety of disorders such as anemia, infection,
or leukemia
• Measures red blood cells, white blood cells, hemoglobin, hematocrit, and
platelets
• Check platelet count for unexplained bruising
• Check CBC with differential for neutrophil shift in suspected infection for fever
• Check RBC, Hgb and Hct for anemia if patient c/o fatigue
• Check WBC for inflammation or possible cancer if patient has unexplained wright
loss
,Comprehensive Metabolic Panel (CMP)
• Includes several tests that measure substances in the blood giving information
about the balance of fluid and electrolytes as well as the status of the body's
metabolism, liver function, and kidney function
• Used to screen, monitor, and diagnose a variety of diseases and conditions such
as hydration and electrolyte levels, diabetes, kidney disease, and liver disease
• Also used to monitor the utilization of specific medications such as diuretic
therapy or antihypertensive agents
• In patients with edema check kidney function
• Monitor electrolytes for abnormalities in cardiac dysrhythmias
, Chief complaint Test Rationale
Fever CBC Check CBC with differential for neutrophil shift in suspected infection
Unexplained bruising CBC Check platelet count
Fatigue both Check RBC, Hgb and Hct for anemia, CMP for potential liver or kidney abnormalitie
Cardiac dysrhythmias CMP Monitor electrolytes for abnormalities
Unexplained weight loss Both Check WBC for inflammation or possible cancer, CMP for glucose, liver or kidney ab
Edema CMP Check for kidney function
ANSWERS
WEEK 1
Differential Diagnosis: process involves using clinical reasoning to distinguish between
two or more conditions that share similar signs or symptoms
• Begins as a list of common and uncommon diagnoses that are relevant to the
patient's chief complaint or specific symptom.
• A thorough list of potential diagnoses based on the patient's presenting
symptoms must be developed and narrowed based on subjective, objective, and
diagnostic data
• The subjective history and review of systems are the first steps in gathering data
to narrow the potential differentials, followed by the physical examination
• During the HPI, a series of directed, open-ended questions are asked to gain
information about the complaint using the OLD CARTS mnemonic
(Onset, Location, Duration, Character, Aggravating factors, Relieving
factors, Timing, and Severity).
• Findings from the focused PE are used to narrow down the list of potential
diagnoses.
• If the diagnosis cannot be finalized based on data from the subjective history and
physical examination, diagnostic testing is utilized to assist in determining the
correct diagnosis.
• ALL diagnostic tests have false-positive and false-negative results. There are NO
perfect tests.
Diseased individuals who test positive are true positives and non-diseased individuals
who test negative are true negatives.
• An individual with a false positive will likely have further testing, which may lead
to: exposure to potentially invasive tests, fear about having these tests, increased
healthcare costs, being labeled with an inaccurate diagnosis, receiving
inappropriate treatment.
Diseased individuals who test negative are false-negatives and non-diseased who test
positive are false-positives.
• An individual with a false-negative who has a potentially treatable disease may
become sicker or die because the disease is not detected and treatment is
delayed.
Positive Predictive Value is the percentage of diseased individuals out of those who test
positive. (Proportion of patients with a positive test who have the disease)
• Positive predictive value increases with prevalence; thus, low prevalence value
yields a low positive predictive value and implies a high false-positive rate
,Negative Predictive Value is the percentage of non-diseased people out of those who
tested negative
• Negative predictive value is inversely correlated with prevalence
• Negative predictive value decreases with prevalence, and sensitivity/specificity
do not vary.
Predictive values depend on the prevalence of disease in the population.
Pretest probability is the chance the patient has the disease, estimated before the
results of the test are known.
• It is based on the probability of the suspected disease given the patient's
symptoms or clinical context
• If the pretest probability is high, diagnostic testing may be warranted to clarify or
confirm a diagnosis
Specificity: proportion of ‘test negative’ of total without the disease; the number of true
negatives over all negatives.
Sensitivity is the proportion of patients with the disease that have a positive result; it is
the number of true positives divided by the total number of patients who have the
disease.
Complete Blood Count (CBC)
• Used to obtain data in evaluating a variety of disorders such as anemia, infection,
or leukemia
• Measures red blood cells, white blood cells, hemoglobin, hematocrit, and
platelets
• Check platelet count for unexplained bruising
• Check CBC with differential for neutrophil shift in suspected infection for fever
• Check RBC, Hgb and Hct for anemia if patient c/o fatigue
• Check WBC for inflammation or possible cancer if patient has unexplained wright
loss
,Comprehensive Metabolic Panel (CMP)
• Includes several tests that measure substances in the blood giving information
about the balance of fluid and electrolytes as well as the status of the body's
metabolism, liver function, and kidney function
• Used to screen, monitor, and diagnose a variety of diseases and conditions such
as hydration and electrolyte levels, diabetes, kidney disease, and liver disease
• Also used to monitor the utilization of specific medications such as diuretic
therapy or antihypertensive agents
• In patients with edema check kidney function
• Monitor electrolytes for abnormalities in cardiac dysrhythmias
, Chief complaint Test Rationale
Fever CBC Check CBC with differential for neutrophil shift in suspected infection
Unexplained bruising CBC Check platelet count
Fatigue both Check RBC, Hgb and Hct for anemia, CMP for potential liver or kidney abnormalitie
Cardiac dysrhythmias CMP Monitor electrolytes for abnormalities
Unexplained weight loss Both Check WBC for inflammation or possible cancer, CMP for glucose, liver or kidney ab
Edema CMP Check for kidney function
