Diagnostic Testing Flashcards
Cytology:
Analysis of cells: how they form and function.
Laboratory tests:
- Cytology: analysis of cells: how they form and function
- Hematology: complete blood count, WBC, RBC, platelets.
- Coagulation studies: how well id the blood clotting (partial thromboplastin time, prothrombin time)
- Arterial Blood Gas (ABG): alveolar ventilation, oxygenation, acid-base balance, disease progression.
Arterial Blood Gas (ABG) can give information about
- alveolar ventilation
- oxygenation
- acid-base balance
- disease progression
would the venous blood gas lab result be the same as arterial blood gas?
no
PaCO2 > 50 =
respiratory failure
- Failure of pulmonary system to meet metabolic demands of body
- Extent of failure is determined by accompanying change in pH
Acidosis + low HCO3 =
primary
metabolic acidosis
Is the problem uncompensated or compensated/compensating? Look at…
CO2
-
UNCOMPENSATED
- pH is outside the normal range
- PaCO2 is within the normal range
-
PARTIALLY COMPENSATED
- Both pH and PaCO2 are outside the normal range
-
COMPENSATED
- pH is within normal range
- PaCO2 is outside normal range
Chronic respiratory acidosis: kidneys __________ bicarbonate
hold
Corresponding increase/decrease in HCO3- which indicates that the _____________ system is compensation
metabolic
Corresponding increase/decrease in PaCO2 which indicates that the _____________ system is compensation
respiratory
Kidneys can compensate for chronic respiratory disorders by either holding or dumping bicarbonate. Chronic respiratory acidosis: kidneys __________ bicarbonate
hold
In chronic respiratory alkalosis: kidneys will __________ bicarbonate
get rid of
crime = acid police = Bicarbonate (HCO3) criminals = H+
nice
to get rid of the crime, the police hold on to criminals to be excreted by the kidneys
What affects Forced Vital Capacity?

Restrictive diseases
(fibrosis, scoliosis, diaphgram can’t move, obesity, pulmonary edema…)
Forced Expiratory Volume in 1 sec

- Reflects airflow in large (& medium sized) airways
- 75% - 80% of FVC should be exhaled in the first second
- If decreased = obstructive disease
- Large lungs = large FEV1
- Large airway diameter = large FEV1

Measure volume and flow of air during inspiration and exhalation
Pulmonary Function Testing (PFT)
Provides graphic display of inspiratory and expiratory flows and volumes
Flow volume loops
Max amt of gas pt can exhale forcefully & quickly
Forced Vital Capacity (FVC)
FEV1/FVC
- Decreased = obstructive disease
- Near normal or elevated = restrictive disease
Normal Forced Vital Capacity
80%
- Mild: 60-79%
- Moderate: 51-59%
- severely impaired < 50
Normal Forced Expiratory Volume in 1 second:
80%
- Mild: 60-79%
- Moderate 51-49%
- Severe < 40%
Normal FEV1/FVC =
75%
- Mild 60-74%
- Moderate: 41-59%
- Severe: <40%
What causes FVC to decrease?
restriction diseases, whatever restricts air into the lungs:
fibrosis, scoliosis, obesity, diaphragm can’t move.
What causes Forced Expiratory Volume in 1 sec to decrease?
obstructive diseases
- if FEV1 and FEV1/FVC = decreased (less than 75%)
- RV = increased
- TLC = normal or increased
obstruction
Obstructive or restrictive?

Obstructive diseases causes Forced Expiratory Volume in 1 sec to decrease
Obstructive or restrictive?

restrictive diseases causes FVC to decrease, and TLC, RV, FRC decrease
- TLC = decreased
- RV, VC, and FRC = usually decreased
Restrictive
x-rays go through body without being absorbed (dark areas) are more..
radiolucent
x-rays thta are absorbed in lighter areas are more
radiopaque
air in an x-ray is______
rediolucent
bone is a x-ray is white because is
radiopaque
in an radiograph what is lighter (whiter) muscle or fat?
muscle is lighter
- Standard for looking at anatomy of chest
- Views usually described as PA, AP, Lateral
Chest X-ray (CXR)



- COPD
- Barrel chest
- Widened intercostal spaces
- Flattened hemi-diaphragms
- Squared off costophrenic angles
- Rib angles approaching 90 degrees

Pneumonia

atelectasis
partial collapse

atelectasis
Used to look for pulmonary nodule
Computed Tomography (CT Scan)
Used primarily for soft tissue and lymph nodes
MRI (Magnetic Resonance Imaging)
imaging test that uses x-rays and special dye to see inside the arteries
Pulmonary Angiogram
Direct visualization of the bronchial tree through a scope
Bronchoscopy
Radionuclide V/Q Scan
Examine by x-ray—how areas of lung are being ventilated and perfused:
- Inhale radioisotope
- Inject radioisotope
- Poor ventilation: may be airway obstruction
- Poor perfusion: may be PE

Radionuclide V/Q Scan:
Examine by x-ray—how areas of lung are being ventilated and perfused

Radionuclide V/Q Scan
True or false: bronchoscopy can be used to clear secretions
true

Pulmonary Angiogram

Pulmonary Angiogram
- Catheter inserted and carefully fed into and through the right side of the heart to the pulmonary artery (leads to the lungs)
- Dye injected in to the catheter once in the correct location
- X-ray images are taken to see how the dye moves through the lungs’ arteries
- Dye helps detect blockages to blood flow
Pulmonary Angiogram

Better view of soft tissue than CT scan, but is more expensive and takes longer
MRI

Amount of gas (CO, carbon monoxide) entering the pulmonary blood flow per unit time
DL or DLCO (diffusing capacity of the lung)
What gas is used in DLCO or DL (diffusing capacity of the lung)?
CO (carbon monoxide) is used as it has a greater affinity for hemoglobin
Diffusing capacity of the lungs can be reduced in three cases:
- Decreased hemoglobin
- Increased thickness of alveolar-capillary membrane
- Decreased surface area for diffusion (primary factor), (COPD).
Which is the most important confounding factor in PFT?
poor effort from the patient,
make sure pt puts maximun effort
In PFT, if the pt’s value falls outside the predicted value by more than ____% is considered abnormal
25%
heard over the trachea, ratio?
tracheal sound
1:1 with gap
Sound heard over the sternum or manubrium, ratio?
Bronchial
1:2 with gap
Sound heard anteriorly at the 1st and 2nd ICS and posteriorly between the scapulae
bronchovesicular
1:1 continuous
Heard throughout lung periphery
vesicular
3:1 continuous
(smoking) pack years =
packs per day x years smoked
70 pack years =
1 pack per day for 70 years
or 2 pack per day for 35 years
10 pack year
1 pack per day for 10 years
2 packs 5 years
PFT measured again 5-20 minutes after bronchodilator. Normal or PURELY restrictive disease
should show differences in what?
no difference