Pulmonary Diagnostic Tests and Procedures Flashcards
what are the 4 types of chest imaging that can be done?
chest radiograph
computed tomography (CT)
magnetic resonance imaging (MRI)
ventilation and perfusion scans
what is a chest radiograph?
diagnostic test to determine anatomic abnormalities and pathological processes
air is dark, bone is white
what does white hilum on a chest radiograph indicate?
increased vascularity of the pulmonary arteries
what is the decubitus view used for?
to confirm the presence of an air-fluid level in the lungs or a small pleural effusion (taken to rule out a pleural effusion)
what is the lordotic view used for?
to visualize the apcial or middle (R middle or L lingular segments) region of the lungs or specifically to screen for pulmonary tuberculosis
what is the oblique view used for?
to detect pleural thickening, to evaluate the Carina, or to visualize the heart and great vessels
what is the AP view used for?
taken at the pt’s bedside in supine (abdominal contents tend to raise the diaphragm) or in semirecumbent
what should the hemidiaphragms look like in a chest radiograph?
smooth and rounded
if the hemidiaphragms are flat, what is this indicative of?
obstructive disease
what is the hila?
the root of the lungs (pulmonary blood vessels, bronchi, and group of lymph nodes)
what is a silhouette sign?
when the lines of demarcation bw 2 structures is partially or completely obliterated (can’t see it)
what is computed tomography (CT)?
digital chest radiography involves in narrow beam of x-rays moving across the field of examination
CT scans are primarily used for dx of what two things?
tumors and calcification/nodules
what does CT with contrast enhancement help visualize?
vasculature and lung perfusion
what is the gold standard test for ruling out a PE? (KNOW THIS)
positron CT (helical CT)
what are the advantages of CT?
much more sensitive
evaluates lung, heart, mediastenum, pleura, chest wall, upper abdomen
localized disease
guidance of interventional procedures
can detect occult pneumothorax or effusions
evaluates chest tube placement
can contribute new info
may detect unsuspected abnormalities
what are the disadvantages of CT?
risk of transporting a pt out of the ICU
significant increased radiation
risks of IV contrasts if given
what is pulmonary arteriography?
x-ray w/contrast dye injected into the blood vessels to look for obstructions
used to be the gold standard for PE but is too invasive and so now CT is more widely used
what is magnetic resonance imaging (MRI)?
magnetic field, radio waves and a computer to produce detailed pics of the structures w/in the chest
MRI is primarily indicated for evaluating what?
chest wall processes that may involve bone, muscles fat, or pleura
what are ventilation and perfusion scans?
2 nuclear scan tests used to measure ventilation and perfusion
measures blood flow and air flow
what is the perfusion scan?
radioactive albumin injected into the vein and scans the pt’s lungs as blood flow through them to detect the location of an emboli
what does a decreased uptake of the radioisotope in a perfusion scan indicate?
a problem with blood flow, including occlusion of the pulmonary arteries (pulmonary embolism)
what is the ventilation scan
radioactive gas is inhaled and scans the lungs to measure air flow
what does a decreased uptake of the radioisotope in a ventilation scan indicate?
reduced breathing and ventilation ability or airway obstruction (pneurmonia or COPD)
what does a bronchoscopy allow us to see?
normal and variant anatomy and gross pathological changes in the bronchial wall and lumen
what can a bronchoscopy be used for?
tissue biopsy, secretion sampling/removal
direct visualization of the bronchial tree
infection
PTFs provide clinicians with what 3 pieces of info?
integrity of airways
fxn of respiratory musculature
condition of lung tissue
what do PFTs measure?
lung volumes and capacities
gas flow rates
gas diffusion
flow-volume loop
what does the diffusing capacity of the lungs for CO look at?
the integrity of the membrane and ability of gas to perfuse
what is forced vital capacity?
max volume exhaled as quick as possible
what is FEV1?
what is forced expiratory volume in 1 sec
what does FEV1 of >2L mean?
little/no obstruction
what does FEV1 of 1-2L mean?
mild to moderate obstruction
what does FEV1 of <1L mean?
severe obstruction
what is a normal FEV1/FVC ratio? (KNOW THIS)
75%
FEV1/FVC ratio of >80-90% indicates what? (KNOW THIS)
restrictive disease
FEV1/FVC ratio of <75% indicates what? (KNOW THIS)
obstructive disease
FEV1/FVC ratio of <60% indicates what? (KNOW THIS)
severe obstructive disease
do ppl with large lung volumes and decreased FVC have obstructive or restrictive disease?
obstructive
do ppl with small lung volumes and possibly low FVC have obstructive or restrictive disease?
restrictive
what gas flow rate identifies small airway disease? (KNOW THIS)
forced midexpiratory flow
what is forced midexpiratory flow?
the volume of air exhaled over the middle half of the FVC, divided by the time required to exhale it
normally 4L/sec
what is forced expiratory flow?
the average expiratory flow during early phase exhalation
normally >5L/sec (300 L/min)
what is max voluntary ventilation?
the max volume of gas a patient can move for 1 minute
160-180 L/min
normal values can vary 25-30%
what is peak expiratory flow?
max flow that occurs at any point in the time during the FVC
normally 9-10 L/sec
decreased peak flow reflects what?
nonspecific mechanical problems
what are bronchodilators?
beta-2 agonists that target the smooth muscles in the bronchioles of the lung
inhibits the effects of the parasympathetic NS
causes bronchiole dilation
normally, would bronchodilators make a difference in PFTs?
no
if bronchodilators make a positive difference in PFTs b4 and after use, is the change reversible?
yes
a __% change in PFTs after bronchodilators in at least 2 of the following would indicate a reversible airway obstruction :
FEV1, FVC, or FEV25-75
12%
what is the diffusing capacity of the lung (DL)
measures the integrity of the functional unit (alveoli and pulmonary blood in the capillary)
what is the diffusing capacity of the lungs for carbon monoxide (DLCO)?
measures the amount of gas entering the pulmonary blood flow per unit of time using CO as the gas bc of its high affinity for Hgb
what should normal diffusing capacity be?
20-30 mL/min/mmHg
what are the 3 key factors for abnormal DLCO testing?
1) hemoglobin - decreased quantity per unit of blood
2) alveolar-capillary membrane - increased thickness of the membrane
3) surface area - decreased functional surface area available for diffusion
what would a false test result in DLCO testing mean?
there is not enough hemoglobin
what are the steps for interpreting PTFs?
1) look at the FEV1% (if <70%=obstruction)
2) determine severity of obstruction (>2=little/no obstruction, 1-2=mild to moderate obstruction, <1=severe obstruction)
3) determine if the obstruction is fixed or reversible
4) determine if restrictive disease is present
5) determine what kind of restrictive disease is present (reduced DCLO)
6) determine severity of ossification
when the entire flow volume loop shift to the R, is this indicative of restrictive or obstructive disease?
restrictive
what can ABGs tell us?
acid-base balance, ventilation, and oxygenation
do acids or bases give up H+ ions?
acids
do acids or bases take up H+ ions?
bases
what does pH give us insights into?
respiratory or metabolic
if pH is <7.35 what is this indicative of?
acidosis
if pH is >7.45 what is this indicative of?
alkalosis
what is normal PaCO2?
40
what is normal PO2?
97
what is normal HCO3?
24
what is normal oxygen saturation?
97%
does hyperventilation lead to respiratory acidosis or alkalosis?
respiratory alkalosis
does hypoventilation lead to respiratory acidosis or alkalosis?
respiratory acidosis
does decreased PaCo2 indicate respiratory acidosis or alkalosis?
respiratory alkalosis
does increased PaCo2 indicate respiratory acidosis or alkalosis?
respiratory acidosis
does hyperventilation cause a drop or spike in pH?
drop in pH?? should be a spike??
does hypoventilation cause a drop or spike in pH?
spike in pH??
should be a drop??
what ABG is a direct reflection of the adequacy of alveolar ventilation?
PaCo2
what is normal alveolar ventilation?
40 mmHg
what does PaCo2 of <40 indicate?
hyperventilation
what does PaCo2 of >40 indicate?
hypoventilation
what does PaCo2 of >50 indicate?
ventilatory failure
do the lungs or kidneys regulate blood acids?
lungs
do lungs or kidneys regulate blood bases?
kidneys
high PaCo2 and low HCO3 is associated with high or low pH?
low pH
high HCO3 and low PaCo2 is associated with high or low pH?
high pH
what does PaO2 bw 60-80 indicate?
mild hypoxemia
what does PaO2 bw 40-60 indicate?
moderate hypoxemia
what does PaO2 40 indicate?
severe hypoxemia
what is the difference bw SaO2 and SpO2?
SaO2 measures O2 through an arterial blood gas sample
SpO2 measure O2 through pulse ox
what does the acronym ROME mean?
respiratory opposite (pH and Co2 go in opposite directions)
metabolic equal (pH and HCO3 go in the same direction)
if pH is high and PCo2 is low, is this respiratory/metabolic, alkalosis/acidosis?
respiratory alkalosis
if the pH is low and PaCo2 is high, is this respiratory/metabolic, alkalosis/acidosis?
respiratory acidosis
is PaCo2 the respiratory or metabolic component?
respiratory
is HCO3 the respiratory or metabolic component?
metabolic
if the pH is high and HCO3 is high, is this respiratory/metabolic, alkalosis/acidosis?
metabolic alkalosis
if the pH is low and HCO3 is low, is this respiratory/metabolic, alkalosis/acidosis?
metabolic acidosis
what is the direct measure of O2 saturation through arterial blood sampling?
PaO2
what does pulse ox measure?
SpO2
what are the typical hemotological tests?
ABGs, electrolyte analysis, complete blood counts, and coagulation studies
what is anemia?
low hemoglobin, low RBCs, and low hematocrit
what is polycythemia?
increased hemoglobin, RBC, or hematocrit
what is leukocytosis?
increased WBCs
what is leukopenia?
decreased WBCs
how does a patient with low RBCs and Hgb present?
cyanotic, decreased muscle power, decreased endurance, and increased HR
what is the risk of decreased platelets?
bleeding
what is the risk of increased platelets?
clotting
