Lecture 20: Pulmonary Outcomes and Diagnostics Flashcards
what is a dyspnea scale used for
measures degree of breathlessness in pts with a pulmonary dx or pts who have primary functional limits from shortness of breath
highly responsive to exertion dyspnea but not as useful for dyspnea at rest
0-4 scale
modified MRC dyspnea scale scores
0 = only breathless with strenuous exercise
1= SOB when hurrying on the level or walking uphill
2 = walk slower than other people of the same age on level ground bc of breathlessness or have to stop for breath when walking on my own pace on level ground
3 = stop for breath after walking about 100 meters or after a few min on the level
4 = too breathless to leave the house or breathless when dressing/undressing
describe the BORG dyspnea scale
0-10 scale
less specific on functional limit
pt reported
2nd ventilatory threshold at 5-7 on scale
use of 6MWT with pulmonary pts
most used submit exercise test
easily converted to METs and VO2 max
American Thoracic Society originally developed
Drop in SpO2 during walk tests is associated with worse outcomes and impaired functional activity tolerance
MCID = 54
6MWT average values and values predictive of hospitalization or mortality for COPD pts
average = 380 m
<200m = predictive of hospital/mortality
gait speed use for pulmonary population
almost perfect measure
can be assessed in all settings
MCID in pulm rehab = 0.08-0.11 m/s
only outcome measure that provides data related to potential discharge locations/ambulatory locations/etc
gait speed cut off scores for COPD pts
slow = <0.8 m/s
normal = >/= 0.8 m/s
what is St. George’s Respiratory Questionnaire (SGRQ)
designed to measure impact of overall health, daily life, and perceived well being in pts with obstructive airway disease
combines frequency and severity of symptoms with activities that are limited by breathlessness
scored out of 100
higher scores = more limits
MCID = 4 for minimal improvement, 8 for moderate, 12 for high
what is a chest x-ray and that does it show
static view
shows air, fat, fluid, bone, other tissues
air = black
fat, fluid, bone, and other tissues = variations from gray to white
chest x-ray views
anterior to posterior = frontal plane
lateral = sagittal plane
indications for a chest X-ray
first line of imaging for any respiratory distress
suspicion for pulmonary pathology
post line or device placement
post intubation or extubation
what is the costophrenic angle
junction of the costal diaphragmatic and pleural surfaces
should be a sharp angle ~30 degrees
when is a CT used in pulmonary cases
used to identify structural defects of the lungs or pulmonary vasculature
more detailed than CXR
can be performed with or without IV contrast depending on indication and comorbidities
indications for CT scan with pulmonary pts
lung cancer
ARDS/Covid
any bleeding
structural details
when is a CTA used in pulmonary cases and how does it work
radiopaque IV contrast injected prior to CT scan
shows vascular abnormalities or perfusion deficits (vascular obstruction, filling defects, impairments in flow rate)
first line of imaging used to diagnose PE
CTA indications for pulmonary pts
PE
ARDS
IPF
when is a PET scan used in pulmonary cases
nuclear imaging that can detect glucose uptake, blood flow, and pulmonary metabolism
noninvasive, used to assess for presence of lung tumor metastasis in thoracic cavity
not as accessible as other scans (CT/MRI), expensive, requires equipment
when is a MRI used with pulmonary pts
evaluates pulmonary anatomy, thoracic cavity structures, pulmonary blood flow
similar diagnostic accuracy as PET imaging but less expensive and more available
MRA = magnetic resonance angiogram (MRI with contrast to evaluate vasculature)
MRI indications for pulmonary pts
any conditions involving bone, mm, fat of thoracic cavity
pre-op for sx guidance
lung cancer
what is a ventilation perfusion scan (V/Q scan)
ventilation = air in lungs
perfusion = blood in lungs
measures ventilation
- xenon gas inhaled and pt holds breath
- V scans over lung fields and can see Xenon gas
measures perfusion
- radioactive IV contrast injected
- Q scans over lung fields can see where the blood is perfusing
when is a V/Q scan indicated
PE
IPF/ARDS
how are V/Q scans quantified and what do certain results indicate
scans occur simultaneously and result with a ration of V to Q
both V and Q are greater in lung bases than apex normally
perfusion defect with normal ventilation = suggests PE
ventilation defect with normal perfusion = suggestive of alveolar fibrosis/destruction or airway obstruction
what is a bronchoscopy
fiber optic eval of lower respiratory tract; usually trachea/bronchi/segmental bronchi
flexible optic scope inserted through nose or mouth to show airways
indications for a broncoscopy
visualizing bronchial structures
foreign object removal or biopsy
clearing out of secretions
taking cultures of secretions for infection identification
when is arterial blood gas used in pulmonary pts and what is it
interpretation of blood pH, PaO2/CO2, HCO3 to compare clinical symptoms and SpO2
indications for pulmonary pts:
- respiratory failure/distress
- altered mental status (AMS)
- to determine O2 delivery device or make changes to mechanical ventilation
what is pulmonary function testing (PFT)
provides info about airway integrity, respiratory mm function, and condition of lung tissues
allows for diagnosis and classification of pulmonary diseases
classifies as restrictive, obstructive, or mixed etiology
3 types:
- lung volumes
- spirometry
- diffusing capacity
what does spirometry measure
speed at which air is exhaled
what does diffusing capacity measure
how well gas diffuses
what is body plethysmograph
has self contained spirometry measurements
much more accurate than other methods of spirometry since it is a closed system
what is forced vital capacity (FVC)
max volume of air exhaled as forcefully and as quickly as possible
expressed in liters
most dependent in amount of force (strength) used in early exhalation when lung is most expanded
reduced in both restrictive and obstructive diseases
what is forced expiratory volume in 1 second (FEV1)
max volume of air exhaled in first second of max exhalation
reflective of airflow in large airways
the Lower the FEV1 %, the more obstructive the disease process
progressive decline linear to worsening of disease
what is FEV1/FVC ratio (%)
calculation that measure the proportion of the FVC that can be exhaled in the first second of forced exhalation
the lower the ration %, the more severe the obstructive disease
anything less than 70% is abnormal
what is diffusing capacity of the lung (DLCO)
measures how well gas diffuses across the alveolar-capillary membrane
amount of gas entering pulmonary blood flow per unit of time
expressed as % of gas diffusing into blood
describe forced vital capacity for resistive and obstructive diseases
R = decreased
O = decreased or normal
describe forced expiratory volume in 1 sec (FEV1) for resistive and obstructive diseases
R = decreased or normal
O = decreased
describe FEV1/FVC ratio for resistive and obstructive diseases
R = normal
O = decreased
describe total lung capacity for resistive and obstructive diseases
R = decreased
O = increased or normal
application of PFTs (VC and TLC) to restrictive disease
decreased VC and TLC
biggest limits to functional endurance are decreased inspiratory reserve volume and expiratory reserve volume
application of PFTs to obstructive disease
increased VC and TLC
biggest limits to functional endurance are increased expiratory reserve volume and residual volume
PFT pattern for restrictive disorders- FEV1 and FVC (i.e. interstitial lung diseases, IPF, PNA, ARDS, NMD)
proportionally decreased FEV1 and FVC
FEV1/FVC near normal
PFT pattern for obstructive disorders- FEV1 and FEV1/FVC ratio (i.e. COPD, emphysema, CF)
FEV1 < 60%
FEV1/FVC ratio <70%
PFT pattern for reactive airways (reversible or partially reversible obstruction like asthma)
decrease of FEV1 by 10-20% with activity or trigger
what is GOLD staging for COPD
used to stratify severity of disease
guides treatment
predictive of functional activity tolerance
values can worsen from baseline if exacerbation occurs
what is diffusing capacity of the lung (DLCO)
measures integrity of the functional lung unity (respiration/oxygenation)
not a measure of any pulmonary mechanics (ventilation)
abnormal DLCO caused by
- degreased Hgb to carry O2
- increased thickness of alveolar-capillary membrane
- decreased surface area available for gas exchange (main factor)
what constitutes mild, moderate, and severe decrease in DLCO values
normal = >75% and up to 140%
mild decrease = 60-74%
moderate = 40-59%
severe = <40%
