Exam 2 Pulmonary Flashcards
Indications for PFT, Spirometry, DLCO
- airway fx
- lung volume
- diffusion capacity
indications for ABG, DLCO, ventilation perfusion scan
gas exchange
PFT/Spirometry Goal
Ultimately two FEV1’s and FVC’s within 200ml and 5% of each other
pft/ spirometry technique
Sit up straight
Seal nares
Fully seal mouthpiece
Maximal inspiration without coughing or hesitation
Blast out expiration “forced” a minimum of 6 seconds up to 15 seconds
Repeated until three acceptable flow volume loops obtained
Never allow more than 8 blows (risk of passing out, blowing off all CO2)
Forced vital capacity aka FVC
total amount of air expelled in 6 sec
reflects how well pt took deep breath in and out
Healthy FEV1
70-80% first second
forced expiratory volume 1 sec (FEV1)
assess airway obstruction
what age does FEV1 decline
30-35 ml/yr in healthy non smokers
what helps calculate predicted values for pft
ht
age
gender
face
restriction pattern on pft
sharp peaked appearance
prevents full lung expansion
decreased FVC with normal or above FEV1/FVC ratio
restriction pattern FEV1/FVC ratio
FEV1/FVC ratio > 70%
diseases with restriction on pft
Parenchymal lung disease/chest wall disease
IPF/ILD, Kyphoscoliosis, polio, ALS, morbid Obesity (anything that effects chest wall)
obstruction pattern on pft
scoop appearance
Airflow reduced airways narrow, air trapping
FEV1↓ ** ↓ FEV1/FVC ratio <70%
dt narrowing of airways, dt air trapping
diseases with obstruction on pft
copd
asthma
Quantify Severity of Illness
Spirometry: FEV1 % Predicted Gold guidelines
GOLD 1: Mild >/= 80%
GOLD 2: Moderate 50-79%
GOLD 3: Severe 30-49%
GOLD 4: Very Severe < 30%
post bronchodilator - pft
what is considered reversible flow
15% or more and 200ml increase in FEV1 or FVC
diffusion capacity Is done why
Done to assess ability of gas (oxygen) to cross membrane (alveoli) into the blood stream
Decreased diffusion reported as DLCO in (examples)
COPD ILD/Pulmonary fibrosis Obesity Hypoventilation Syndrome Severe Emphysema Interstitial Pneumonitis Sarcoidosis
when does diffusion capacity begin to correlate with need for o2 at night typically
when diffusion capacity starts to reach 40-50
will need overnight pox to assess o2 need at night
O2 testing and qualifying with ABG or room air test
PO2<55% or SAO2 88% or below
o2 testing and qualifications with pt with chf/cor pulmonale with documented edema
PO2 55% or below or SAO2 89% or below (1% difference from norm)
continuous nocturnal pox recording that qualifies o2 need
Total of 5 minutes or more NON CONSECUTIVE with pox 88% or below or 89% or below for CHF as above.
respiratory failure - 2 types
type 1 hypoxic
type 2 hypercapnic
type 1 hypoxic RF
PaO2 < 60 (might not have ABG)
PCO2 normal
Disorder of oxygenation
type 2 hypercapnic HF
PaCO2 > 50
When we know pt has chronically elvated CO2, they can be considered mixed or just hypercapnic
PaO2 < 60 or has been corrected and PCO2 remains elevated
Oxygen content is dependent on what
hgb concentration and hgb/o2 saturation
pox is what
estimate of percentage of oxygenated hgb in blood in infra-red spectra
+/- 3 accuracy
pao2 defines
measures oxygen tension not content
part of abg
pco2 is measurement of what
ventilation, what we exhale off when breathing
6 minute o2 test, respiratory problem
Drop of 5% or more in oxygen saturation
6 min o2 test, excessive HR response with no fall in o2 level indicates
deconditioning
cardiac problem
ph value
7.35-7.45
pco2
35-45
po2
70-100
hco3
23-38
increased pco2
alkaline condition
decreased pco2
acidic condition
po2 value means
oxygen tension
hco3 increase
alkaline
hco3 decrease
acidic
