1.
ADVANCED AHN 1
CARE OF PATIENT WITH ACUTE CONDITIONS OF
RESPIRATORY SYSTEM DISORDERS
PRESENTATION ON “PULMONARY FUNCTION
TEST & RESPIRATORY LAB STUDIES”
By Demiso G. (BSc , MSc in AHN student)
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2.
Objectives
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 Define pulmonary function test
 Interpret each types of pulmonary function test
 Interpret and collecting sputum
 Evaluating and collecting plural effusion
 Collecting and interpret arterial blood gas analysis

3.
Outline
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 Pulmonary function test
 Lab studies (respiratory):
 Sputum test
 Thoracentesis
 ABG analysis

4.
Brainstorming
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What are lung function tests?

5.
Pulmonary function test
 Lung function tests, also known as pulmonary function
tests (PFTs), are a group of tests that check to see if your
lungs are working right.
The tests look for:
 How much air your lungs can hold
 How well you move air in and out of your lungs
 How well the lungs move oxygen into your bloodstream.
 Your blood cells need oxygen to grow and stay healthy.
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6.
Indications of PFT
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Pulmonary Evaluation:
 ƒ
Presence of impairment
 ƒ
Type of Pulmonary dysfunction
 ƒ
Monitor the progression of known disease
 ƒ
Monitor the treatment response of known disease
Preoperative Assessment:
 ƒ
Estimate the risk for postoperative complications
 ƒ
Tolerance for lung resection (resectability)
Disability Evaluation

7.
PFT is recommend for patient having symptom
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 Shortness of breath
 Coughing
 Coughing up mucus or phlegm
 Wheezing
 Difficulty breathing
 Fatigue
 History of smoking

8.
Pulmonary Function Tests includes :
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 ‰
Spirometry
 ‰
Lung Volumes
 ‰
Diffusion Capacity
 ‰
Maximal Voluntary Ventilation (MVV)
 ‰
Maximal Inspiratory Pressure (Pi max)
 ‰
Maximal Expiratory Pressure (Pe max)
 ‰
Arterial Blood Gas (ABG)
 ‰
Walking Oxymetry
 ‰
Broncho challenge Tests

9.
An approach to PFT interpretation
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Confirm patient demographic data
 Interpretation involves comparison of the patient’s
values with reference values:-
Depend on age, sex, race and ethnicity, height
 African Americans have values that are 12% lower
than Caucasians
Threshold for Normal FEV1/FVC
 80-120% predicted
 Age-adjusted lower limits of normal

10.
An approach to PFT interpretation….
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Measures the lung volume change during forced
breathing maneuvers:
 Forced vital capacity (FVC) – amount of air that can
be exhaled in 1breath with maximum force
 Forced expiratory volume in 1sec (FEV1)
 Measure of airflow = FEV1/FVC ratio
 Peak flow rate (PEF, PEFR) – highest flow rate
achieved during expiration

11.
Flow volume loops
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 The FEV1/FVC ratio changes with age
 The FEV1/FVC ratio declines in normal people as
they get older
‒ An average FEV1/FVC in a 20 year old is 87%
‒ An average FEV1/FVC in an 84 year old is 71%
 The lower limit of normal in an 84 year old is 59%!

12.
Flow volume loops….
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 If the FEV1/FVC ratio is normal, then the patient is
NOT obstructed.
 Obstruction is present if the FEV1/FVC ratio is
reduced.
 Reversible obstruction‒ 12% increase and 200 mL
increase in FVC or FEV1with bronchodilator

13.
1, Lung volume test
 This test measures the amount of air you can hold in
your lungs and the amount of air that remains after you
exhale (breathe out)
 You will be asked to wear a nose clip and you will be
given instruction on how to breathe through a
mouthpiece.
 The test takes about 15 minutes.
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14.
2. Lung volumes and capacities
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15.
Lung volumes & capacities….
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 Tidal Volume (VT):The volume of air entering the nose or
mouth per breath (500 ml)
 Residual Volume (RV): The volume of air left in the lungs
after a maximal forced expiration(1.5L)
 Expiratory Reserve Volume (ERV): The volume of air that is
expelled from the lung during a maximal forced expiration that
starts at the end of normal tidal expiration (1.5L)
 Inspiratory Reserve Volume (IRV): The volume of air that is
inhaled into the lung during a maximal forced inspiration
starting at the end of a normal tidal inspiration (2.5L)

16.
Lung volumes & capacities….
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 Functional Residual Capacity (FRC): the volume of air
remaining in the lungs at the end of a normal tidal expiration (3L)
 Vital Capacity (VC): The volume of air that is expelled from the
lung during a maximal forced expiration effort starting after a
maximal forced inspiration (4.5L)
 Total Lung Capacity (TLC): The volume of air that is inhaled
into the lung after a maximal inspiration effort (5-6 L)
 Inspiratory Capacity (IC): The volume of air that is inhaled into
the lung during a maximal forced inspiration effort that begins at
the end of a normal tidal expiration (VT+IRV=3L)

17.
3. Spirometry
 The most common type of lung function test.
 It measures how much and how quickly you can move
air in and out of your lungs
 So called measure of airflow
 During this test, you forcefully exhale and then inhale
into a tube connected to a machine called a spirometer.
 The spirometer measures the amount of air you blew out
of your lungs and then inhaled back into your lungs.
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18.
Spirometry…..
 You will be asked to repeat this test two or three times to
get an accurate measure of your lung function.
 It takes approximately 30 minutes to complete this test.
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19.
Indications For Spirometry
 Evaluation of unexplained dyspnea, cough, or wheezing
 Suspected COPD or asthma with no previous spirometry
 Known asthma or COPD with uncertain control
 Known asthma or COPD when assessing response to treat.
 Periodic assessment (every 1-2 years) of asthma to assess for
changes in therapy
 Assessment of vital capacity in patients with known NMD.
 Pre-operative assessment in patients with known or suspected
lung disease
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20.
Interpret the PFTS with a systematic approach
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Patterns of disease with LFT is divided into three:-
1. Obstructive FEV1/FVC < 0.7 (or <LLN):-
 These diseases cause airways to become narrow, making it
hard for air to flow out of the lungs.
1. Restrictive FEV1/FVC reduced with low lung volumes
 Because of the lungs or chest muscles aren't able to expand
enough.
 This reduces air flow and the ability to send oxygen into the
bloodstream.
1. Mixed are both obstructive and restrictive

21.
…..
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22.
Obstructive Lung Diseases:
 ‰
Emphysema & Chronic Bronchitis ( COPD)
 ‰
Cystic Fibrosis
 ‰
Asthma
 ‰
Bronchiectasis
 ‰
Some Interstitial Lung Disease: (combined)
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23.
™
Restrictive Lung Diseases:
 CHF
 Atelectasis
 Fibrosis
 Tumor
 Pregnancy and obesity
 Kyphosis
 Ascites and infusion
Goal: to evaluate the reversibility of the airway obstruction.
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24.
Spirometry Interpretation
 The normal value of FEV1 and FVC vary depending
on:
1. Age
2. Gender
3. Race
4. Height
 The FEV1/FVC is within a normal range 74%).
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25.
4. Gas diffusion capacity test:
 This test measures how oxygen and other gases move
from the lungs to the bloodstream.
 Measure of gas exchange across the alveolar/capillary
membrane
 Affected by age, body size, gender, hemoglobin, and lung
volume
 Measured by carbon monoxide uptake
 You'll wear a mouthpiece connected to a machine
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26.
Gas diffusion capacity test….
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 Measurements will either be taken as you breathe in or as you
breathe out
 You will be asked to inhale (breathe in) a very small, non-
dangerous amount of CO2 or other type of gas.

27.
Gas diffusion capacity test….
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Decreased Diffusing Capacity
 Anemia
 Right-left intracardiac shunt
 Poor inspiration
 Interstitial lung disease
 Emphysema
 Pulmonary vascular disease

28.
5. Exercise stress test.
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 This test looks at how exercise affects lung function.
 These tests may be used together or by themselves,
depending on your specific symptoms or condition
 You'll be attached to monitors and machines that will
measure blood oxygen, blood pressure, and heartbeat.
 This helps show how well your lungs perform during
exercise
Goal: detects the hidden diffusion defect.

29.
Exercise stress test….
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 Technique: check O2 saturation at rest, 4 min and 6 min
walk.
 Walking oxygen desaturation:
- Diffusion defect and
-V/Q mismatch
 Criteria for Oxygen Supplementation (Home Oxygen):
1. PO2 <55 or oxygen saturation <88%
2. PO2 <59 with pulmonary hypertension

30.
General direction for LFT
 To ensure breathing is normal and unrestricted
Patient preparation and education on:-
 Don't eat a heavy meal before the test.
 Avoid food or drinks with caffeine.
 Don't smoke or do heavy exercise for 6hr before the test
 Wear loose, comfortable clothing.
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31.
2. Lab studies (respiratory)
A. Sputum test
B. Thoracentesis
C. ABG analysis
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32.
A.Sputum test
 A sputum test, also known as a sputum culture.
 Is a test that may order when you have a RTI or other
lung-related disorder to determine what is growing in the
lungs.
 Sputum is a thick substance that accumulates when
bacteria or fungi grows and multiples in the lungs or
bronchi.
 As it accumulates, the growing substance can make
breathing more difficult and cause coughing
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33.
SPUTUM TEST CON’T…
A sputum test can diagnose:
 Bronchitis
 Lung abscess
 Pneumonia
 Tuberculosis
 COPD
 Cystic fibrosis
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34.
SPUTUM TEST CON’T…
Person having any of the following symptoms, you may
need a sputum test:
 Cough
 Fever
 Chills
 Fatigue
 Muscle aches
 Breathing problems
 Chest pain
 Confusion
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35.
What to expect during a sputum test?
 During a sputum test, you will be asked to cough
deeply enough to bring up a large quantity of sputum
so your can evaluate it.
 The most challenging part of the test is to produce a
sample size large enough for it to be tested.
 Saliva that lives in the upper airways is not useful for
this test.
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36.
Evaluate the color of the sample.
 Off-white, yellow or green sputum can indicate you
have pneumonia or bronchitis
 Red or rusty can indicate you have a more serious
condition that needs more testing
 Grey or black can indicate that you are a smoker or
someone who works in a sooty place (like a coal
mine)
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37.
How much sputum is normal?
 The normal lung produces approximately 20 – 30 ml of
mucus per day to assist with the functioning of the muco-
ciliary escalator.
 Mucus is called sputum when an excess amount is
produced within the airways and needs to be expectorated.
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38.
SPUTUM TEST CON’T……………
 Sputum from your lungs is usually thick and sticky.
 Saliva comes from your mouth and is watery and thin.
 Do not collect saliva
 Keep doing this until the sputum reaches the 5 ml line or
more on the plastic cup.
 Take a very deep breath and hold the air for 5 seconds.
Slowly breathe out.
 Write on the cup the date you collected the sputum.
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39.
Results from a sputum test
 Patient sputum sample will be sent to a laboratory within 1-
2hrs of production.
 A pathologist will run tests to determine if the growth is a
bacterium, virus or fungus.
 Pathologist will send a report to your doctor as soon as
possible. Typically, within a few days.
 Rapid TB tests can be ready in as little as 24 hours, but results
for other lung diseases can take as long as eight weeks.
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40.
What is the role of nurse in sputum test?
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 Health education about sputum dispose
 How to coughing and sneezing
 About breathing exercise
 Using PPE while patient serving
 Family’s counseling about TB,Corona and etc.
 Isolation and quarantine until underlying cause is
identified

41.
ii. Thoracentesis
 Thoracentesis is a invasive procedure that is performed to
remove fluid from around the lung.
 The lung is covered with a tissue called the pleura.
 The inside of the chest is also lined with pleura. The space
between these two areas is called the pleural space.
 This space normally contains just a thin layer of fluid(15-20 ml)
 However, some conditions such as pneumonia, cancer, CHF,
liver failure and respiratory infection may cause excessive fluid
to develop (pleural effusion)
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42.
Site and position of needle insertion
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43.
Thoracentesis…………
 To remove this fluid for evaluation (testing) or improve a
patient’s breathing, a procedure called a thoracentesis
 Thoracentesis involves placing a thin needle or tube into
the pleural space to remove some of the fluid.
 The needle or tube is inserted through the skin, between the
ribs and into the chest.
 The needle or tube is removed when the procedure is
completed.
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44.
Thoracentesis…………
 If a person needs more fluid drained, sometimes the tube
is left in place for a longer time
 The procedure takes about 30 minutes but expect your
visit to last 1-2 hours to include preparation, and
observation in recovery.
 The fluid is then sent to a laboratory for pleural fluid
analysis.
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45.
Thoracentesis…………
 The American Thoracic Society says that the most
common reasons to perform thoracentesis are:
1. To diagnose the cause of new pleural effusion
2. To improve comfort
3. To diagnose cancer or improve cancer symptoms
4. To diagnose a suspected infection
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46.
What are the Risks of a Thoracentesis?
 Pain during placement
 Bleeding
 Collapsed lung
 Bruise
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47.
Preparation for a Thoracentesis
 Instructions about need to prepare for the procedure;-
 Not taking medications prior to or the day of the procedure
 To hold eating or drinking for some time period before it.
 Position:- sitting in a chair or lying on a table
 Use an ultrasound to confirm the correct area where the needle will
go. They may also use CT guidance.
 Usually an adult or older child remains awake when a thoracentesis is
done.
 The skin is cleaned with a disinfectant before the needle is inserted.
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48.
Preparation for a Thoracentesis…..
 Local numbing medicine is injected into the skin first.
 The fluid may drain through the needle by doctor.
 When the fluid is removed, the needle and tube are removed
and a bandage is placed over the insertion site wound.
 The wound closes on its own without the need for stitches.
 Perform a follow-up X-ray right after the thoracentesis.
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49.
Rx Action Steps
Call your healthcare provider if you have:
 Bleeding from the needle site
 New, sudden difficulty breathing
Pain taking a deep breath
A cough that produces blood
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50.
Rx Action Steps….
 After thoracentesis, a lab test called a pleural fluid
analysis may be performed to figure out the cause of
fluid accumulation around one or both of your lungs.
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51.
Understanding the results
 The lab classifies your fluid buildup as either exudate or
transudate.
 Exudate is cloudy in appearance, and it normally contains
high levels of protein and a compound known as lactate
dehydrogenase (LDH).
 It’s most commonly the result of inflammation caused by
an infection of the lungs, such as pneumonia or TB.
 An exudate can also be related to cancer.
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52.
Understanding the results….
 Transudate is a clear fluid that contains little or no protein and
low levels of LDH.
 It usually signifies the failure of an organ such as the liver or
heart.
 If the pleural fluid analysis suggests cancer, further tests
including a closer evaluation of the lungs and other organs.
 Your treatment will depend on the underlying cause of the
pleural effusion.
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53.
C. ABG (Arterial blood gas) analysis
A vital role in monitoring of
 Postoperative patients,
 Patients receiving oxygen therapy,
 Those on intensive support,
 Patients with significant blood loss, sepsis, and comorbid
conditions like diabetes, kidney disorders,
 Cardiovascular system (CVS) conditions
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54.
Why do we order a blood gas analysis?
 Aids in establishing diagnosis
 Guides treatment plan
 Improvement in the management of acid/base
 Acid/base status may alter levels of electrolytes critical to
the status of a patient
 Effectiveness of gas exchange
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55.
Limitations of blood gas analysis
 Can not yield a specific diagnosis.
E.g. A patient with asthma may have similar values to
another patient with pneumonia
 Does not reflect the degree to which an abnormality
actually affects a patient.
 Cannot be used as a screening test for early pulmonary
disease.
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56.
Obtaining an arterial sample
Order of preference:
 Radial > brachial >femoral artery
Radial artery is preferred:
 Ease of palpation and access
 Good collateral supply.
Collateral supply to the hand:
 Confirmed by the modified Allen's test
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57.
Modified Allen's test
 Ask the patient to make a tight fist.
 Apply pressure to the wrist:
 Using the middle and index fingers of both hands
 Compress the radial and ulnar arteries at the same time
 While maintaining pressure:
 Ask the patient to open the hand slowly.
 Lower the hand and release pressure on the ulnar artery
only.
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58.
Modified Allen's test….
 Positive test:
 The hand flushes pink or returns to normal color within 15seconds
 Negative test:
 The hand does not flush pink or return to normal color within 15
seconds
 Indicating a disruption of blood flow from the ulnar artery to the
hand
 Radial artery should not be used
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59.
Sampling
 Arm of the patient
 Palm up on a flat surface
 Wrist dorsiflexed at 45°.
 Puncture site :
 Cleaned with alcohol or iodine
 Allow the alcohol to dry
 Local anesthetic
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60.
Sampling……..
 Radial artery should be palpated for a pulse
 Syringe with a 23/25 gauge needle should be inserted
at an angle just distal to the palpated pulse.
 After the puncture, sterile gauze should be placed
firmly over the site and direct pressure applied for
several minutes to obtain hemostasis
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61.
Errors
1. Always note the percentage of inspired air (FiO2 )
2. Avoid air bubbles in syringe.
3. Avoid delay in sample processing.
4. Accidental venous sampling.
5. Do not use excess heparin as
 It causes sample dilution
 Excess of heparin may affect the pH
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62.
The 6 easy steps to ABG Analysis
1. Is the PH normal?
2. is the O2 is normal?
3. Is the CO3 is normal?
4. Match the CO2 or the HCO3 with the PH?
5. Does the CO2 or the HCO3 go to opposite direction
of PH?
6. Are the PO2 or the O2 is normal?
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63.
Normal & abnormal values of ABG analysis
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64.
Acid-base in balance
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65.
Steps of interpretation
Step 1: Anticipate the disorder
 keeping in mind the clinical settings and the condition
of the patient
E.g., the patient may present with a history of insulin-
dependent diabetes mellitus (IDDM), which may
contribute to a metabolic acidosis
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66.
Step 2: Check the pH
 pH < 7.35: Acidosis
 pH > 7.45: Alkalosis
 pH = 7.35-7.45: Normal/mixed disorder/fully
compensated disorder
 Note: If mixed disorder, pH indicates stronger
component
 If PH is < 6.8 or > 8.0 death occurs.
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67.
Clues to a mixed disorder:
 Normal pH with abnormal HCO3 or pCO2
 pCO2 and HCO3 move in opposite directions
 pH changes in an opposite direction for a known primary
disorder
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68.
Step 3: Check SaO2 /paO2
 SaO2 is a more reliable indicator as it depicts the
saturation of hemoglobin in arterial blood.
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69.
Step 4: Check CO2 and HCO3(bicarbonate) levels
 Identify the culprit
 Is it a respiratory/metabolic/mixed disorder?
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70.
Step 5: Check base excess (BE).
 Defined as amount of base required to return the pH to a
normal range.
 If it is positive, the metabolic picture is alkalosis.
 If it is negative, the metabolic picture is acidosis.
 Either of bicarbonate ions/base excess can be used to
interpret metabolic acidosis/alkalosis.
 Normal BE in blood is -2 to + 2 mmol/L.
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71.
Step 6: Check for compensation.
 Is there a compensatory response with respect to the
primary change?
 If yes: compensated
 If no: Uncompensated.
 In case of compensation, does it bring the pH to a
normal range?
 If yes: fully compensated
 If no: Partially compensated
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72.
Summary of acid base
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73.
Exercise (Example: 1)
 If pH is 7.21, HCO3- is 14, and CO2 is 40.
Interpretation
 CO2 is normal
 HCO3- is decreased
 A case of metabolic acidosis.
 Expected compensation would be a decrease in CO2
causing respiratory alkalosis.
 Now consider this table ---
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74.
Example-2
PH: 7.55, paCO2: 49.0, HCO3 : 48.2
Interpretation
PH: 7.55 (alkalosis and increased )
PaCO2: 49.0 (increased)
HCO3: 48.2 (increased)
 paCO2 is increased - retention of CO2 causes acidosis
 HCO3 is increased - increased base causes alkalosis
 So, the primary disorder is metabolic alkalosis.
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75.
Example -3
A patient is in intensive care because he suffered a severe
myocardial infarction 3 days ago. The laboratory reports the
following values from an arterial blood sample: What is the
possible diagnosis of this patient?
PH = 7.3
HCO3- = 20 mEq / L ( 22 - 26)
PCO2 = 32 mm Hg (35 - 45)
Metabolic acidosis
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76.
Examples 4 …………
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 Chaltu is a 45-year-old female admitted to the nursing unit
with a severe asthma attack. She has been experiencing
increasing shortness of breath since admission three hours
ago.
Clinical Laboratory:
 PH = 7.22
 PaCO2 = 55
 HCO3 = 25
Respiratory acidosis.

77.
…
Treat the patient
not the ABG!!!
Thank you
7-Feb-23
PFT & Its lab studies
77