12/13/2017

1

Pulmonary Assessment

Reid Blackwelder, MD, FAAFP

Professor and Chair, Family Medicine

Quillen Colege of Medicine, ETSU

Objectives

• Understand anatomy and physiology of

pulmonary assessment techniques

• Remember approaches to CXR

interpretation and ABG

• Recognize common spirometry patterns

• Know when to use provocative testing

Control of Respiration Normal Oxygen Transport from Air to Tissues

Normal Oxygen Transport from Air to Tissues

1. Nose: Filters large particles (> 10um). 2. Vocal cords: Protects from aspiration.

3. Lower airway branching: Filters intermediate particles (2–10um).

4. Alveolar: A. Ciliary function.

B. Macrophage.C. Secretory IgA.

5. Cough: Protective reflex mechanism that removes foreign particles and

mucus from the airway.

Effective cough requires:1. Cough receptors

2. Afferent fibers 3. Cough center in the brain

4. Efferent fibers (phrenic & spinal motor nerves innervate diaphragm &

intercostal muscles).

Normal Respiratory Defense

12/13/2017

2

Intial Assessment

• History

• Physical exam

– Vitals

– Include pulse ox

– Watch (or instruct team) for changes with activity

Subjective

• HPI

– Dyspnea

– Cough

– Wheeze

– Consider pulmonary and cardiac causes

• Past Medical History

– Lung problems

• Social Hx

– Smoking

– Environmental exposures

• Apnea

• Tachypnea

• Stridor

• Cough

• Wheezing

Respiratory Signs and Symptoms

Objective

• VS for tachypnea (>12-16)

• Description of habitus

– Tripod position

– Pectus

– Scoliosis

• Abnormal sounds (never listen through gown)

– Stridor

– Crackles/Rhonchi vs wheezes

– Results of maneuvers

Pulmonary Findings on Exam

Effusion Consolidation COPD Pneumothorax

Trachea Dev Contralateral None None Contralateral

Fremitus Decreased Increased Decreased Decreased

Percussion Dull Dull resonance resonance

Pectoriloquy Decreased Increased Decreased Decreased

Breath Sounds Decreased Decreased Crackles Decreased

Lung Sounds

• Nice link with basic review

• https://www.easyauscultation.com/lung-

sounds

12/13/2017

3

Special Maneuvers

• Vocal fremitus

– Ulnar edge of hand on chest wall

– Patient says “ninety-nine” or “one, two, three”

• Increased vibrations from increased density

• Decreased from fatty tissue, COPD, effusion

• Percussion

– Most students and residents do not do this well!

– Dullness from consolidation, effusion

Special Maneuvers

• Pectoriloquy/Egophony

• Spoken words are attenuated as they move

through airspace

• If consolidation present, attenuation is reduced

– Increased transmission is pectoriloquy

• Ninety-nine again

– The change in pitch is called egophony

• Patient says “eee” heard as “aay”

• Remember pneumonia is a clinical not

radiologic dx!

CXR Method

• Airway

• Bones

• Cardiac

• Diaphragm

• Effusions

• Free Air

• Gadgets

• Hilum

• Interstitium

Cardiomegaly

Effusions Effusions

12/13/2017

4

Infiltrate Where is the Infiltrate?

Infiltrate Infiltrate Patterns and Pathogens

• CXR Pattern Possible Pathogens

• Lobar S.Pneumo, Kleb, H flu, Gram Neg

• Patchy Atypicals, Viral, Legionella

• Interstitial Viral, PCP, Legionella

• Cavitary Anaerobes, Kleb, TB,

S.Aureus,fungi

• Large effusion Staph, Anaerobes, Kleb

Brief Acid-Base Review

• pH 7.47 PCO2 20 HCO3 19

– Dx?

– Respiratory alkalosis

• pH 7.25 PCO2 60 HCO3 27

– Dx?

– Respiratory acidosis

• pH 7.10 PCO2 10 HCO3 6

– Dx?

– Metabolic acidosis

pH Determines

• Acidemia (<7.35-7.40)

• Alkalemia (>7.45)

12/13/2017

5

Acidemia

• If the primary process is Metabolic

– The HCO3 must be < 24

– Metabolic Acidosis

• If the primary process is Respiratory

– The pCO2 must be > 45

– Respiratory Acidosis

Alkalemia

• If the primary process is Metabolic

– The HCO3 must be > 27

– Metabolic Alkalosis

• If the primary process is Respiratory

– The pCO2 must be << 40

– Respiratory Alkalosis

Evaluate Compensation!

Metabolic Acidosis

✶Decrease in pCO2 = 1.3 (decrease in

HCO3)

✶pCO2 will not go < 10

✶Max compensation takes 12-24 hrs

A Patient with DKA

✶HCO3 8, and pCO2 20

✶Decrease in pCO2 = 1.3 (24 – 8)

= 20.8

✶pCO2 = 40 – 20.8

= 19

✶Compensated Metabolic Acidosis

A Patient with DKA

✶HCO3 8, and pCO2 28

✶Decrease in pCO2 = 1.3 (24 – 8)

= 20.8

✶pCO2 = 40 – 20.8

= 19

✶Inadequately compensated Metabolic

Acidosis

✶Possible etiology?

Causes of Respiratory Acidosis

• CNS depression

• Sedative OD

• Acute airway obstruction

• COPD

• Pulmonary edema/infection

• Neuromuscular disorders

• Cardiopulmonary arrest

12/13/2017

6

Causes of Respiratory Alkalosis

• Anxiety (hyperventilation)

• CNS tumor/infection/stroke

• Pulmonary emboli

• Pneumonia

• Drugs

Salicylates, catecholamines, progesterone

• Hypoxia

• Fever

• Sepsis

Lung Volumes

IRV

TV

ERV

• 4 Volumes

– Inspiratory reserve

– Tidal

– Expiratory reserve

– Residual

• 4 Capacities

– Inspiratory

– Functional residual

– Vital

– Total Lung

RV

IC

FRC

VC

TLC

RV

Residual volume (RV)

• Volume of air remaining in the lungs at the

end of maximal expiration.

• Normally accounts for about 25% of TLC

• Increased in airway narrowing with

– Air trapping (Asthma)

– Loss of elastic recoil (emphysema).

• Decreased with

– Increased elastic recoil (pulmonary fibrosis)

Pulmonary Function

Office Spirometry…

• Do it!

• Critical for diagnosis

and management

• Convenient

• A procedure so you

can charge for it

Forced Expiratory Volume (FEV)

12/13/2017

7

FEV1Volume of air which can be forcibly exhaled

from the lungs in the first second of a forced

expiratory maneuver.

Flow-Volume Loop: Air Flow vs. Volume

Graphic representation ofthe inspiratory andexpiratorymaneuvers

Effort

Dependentflow-limiting

segment at upper

airways

Effort

Independentflow limiting

segment at

lower airways

FEF 25%

Peak Flow

• Obstruction

Flow-Volume Loop

• Restriction

Flow-Volume Loops

Flow-Volume Loops Patterns of ImpairmentObstructive Restrictive

Normal/Big lungs Small lungs

Low Flow Normal Flow

FVC Nl or

FEV1

FEV1/FVC

TLC Nl or

RV

For low FVC, measure lung volumes

12/13/2017

8

Spirometry

NormalLow FEV1/FVC Low FVC

Obstructive Suspect asthma Restrictive

Bronchodilator Trial

FEV1

Asthma

No Change

COPD

DLCO

Nl: Bronchitis Emphysema

DLCO

Methacholine Challenge

FEV1

Asthma

FEV1 Nl

Normal

Bronchoprovocation Testing

• PFTS are tools in the diagnosis of asthma

– Measurement of peak expiratory flow rate

– Spirometry

• May be normal between symptomatic

episodes

• Asthma has characteristic variable airflow

limitation

– Symptoms may only occur with certain

exposures, activity

Bronchoprovocation Testing

• Assesses Bronchial HyperResponsiveness

to external triggers (BHR)

• Excessive response to an aerosolized

provocation that triggers little or no

response in a normal person

• Distinguishes most patients with asthma

– Useful if dx of asthma in question

– Establish dx of occupational asthma

Methacholine challenge testing

• Cholinergic agonist, induces bronchoconstriction

• Patient inhales one or more increasing

concentrations of Methacholine

• Spirometry before and after

• Test stopped if FEV1 decreases > 20% of

baseline

• Negative if does not decrease by 20% with max

dose: makes dx asthma very unlikely

Exercise testing

• Inhale dry, cool air during exercise

– Ambient room temp 68-77 F

– 50% relative humidity

• Treadmill or bicycle

– Exercise at target HR for at least 4 minutes

• Spirometry before and after over periods of time

• Abnormal is fall in FEV1 by 10%

– More than 15% suggests exercise induced

bronchospasm

12/13/2017

9

Take Home Points

• Good history and proper exam critical tools

• Fully evaluate CXR and ABG

• Office spirometry should be done!