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Objectives Pulmonary Assessment • Understand anatomy and physiology of pulmonary assessment techniques • Remember approaches to CXR Reid Blackwelder, MD, FAAFP interpretation and ABG Professor and Chair, Family Medicine • Recognize common spirometry patterns Quillen Colege of Medicine, ETSU • Know when to use provocative testing

Control of Respiration Normal Oxygen Transport from Air to Tissues

Normal Oxygen Transport from Air to Tissues Normal Respiratory Defense

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).

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Intial Assessment Subjective

• History • HPI – Dyspnea • Physical exam – Cough – Vitals – Wheeze – Include pulse ox – Consider pulmonary and cardiac causes – Watch (or instruct team) for changes with activity • Past Medical History – Lung problems • Social Hx – Smoking – Environmental exposures

Respiratory Signs and Symptoms Objective

• Apnea • VS for tachypnea (>12-16) • Tachypnea • Description of habitus • Stridor – Tripod position • Cough – Pectus • Wheezing – Scoliosis • Abnormal sounds (never listen through gown) – Stridor – Crackles/Rhonchi vs wheezes – Results of maneuvers

Pulmonary Findings on Exam Lung Sounds

Effusion Consolidation COPD Pneumothorax • Nice link with basic review Trachea Dev Contralateral None None Contralateral • https://www.easyauscultation.com/lung- Fremitus Decreased Increased Decreased Decreased sounds

Percussion Dull Dull resonance resonance

Pectoriloquy Decreased Increased Decreased Decreased

Breath Sounds Decreased Decreased Crackles Decreased

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Special Maneuvers Special Maneuvers

• Vocal fremitus • Pectoriloquy/Egophony – Ulnar edge of hand on chest wall • Spoken words are attenuated as they move – Patient says “ninety-nine” or “one, two, three” through airspace • Increased vibrations from increased density • If consolidation present, attenuation is reduced • Decreased from fatty tissue, COPD, effusion – Increased transmission is pectoriloquy • Percussion • Ninety-nine again – Most students and residents do not do this well! – The change in pitch is called egophony – Dullness from consolidation, effusion • Patient says “eee” heard as “aay” • Remember pneumonia is a clinical not radiologic dx!

CXR Method Cardiomegaly • Airway • Bones • Cardiac • Diaphragm • Effusions • Free Air • Gadgets • Hilum • Interstitium

Effusions Effusions

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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 Determines • pH 7.47 PCO2 20 HCO3 19 – Dx? • Acidemia (<7.35-7.40) – Respiratory alkalosis • pH 7.25 PCO2 60 HCO3 27 • Alkalemia (>7.45) – Dx? – Respiratory acidosis • pH 7.10 PCO2 10 HCO3 6 – Dx? – Metabolic acidosis

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Acidemia Alkalemia

• If the primary process is Metabolic • If the primary process is Metabolic – The HCO3 must be < 24 – The HCO3 must be > 27 – Metabolic Acidosis – Metabolic Alkalosis • If the primary process is Respiratory • If the primary process is Respiratory – The pCO2 must be > 45 – The pCO2 must be << 40 – Respiratory Acidosis – Respiratory Alkalosis

Evaluate Compensation! Metabolic Acidosis A Patient with DKA

✶Decrease in pCO2 = 1.3 (decrease in ✶HCO3 8, and pCO2 20 HCO3) ✶Decrease in pCO2 = 1.3 (24 – 8) ✶pCO2 will not go < 10 = 20.8 ✶Max compensation takes 12-24 hrs ✶pCO2 = 40 – 20.8 = 19 ✶Compensated Metabolic Acidosis

A Patient with DKA Causes of Respiratory Acidosis

• CNS depression ✶HCO3 8, and pCO2 28 • Sedative OD ✶ Decrease in pCO2 = 1.3 (24 – 8) • Acute airway obstruction = 20.8 • COPD ✶ pCO2 = 40 – 20.8 • Pulmonary edema/infection = 19 • Neuromuscular disorders ✶Inadequately compensated Metabolic • Cardiopulmonary arrest Acidosis ✶Possible etiology?

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Causes of Respiratory Alkalosis Lung Volumes • Anxiety (hyperventilation) • 4 Volumes • CNS tumor/infection/stroke – Inspiratory reserve • Pulmonary emboli – Tidal IRV – Expiratory reserve • Pneumonia IC VC – Residual • Drugs TV TLC • 4 Capacities Salicylates, catecholamines, progesterone ERV – Inspiratory • Hypoxia FRC – Functional residual • Fever RV RV – Vital – Total Lung • Sepsis

Pulmonary Function 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)

Office Spirometry… Forced Expiratory Volume (FEV) • Do it! • Critical for diagnosis and management • Convenient • A procedure so you can charge for it

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vs. V FEV1 Flow-Volume Loop: Air Flow olume

Volume of air which can be forcibly exhaled Graphic Effort Effort representation of Dependent Independent from the lungs in the first second of a forced flow-limiting flow limiting the inspiratory and segment at upper segment at Peak Flow expiratory maneuver. expiratory airways lower airways maneuvers FEF 25%

Flow-Volume Loop Flow-Volume Loops • Obstruction

• Restriction

Flow-Volume Loops Patterns of Impairment Obstructive 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

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Spirometry

Low FEV1/FVC Normal Low FVC

Obstructive Suspect asthma Restrictive

Methacholine Challenge

DLCO Bronchodilator Trial FEV1 FEV1 Nl

FEV1 No Change Asthma Normal

COPD Asthma DLCO

Nl: Bronchitis Emphysema

Bronchoprovocation Testing Bronchoprovocation Testing • PFTS are tools in the diagnosis of asthma – Measurement of peak expiratory flow rate • Assesses Bronchial HyperResponsiveness – Spirometry to external triggers (BHR) • May be normal between symptomatic • Excessive response to an aerosolized episodes provocation that triggers little or no • Asthma has characteristic variable airflow response in a normal person limitation • Distinguishes most patients with asthma – Symptoms may only occur with certain – Useful if dx of asthma in question exposures, activity – Establish dx of occupational asthma

Methacholine challenge testing Exercise testing • Inhale dry, cool air during exercise • Cholinergic agonist, induces bronchoconstriction – Ambient room temp 68-77 F • Patient inhales one or more increasing – 50% relative humidity concentrations of Methacholine • Treadmill or bicycle • Spirometry before and after – Exercise at target HR for at least 4 minutes • Test stopped if FEV1 decreases > 20% of • Spirometry before and after over periods of time baseline • Abnormal is fall in FEV1 by 10% • Negative if does not decrease by 20% with max – More than 15% suggests exercise induced dose: makes dx asthma very unlikely bronchospasm

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Take Home Points • Good history and proper exam critical tools • Fully evaluate CXR and ABG • Office spirometry should be done!

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