Physical Exam

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    Airflow Limitation

    Taken from JAMA rational clinical exam series:

    • Physiology:
      • Airflow limitation resting airway diameter is abnormally small.  This leads to a decrease in tethering forces Airflow limitation can occur due to a variety of reasons:
        • Emphysema: the lung parenchyma is destroyed. This causes a decrease in the tethering forces that keep the airway open.
        • Asthma: smooth muscle around the area is hyperreactive to stimuli.
        • Chronic bronchitis: Increased mucous production in the airways leading to decreased airway diameter.
      • It is significantly more difficult to empty lungs than to fill them due to natural physiologic decrease in airway diameter on expiration.  This leads to air trapping and hyperinflation.
    • History:
      • Background Info
        • Exposure to sigarette smoke (≥70 pack-yrs LR+ 8.0, never smoked LR- 0.16)
          • UPDATE: >40 pak years of smoking is a single best historical feature.
          • Length of smoking works as least as well as pack years (studied).
        • Occupational & Environmental pollutants.
        • Personal/family history of atopic diseases.
        • Age: (AL is not part of normal aging process!!, but age is proxy for toxin/smoke exposure).
      • Symptoms:
        • Wheezing, coughing, sputum production.
          • Sputum production ≥1/4 cup (LR+ 4)
          • Wheeze (LR+ 3.8)
          • (No symptom useful for ruling-in or ruling-out).
        • Chronic bronchitis: sputum production for at least 3 consecutive months in at least 2 years.
    • Exam:
      • Inspection
        • Cough? (intermittent, poor k=0.29)
        • Look for A-P diameter (very specific, esp in children Sp 99%)
      • Vital signs:
        • Pulsus Paradoxus (Sn 45%, Sp 88% - most sensitive 2nd to Match test)
          • During tidal breathing, BP cuff inflated above systolic.  Slowly deflate until hear sound only during expiration, continue to deflate until hear during inspiration.
          • Expiration BP > Inspiration BP
          • ≥15mmHg differnece = positive.
      • Palpation
        • Palpate cardiac apex (in hyperinflation apex shifts centrally).  (LR 4.6 specific, not sensitive, useful if present)
          • Either cannot palpate or palpate centrally in subxiphoid.
      • Percussion
        • Hyperresonance? (very precise, and quite accurate.  LR+ 4.8 LR-0.73, Sn 32% Sp94%. one of most sensitive tests).
        • Diaphragmatic Excursion (normal 5-6cm, decreased in COPD)
      • Auscultation
        • Auscultate bilaterally over lower, middle, and upper lung fields posteriorly, anteriorly, and along mid-axillary line. 
        • Types of sounds:
          • Wheezing - high pitched musical tones during expiration. (most precise, Sn 15%, Sp 99.6%, rules in if heard!)
          • Rhonchi - Lower pitched wheeze
          • Intensity of breath sounds (scoring systems are poor). (less precise k=0.30-0.63)
      • Measures of airflow:
        • Forced Expiratory Time:
          • Take deep breath and forcefully exhale until no more air can be expelled. (keep mouth + glottis open as if yawning).
          • Listen over larynx or trachea with stethoscope the duration of airflow (measure with stopwatch, record to 0.1s).
          • Can do multiple measurements and average
          • Results:
            • <6 seconds --> decrease in likelihood of AL  (LR+ 0.45)
            • 6-9s --> great increase in likelihood of AL  (LR+ 2.7)
            • 9s --> FEV1/FVC of 70%, a level that dx an airflow limitation. (LR+ 4.8)
        • Match test
          • Hold burning match at 10cm from pt's widely opened mouth.  If match is still burning w/ forced expiration --> positive.
          • DO NOT DO if patient is on O2.
        • Peak Flow Meter:
          • Only useful in assessing response to therapy.
          • Studies: only improved accuracy of clinical exam for 1 of 4 MDs studied.  Was equivalent to auscultating a wheeze.

    Does this patient have clubbing?

    • Conditions associated:
      • Neoplastic intrathoracic:
        • Bronchogenic carcinoma
        • Malignant mesothelioma
        • Pleural Fibroma
        • Mestastatic osteogenic sarcoma
      • Suppurative intrathoracic disease
        • Lung Abscess
        • Bronchiectasis
        • Cystic Fibrosis
        • Empyema
        • Chronic cavitary mycobacterial or fungal infection
      • Diffuse pulmonary disease
        • IPF
        • Asbestosis
        • Pulmonary AV malformations
      • CV Disease
        • Cyanotic congenital heart disease
        • Infective endocarditis
        • Arterial graft sepsis
        • Brachial AV fistula
        • Hemiplegic stroke
      • GI
        • IBD
        • Celiac Disease
      • Hepatobiliary Disease
        • Cirrhosis (particularly biliary and juvenile)
      • Metabolic
        • Thyroid acropachy
    • How to measure clubbing:
      • 1. General Appearance
      • 2. Nailfold angles (normal nail comes out at 160°, but in clubbing it is 180° or more.
      • 3. Phalangeal Depth Ratio (Normal Distalphalangeal finger depth DPD < interphalangeal depth (IPD)
        • Normal DPD < IPD
        • Clubbing DPD >IPD
      • 4. Schamroth Sign (Diamond)
        • Very little clinical testing of this.
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