Physical Exam

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.