Physical Exam Pearls – 4 (Lungs)

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So far we’ve surveyed a variety of random tips on performing physical exam of the eye, HENT, and Cardiac systems.  Onward to the Lungs.

1.  Inspection is paramount in evaluating how sick a patient is.  Auscultation is key to diagnosis, but not to assessing severity.

• Central Cyanosis = intubate now.  If unable, give 10L oxygen by mask & bag if needed (and call 911 of course).
• Stupor (retention) or Agitation (hypoxia) = pre-terminal (intubate now, or as above).
  • It’s impossible to distinguish the agitation of hypoxia from that of psychosis or drugs.  Asthmatics have died when placed in ER “quiet rooms.”
• Retractions (tracheal notch, supraclavicular, or intercostal use of accessory muscles, which is by definition involuntary) — Needs same day Dx & Tx
• Nasal Flaring — like retractions, mostly seen in Peds, uncommon among adults

2.  Respiratory Rate  — Serious in an adult if ≥24, though must control for fever (give acetaminophen 1 to 1.3 grams & reevaluate)

• Anxiety (e.g. panic disorder) can also cause rapid respirations, but…
• Severe respiratory distress can cause anxiety

3.  Tactile Fremitus —  I rarely perform it.

3a.  In a patient w/ pleuritic chest pain (possible pleural effusion), I check egophony instead.  Auscultate bilaterally (from bottom up) while patient repeats “eee” (ē).  If one side sounds like “-ay” (ā, as in “day”), there’s consolidation.

• Can also try whispered pectoriloquy [what a beautiful term!]:  Pt. repeats “blue moon” softly; it’s auscultated louder on side with consolidation.  Problem is, a true whisper (without vibration in voice) may not reveal it.

4.  Percussion  —  The only time I perform it is in patient with pleuritic chest pain, or unilaterally decreased breath sounds:

• Dullness = consolidation (pneumonia, effusion)
• Confirm as in 3a. above

4a.  Percussion may also be useful in cyanotic patient in extremis:

• Unilateral Hypertympany suggests tension pneumothorax, especially if no breath sounds ipsilaterally, trachea deviated to other side, distended neck veins, & hypotension
• Inserting large-bore needle over upper margin of 3^rd rib [inferior aspect of 2^nd intercostal space] in mid-clavicular line can be life-saving.  Leave needle or angiocath in place.

5.  Auscultation  —  Don’t just listen to “see what’s there.”  Know from your history what you’re looking for.  For example, if you want to rule out / in:

• Pneumonia (pt. with fever & cough)  —  Inch your stethoscope around the entire chest, esp. the axillas, listening for a focal patch of inspiratory rales.
• Asthma  —  Listen in a few fields bilaterally, front & back, for:
  • Wheezes (long expiratory sound, usually high-pitched)
  • Rhonchi (squeaks / gurgles, on inspiration / expiration)
  • Long expiratory phase (expiration greater than inspiration; “E > I”), sometimes only heard upon forced expiration.
  • Even with clear lungs, E > I = Bronchospasm !!!!!  For normal lungs, always include “I > E” in your charting, so you remember to listen for it.
• Upper Airway Obstruction  —  Pretty rare; just don’t get fooled when you hear Stridor & think it’s a wheeze.  The latter is expiratory, whereas Stridor is a long, high-pitched sound heard best over the neck, only during inspiration.
  • Short high-pitched inspiratory sounds are usually rhonchi, from the lungs (not upper airway)
  • Stridor should be pure, without any other adventitious sounds, since upper airway disease doesn’t affect the lungs.  If you hear lots of different sounds, odds are it’s all pulmonary, not upper airway.
  • Seek stridor on patients likely to have upper airway disorders — choking victims, angioedema from anaphylaxis, epiglottitis or other upper airway infections, neuromuscular disorders that affect lower cranial nerves (bulbar palsies), etc.
• Heart Failure (pt. with cardiac risks)  —  Bibasilar rales.  Start at the bases posteriorly, inch your way up, listening carefully during inspiration, comparing bilaterally as you go.
• Pleuritic Chest Pain (effusion, pneumothorax)  —  compare both sides for unilateral absent breath sounds.
• TB  —  Don’t miss the tops of chest for apical rales (uncommon, even with active TB)

6.  Auscultation  —  Spurious Sounds

• Nasal noises can confound.  If the lungs sound weird, I may take the stethoscope out of one ear & move to the patient’s side so I can listen to the back with one ear, & hear what’s coming out the nose & mouth with the other.
• G-I gurgles can also interrupt.  I might have the patient pause between breaths; anything heard then ain’t from the lungs.
• No breath sounds — patient may be breathing very quietly.  As for many maneuvers, it can help to demonstrate (“Breathe like this, through your mouth” & you take deep, determined breaths with mouth wide open).

7. Pulse Oximetry  —  Potentials for Error

• Blood pressure cuff inflation causes a false-low O2 Sat if the sensor is on the same hand (due to hypoperfusion)
• Nail Polish: Green & blue polish might cause an O2 Sat drop of 5%.  Mount the sensor sideways on the finger to check.  Red polish doesn’t seem to matter
• Skin Color  —  shouldn’t matter, though one study found dark skin caused false-high O2 Sats by about 3%
• Severe venous congestion (e.g. severe CHF) may give false-low readings, though clinically I’d be hesitant to blame error instead of the disease itself.
• Anemia shouldn’t contribute unless the hemoglobin is <5 grams, & even then it isn’t so clinically relevant
• Acute hypothermia may cause delayed detection of hypoxemia
• Hypoperfusion (B/P <80 mmHg) causes false-low readings
• Carboxyhemoglobin in carbon monoxide poisoning or in heavy smokers cause significant deceptively-normal false-high readings
• Methemoglobinemia causes fale-high O2 Sats.  It’s usually caused by Dapsone, though other culprits have included aniline dyes (industrial exposure, or as drug-of-abuse), nitrites, and chloroquine.
• Sickle hemoglobin usually gives normal readings, though false highs & lows have been reported.  This would be an issue in critically ill patients, who’d require a blood gas for confirmation.

Today’s posting was brief.  Next posting will cover the Abdomen