Nurses Guide to Lung Auscultation of lung sounds and the comprehensive respiratory assessment (with audio!)
Respiratory Assessment & Lung Sounds: A Nurse's Guide (with Audio)
A solid respiratory assessment is about far more than just listening to lung sounds. It's a full sequence — inspection, palpation, percussion, and auscultation — that lets you catch respiratory trouble early.
This guide walks through the complete respiratory exam the way it actually plays out at the bedside, with real lung sound audio for each adventitious breath sound so you can train your ear. The lungs oxygenate the blood that keeps every tissue alive — if they quit, your patient has minutes. That's why this assessment matters in the ER, urgent care, and every inpatient and outpatient setting.
Respiratory Distress vs Respiratory Failure
Recognizing and responding to these two states quickly is core nursing work, and the difference matters.
Respiratory Distress
Distress is the difficulty or discomfort of breathing from inadequate oxygenation or ventilation. It's a symptom, not a diagnosis — a sign of an underlying problem. Watch for increased respiratory rate, accessory muscle use, nasal flaring, and cyanosis. Causes range from acute events like asthma attacks or pulmonary embolism to chronic ones like COPD exacerbations. When assessing, look at the whole patient: can they speak in full sentences? What's their skin color? And keep eyes on the respiratory rate and oxygen saturation.
Respiratory Failure
Failure is the more severe state, where the respiratory system fails at one or both of its gas-exchange jobs — oxygenation and CO2 elimination. It comes in two types:
Signs are more ominous than distress: confusion, lethargy, and possible loss of consciousness from hypoxia or hypercapnia. You may see tachypnea, bradypnea, or irregular breathing. In severe cases, respiratory arrest follows. These patients often need BiPAP or intubation — see RSI Intubation for Nurses.
The Advanced Respiratory Assessment
Vital Signs
Vitals give you objective, fast data on oxygenation status — start here.
COPD & Oxygen Saturation
COPD patients run lower baselines, often 88–92%. Oxygen is usually started if they drop below 88%, but be careful not to over-oxygenate a COPD patient — too much O2 can drive up their CO2 and cause hypercapnia. For the full breakdown, see Oxygen Delivery Devices & Flow Rates.
Capnography
Capnography measures the partial pressure of CO2 in exhaled air in real time — invaluable in critical care, the OR, and during sedation. A capnograph attaches to the airway (ET tube, mask, or nasal prongs) and reports end-tidal CO2 (EtCO2) as both a number and a waveform.
Reading the Capnography Waveform
The capnogram (the waveform) moves through distinct phases:
Start of exhalation. CO2 should be near zero if the patient isn't rebreathing.
A sharp rise as dead space clears and alveolar gas reaches the airway.
A gradual rise reflecting alveolar exhalation. Its shape shifts with ventilation and perfusion.
A sharp drop as fresh gas enters and CO2 falls.
Interpreting the Waveform
The "Sharkfin" = Bronchospasm
Normally the waveform has a crisp upstroke and a flat plateau (a sharp alpha angle between them). In bronchospasm or airway obstruction, that angle widens and the curve slopes into a rounded "sharkfin" shape. A sloped, sharkfin waveform — not a sharp one — is the sign of obstruction.
EtCO2 During CPR
EtCO2 is a great gauge of CPR quality. Aim for >10 mmHg during compressions (at 100–120/min); a low value suggests ineffective compressions. A sudden jump in EtCO2 can be the first sign of ROSC.
Inspection
You can learn a lot just by looking — distress is often obvious before you ever touch a stethoscope.
Audible Breath Sounds
Some abnormal sounds are loud enough to hear without auscultating — these are "audible breath sounds." The worst of them is stridor, which signals an upper airway obstruction in the larynx or trachea and demands urgent evaluation.
Overall Appearance & Positioning
Anxiety, restlessness, or lethargy may flag hypoxia or impending failure. Patients in distress also instinctively position themselves to breathe better:
- Orthopnea: trouble breathing lying flat, so they sit up or stack pillows.
- Tripod position: leaning forward on the hands to ease breathing, common in emphysema and chronic bronchitis.
Thorax & Trachea
Check for asymmetry. A deviated trachea can indicate a tension pneumothorax. The chest should be wider than it is deep — COPD patients may be "barrel-chested." Asymmetric expansion can occur with a large pleural effusion.
Work of Breathing
Breathing should be effortless and regular. Increased effort shows up as:
- Tachypnea: rapid breathing, sometimes with audible sounds.
- Accessory muscle use: straining of neck, shoulder, or abdominal muscles.
- Nasal flaring: widening nostrils with each breath, especially in kids.
- Retractions: inward pull of the soft tissues between/around the ribs — a sign of severe effort, seen in severe asthma, COPD, or upper airway obstruction.
When breathing gets hard, the body recruits the sternocleidomastoid and scalenes on inspiration and the intercostals/abdominal muscles on expiration. The more accessory muscles in play, the worse the distress.
Cyanosis & Clubbing
Cyanosis — bluish skin and mucous membranes — is a late sign of hypoxia; check the lips, tongue, and extremities. It may be hard to see in severe anemia or darker skin tones, so the mucous membranes are more reliable. Clubbing (bulbous fingertip swelling) reflects chronic hypoxic conditions like COPD and congenital heart defects.
Palpation (Tactile Fremitus)
We rarely think of palpating the lungs, but it offers real information, and it's done before auscultation. Tactile fremitus is the vibration felt on the chest wall when a patient speaks, transmitted through the bronchopulmonary tree.
Honest Take: How Often Is This Used?
In practice, fremitus is rarely performed anymore — chest x-rays and CT scans give more accurate information about consolidation, effusions, and the like. It's still worth knowing for the exam and the occasional bedside clue.
How to Assess Tactile Fremitus
Sit the patient upright and have them repeat a low, resonant phrase like "ninety-nine" or "one-to-one."
Place the palmar or ulnar surface of your hands on symmetric areas of the chest and back, and compare the vibrations side to side.
Increased over consolidation (pneumonia). Decreased over a pleural effusion, pneumothorax, or emphysema. Asymmetry suggests unilateral pathology.
Percussion of the Lungs
Percussion means tapping on the chest wall and listening to judge how airy or dense the underlying lung is. Like fremitus, it's underused in modern practice but still useful, and it's done before auscultation.
How to Percuss
Patient sitting or standing comfortably, with the area exposed while respecting privacy.
Press one middle finger firmly on the chest, then tap it with the middle finger of your other hand, lifting quickly to create a clear sound.
Percuss in a ladder pattern, comparing symmetric spots on both sides to catch asymmetry.
Interpreting Percussion Sounds
Auscultation of Lung Sounds
Auscultation — listening with a stethoscope — is the heart of the respiratory exam. It reveals normal and abnormal (adventitious) breath sounds that point to specific conditions.
Normal Breath Sounds
- Vesicular: soft, rustling sounds heard over most lung fields, made by air in the smaller airways and alveoli.
- Bronchial: louder, higher-pitched sounds heard over the trachea and larynx, from air in the larger airways.
Normal lung sounds are clear and uninterrupted.
🔊 Listen: Vesicular Breath Sounds (Normal)
Adventitious Breath Sounds
Adventitious sounds are abnormal sounds layered on top of normal breathing, usually signaling pathology in the lungs or airways. Here's each one — what it sounds like, what causes it, how it's treated, and a recording so you can hear it.
Wheezes
Wheezes are high-pitched sounds of bronchospasm — the airways are tight and air is squeezing through.
- Characteristics: high-pitched, musical; mostly on expiration but can be inspiratory too.
- Causes: narrowed airways — asthma, COPD, bronchitis.
- Treatment: inhalers/nebs to open the airways, steroids for the underlying asthma or COPD, and antibiotics in select cases.
🔊 Listen: Wheezing
Crackles (Rales)
Crackles sound like rattling inside the lungs and usually mean fluid.
- Characteristics: crackling or rattling, fine or coarse. Fine crackles sound like rubbing hair between your fingers; coarse crackles are louder and lower.
- Causes: fluid in the airways — pulmonary edema, pneumonia, heart failure.
- Treatment: often diuresis (e.g., Lasix) and fluid restriction when due to pulmonary edema or CHF.
🔊 Listen: Crackles
Rhonchi
Rhonchi are low-pitched rattles, similar to crackles, but they often clear with a cough.
- Characteristics: low-pitched, snoring or rattling.
- Causes: secretions or obstruction in the larger airways — common in bronchitis or with mucus.
- Treatment: treat the underlying cause, sometimes with antibiotics or cough medication.
🔊 Listen: Rhonchi
Pleural Rub
A pleural (or pulmonary friction) rub is a low-pitched creaking heard when inflamed pleural surfaces rub together.
- Characteristics: low-pitched, grating or creaking; heard on both inspiration and expiration.
- Causes: inflamed pleura rubbing together — pleuritis, or after a pulmonary embolism.
- Treatment: treat the underlying cause; sometimes antibiotics, NSAIDs, and supportive care.
🔊 Listen: Pleural Rub
Stridor
Stridor is a high-pitched sound heard on inspiration without a stethoscope — a red flag that something is blocking the upper airway (swelling or a foreign body).
- Characteristics: high-pitched, heard best on inspiration.
- Causes: upper-airway blockage — croup, foreign body aspiration, or laryngeal edema.
- Treatment: may require rapid sequence intubation or removal of the foreign object; steroids for croup.
Stridor Is an Airway Emergency
Audible inspiratory stridor means the upper airway is compromised. Don't wait — escalate early and prepare for a difficult airway.
🔊 Listen: Infant Stridor
Clinical Pearls
Related Guides
References
- Bickley, L. S. (2021). The thorax and lungs. In Bates' Guide to Physical Examination and History Taking (13th ed., pp. 209–243). Wolters Kluwer.
- Ernstmeyer, K., & Christman, E. (Eds.). (2021). Respiratory assessment. In Nursing Skills (Ch. 10). Chippewa Valley Technical College. NCBI Bookshelf
- Feller-Kopman, D. J., & Schwartzstein, R. M. (2024). The evaluation, diagnosis, and treatment of the adult patient with acute hypercapnic respiratory failure. UpToDate.
