Assessing the Thorax and Lungs

The chest is the one region where a nurse can detect a patient deteriorating before any monitor announces it. Respiratory rate is the earliest vital sign to change in sepsis, in hemorrhage, in opioid oversedation and in heart failure — and it is the vital sign most often invented rather than counted. This chapter teaches the thoracic exam the way it is actually performed at the bedside: the bony landmarks you find with your fingertips, the lobes lying underneath them, and then the four steps in their fixed order — inspection, palpation, percussion, auscultation. You will learn what resonance sounds like against dullness, why bronchial breath sounds in the periphery mean consolidation, why a wheeze that disappears is worse than a wheeze that does not, and how to write a lung note precise enough that the next nurse can tell whether the patient improved. Every finding here has an escalation threshold attached, because a chest exam that ends in your head instead of in an SBAR call helps no one.

Section 1Landmarks, Lobes and the Respiratory Baseline

Reference lines and the bony landmarks you can find in the dark

A lung finding without a location is nearly useless. “Crackles in the chest” tells the next nurse nothing; “fine end-inspiratory crackles, bilateral posterior bases, below the level of the scapular tips” tells them exactly where to listen at 0300 to see whether the patient got better. Naming a location requires two coordinates: a horizontal one from the ribs and intercostal spaces, and a vertical one from a reference line. Learn to find both by touch, because you will often be assessing in a dim room with a patient who does not want to sit forward.

Start at the suprasternal notch, the hollow at the top of the sternum. Walk your fingers down about 5 cm until you feel a firm ridge — the sternal angle, or angle of Louis, where the manubrium meets the body of the sternum. The second rib articulates here, so the space just below your finger is the second intercostal space. From that single landmark you can count every rib on the anterior chest. Count in the intercostal spaces, not on the ribs, and remember that the costal cartilages of ribs eight through ten fuse rather than attach to the sternum, so anterior counting becomes unreliable below about the seventh rib. The sternal angle also marks the level where the trachea bifurcates into the right and left mainstem bronchi (roughly T4 to T5) — useful, because that is exactly where normal breath sounds are loudest and most tubular.

Posteriorly, ask the patient to flex the neck forward and find the vertebra prominens, the prominent spinous process of C7. Below it lies T1. The inferior angle of the scapula sits at approximately the seventh rib or seventh intercostal space and is the practical marker for “the bases.” The vertical reference lines are: midsternal, midclavicular and anterior axillary anteriorly; anterior, mid- and posterior axillary laterally; and vertebral (midspinal) and scapular posteriorly. The costal angle, formed where the two costal margins meet at the xiphoid, is normally less than 90 degrees and widens in chronic air trapping.

What lies beneath: lobes, fissures and lung borders

The right lung has three lobes, the left has two plus the lingula, which is the left lung’s anatomic answer to the right middle lobe. The clinically important fact is where those lobes sit relative to the skin. The oblique (major) fissures run from about the T3 spinous process posteriorly, around the chest, to the sixth rib at the midclavicular line. Everything you auscultate on the posterior chest below the scapular tips is lower lobe. The right horizontal (minor) fissure runs from the fourth rib at the sternum to the fifth rib at the midaxillary line, so the right middle lobe is heard on the anterior and right lateral chest only — never on the back. This is why nurses who auscultate only the posterior chest miss right middle lobe pneumonia and aspiration, and why the lateral chest wall at the midaxillary line is a mandatory part of the exam, not an optional one.

The lung apices extend 2 to 4 cm above the inner third of the clavicles, so a finding “above the clavicle” is still lung. The lower borders sit at roughly the sixth rib at the midclavicular line, the eighth rib at the midaxillary line, and the level of T10 posteriorly, descending to about T12 on deep inspiration. Below those borders you are percussing liver on the right and stomach or spleen on the left, which is why a dull note at the right base near the sixth rib is normal liver and not consolidation.

The respiratory baseline and the order of the exam

Count respirations for a full 30 seconds and multiply by two when the pattern is regular, and for a full 60 seconds when it is irregular, when the patient is an infant, or when the rate is at either extreme. Count without announcing it — keep your fingers on the radial pulse and watch or feel the chest, because a patient who knows you are counting breathes differently. Document rate, depth (shallow, normal, deep) and rhythm (regular, irregular), plus effort and oxygen saturation with the delivery device and flow rate. “RR 18” alone is an incomplete vital sign.

Oxygen saturation by pulse oximetry is normally 95% to 100% on room air. A saturation of 90% corresponds roughly to a PaO2 of 60 mmHg — the shoulder of the oxyhemoglobin dissociation curve, below which small further drops in saturation mean large drops in PaO2. For most patients with chronic carbon dioxide retention the prescribed target is 88% to 92%, because excess oxygen worsens ventilation-perfusion matching and can blunt ventilatory drive; titrate only within the ordered range. That target is never a reason to withhold oxygen — a patient who is acutely and severely hypoxemic is given oxygen first, and the target range is re-established once they are safe. Always chart saturation with its context: “SpO2 94% on 2 L/min nasal cannula” means something entirely different from “SpO2 94% on room air.”

Section 2Inspection and Palpation of the Thorax

Inspection: what the first ten seconds tell you

Inspection begins before you touch anything, and often before you speak. Expose the chest with the patient sitting upright, gown open, room warm and light good. Stand back far enough to see the whole thorax and watch a full minute of breathing. Note position first: a patient sitting bolt upright, leaning forward on their elbows, is in the tripod position and is recruiting every accessory muscle they have. Note speech: a patient who can speak only three or four words between breaths is in significant distress regardless of the number on the pulse oximeter.

Look at shape. The normal adult chest is wider than it is deep; the anteroposterior to transverse diameter ratio is about 1:2 (ranging to 5:7). In a barrel chest the ratio approaches 1:1, the ribs run horizontally rather than sloping down at roughly 45 degrees, and the costal angle exceeds 90 degrees — the configuration of chronic air trapping in emphysema and long-standing asthma, and an expected finding in infants under about two years and in some older adults with kyphosis. An increased anteroposterior diameter is a chronic finding, so it never explains a new symptom — do not let it talk you out of an acute change. Note also pectus excavatum (a sunken sternum), pectus carinatum (a protruding sternum), kyphosis, scoliosis and any surgical scars or chest tube sites.

Look at effort. Normal quiet breathing is almost invisible: the chest rises symmetrically, the accessory muscles are silent, and the ratio of inspiration to expiration is about 1:2. Abnormal effort shows as retractions (skin sucking in above the clavicles, between the ribs, or below the xiphoid), nasal flaring, grunting (an infant generating their own positive end-expiratory pressure — always ominous), head bobbing in an infant, use of the sternocleidomastoid, scalene and trapezius muscles, and pursed-lip breathing. Watch for paradoxical movement, where a segment of chest wall moves inward on inspiration — flail chest after trauma. Finally, look at the fingers: the normal nail-bed angle is about 160 degrees, and clubbing (angle 180 degrees or more, with a spongy nail bed) signals months to years of hypoxemia, not an acute event.

Breathing patterns worth naming

Palpation: tenderness, expansion, fremitus and crepitus

Palpate with warm hands and a stated purpose. First, palpate for tenderness, masses and lesions with the finger pads over the anterior, lateral and posterior chest wall, and note whether pain is reproducible with pressure — reproducible chest wall tenderness suggests a musculoskeletal or costochondral source, but it never rules out a cardiac or pulmonary cause on its own. Confirm the trachea is midline by placing an index finger in the suprasternal notch and slipping it gently to each side to compare the spaces between the trachea and the sternocleidomastoid. Deviation is a late and dangerous sign.

Next assess chest expansion. Standing behind the seated patient, place your thumbs along the spine at about the level of the tenth rib with your palms lightly on the posterolateral chest, and slide medially just enough to raise a small skin fold between your thumbs. Ask for a deep breath. Your thumbs should move apart symmetrically, separating about 3 to 5 cm. Asymmetry is the finding that matters: the side that lags is the abnormal side — think pneumothorax, pleural effusion, lobar pneumonia, atelectasis, splinting from rib fracture, or post-operative guarding.

Then assess tactile fremitus, the palpable vibration of the voice transmitted through lung tissue. Use the ball of the palm or the ulnar surface of one hand, move in a side-to-side ladder pattern, and ask the patient to repeat “ninety-nine” or “one-one-one” in a low voice each time you move. Fremitus is normally strongest near the large airways — the second intercostal spaces anteriorly and between the scapulae posteriorly — and fades toward the bases. Compare sides, not absolute intensity. Solid, consolidated lung conducts sound better, so fremitus increases in pneumonia. Air, fluid or fat between your hand and the lung conducts it worse, so fremitus decreases in pneumothorax, pleural effusion, emphysema, bronchial obstruction and simply in a thick chest wall or a very muscular back.

Finally, feel for crepitus — subcutaneous emphysema. It feels like fine bubble wrap or crackling tissue paper under the skin, usually over the upper chest, neck or around a chest tube insertion site. It means air has escaped into the subcutaneous tissue and demands immediate assessment for pneumothorax, a disconnected or malpositioned chest tube, or airway injury. Mark the borders with a skin pen, note the time, and escalate.

Section 3Percussion and Diaphragmatic Excursion

How to percuss so the note means something

Percussion is the step students skip and experienced nurses use to answer one question quickly: is there air where there should be air? Sound produced by tapping the chest wall penetrates only about 5 to 7 cm, so percussion assesses the outer lung, not deep structures — a small central lesion will be silent to your fingers.

Use indirect percussion. Hyperextend the middle finger of your non-dominant hand — the pleximeter — and press its distal interphalangeal joint firmly into an intercostal space, keeping the rest of that hand off the chest wall so it does not damp the vibration. With the dominant hand, flex the wrist (not the elbow or shoulder) and strike the pleximeter’s DIP joint sharply with the tip of your middle finger — the plexor — using a quick, bouncing motion. Deliver two taps, then withdraw immediately; a finger left in place absorbs the sound you are trying to hear. Keep your fingernail short, or you will hurt both of you.

Percuss over intercostal spaces only. Bone gives a dull, useless note, so avoid the sternum, ribs, scapulae and vertebrae. Work in the same side-to-side ladder as the rest of the exam: right apex, left apex, right second interspace, left second interspace, and downward, comparing each pair before moving on. Anteriorly, percuss from above the clavicles to the sixth rib. Posteriorly, ask the patient to cross their arms in front to swing the scapulae laterally, then percuss from C7 down to T10, staying medial to the scapular borders and finishing along the lateral chest.

The five percussion tones

Two normal findings trip up beginners. Dullness at the right base at about the fifth to sixth intercostal space anteriorly is liver, and tympany in the left lower anterior chest is the gastric air bubble — neither is pathology. Cardiac dullness is expected from the third to fifth interspaces left of the sternum. Anything else that is dull where it should be resonant deserves a careful auscultation of that exact spot.

Diaphragmatic excursion

Diaphragmatic excursion measures how far the diaphragm travels between full expiration and full inspiration, and it is the cleanest bedside test of ventilatory mechanics available without equipment. With the patient sitting and leaning slightly forward, ask them to exhale fully and hold. Percuss down the posterior chest along the scapular line until resonance changes to dullness, and mark that spot. Let them breathe, then ask them to inhale deeply and hold. Percuss down again until the note changes, and mark the second spot. The distance between the two marks is the excursion, and it is measured on both sides.

Expected excursion in a healthy adult is 3 to 5 cm, and up to 7 to 8 cm in a tall, well-conditioned adult. The right side may sit slightly higher than the left because of the liver. Reduced excursion appears in emphysema (a flattened, already-depressed diaphragm), atelectasis, pleural effusion, severe obesity, ascites, late pregnancy, phrenic nerve injury and simple splinting from pain. Asymmetry — one side moving well and the other barely at all — is the more alarming pattern and points to unilateral disease or a paralyzed hemidiaphragm.

Section 4Auscultation and Voice-Transmitted Sounds

Technique and sequence

Use the diaphragm of the stethoscope, pressed firmly enough to leave a light ring on the skin, and always on bare skin — auscultating through a gown produces rustling artifact that beginners confuse with crackles. Ask the patient to sit upright and breathe slowly and a little more deeply than usual through an open mouth. Nose breathing adds turbulence; mouth breathing gives clean sounds. Listen to at least one full inspiration and expiration at every site, and stop and let the patient rest if they become dizzy or lightheaded from hyperventilating.

Move in the same side-to-side ladder used for percussion: apices first, then downward, comparing each pair before descending. Posteriorly, listen at approximately eight to ten paired sites from above the scapulae down to the level of T10, staying medial to the scapular borders. Then listen laterally at the midaxillary lines from the axilla to the seventh or eighth rib — this is where the right middle lobe and the lingula live. Then listen anteriorly from above the clavicles down to the sixth rib, moving the breast tissue aside rather than listening through it. If a patient cannot sit up, listen posteriorly with them rolled to each side and document their position, because gravity changes findings.

Describe what you hear along four axes: location, timing in the respiratory cycle (inspiratory, expiratory or both, early or late), quality, and whether it clears with coughing. A crackle that clears after two deep breaths and a cough is atelectatic and usually resolves with mobilization and incentive spirometry; a crackle that persists is not.

Normal breath sounds

Adventitious sounds

Two distinctions carry the most clinical weight. First, rhonchi versus crackles: ask the patient to cough and listen again. Sounds that clear were secretions sitting in an airway; sounds that persist reflect fluid or disease in the tissue. Second, wheeze versus stridor: a wheeze is expiratory and comes from the lower airways; stridor is inspiratory, comes from obstruction of the extrathoracic upper airway — anywhere above the thoracic inlet, whether supraglottic (epiglottitis), glottic (laryngospasm, vocal cord edema) or subglottic (croup, post-extubation edema) — and buys the patient minutes rather than hours. Confusing them delays an airway response.

Voice-transmitted sounds

When percussion is dull and breath sounds are bronchial where they should be vesicular, three quick maneuvers confirm consolidation. Perform each with the stethoscope diaphragm over the suspicious area, comparing to the same spot on the opposite side.

Bronchophony: ask the patient to say “ninety-nine” repeatedly. Normally the words are muffled and indistinct. Over consolidated lung they become louder and clearer. Egophony: ask the patient to say a long “eeee.” Normally you hear a muffled “eeee.” Over consolidation it converts to a nasal “aaaa” — the classic E-to-A change, also heard just above the fluid level of a pleural effusion where lung is compressed. Whispered pectoriloquy: ask the patient to whisper “one-two-three” or “ninety-nine.” Normally the whisper is faint and unintelligible. Over consolidation the whispered words come through crisply, as if the patient were speaking directly into your stethoscope. All three are increased in consolidation and decreased or absent over a pneumothorax or a large effusion, for the same reason fremitus behaves that way: solids conduct sound, air and fluid do not.

Section 5Red Flags, Lifespan Variation, Documentation and Escalation

Findings that mean escalate now

The earliest sign of hypoxia is not cyanosis. It is restlessness, anxiety, agitation or new confusion, because the brain is the first organ to complain. A patient who was oriented at 0800 and is now pulling at their lines at 1000 is hypoxic until you prove otherwise. Cyanosis is a late sign requiring roughly 5 g/dL of deoxygenated hemoglobin, which means a profoundly anemic patient may never become visibly cyanotic despite dangerous hypoxemia.

Lifespan and skin-tone variation

Infants and children. The infant chest is round, with an anteroposterior to transverse ratio near 1:1 until about age two, so a “barrel chest” in a toddler is normal. Infants breathe primarily with the diaphragm, so watch the abdomen rise; thoracic breathing establishes around age six or seven. Count for a full 60 seconds, ideally while the infant is quiet or asleep. The chest wall is thin and sounds transmit widely, so bronchovesicular sounds throughout the lung fields are normal in children and would be abnormal in an adult. Retractions, nasal flaring, grunting and head bobbing form the visual distress score you should chart every time. Infants in the early months breathe preferentially through the nose, so nasal congestion alone can cause real distress.

Pregnancy. The enlarging uterus elevates the diaphragm by up to 4 cm, the transverse chest diameter increases about 2 cm and the costal angle widens. Tidal volume rises 30% to 40% under progesterone, so minute ventilation increases while the respiratory rate stays essentially normal. Physiologic dyspnea affects most pregnant patients and is typically mild, gradual and present at rest but not worsening. Sudden dyspnea, tachypnea, chest pain or hypoxemia in pregnancy is never physiologic — pregnancy is a hypercoagulable state and pulmonary embolism is a leading cause of maternal death.

Older adults. Costal cartilage calcifies, kyphosis increases the anteroposterior diameter, respiratory muscles weaken and elastic recoil falls, so chest expansion and diaphragmatic excursion decrease. Cough strength and ciliary clearance decline, which is why immobility so quickly produces atelectasis and pneumonia. Fine crackles at the bases that clear after several deep breaths and a cough are usually atelectatic, not heart failure. Critically, older adults often do not mount a fever or a productive cough with pneumonia — new confusion, a fall, anorexia or simply a rising respiratory rate may be the only presentation. Take a respiratory rate over 24 in an older adult seriously.

Skin tone. Cyanosis, pallor and erythema are unreliable when assessed only on the outer skin of patients with richly pigmented skin. Assess oral mucosa, the tongue, the conjunctivae, the palms and soles and the nail beds in natural or full-spectrum light. Central cyanosis appears as a gray or ashen cast to the lips, tongue and oral mucosa rather than a blue tint. Pallor may present as ashen, gray or yellow-brown rather than white. Erythema is often easier to feel than to see — compare warmth and induration to the opposite side. Be aware also that pulse oximetry systematically overestimates arterial saturation in patients with darker skin pigmentation, producing occult hypoxemia; when the number looks acceptable but the patient is working hard, believe the work of breathing and request an arterial or venous blood gas.

Charting the lung exam

Document what you observed and measured, not what you concluded. Include location, timing, quality, response to cough, position of the patient, oxygen device and flow, saturation, and the patient’s own words in quotation marks. Compare the two entries below.

Delegation, scope and the SBAR call

Apply the five rights of delegation: right task, right circumstance, right person, right direction and communication, right supervision and evaluation. The registered nurse may delegate data collection tasks on a stable patient but never delegates assessment, interpretation, teaching, evaluation, or any aspect of care for an unstable or deteriorating patient.

When a red flag appears, escalate with SBAR. Have the chart, the last two sets of vitals and the medication list in front of you before you dial. A worked example: Situation — “This is Marcus Ellis, RN, on 4 West. I am calling about Mrs. Alvarez in room 412, a 74-year-old two days post right hip arthroplasty. She has new shortness of breath and her oxygen saturation has fallen to 88% on room air.” Background — “She has a history of heart failure and COPD, home oxygen 2 L at night. She has been on bed rest since surgery and has not ambulated today. Baseline saturation on admission was 95% on room air.” Assessment — “Respirations 30 and shallow, heart rate 118, blood pressure 104 over 62, temperature 37.9 Celsius. She is using accessory muscles and speaking in short phrases. Fine crackles at both bases that do not clear with cough, decreased breath sounds at the right base, dullness to percussion there. No stridor, trachea midline. She is more confused than this morning. I have her upright and on 2 L nasal cannula under the standing hypoxia protocol, which brought her to 92%.” Recommendation — “I think she needs to be seen now. I am requesting a chest x-ray, arterial blood gas and an oxygen order, and I would like to know whether you want a rapid response called. Can you come to the bedside?” Then close the loop: repeat the orders back, document the time of the call and the response, and reassess.

Words worth knowing