Pulmonary · Topic 26 of 28

Chest Trauma: Rib Fractures, Flail Chest & Hemothorax

Pulmonary · thoracic trauma

Chest Trauma: Rib Fractures, Flail Chest & Hemothorax

Rib fractures kill older adults through pain and pneumonia; flail chest marks contusion beneath; drain hemothorax and operate for 1500 mL or ongoing bleeding.

Key numbers

Flail chest: 3+ ribs, 2 breaks each≥ 3 ribs × ≥ 2 sites

Massive hemothorax ≥ 1500 mL: thoracotomy≥ 1500 mL or > 200 mL/h

01 · DoMultimodal analgesia so the patient can breathe

Pain control is the core treatment: NSAIDs first-line with acetaminophen, opioids titrated only if needed, and epidural or intercostal nerve block when the patient still cannot cough or breathe deeply.

02 · What it isFlail chest: 3+ ribs, 2 breaks each

Flail chest = 3 or more adjacent ribs each fractured in 2 or more places, creating a segment that moves paradoxically (inward on inspiration); it marks a significant underlying pulmonary contusion.

03 · DoMassive hemothorax ≥ 1500 mL: thoracotomy

Drain a visible hemothorax with a chest tube; operate (thoracotomy) for hemodynamic instability, initial drainage ≥ 1500 mL, or ongoing output > 200 mL/h for 2–4 hours.

Causes & risk factors

Why it happens

Older adults: rib fractures can kill must knowIn older adults even a minor fall can fracture ribs; pain-driven splinting leads to atelectasis and pneumonia, and mortality with multiple rib fractures in older patients is up to 20%.

Rib level predicts hidden organ injuryFractures of ribs 1–2 signal high-energy force with possible aortic, subclavian or cardiac injury; fractures of ribs 7–12 raise concern for splenic or other abdominal injury.

Diagnosis & monitoring

Work-up

Chest x-ray misses half of rib fracturesChest x-ray detects only about 50% of rib fractures; CT is more sensitive and also shows contusion, pneumothorax and associated injuries.

Do right now

In this order

First moves

Massive hemothorax ≥ 1500 mL: thoracotomy≥ 1500 mL or > 200 mL/h

→

Multimodal analgesia so the patient can breathe

→

Admit: 3+ rib fractures or poor reserve

→

Incentive spirometry, supported cough, early mobility

Why each step

Massive hemothorax ≥ 1500 mL: thoracotomyDrain a visible hemothorax with a chest tube; operate (thoracotomy) for hemodynamic instability, initial drainage ≥ 1500 mL, or ongoing output > 200 mL/h for 2–4 hours.

Multimodal analgesia so the patient can breathePain control is the core treatment: NSAIDs first-line with acetaminophen, opioids titrated only if needed, and epidural or intercostal nerve block when the patient still cannot cough or breathe deeply.

Admit: 3+ rib fractures or poor reserveAdmit patients with 3 or more rib fractures or underlying cardiopulmonary disease; in older adults, an oxygen requirement or SpO₂ < 95%, pneumothorax or sternal fracture predicts ICU need.

Incentive spirometry, supported cough, early mobilityPrevent pneumonia with incentive spirometry, deep breathing, supported coughing (splinting with a pillow), early mobilization and frequent position changes; never bind or strap the chest.

Management

Orders

Surgical rib fixation within 72 hoursConsider surgical stabilization of rib fractures for hemodynamically stable flail chest, ≥ 3 severely displaced ipsilateral fractures of ribs 3–10, or failure to wean — ideally within 48–72 hours of injury.

Flail chest: oxygen, analgesia, careful fluidsTreat flail chest with humidified oxygen and aggressive analgesia, ventilating mechanically when needed; avoid both hypovolemia and fluid overload, which worsens contusion edema.

Ventilate for PaO₂ < 65 mmHgGive oxygen for mild hypoxemia (SaO₂ 91–94%); mechanical ventilation is usually needed for moderate–severe hypoxemia (PaO₂ < 65 mmHg or SaO₂ < 90% on room air) or hypercarbia.

Small-bore pigtail for stable hemothoraxIn hemodynamically stable patients, a 14 F pigtail catheter is a reasonable alternative to a 28–32 F tube for traumatic hemothorax; a small hemothorax (< 300 mL) in a stable patient can be observed.

Red flags & don'ts

Avoid harm

Pulmonary contusion worsens over 24–48 hours complicationPulmonary contusion causes hypoxemia that worsens over time and may not appear on chest x-ray for 24–48 hours; CT is more sensitive. Watch for pneumonia and ARDS.

Retained hemothorax: early VATS within 4 days complicationRetained hemothorax risks empyema and fibrothorax; perform video-assisted thoracoscopic evacuation early (within about 4 days) rather than trying intrapleural thrombolytics first.

Hemothorax or pulmonary contusion?

Commonly confused

Where the blood is	Pleural space
Chest x-ray	Visible once about 500 mL
Main danger	Hemorrhagic shock; retained clot, empyema
Treatment	Chest tube; thoracotomy for massive bleeding

More detail

Reference

Show 6 reference facts

Hemodynamic instability contraindicates rib fixation; traumatic brain injury and pulmonary contusion are not absolute contraindications.

Prophylactic antibiotics are not indicated for chest tubes placed for blunt trauma; they are reserved for penetrating injuries, operative exploration and drainage of a retained hemothorax.

Paradoxical flail motion disappears during positive-pressure ventilation, though the segment may bulge more on inflation; pain and splinting can also hide it.

Rib fractures may fail to heal (nonunion), causing chronic pain, clicking and exertional dyspnea; nonunion or malunion is an indication for surgical fixation.

Blood drained from a traumatic hemothorax can be autotransfused, reducing crystalloid and donor blood requirements.

A hemothorax usually needs about 500 mL of blood to be visible on chest x-ray; E-FAST and CT detect smaller collections.

Pearl

In chest-wall trauma, pain control is respiratory therapy: the patient who cannot cough gets pneumonia.

Sources · Merck Manual Professional — Rib Fracture (updated May 2026) · Merck Manual Professional — Flail Chest (updated May 2026) · Merck Manual Professional — Hemothorax (updated May 2026) · Merck Manual Professional — Pulmonary Contusion (updated May 2026) · Coccolini F et al. Thoracic trauma WSES-AAST guidelines. World J Emerg Surg 2025;20:78 (PMC12522690) · Patel NJ et al. Management of simple and retained hemothorax: EAST practice management guideline. Am J Surg 2021 — abstract via Europe PMC · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).