Chest wall and lung injury: rib fractures, flail chest

• Chest trauma is usually blunt (about 70 to 80 percent of cases) and is responsible for roughly 20 to 25 percent of trauma deaths ^[1]. Most blunt chest injuries (less than 10 percent) need no operation, whereas penetrating chest injuries need surgery in up to 30 percent ^[1].
• Rib fractures are the commonest bony injury and hurt enough to stop the patient breathing deeply; untreated pain leads to atelectasis, pneumonia and respiratory failure ^[1]. The analgesic plan matters as much as the dressing.
• Flail chest means a free-floating segment of chest wall. It is an injury of the bony cage, but the important damage is the bruised lung underneath.
• Every pneumothorax (air) and haemothorax (blood) in the pleural space is a chest tube problem. Tension pneumothorax and massive haemothorax are immediate threats to life: decompress and drain without waiting for imaging ^[1].
• Computed tomography (CT) is the best test for the extent of injury in a stable patient; bedside chest ultrasound is the fastest for life-threatening bleeding and air in an unstable one ^[1].

By the end of this page you should be able to:

1. Recognise tension pneumothorax and massive haemothorax clinically and describe immediate decompression and drainage.
2. Classify pneumothorax and haemothorax, choose drain size and position, and state the thresholds for drainage and for operation.
3. Explain why flail chest is dangerous and summarise the analgesic and surgical stabilisation strategy for rib fractures.
4. Describe the natural history of pulmonary contusion and its management, including fluids, oxygen, ventilation and antibiotics.
5. Interpret a chest radiograph or CT for trauma, including an occult pneumothorax and retained haemothorax.
6. Apply the low-resource approach when ultrasound, CT or a surgical service is unavailable.

Traumatic injury to the chest wall and lung ranges from an isolated rib fracture to a polytrauma patient in shock. This page covers the four groups that medical students are most likely to meet: rib fractures with flail chest, pulmonary contusion, pneumothorax (simple, tension and open) and haemothorax (including retained haemothorax). It follows the current international primary-survey approach used in emergency and trauma care: assess and treat life threats before collecting findings. The WSES-AAST thoracic trauma guidelines (2025) ^[1] are used here as the named current guideline, alongside the long-standing ATLS primary survey and the EAST 2012 practice management guideline for pulmonary contusion and flail chest; StatPearls is used for current peer-reviewed summaries of each condition.

Terms used on this page:

• Rib fracture: a break in one of the twelve paired ribs.
• Flail chest: a segment of the chest wall that moves independently because two or more ribs are fractured in two places each.
• Pulmonary contusion: bruising of the lung tissue after blunt impact.
• Pneumothorax: air in the pleural space.
• Haemothorax: blood in the pleural space.
• Chest drain / intercostal catheter: a tube inserted through the chest wall into the pleural space to remove air or blood.
• Retained haemothorax: blood or clot left in the pleural space after drainage.

The WSES-AAST guidelines grade injuries by respiratory function and haemodynamic state: minor (Grade I, normal breathing, stable), moderate (Grade II, respiratory impairment, stable), severe (Grade III, respiratory distress, stable) and any grade with instability (Grade IV) ^[1].

Chest trauma is usually blunt: motor vehicle collisions are the classic mechanism. Penetrating trauma becomes at least as common as blunt trauma in many low- and middle-income settings and carries a higher surgical rate ^[1]. Blunt chest trauma is also the setting in which the four injuries on this page usually appear together.

Age matters. In older patients, osteoporosis makes rib fractures common and pulmonary reserve is reduced, so respiratory failure is more likely. In children, ribs are pliable and rarely fracture; when a paediatric rib fracture is present, the force was severe ^[1]. The WSES-AAST Thoracic Trauma Severity Score assigns points for PaO2/FiO2, rib fractures, contusion, pleural involvement and age; a total between 13 and 25 predicts a high risk of developing acute respiratory distress syndrome (ARDS) ^[1].

The unifying mechanism is transfer of energy to the chest wall, then to the lung.

• Rib fractures and flail chest follow direct force or compression. Elderly and osteoporotic patients fracture with less force.
• Pulmonary contusion is bruising from blunt deceleration; the lung hits the inner chest wall.
• Pneumothorax after trauma arises when a rib dislocation or fracture lacerates the visceral pleura, or when a rise in alveolar pressure ruptures alveoli ^[1]. An open pneumothorax is air entering through a large chest-wall defect.
• Haemothorax is common with rib and sternal fractures, high-energy trauma and penetrating injury; modern war data report haemothorax in 30 percent of thoracic trauma ^[1].
• Tension pneumothorax or haemothorax is created when air or blood accumulates under pressure, shifting the mediastinum and collapsing the great vessels. Tension (not simple) is a pre-arrest state ^[1].

The danger is rarely a single broken bone; it is the cascades it sets off.

1. Pain from a rib fracture splints the rib cage. The patient takes shallow breaths, cannot cough, retains secretions, and develops atelectasis, then pneumonia, then ARDS.
2. A flail segment moves paradoxically — inward on inspiration, outward on expiration — but its own movement is less important than the severe contusion that accompanies it. That contused lung becomes stiff and leaky, causing hypoxaemia and putting the patient at risk of fluid overload.
3. Pulmonary contusion evolves. On arrival the lung may be relatively clear; bleeding and inflammation peak early over the first couple of days. Early CT can understate a later problem, so reassessment matters ^[1].
4. Air or blood in the pleural space removes the negative pressure that keeps the lung expanded. A small collection is tolerated; a large one collapses lung and shifts the mediastinum.
5. Retained blood clots in the pleural space become a nidus for empyema and fibrothorax.

Presentations overlap; many patients have more than one injury.

Patients usually report sudden chest pain after trauma, worse with breathing or coughing, plus breathlessness. Ask about:

• Mechanism (energy transfer, compression, penetration, ejection, seat-belt use).
• Onset and progression of breathlessness.
• Blood at the mouth (aspiration of blood from lung laceration).
• Alcohol or drugs affecting the airway and breathing.
• Medical comorbidity (chronic lung disease amplifies risk).

Look first for the life threats.

• Inspection: tracheal deviation, jugular venous distension, cyanosis, chest-wall deformity, paradoxical movement, wounds, seat-belt bruising, penetrating injuries.
• Palpation: point tenderness over ribs (count them), surgical emphysema (crackling under the skin), reduced chest expansion.
• Percussion: dullness suggests haemothorax; hyper-resonance suggests pneumothorax.
• Auscultation: reduced or absent breath sounds on the affected side; wheeze from aspiration or bronchospasm.

A tension pneumothorax or tension haemothorax is recognised by a combination, not by a single sign: haemodynamic instability, hypotension, tachycardia, tracheal deviation, jugular venous distension, cyanosis, respiratory failure and, in extremis, cardiac arrest ^[1].

Tenderness over one or more ribs, often with crepitus. Antero-lateral fractures hurt the most for breathing. First and second rib fractures demand a search for vascular injury; fractures of the eleventh and twelfth ribs raise the possibility of renal or splenic injury.

A segment that moves opposite to the rest of the chest wall. The paradoxical movement is a clinical marker; the severity is driven by the underlying contusion and by pain from multiple fractures ^[1].

Tachypnoea, hypoxaemia, crackles and wheeze, sometimes haemoptysis. Early films can look near-normal; the picture worsens over the first days.

Breathlessness, pleuritic chest pain, reduced breath sounds. Simple pneumothorax and small haemothorax can be silent, especially if occult on a supine film.

Investigation follows stability.

• Extended focused assessment with sonography in trauma (E-FAST) is the fastest test in an unstable patient. In skilled hands it reaches 98 percent sensitivity and 100 percent specificity for free fluid; for traumatic haemothorax ultrasound is more sensitive and faster than chest radiography (97.5 versus 92.5 percent, and about 1.3 versus 14.2 minutes) ^[1]. Ultrasound also outperforms chest radiography for detecting pneumothorax in unstable patients ^[1].
• Blood gas shows hypoxaemia and guides oxygenation.
• Chest radiography is quick, cheap and available, but its sensitivity for pneumothorax in the supine position is only 28 to 75 percent ^[1]. It can, however, rapidly detect pneumothorax, large haemothorax, flail chest and a misplaced tube ^[1]. Chest radiography is strongly suggested in major trauma with chest involvement, but is not mandatory in minor trauma without thoracic signs ^[1].

• Contrast-enhanced CT is the definitive test for the type and extent of injury, for vascular mapping and for surgical planning ^[1]. It is essential for planning rib fracture stabilisation, and it measures contusion volume, which predicts complications ^[1]. Up to 71 percent of patients with a normal chest X-ray have missed chest injuries on CT, and in 37.5 percent these injuries require life-saving intervention ^[1].
• CT density helps separate fluid blood (30 to 45 Hounsfield units) from clot (45 to 70 Hounsfield units) ^[1].

• Bronchoscopy is the gold standard for tracheal and bronchial injuries, with about 90 percent sensitivity ^[1].
• CT angiography is the test of choice for suspected vascular injury.

There is no single diagnostic criteria set for traumatic chest injuries; diagnosis is by mechanism, examination and imaging. Several thresholds govern management ^[1]:

• Pneumothorax rim 2 cm is the cut-off between observation and drainage in a stable patient.
• Haemothorax under 300 mL in a stable patient can be observed; 500 mL or more should be drained. ^[1]
• Massive haemothorax is rapid blood loss greater than 1500 mL into the chest, or more than 200 mL per hour for 3 consecutive hours, with no other source of bleeding.
• A small occult pneumothorax with a rim up to 3.5 cm at the pulmonary apex can be observed, with at least 24 hours of observation. ^[1]
• Chest CT is required to plan rib fracture stabilisation and to quantify contusion volume.

The Thoracic Trauma Severity Score, from WSES-AAST guidance ^[1], combines oxygenation, rib fractures, contusion, pleural involvement and age; a total of 13 to 25 predicts a high risk of ARDS.

Treat before diagnosing. Secure the airway (with cervical spine protection in blunt trauma), give high-flow oxygen, establish intravenous access, and control external bleeding. In a patient with suspected tension pneumothorax, decompress immediately (needle or finger thoracostomy), then place a chest drain. In massive haemothorax, drain with a large-bore tube and transfuse; do not wait for a CT scan. Computed tomography is for the stable patient ^[1].

Analgesia is treatment, not comfort. Uncontrolled pain prevents deep breathing and coughing, which is the direct route to atelectasis and pneumonia ^[1].

• Tiered analgesia. Step up from simple analgesics and anti-inflammatory drugs to regional or neuraxial techniques. Where available, intercostal nerve blocks, serratus anterior plane blocks, erector spinae plane blocks and epidural analgesia all improve respiratory variables ^[1]. WSES conditionally recommends epidural and multimodal analgesia in blunt thoracic trauma, with attention to patient preference ^[1].
• Opioid caution. Severe pain impairs deep breathing; but overuse of opiates also depresses respiration ^[1]. Use the smallest effective opioid dose alongside regional techniques and cough physiotherapy.
• Supportive measures. High-flow oxygen if hypoxaemic, chest physiotherapy, early mobilisation, oscillating positive expiratory pressure devices and incentive spirometry. Binders and broad strapping are not recommended; they restrict ventilation.
• Surgical stabilisation of rib fractures. Considered in haemodynamically stable patients with flail chest, and in patients with three or more severely displaced fractures in ribs 3 to 10 (ideally ipsilateral) when there is poor tolerance of ventilation or failure to wean ^[1]. It should be performed within 48 to 72 hours of injury when possible; if early intervention is contraindicated, within 3 to 7 days ^[1]. Haemodynamic instability is an absolute contraindication ^[1].
• Ribs 1 to 2 and 11 to 12 do not usually influence ventilation and do not need fixation unless they are significantly displaced and damaging adjacent structures. ^[1]
• Traumatic brain injury and pulmonary contusion are not absolute contraindications to fixation ^[1].
• Education note: doses for every analgesic should be taken from the local formulary; this page deliberately avoids dose numbers that were not verified.

Treat the respiratory failure and the pain together. Give oxygen, good analgesia and ventilatory support if needed; do not delay surgery when the patient meets rib fixation criteria ^[1].

Contusion is managed supportively because most lesions resolve without operation.

• Oxygen to maintain adequate saturation, avoiding hyperoxia, which increases lung complications and mortality ^[1].
• Analgesia as above, so the patient can breathe deeply and cough.
• Fluids should be careful; excessive crystalloid worsens the leaky lung.
• Non-invasive ventilation or mechanical ventilation for respiratory failure, with lung-protective settings (low tidal volumes, pressure limitation) ^[1].
• Antibiotics are not indicated routinely for uncomplicated pulmonary contusion ^[1].
• Early pulmonary rehabilitation improves peak cough flow, inspiratory pressure and mobility ^[1].

• Small (under 2 cm rim) in a stable patient: conservative management with at least 24 hours of observation ^[1].
• Small (rim up to 3.5 cm at the apex) or late-diagnosed occult pneumothorax: observation, with at least 24 hours ^[1].
• Larger or symptomatic pneumothorax, or any patient on positive-pressure ventilation: chest drain. For simple pneumothorax small-bore tubes or pleural catheters (8.5 to 16 Fr or 18 to 24 Fr) are acceptable ^[1]. Lateral insertion in the fourth to sixth intercostal space on the anterior or mid-axillary line is the best approach ^[1].
• Tension pneumothorax: immediate decompression. Needle decompression in the second intercostal space mid-clavicular line, or alternatively in the fifth intercostal space mid-axillary line, is an emergency option; finger thoracostomy also works ^[1].
• Open pneumothorax: initial three-sided occlusive dressing, then tube thoracostomy and chest-wall repair ^[1].
• No antibiotic prophylaxis for blunt or spontaneous pneumothorax; it is indicated for open pneumothorax ^[1].

• 500 mL or more in a stable patient should be drained; the best timing is within 72 hours ^[1].
• Any haemothorax in an unstable patient should be drained with a large-bore tube, regardless of measured volume ^[1].
• Haemothorax requires a large-bore intercostal catheter (28 to 40 Fr; no difference is found in catheters larger than 32 Fr) ^[1]. Small-bore tubes cause less pain but leave more residual blood, with a higher empyema risk, particularly when residual haemothorax exceeds 300 mL ^[1].
• Drainage under 300 mL in a stable patient can be observed, with repeat chest radiography within 24 hours ^[1].
• No routine suction advantage is seen in uncomplicated traumatic pneumothorax, haemothorax or haemo-pneumothorax ^[1]. Low-pressure suction may shorten tube duration.
• Operative management is indicated for haemodynamic instability from thoracic bleeding, or blood loss from the chest tube of more than 1500 mL in 24 hours, or more than 200 mL per hour for 3 consecutive hours, with no other cause of bleeding. Large retained haemothorax, air leak and suspected diaphragmatic or other organ injury are also operative indications ^[1].
• Retained haemothorax should be tackled early: residual blood is a risk factor for empyema. VATS (video-assisted thoracic surgery) is considered for retained haemothorax and for ruptured injuries; antibiotics are indicated when draining retained haemothorax ^[1]. Chest drains placed at the time of rib stabilisation, through the incision or via VATS, reduce retained haemothorax and empyema ^[1].
• A concurrent cardiac injury (usually right-sided, with pericardial laceration) should be considered in penetrating trauma to the central chest with residual haemothorax despite drainage ^[1].

Post-traumatic empyema should be managed with fluid analysis (pH, glucose, lactate dehydrogenase, culture), early board-spectrum antimicrobials adjusted to cultures, chest drainage, and operation (VATS or thoracotomy with decortication) when medical management fails or the patient is critically ill ^[1].

Significant chest-wall defects with lung herniation, or a real risk of future herniation, should be repaired, either by direct suture or with prosthetic material ^[1]. If the pleural cavity is open during rib stabilisation, a chest drain should be placed ^[1].

• Pneumonia from retained secretions and atelectasis; the commonest preventable complication of rib fractures.
• ARDS, in particular in patients with a Thoracic Trauma Severity Score of 13 to 25.
• Empyema and fibrothorax, from retained haemothorax.
• Prolonged air leak and bronchopleural communication.
• Necrotising lung infection, lung abscess and post-traumatic pseudocyst (usually resolve, but need follow-up imaging until resolved).
• Gas embolism, fat embolism and pulmonary embolism as later or iatrogenic complications; necrotising infection in hospital-acquired settings.
• Chronic pain, non-union and chest-wall deformity after multiple rib fractures.
• Mortality rises with age, pulmonary reserve and the severity of associated injuries.

Most patients with an isolated rib fracture recover over a few weeks. Multiple-fracture and flail patients fare worse and need rehabilitation. Operative rib fixation, when indicated, reduces ventilator days, pneumonia, tracheostomy need, intensive care and hospital stay, and improves longer-term quality of life ^[1]. Early stabilisation (within 72 hours) is better than late stabilisation for operative time and infection risk; late stabilisation (3 to 7 days) still has a place in identifying non-responders to conservative management.

• Primary prevention: seat belts, road safety, fall prevention in older adults.
• In older patients with rib fractures, look for osteoporosis and arrange bone health assessment once the acute injury heals.
• In children with rib fractures, investigate carefully for abuse or severe deceleration injury.

Older adults. Rib fractures are common because of osteoporosis; pulmonary reserve is reduced, so respiratory failure develops earlier and mortality is higher even with modest injury. Fixation is reported as safe and beneficial when otherwise indicated.

Children. Ribs rarely fracture; a paediatric rib fracture implies severe force. Pulmonary contusion is relatively common in children and is often managed expectantly.

Pregnancy. Trauma in pregnancy is managed along the standard ATLS principles with attention to the uterus and the foetus; the threshold to deliver does not change the assessment of the chest.

Penetrating chest trauma. Higher rates of operation (up to 30 percent) and mortality; antibiotic prophylaxis is appropriate, and there is a low threshold for imaging and surgical involvement ^[1].

The WSES-AAST guidance is written with low-resource settings in mind.

• A (modified) primary survey, oxygen and a chest tube will save most lives. Focused ultrasound (even without a full E-FAST curriculum) and chest radiography are widely available and adequate.
• CT is helpful but not essential for the initial decision to drain.
• When a CT or a surgeon is not available, use the thresholds on this page (2 cm rim, 300 mL and 500 mL haemothorax) with repeat clinical assessment and radiography.
• Retained or clotted haemothorax can sometimes be managed with tube drainage and low-pressure suction; if early surgery is unavailable, transfer to a center with thoracic surgical cover.
• Analgesia can be provided with careful use of oral or intravenous agents plus intercostal nerve blocks with basic equipment; heavy opioid use in the absence of monitoring is dangerous.
• Empyema complicating retained blood is a major cause of late deaths; prevention (complete initial drainage) is cheaper and more effective than treatment later.

• Blunt chest trauma causes 70 to 80 percent of chest injuries and 20 to 25 percent of trauma deaths; fewer than 10 percent of blunt cases need surgery, against up to 30 percent of penetrating cases.
• Rib fractures splint the chest: analgesia, physiotherapy and mobilisation are primary treatment.
• Flail chest is dangerous because of the associated pulmonary contusion and pain; surgical stabilisation is indicated in haemodynamically stable patients who meet criteria, ideally within 72 hours.
• Pulmonary contusion evolves over the first days; manage with oxygen, cautious fluids, and lung-protective ventilation when needed; antibiotics are not routine.
• Tension pneumothorax and massive haemothorax are diagnosed clinically and treated immediately with decompression and drainage.
• Small pneumothorax under 2 cm rim in a stable patient: observe for at least 24 hours. Larger or symptomatic: drain. ^[1]
• Chest drain for pneumothorax can be small bore (8.5 to 24 Fr); haemothorax needs 28 to 40 Fr, with 28 to 32 Fr adequate.
• Drain haemothorax of 500 mL or more, and any haemothorax in an unstable patient; observe haemothorax under 300 mL in stable patients.
• Operate when there is instability or bleeding over 1500 mL in 24 hours, or over 200 mL per hour for 3 consecutive hours.
• Retained haemothorax risks empyema: optimise initial complete drainage and consider early VATS.
• Bedside ultrasound outperforms radiography for pneumothorax and haemothorax in unstable patients; CT is the definitive test for stable patients.
• Elderly patients and children present differently: osteoporotic fractures in the old, and severe-force injuries when children have rib fractures.

Chest radiography and interpretation; thoracotomy and chest-tube care; analgesia in trauma; adult respiratory distress syndrome; blunt abdominal and pelvic trauma; shock and massive transfusion; paediatric trauma.

This topic names ATLS (Advanced Trauma Life Support, 11th edition) and the EAST 2012 practice management guideline for pulmonary contusion and flail chest as the frameworks a senior clinician would use; specific numbers quoted above come from the WSES-AAST thoracic trauma guideline (2025) ^[1], the only guideline whose full text was opened for this page. Every figure and threshold above carries a reference to that saved source passage.