Pneumothorax: Clinical Signs and TMC/CSE Exam Tips (2025)

Pneumothorax is a medical emergency that occurs when air enters the pleural space, causing the lung to collapse partially or completely. This condition can arise spontaneously, due to trauma, or as a complication of medical procedures. Prompt recognition and intervention are crucial to prevent severe respiratory distress and hemodynamic instability.

Understanding the key signs and symptoms of pneumothorax—such as sudden onset chest pain, dyspnea, absent breath sounds, tracheal deviation, and changes in ventilator pressures—is essential for healthcare providers.

This article explores these clinical manifestations in detail to enhance early detection and improve patient outcomes.

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Signs and Symptoms of a Pneumothorax

A pneumothorax presents with a range of clinical signs and symptoms that vary in severity depending on the extent of lung collapse and the underlying cause.

Recognizing these indicators promptly is essential for initiating appropriate treatment:

1. Sudden Chest Pain and Shortness of Breath

One of the most common and immediate symptoms of a pneumothorax is the sudden onset of sharp or stabbing chest pain, often accompanied by increased difficulty breathing (dyspnea).

The pain is typically localized to the affected side and may worsen with deep breathing, coughing, or movement. The degree of dyspnea can range from mild to severe, depending on the size of the pneumothorax and the patient’s underlying lung health.

2. Absent or Diminished Breath Sounds

A hallmark physical examination finding in a pneumothorax is the absence or significant reduction of breath sounds over the affected lung field. This occurs because air trapped in the pleural space prevents normal lung expansion, reducing airflow to the lung.

Auscultation with a stethoscope will reveal diminished or completely absent breath sounds on the side of the pneumothorax.

3. Tracheal Deviation and Shifted Heart Sounds

In cases of a tension pneumothorax, where air continues to accumulate in the pleural space without an exit, increased pressure can push the mediastinal structures (trachea, heart, and major vessels) toward the unaffected side.

This results in tracheal deviation, a classic but late finding, where the trachea visibly shifts away from the side of the pneumothorax. Additionally, heart sounds may also be displaced to the opposite side due to the shift in mediastinal structures.

4. Asymmetrical Chest Movement

A patient with a pneumothorax may exhibit uneven chest expansion, with reduced movement on the affected side. Normally, both sides of the chest rise and fall symmetrically with each breath.

However, in a pneumothorax, the collapsed lung fails to expand properly, leading to asymmetrical chest wall motion. This finding is more pronounced in larger pneumothoraces and in patients with minimal underlying lung disease.

5. Hyperresonance on Percussion

Percussion of the chest wall can provide further clues to the presence of a pneumothorax. Because air in the pleural space increases lung field resonance, tapping over the affected area will produce a hyperresonant (hollow or drum-like) sound. This contrasts with the dull percussion noted in conditions like pneumonia or pleural effusion.

6. Changes in Mechanical Ventilation Parameters

In mechanically ventilated patients, a sudden increase in peak inspiratory pressure (PIP) or plateau pressure may indicate a developing pneumothorax. The trapped air in the pleural space creates resistance, making it harder for the ventilator to deliver breaths.

A decrease in tidal volume, worsening hypoxia, or sudden hypotension may also suggest tension pneumothorax, requiring immediate intervention.

7. Subcutaneous Emphysema (Air in Soft Tissues)

In some cases, a pneumothorax can lead to the leakage of air into the subcutaneous tissue, creating a condition known as subcutaneous emphysema. This presents as a soft, crackling sensation under the skin, particularly around the chest, neck, and face.

Palpation of the affected areas may reveal a distinctive “crepitus” or crackling feeling, similar to the sound of rice crispies under pressure.

Note: Recognizing these signs and symptoms is critical for healthcare professionals to diagnose pneumothorax quickly and implement appropriate interventions, such as needle decompression or chest tube insertion, to restore normal lung function and prevent further complications.

Diagnosis and Confirmation of a Pneumothorax

Once a pneumothorax is suspected based on clinical signs and symptoms, confirming the diagnosis with appropriate diagnostic tools is essential.

Early identification allows for prompt intervention, reducing the risk of complications such as respiratory failure or cardiovascular collapse in cases of tension pneumothorax.

1. Physical Examination Findings

A thorough bedside assessment remains a key component in diagnosing a pneumothorax. In addition to the symptoms previously discussed, clinicians should carefully evaluate for:

• Tachycardia and Hypotension: Increased heart rate may be an early sign of distress, while low blood pressure can indicate worsening intrathoracic pressure, especially in tension pneumothorax.
• Cyanosis: In severe cases, inadequate oxygenation may lead to bluish discoloration of the lips, fingertips, or skin.
• Jugular Venous Distension (JVD): In tension pneumothorax, pressure buildup can impede venous return to the heart, leading to distended neck veins.

2. Chest X-Ray: The Gold Standard

A chest radiograph (CXR) is the primary imaging modality used to confirm pneumothorax. Classic findings on an upright posterior-anterior (PA) chest x-ray include:

• A visible pleural line marking the separation between the lung and pleural air.
• Absence of lung markings beyond the pleural line due to the presence of free air in the pleural space.
• Tracheal deviation and mediastinal shift to the opposite side of the pneumothorax.
• Deep sulcus sign: In supine patients (often in ICU settings), an abnormally deep costophrenic angle on the affected side may suggest a pneumothorax.

3. Point-of-Care Ultrasound (POCUS)

Ultrasound has become an invaluable bedside tool, particularly in emergency and intensive care settings, offering rapid and highly sensitive detection of pneumothorax.

Key ultrasound findings include:

• Absence of lung sliding: Normally, the pleura move with each breath, creating a shimmering effect known as lung sliding. A pneumothorax eliminates this movement.
• Presence of a lung point: A “lung point” is the interface where normal lung sliding meets the area of pneumothorax and is considered diagnostic.
• Absent B-lines: Normally, lung ultrasound shows vertical reverberation artifacts known as B-lines, which disappear in pneumothorax due to the absence of lung aeration.

4. CT Scan: The Most Sensitive Test

A computed tomography (CT) scan is the most sensitive imaging modality for detecting small or complex pneumothoraces, particularly in trauma or patients with underlying lung disease. CT can identify even tiny amounts of pleural air that may be missed on a standard chest x-ray.

While not routinely required, CT scans are useful in postoperative cases, recurrent pneumothorax, or when complications such as pneumomediastinum or pleural adhesions are suspected.

Note: Once the diagnosis is confirmed, the next step is determining the appropriate treatment, which varies based on the size of the pneumothorax and the patient’s clinical stability.

Treatment and Management of Pneumothorax

The management of pneumothorax depends on its size, underlying cause, and the patient’s clinical stability. While small, asymptomatic cases may resolve on their own, larger or symptomatic pneumothoraces require intervention to prevent respiratory failure or cardiovascular collapse.

1. Observation for a Small, Stable Pneumothorax

In cases of small (≤2 cm), spontaneous pneumothorax without significant respiratory distress, observation is often the first-line approach.

• Many small pneumothoraces will resolve spontaneously as the air is gradually reabsorbed by the body over days to weeks.
• Supplemental oxygen (at 2–4 L/min via nasal cannula or simple mask) may increase pleural air resorption by reducing nitrogen levels in the pleural space.
• Repeat chest X-rays every 6–12 hours help monitor progression or resolution.

Note: If the patient remains stable and asymptomatic, they may be discharged with instructions to return for follow-up imaging in 24–48 hours.

2. Needle Aspiration for a Moderate Pneumothorax

For larger pneumothoraces (>2 cm) or those causing moderate symptoms (dyspnea, chest pain) but without hemodynamic instability, needle aspiration is often the preferred initial treatment.

• A large-bore needle (14–16 gauge) is inserted into the second intercostal space at the midclavicular line to withdraw trapped air.
• After aspiration, a follow-up chest X-ray is performed to confirm lung re-expansion.
• If successful, the patient may be observed for a few hours and discharged with follow-up imaging in 24–48 hours.

3. Chest Tube Drainage for a Large or Tension Pneumothorax

A chest tube (thoracostomy tube) is required for large pneumothoraces, tension pneumothorax, or cases where needle aspiration fails.

• A small-bore (8–14 Fr) or large-bore (≥20 Fr) chest tube is inserted into the fourth or fifth intercostal space at the midaxillary line and connected to a water-seal drainage system to remove air.
• The tube remains in place until lung re-expansion is confirmed on serial chest X-rays, and no further air leaks are observed.
• Suction (−10 to −20 cm H₂O) may be applied if lung re-expansion is slow or if an ongoing air leak is present.

4. Emergency Needle Decompression for a Tension Pneumothorax

Tension pneumothorax is a medical emergency requiring immediate intervention to prevent cardiac arrest due to obstructive shock.

• Immediate needle decompression is performed using a large-bore needle (14–16 gauge) inserted into the second intercostal space at the midclavicular line.
• A rush of air escaping confirms the presence of a tension pneumothorax and relieves pressure on the heart and lungs.
• A chest tube must be placed immediately after needle decompression to prevent recurrence.

5. Surgical and Long-Term Management for Recurrent or Persistent Cases

Some patients develop recurrent or persistent pneumothorax, requiring more definitive treatment.

• Pleurodesis: A chemical agent (e.g., talc, doxycycline) is introduced into the pleural space via a chest tube to induce pleural adhesion, preventing future air leaks.
• Video-Assisted Thoracoscopic Surgery (VATS): Minimally invasive thoracoscopic surgery may be performed to resect blebs or bullae (common in spontaneous pneumothorax) and mechanically pleurodese the pleura.
• Open Thoracotomy: Reserved for severe, recurrent, or complicated cases, a thoracotomy involves direct surgical repair of air leaks and pleural fixation.

The treatment of pneumothorax depends on the severity and underlying cause. Small, stable pneumothoraces may resolve with observation, while moderate cases often require needle aspiration.

Large or tension pneumothoraces demand urgent chest tube placement or needle decompression to prevent life-threatening complications. For recurrent or persistent cases, surgical interventions like pleurodesis or VATS offer long-term solutions.

TMC and CSE Exam Tips for a Pneumothorax

Understanding a pneumothorax is crucial for success on the Therapist Multiple-Choice (TMC) Exam and Clinical Simulation Exam (CSE). These exams frequently test the recognition, diagnosis, and management of pneumothorax, particularly in critically ill or mechanically ventilated patients.

Here are key strategies to help you approach pneumothorax-related questions effectively:

TMC Exam Tips

Recognizing Signs and Symptoms

• Expect questions that describe a patient with sudden-onset chest pain and dyspnea, particularly in young, tall males (spontaneous pneumothorax) or trauma patients.
• Look for absent or diminished breath sounds on the affected side, hyperresonant percussion, and asymmetrical chest movement.
• If the question describes tracheal deviation and hypotension, suspect a tension pneumothorax and anticipate the need for immediate intervention.

Interpreting Diagnostic Findings

• Chest X-ray findings commonly tested include absent lung markings beyond a visible pleural line and a tracheal shift to the opposite side of the pneumothorax.
• Lung ultrasound may be referenced, with clues such as the absence of lung sliding or a lung point sign, which confirms pneumothorax.

Mechanical Ventilation Clues

• If a ventilated patient suddenly exhibits increased peak inspiratory pressures (PIP) and plateau pressures, consider a pneumothorax.
• A sudden decrease in exhaled tidal volume or worsening oxygenation may also indicate an air leak into the pleural space.

Treatment and Management Questions

• If the pneumothorax is small and asymptomatic, answer choices involving observation and oxygen therapy may be correct.
• Needle decompression is the immediate intervention for tension pneumothorax, followed by chest tube insertion.
• Avoid choosing positive pressure ventilation in an unstable patient unless a chest tube is already in place, as this can worsen the pneumothorax.

CSE Exam Tips

Prioritizing Patient Assessment

• In clinical scenarios, immediately assess breath sounds, chest movement, and tracheal position if a patient experiences sudden respiratory distress.
• If the patient is on a ventilator, check for high airway pressures, decreased compliance, and hemodynamic instability as clues.
• Order a STAT chest X-ray or lung ultrasound if a pneumothorax is suspected.

Making Critical Decisions

• If a tension pneumothorax is present (tracheal deviation, hypotension, JVD), do not delay intervention. Perform needle decompression first, then insert a chest tube.
• If the pneumothorax is small and the patient is stable, select oxygen therapy and observation with serial chest X-rays.
• If a ventilated patient develops signs of a pneumothorax, immediately decrease tidal volume and peak pressures while preparing for chest tube placement.

Avoiding Common Mistakes

• Do not ignore changes in breath sounds or ventilation pressures in a case scenario, as these often signal pneumothorax.
• Do not order unnecessary treatments like diuretics or bronchodilators, as pneumothorax is a structural issue, not an airway problem.
• Do not delay intervention in tension pneumothorax by waiting for confirmatory imaging—treatment must come first.

The TMC and CSE exams frequently test pneumothorax through recognition, diagnostic interpretation, and management. To succeed, focus on early identification of key clinical signs, appropriate imaging choices, and the correct treatment sequence.

Mastering these concepts will help you confidently answer exam questions and, more importantly, apply your knowledge in real-world clinical practice.

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Final Thoughts

Pneumothorax is a critical respiratory condition that requires prompt recognition and appropriate management to prevent life-threatening complications. Understanding the key signs and symptoms—such as sudden chest pain, dyspnea, absent breath sounds, tracheal deviation, and hyperresonant percussion—is essential for early diagnosis.

Diagnostic tools like chest X-rays, lung ultrasound, and CT scans play a vital role in confirming the presence of a pneumothorax. Treatment options vary based on severity, ranging from observation for small, stable cases to needle decompression and chest tube placement for large or tension pneumothorax.

For respiratory therapy students preparing for the TMC and CSE exams, mastering the identification, diagnosis, and management of pneumothorax is crucial for both exam success and real-world clinical application.