Pulmonary · Topic 19 of 28

Pneumothorax

Pulmonary · pleural air

Pneumothorax

Decompress a tension pneumothorax on clinical grounds alone, observe the stable primary one, and put a chest tube in the secondary one.

Key numbers

Secondary pneumothorax: chest tube and admitdrain < 14 Fr

Adults: decompress at 4th–5th intercostal space4th–5th ICS (adults)

Over 50 and a smoker: manage as secondaryage > 50 + smoking

01 · DoDecompress tension now — no X-ray

Diagnose tension pneumothorax clinically and decompress immediately with a 14- or 16-gauge needle catheter — never wait for a chest radiograph — then place a chest tube right away.

02 · DoAsymptomatic primary pneumothorax: observe

A primary spontaneous pneumothorax without significant symptoms can be observed regardless of size — repeat the film at about 4 hours, then follow up as an outpatient until it resolves.

03 · DoSecondary pneumothorax: chest tube and admit

Secondary spontaneous pneumothorax (COPD, cystic fibrosis, Pneumocystis, any lung disease) is more dangerous: insert a small-bore chest tube (under 14 Fr) and admit. Traumatic pneumothorax also gets a tube.

Causes & risk factors

Why it happens

Primary: tall, thin young smokers, no lung diseasePrimary spontaneous pneumothorax arises without known lung disease, classically in tall, thin young men, from ruptured apical blebs; tobacco and cannabis smoking raise the risk.

Presentation

What you'll see

Tension: hypotension, absent breath sounds, tracheal shift must knowTension pneumothorax: pleural pressure stays positive, collapsing the lung, shifting the mediastinum and cutting venous return — hypoxemia, hypotension, absent breath sounds, hyperresonance, contralateral tracheal shift, then PEA arrest.

Ventilated patient, sudden hypotension: think tensionMost tension pneumothoraces occur during positive-pressure ventilation or resuscitation; sudden hypotension in a ventilated patient with diminished breath sounds and hyperresonance is presumed tension and treated at once.

Supine film: look for the deep sulcus signEven a large pneumothorax can be missed on a supine film; a deep sulcus sign may be the only clue. Confirm stable cases with an upright inspiratory film, bedside ultrasound or CT.

Do right now

In this order

First moves

Decompress tension now — no X-ray

→

Adults: decompress at 4th–5th intercostal space4th–5th ICS (adults)

→

Secondary pneumothorax: chest tube and admitdrain < 14 Fr

→

Symptomatic primary: aspirate or ambulatory valve

Why each step

Decompress tension now — no X-rayDiagnose tension pneumothorax clinically and decompress immediately with a 14- or 16-gauge needle catheter — never wait for a chest radiograph — then place a chest tube right away.

Adults: decompress at 4th–5th intercostal spaceATLS (10th ed.) decompresses adults in the 4th or 5th intercostal space between the anterior and midaxillary lines, by needle or finger thoracostomy; the 2nd intercostal space, midclavicular line, remains the classic and pediatric site.

Secondary pneumothorax: chest tube and admitSecondary spontaneous pneumothorax (COPD, cystic fibrosis, Pneumocystis, any lung disease) is more dangerous: insert a small-bore chest tube (under 14 Fr) and admit. Traumatic pneumothorax also gets a tube.

Symptomatic primary: aspirate or ambulatory valveSymptomatic primary pneumothorax: catheter aspiration (7–9 Fr, 2nd intercostal space, midclavicular line) or an ambulatory one-way valve device; if the lung does not re-expand, place a chest tube and admit.

Management

Orders

VATS after a second episode or persistent leakOffer VATS (bleb stapling plus pleurodesis) after a second primary pneumothorax, for secondary pneumothorax, a persistent air leak or unexpanded lung, and after a first episode in pilots or divers.

Red flags & don'ts

Avoid harm

Re-expansion edema after rapid re-expansion complicationRe-expansion pulmonary edema can follow rapid re-expansion of a lung collapsed for more than 2 days, especially on suction; treat supportively with oxygen, diuretics and cardiopulmonary support.

The rules

Know these

Over 50 and a smoker: manage as secondaryManage a patient over 50 with a significant smoking history as secondary pneumothorax even without a COPD diagnosis — these patients respond poorly to aspiration and deteriorate more often.

Simple or tension pneumothorax?

Commonly confused

Hemodynamics	Stable
Typical setting	Spontaneous or iatrogenic
Diagnosis	Upright chest film or ultrasound
First treatment	Observe, aspirate or chest tube

Teach & follow up

Patient education

Stop smoking: recurrence is about 30%About 30% of primary spontaneous pneumothoraces recur, most within the first year; quitting smoking cuts recurrence, so every patient gets cessation counseling.

Fly 7 days after resolution; never divePatients may fly 7 days after full radiographic resolution; scuba diving is a lifelong contraindication unless definitive surgical prevention has been done.

More detail

Reference

Show 6 reference facts

Most air leaks seal within a week; a leak persisting beyond about 3–5 days (persistent air leak) warrants thoracic surgery referral, or an autologous blood patch or endobronchial valve if surgery is unsuitable.

Radiographic size ≈ 1 − (lung width³ ÷ hemithorax width³): a 5-cm lung in a 10-cm hemithorax is about an 87% pneumothorax; adhesions make the estimate unreliable.

In a randomized trial of large but minimally symptomatic primary pneumothorax, conservative care achieved 94% re-expansion by 8 weeks (vs 98% with a drain) with fewer 12-month recurrences (8.8% vs 16.8%).

Supplemental oxygen for a non-hypoxemic primary pneumothorax has minimal evidence and is not part of current recommendations.

Catamenial pneumothorax recurs within 48 hours of menses onset from thoracic endometriosis; about 10% of primary pneumothoraces are familial (Birt–Hogg–Dubé, lymphangioleiomyomatosis, Marfan).

Iatrogenic pneumothorax follows transthoracic needle biopsy, thoracentesis, central line placement, mechanical ventilation or CPR; symptomatic iatrogenic cases are usually managed first with aspiration.

Pearl

Tension pneumothorax is a clinical diagnosis: the chest film you wait for is time the patient does not have.

Sources · Merck Manual Professional — Pneumothorax (Rahman NM, rev. Jul 2025) · Shorthose M, Barton E, Walker S. The contemporary management of spontaneous pneumothorax in adults. Breathe 2023;19:230135 (PMC10790175) · Iqbal B, Hallifax R, Rahman NM. Pneumothorax: an update on clinical spectrum, diagnosis and management. Clin Med (Lond) 2025;25:100327 (PMC12159893) · Kim M, Moore JE. Chest Trauma: Current Recommendations for Rib Fractures, Pneumothorax, and Other Injuries. Curr Anesthesiol Rep 2020;10:61–68 (PMC7223697; summarizes ATLS 10th ed.) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).