Open Pneumothorax: The Sucking Chest Wound and Why You Never Fully Seal It

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Updated July 2026  |  More ICU clinical guides →

An open pneumothorax — the classic "sucking chest wound" — is a defect in the chest wall large enough that air moves in and out through the hole instead of through the airway. It is one of the few injuries where the wrong dressing can kill the patient faster than no dressing at all, because a fully occlusive seal over a wound that is still leaking from the lung can convert an open pneumothorax into a tension pneumothorax. This guide covers the physiology, the three-sided (vented) dressing, why and when to lift the seal, definitive chest-tube management, and the ICU care that follows.

The physiology: air takes the path of least resistance

Normally the chest wall is airtight, and the negative intrapleural pressure generated by the diaphragm pulls air in through the trachea. When there is a large open defect in the chest wall, air can enter the pleural space directly through the hole. If that opening is about two-thirds the diameter of the trachea or larger, air preferentially moves through the wound rather than down the airway, because it is the lower-resistance path. The result is a lung that cannot expand on the injured side, worsening hypoxia and hypercapnia, and the audible "sucking" as air rushes through the defect with each breath. The larger the hole, the more ventilation is stolen from the airway and lost through the chest wall.

The three-sided dressing: a one-way valve

The field and initial-resuscitation treatment is deceptively simple but easy to get wrong. Place an occlusive material (a commercial chest seal, or a piece of plastic/foil dressing) over the wound and tape it on three sides only, leaving one edge open. On inhalation, the negative pressure pulls the dressing down against the wound and seals it, so air is not sucked into the chest. On exhalation, any air that has accumulated under pressure can push the free edge open and escape. This flutter-valve arrangement stops the open pneumothorax from stealing ventilation while venting air so pressure cannot build. Purpose-built vented chest seals accomplish the same thing with a built-in one-way valve and are preferred when available.

Definitive treatment: chest tube and wound closure

The temporizing dressing buys time; the definitive fix is a chest tube (tube thoracostomy) placed through a separate incision, not through the wound itself, so the tube evacuates the pleural space through a controlled tract while the traumatic defect is closed. Placing a tube through the open wound risks tracking contamination and does not reliably drain the space. Once the tube is in and functioning, the chest-wall defect is closed — small wounds primarily, larger ones may need staged or operative reconstruction. See the chest tube management guide for the nursing details of the drainage system, and the tension pneumothorax guide for the obstructive-shock physiology that a bad dressing can create.

What the ICU nurse watches

Once the patient reaches the ICU with a chest tube and a closed or dressed defect, the priorities are ventilation, the drainage system, and vigilance for recurrence. Watch the respiratory picture: oxygenation, work of breathing, and, if the patient is intubated, airway pressures — a sudden rise in peak pressure with hypotension should prompt an immediate check for tension physiology and a look at whether any occlusive dressing has become fully sealed. Monitor the chest-tube system for an air leak (bubbling in the water seal), fluid output, and tidaling; a large persistent air leak that keeps the lung from re-expanding raises concern for an associated tracheobronchial injury. Because these are penetrating or high-energy wounds, screen for associated injuries in the same trajectory — a hemothorax, a cardiac wound if the defect is in the cardiac box, and diaphragmatic or abdominal involvement for lower wounds. Manage pain aggressively so the patient can cough, deep-breathe, and clear secretions, and resuscitate ongoing blood loss with balanced massive transfusion principles if bleeding is significant.

Where to go from here

Pair this with the tension pneumothorax guide for the physiology a bad dressing can cause, the traumatic hemothorax guide for blood filling the chest, the chest tube management guide for the drainage system, and the penetrating cardiac injury guide for wounds in the cardiac box.