Thoracic surgery and one-lung ventilation

Patient and surgery

In chest surgery one lung is often deflated so the surgeon can work; the other lung must carry all the breathing safely.

Updated Nov 13, 2026

What it is

Many thoracic operations, such as lung resection, video-assisted thoracoscopic surgery and oesophageal surgery, need lung isolation: separating the two lungs so that one is ventilated and the other collapses. Isolation is also used to protect a healthy lung from pus or blood in the other, to control ventilation when there is a bronchopleural fistula or large bulla, and for whole-lung lavage. The two main tools are the double-lumen tube, usually a left-sided one because the right upper lobe bronchus arises close to the carina, and the bronchial blocker, passed through or beside a single-lumen tube and useful when the airway is difficult. Position is confirmed with a flexible bronchoscope and rechecked after the patient is turned to the lateral position. During one-lung ventilation the collapsed lung is still perfused, creating a shunt that causes hypoxaemia; hypoxic pulmonary vasoconstriction and gravity reduce it. Ventilation follows lung-protective principles: modest tidal volumes for the single lung, positive end-expiratory pressure, limited airway pressures and tolerance of some hypercapnia. Thoracotomy is among the most painful incisions, so thoracic epidural or paravertebral and other chest-wall blocks are central to the plan.

What changes in this patient

Preoperative lung function (spirometry and gas transfer, with predicted postoperative values) estimates whether the patient can tolerate the resection.
In the lateral position the dependent lung receives more blood flow; ventilating it alone matches ventilation to perfusion best.
Blood flowing through the non-ventilated lung is a true shunt and lowers arterial oxygen.
Hypoxic pulmonary vasoconstriction diverts blood away from the collapsed lung; high doses of volatile agents and vasodilators weaken it.
The single ventilated lung is at risk of injury from high volumes and pressures.
Pain after thoracotomy is severe and limits coughing and breathing, leading to atelectasis and pneumonia.

Anaesthetic plan (and why)

Review lung function and exercise tolerance with the surgeon — they predict whether the patient will cope with less lung.
Choose a double-lumen tube or a bronchial blocker on the surgery and the airway — blockers suit difficult airways and small patients.
Confirm position with a flexible bronchoscope after intubation and after turning — tubes move with positioning.
Start one-lung ventilation with high inspired oxygen, then lower it as tolerated — saturation usually falls during the first minutes.
Ventilate the single lung protectively: modest volumes, positive end-expiratory pressure, limited pressures — this lowers lung injury.
If saturation falls: high oxygen, recheck position with the bronchoscope, suction, recruit the ventilated lung — malposition is a common cause.
Then add continuous positive pressure to the collapsed lung or briefly ventilate both lungs, warning the surgeon — oxygen reaches the shunt.
Provide thoracic epidural, paravertebral or another chest-wall block — good analgesia allows coughing and deep breaths.
Re-expand the collapsed lung gently under vision at the end — this checks for air leaks and reduces atelectasis.
Extubate early when possible and give physiotherapy and early mobilisation — this protects the remaining lung.

Double-lumen tube or bronchial blocker

Feature	Double-lumen tube	Bronchial blocker
Isolation	Reliable and quick to switch sides	Good, but slower lung collapse
Suction and access	Both lungs can be suctioned separately	Little access to the isolated lung
Difficult airway	Harder to place	Placed through a standard tube, easier
After surgery	Needs exchange if ventilation continues	Blocker removed, tube stays

Risks and complications

Hypoxaemia during one-lung ventilation, most often from tube malposition, secretions or high shunt.
Airway trauma from double-lumen tubes, including bronchial rupture in rare cases.
Lung injury of the ventilated lung and pulmonary oedema after pneumonectomy, worsened by excess fluid.
Re-expansion pulmonary oedema of the collapsed lung, and persistent air leak.
Atrial fibrillation, bleeding and, after pneumonectomy, cardiac herniation or right heart strain.
Severe pain, atelectasis and pneumonia when analgesia is poor; chronic post-thoracotomy pain.

Next step

Call a senior early for persistent hypoxaemia on one lung, a difficult tube placement or a suspected airway injury.
Check a chest radiograph after surgery for lung expansion, drain position and the mediastinum.
Keep fluids restrained after lung resection, especially pneumonectomy, to lower the risk of pulmonary oedema.
Continue regional analgesia after surgery with regular review of pain, breathing and the catheter.
Arrange physiotherapy, incentive breathing exercises and early mobilisation from the first day.

Test yourself

Think of the answer, then tap the question to see it.

What are the main indications for lung isolation?

Protecting a healthy lung from pus or blood, controlling ventilation with a bronchopleural fistula or large bulla, whole-lung lavage, and surgical exposure.

Why is a left-sided double-lumen tube usually preferred?

The right upper lobe bronchus arises close to the carina, so a right-sided tube can easily block it; the left main bronchus is longer.

Why does hypoxaemia occur during one-lung ventilation?

Blood still flows through the collapsed, unventilated lung, creating a shunt; hypoxic pulmonary vasoconstriction only partly reduces it.

What is the first response to falling saturation on one-lung ventilation?

Raise inspired oxygen, recheck tube position with a bronchoscope, suction secretions and recruit the ventilated lung; then consider positive pressure to the collapsed lung.

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Educational content; it does not replace supervised training, your institution's protocols or the anaesthetist's or intensivist's decision. It contains no doses and no ventilator or infusion settings.

Sources: Lung Isolation and One-Lung Ventilation (StatPearls (NCBI Bookshelf), 2024).

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