The goal of this clinical trial is to learn whether using a lower negative pressure (-4 cmH₂O) on a digital chest drainage device after lung resection reduces the time a chest tube must stay in place compared with the commonly used physiologic pressure (-8 cmH₂O), without increasing complications. The trial enrolls adult patients undergoing segmentectomy or lobectomy for lung cancer at a tertiary medical center.

The main questions it aims to answer are:

Does the -4 cmH₂O setting shorten chest tube duration (primary outcome) compared with -8 cmH₂O?

What is the effect of -4 vs -8 cmH₂O on air-leak duration, length of hospital stay, and postoperative complications (e.g., pneumothorax, subcutaneous emphysema, re-intervention), and on the need for pleurodesis or suction readjustment, and 30-day readmission?

Researchers will compare patients assigned to -4 cmH₂O with patients assigned to -8 cmH₂O to see whether the lower pressure improves recovery after lung resection. The trial is prospective, randomized, open-label (two parallel arms; planned sample size ~160; 1:1 allocation). An interaction analysis will also explore whether effects differ between patients with lower vs higher air-leak flow on postoperative day (POD) 1.

Participants will:

Receive standard perioperative care for lung resection.

Provide written informed consent on the day before surgery following a discussion with study staff.

On POD#1 (approximately 7-8 AM), have air-leak flow measured by the digital device.

If no clinically meaningful air leak is present on POD#1 (e.g., 0-10 mL/min by institutional criteria) and the chest tube is likely to be removed, the participant will not be randomized and will continue standard care outside the comparative analysis (screen fail/observational record only).

If an air leak persists on POD#1, the participant will be randomized to -4 or -8 cmH₂O suction and the assigned setting will be maintained until chest tube removal, unless a clinical safety reason requires adjustment.

Undergo routine inpatient assessments already used in standard care (e.g., daily chest X-rays, recording of air-leak flow and drainage volume, monitoring for complications) until discharge.

The study uses a commercially available digital chest drainage system already employed in routine practice. Because it is open-label, neither clinicians nor participants are blinded to the pressure setting. If predefined safety signals occur (e.g., clear increases in complications or prolonged air leaks in one arm), the protocol allows suction adjustment for individual safety and interim review for potential early stopping, in accordance with institutional policies.

Inclusion Criteria:

• Adults ≥19 years of age.
• Undergoing anatomical lung resection (segmentectomy or lobectomy) for confirmed or suspected primary lung cancer at a tertiary center.
• Digital continuous suction device (Thopaz) used as the sole chest drainage system immediately after surgery.
• Able to provide written informed consent on the day before surgery.
• Randomization criterion (in-hospital): On postoperative day 1 (approximately 7-8 AM), a measurable air leak persists and the chest tube is not removed per routine care. Participants with no clinically meaningful air leak on POD1 (e.g., 0-10 mL/min per institutional criteria) will be considered screen failures and will not be assigned to an arm.

Exclusion Criteria:

• Placement of two or more drains (e.g., additional chest tube or JP drain) during the index surgery.
• Intraoperative or immediate postoperative serious complication requiring ICU care.
• Change from the digital suction system to another drainage system prior to randomization or outcome assessment.
• Any condition that, in the opinion of the investigator, makes participation inappropriate (e.g., inability to comply with study procedures or safety concerns).

No plan to share de-identified IPD due to institutional policy and/or consent constraints. Aggregate results will be published, and key study documents (e.g., protocol, SAP) may be made available upon reasonable request.