Suction vs Underwater Seal for HemoPneumoThoraX Trial

Traumatic pneumothorax occurs in up to 20% of major trauma patients and is frequently accompanied by hemothorax, with concomitant hemothorax reported in up to 70% of cases. These injuries are typically managed with placement of a chest tube to evacuate air and blood from the pleural space, facilitate lung re-expansion, and prevent respiratory or hemodynamic compromise. Following placement, chest tubes are commonly managed using either continuous negative-pressure suction (typically -20 cm H₂O) or water seal alone. Although both methods are widely accepted as standard-of-care, substantial variation exists in clinical practice regarding the initial suction status of chest tubes, with decisions often driven by provider preference or institutional norms rather than high-quality evidence.

Suction theoretically promotes lung re-expansion by generating negative intrathoracic pressure; however, studies in postoperative thoracic surgery patients suggest that suction may prolong or exacerbate air leaks, potentially increasing chest tube duration. Prior trauma-focused studies evaluating suction versus water seal have produced conflicting results with respect to chest tube duration, pleural space complications, and hospital length of stay. The predecessor SEAL IT trial conducted at the study institution demonstrated that initial water seal management reduced chest tube duration in patients with traumatic pneumothorax without increasing complications; however, that study excluded patients with larger hemothoraces, leaving uncertainty regarding optimal initial management in patients with hemothorax or hemopneumothorax.

Given the limited and conflicting data in trauma patients with hemothorax or hemopneumothorax, further investigation is warranted to determine whether initial water seal management is noninferior or superior to suction in this population. This trial is designed to address this knowledge gap by evaluating whether initial placement of chest tubes to water seal decreases chest tube duration without increasing complications when compared with initial suction.

This trial is a single-center, non-blinded, clustered randomized controlled trial conducted at Vanderbilt University Medical Center. Adult trauma patients admitted to the trauma service who require placement of a chest tube (percutaneous or open) for treatment of traumatic hemothorax or hemopneumothorax are eligible for enrollment. Patients are excluded if they are younger than 18 years of age, are pregnant, are prisoners, or have had a chest tube placed prior to computed tomography imaging. Randomization is performed using a cluster-by-month design. During odd calendar months (January, March, May, July, September, and November), all enrolled patients will have their chest tubes placed to water seal initially. During even calendar months (February, April, June, August, October, and December), all enrolled patients will have their chest tubes placed to -20 cm H₂O suction initially. This design minimizes treatment contamination and facilitates enrollment in an emergent setting.

For patients randomized to the water seal group, the chest tube will be briefly placed to suction for one minute immediately following placement to evacuate residual air and blood, after which it will be transitioned to water seal. For patients randomized to the suction group, the chest tube will remain on -20 cm H₂O suction after placement. Aside from the initial suction status, all subsequent chest tube management decisions-including changes in suction status, imaging frequency, duration of tube placement, and criteria for removal-will be determined at the discretion of the treating clinical team, consistent with usual care. Any changes in suction status and the reasons for those changes will be documented.

The primary outcome of the trial is the duration of the initial chest tube in place, measured in hours from placement to removal. Secondary outcomes include chest tube-related complications such as transitions from water seal to suction, pneumothorax or hemothorax re-accumulation, need for additional or replacement chest tubes, need for intrapleural tissue plasminogen activator, development of empyema or pneumonia, hypoxic events, need for video-assisted thoracoscopic surgery, unplanned intensive care unit (ICU) admission, acute respiratory failure requiring intubation, length of hospital stay, 30-day mortality, and 30-day readmission. Exploratory outcomes include measures of residual pleural space pathology, air leak persistence, imaging utilization, chest tube-related costs, and ICU-related outcomes.

Data for the study will be collected retrospectively from the electronic health record and stored in a secure REDCap database using coded identifiers to protect participant confidentiality. Patients will be followed for up to 30 days after hospital discharge for assessment of readmissions and subsequent thoracic interventions. The trial is conducted under a waiver of informed consent due to the minimal incremental risk associated with participation, the emergent nature of chest tube placement in trauma patients, and the impracticability of obtaining consent in many cases due to acute illness, altered mental status, or absence of legally authorized representatives. Both initial chest tube management strategies evaluated in this study are considered standard-of-care, and clinicians retain full authority to modify chest tube management at any time to ensure patient safety.

A Data Safety and Monitoring Board will oversee trial conduct and safety. Adverse events will be monitored from the time of enrollment through 30 days following discharge and reported in accordance with institutional and regulatory requirements. Through systematic comparison of initial water seal versus suction management in traumatic hemothorax and hemopneumothorax, the SUS-HPTX trial aims to provide high-quality evidence to inform chest tube management strategies and potentially reduce chest tube duration, complications, and hospital resource utilization in trauma patients.