Chest Drain Insertion Length and Management of Malpositioned Drains in Empyema
If a Seldinger chest drain for empyema has its distal drainage hole sitting in subcutaneous tissue rather than the pleural cavity, the drain must be removed and replaced with proper positioning, as a malpositioned drain will not effectively drain the empyema and risks wound infection or subcutaneous tracking of purulent material. 1
Correct Insertion Depth for Seldinger Drains
The drain should be inserted far enough that all drainage holes are within the pleural cavity, with confirmation by post-insertion chest radiograph. 1
The insertion depth is guided by ultrasound marking of the optimal entry site before the procedure, which should indicate both the skin entry point and the depth to the pleural fluid collection. 1
For small-bore Seldinger drains (8-14F), insert the catheter over the guidewire until resistance is felt or until the measured depth (based on pre-procedure imaging) is reached. 1
A chest radiograph must be performed immediately after insertion to verify that the drain tip and all side holes are positioned within the pleural space, not in the chest wall. 1, 2
Management When Distal Hole is in Subcutaneous Tissue
Do not attempt to advance or reposition a drain that is already secured - this risks introducing infection and creating a false tract. 1
Immediate Actions:
Remove the malpositioned drain entirely if it is not functioning effectively (i.e., not draining the empyema adequately). 1
Insert a new drain at a fresh site using proper technique with ultrasound guidance to ensure correct positioning. 1
An effectively functioning drain should not be repositioned solely because of radiographic appearance; however, if the drain is not draining the empyema because the holes are extrapleural, this constitutes drain failure requiring replacement. 1
Critical Technical Points to Prevent Malposition
Use ultrasound guidance to mark the optimal insertion site and measure the depth to the fluid collection before starting the procedure. 1
Never use substantial force during Seldinger drain insertion, as this risks sudden chest penetration and damage to intrathoracic structures. 1
Insert the drain at the mid-axillary line through the "safe triangle" (bordered by anterior latissimus dorsi, lateral pectoralis major, and horizontal nipple line) to minimize risk of malposition and injury. 1
For empyema specifically, small-bore drains (10-14F) are appropriate and as effective as large-bore drains when properly positioned, though they have higher blockage rates with thick pus (20% success rate for empyema vs 83% for simple effusions). 1, 3
Common Pitfalls
Insufficient insertion depth is a common error with Seldinger technique, leaving drainage holes in the chest wall rather than pleural cavity. 1, 4
Do not skip the post-insertion chest X-ray - this is when malpositions are detected and must be corrected before securing the drain permanently. 1, 2
Blockage risk is highest with empyema (failure rate up to 80% with small-bore drains), so monitor closely for sudden cessation of drainage and flush the drain to check for obstruction. 1, 3
If a drain cannot be unblocked and significant pleural fluid remains, remove and replace it rather than attempting to salvage it. 1
Post-Insertion Verification
Confirm on chest X-ray that all side holes are visible within the thoracic cavity, not overlying the chest wall soft tissues. 1, 2
The drain should be connected to underwater seal drainage and observed for appropriate fluid drainage and/or air bubbling. 1
For empyema, consider intrapleural fibrinolytics (urokinase 40,000 units twice daily for 3 days) once proper drain position is confirmed, as this shortens hospital stay. 1