What is chest drain swinging (tidaling)?
Swinging, or more technically, 'tidaling', is the rhythmic fluctuation of the fluid level in the water seal chamber of a chest drainage system. This movement corresponds to the patient's breathing cycle and is a direct result of the pressure changes within the chest cavity (pleural space).
- During spontaneous breathing: As the patient inhales, the negative pressure in the pleural space increases, causing the fluid level in the water seal to rise. When they exhale, the pressure decreases, and the fluid level falls.
- During mechanical ventilation: For patients on positive pressure ventilation, this process is reversed. The fluid level will fall with inspiration and rise with expiration.
This continuous to-and-fro motion is a positive sign, confirming that the chest tube is properly positioned within the pleural space and remains open (patent).
Is it normal for a chest drain to stop swinging?
It is not a universal rule that a chest drain should always swing. There are several clinically significant reasons why the tidaling might cease. Recognizing the difference between a successful outcome and a potential complication is vital.
The lung has fully expanded
This is the best-case scenario. When the patient's lung has re-expanded and sealed the air or fluid leak that required the chest drain, the pressure in the pleural space normalizes. With the space eliminated, the respiratory pressure changes no longer cause the fluid to fluctuate, and the swinging stops. This is often an indication that the chest tube is ready for removal.
The drain is blocked or kinked
If the chest drain is blocked by a clot, fibrin, or a kink in the tubing, the connection between the pleural space and the drainage system is interrupted. The pressure changes from breathing can no longer be transmitted to the water seal, and tidaling will stop. This is a serious issue that requires immediate attention as it can lead to complications like a tension pneumothorax.
Suction is in use
When a high level of continuous suction is applied to the drainage system, it can overcome the subtle pressure changes caused by respiration. In this case, the fluid level in the water seal will be held steady, and tidaling will be absent. This is a normal and expected finding and does not indicate a problem with the tube. When the suction is momentarily turned off, tidaling should resume if the lung has not yet re-expanded.
The drain is misplaced
If the chest tube becomes dislodged and is no longer positioned correctly within the pleural space, swinging will cease because the tube is no longer in communication with the thoracic pressure changes. A drain tip located against the chest wall can also cause tidaling to stop.
Differentiating swinging from bubbling
It is important to distinguish between tidaling and bubbling, as they signify different aspects of chest drain function.
| Feature | Swinging (Tidaling) | Bubbling |
|---|---|---|
| Appearance | Fluid level moves rhythmically with breathing | Air bubbles escape through the water seal |
| Timing | Synchronous with respiratory cycle | Can be intermittent or continuous |
| Cause | Normal intrapleural pressure changes | Air leaking from the pleural space |
| Significance | Normal: Indicates drain patency and position | Normal: Expected with a pneumothorax |
| Significance | Abnormal (if absent): Indicates occlusion or full lung expansion | Abnormal (if excessive/continuous): Indicates a large air leak or system problem |
| Action | Monitor, check for kinks if absent | Assess for system leaks or worsening air leak |
What to do if your chest drain stops swinging
If you are a patient or caregiver and notice the swinging has stopped, follow these steps in order:
- Assess the patient. First, check the patient for any signs of respiratory distress, such as shortness of breath, chest pain, or increased heart rate. If they are in distress, this is a medical emergency. Seek immediate help.
- Examine the tubing. Carefully inspect the entire length of the drainage tubing, starting from the patient's chest. Look for any kinks, loops, or blockages. Ensure the patient is not lying on the tubing.
- Check the drainage system. Make sure the drainage system is upright and positioned below the level of the patient's chest. Ensure all connections are securely fastened.
- Consider suction. If the patient is on continuous suction, the lack of tidaling is likely normal. Temporarily interrupting the suction (if medically appropriate and ordered) could reveal if tidaling resumes.
- Notify a healthcare professional. If the patient is not on suction and the swinging has stopped without a clear cause, or if the patient is symptomatic, a healthcare provider must be alerted immediately. Further assessment, including a chest x-ray, may be necessary to determine the cause.
For additional guidance on patient care and chest drain management, refer to a trusted resource such as the National Institutes of Health (NIH) guidelines on intercostal chest drains. https://pmc.ncbi.nlm.nih.gov/articles/PMC5606459/
Conclusion
While a chest drain should normally swing in the water seal, this fluctuation is not constant and will stop under certain conditions. The most positive reason for the cessation of swinging is a successfully re-expanded lung. However, a blockage, kinking, or misplacement of the tube can also cause it to stop, requiring immediate medical attention. In the presence of continuous suction, the absence of tidaling is an expected finding. Proper monitoring and understanding of these signs are essential for the safe and effective management of chest drains. When in doubt, a healthcare professional should always be consulted for an expert assessment.
