Bubbling in a chest tube system can often be a normal, expected sign that the device is functioning correctly. A chest tube, also known as a thoracic drain, is a flexible tube inserted into the pleural space (the area between the lung and the chest wall). The primary purpose is to remove abnormal collections of air, such as in a pneumothorax, or fluid, like blood or pus. This allows a collapsed or partially deflated lung to re-expand fully and restore normal respiratory function. The tube is connected to a closed drainage system that facilitates this evacuation while ensuring nothing can travel back into the chest cavity.
Understanding the Water Seal Chamber
The key to understanding chest tube bubbling lies in the design of the drainage system, specifically the water seal chamber. This chamber contains sterile water and functions as a one-way valve, allowing air to exit the chest but preventing atmospheric air from being drawn back in. The water seal helps to re-establish the necessary negative pressure around the lung.
When air from the patient’s pleural space travels through the chest tube and enters the water seal chamber, it passes through the water, creating bubbles. This bubbling is a direct visual confirmation that air is actively leaving the patient’s chest. The water level in this chamber will also typically rise with inhalation and fall with exhalation, a movement called tidaling. Tidaling confirms that the tube remains open and correctly positioned.
The drainage system often includes a collection chamber for fluid and a suction control chamber. If the system is a wet suction model, a constant, gentle bubbling occurs in the suction control chamber, indicating that the prescribed level of suction is being maintained. This should not be confused with the bubbling in the water seal chamber, which indicates air moving out of the patient’s lung space and is the focus of an air leak assessment.
Expected and Normal Bubbling Patterns
Bubbling in the water seal chamber is considered normal under specific circumstances, particularly when the chest tube is first placed to treat a pneumothorax. Immediately following the insertion, you may observe vigorous bubbling as a large volume of trapped air is evacuated from the pleural space. This initial, brisk bubbling is a positive sign that the treatment is immediately effective in removing the unwanted air.
Another expected pattern is intermittent bubbling, which typically correlates with the patient’s breathing cycle or movement. This bubbling may appear briefly during exhalation, coughing, or sneezing, as these actions temporarily increase the pressure inside the chest, forcing air out through the tube. The presence of intermittent bubbling indicates that the air leak from the lung has not yet completely sealed, but the system is working effectively to drain the air.
As the lung heals and the air leak closes, the bubbling in the water seal chamber should gradually decrease in intensity and frequency over time. Eventually, the bubbling will cease entirely. This resolution of bubbling is a strong indicator that the air leak has resolved and the lung has fully re-expanded, often signaling that the chest tube may be ready for removal by the healthcare team.
Identifying Concerning Air Leaks and Required Actions
While some bubbling is normal, a continuous, vigorous bubbling pattern in the water seal chamber is often a sign of a persistent or large air leak that requires immediate evaluation. This sustained, constant flow of bubbles suggests air is escaping into the pleural space without interruption, possibly from a significant tear in the lung tissue or a problem within the drainage system itself.
Continuous Bubbling Assessment
If the leak is internal, the healthcare team must assess the severity and location of the ongoing air escape from the lung. A continuous bubbling may also indicate that the air leak is coming from a loose connection, a crack in the drainage unit, or a leak around the dressing site near the patient’s chest. If the leak is suspected to be from the system, the care team will systematically check all connections and the integrity of the tubing. If a leak is detected outside the chest, securing the connection or replacing the drainage unit can quickly resolve the issue.
Cessation of Bubbling
A sudden and complete cessation of bubbling, especially if the patient is known to have an air leak or shows signs of respiratory distress, can also be a serious warning sign. This abrupt stop may mean the chest tube has become blocked, perhaps by a kink in the tubing or a clot of fluid or blood. An obstruction prevents air from escaping, which can lead to a dangerous buildup of pressure around the lung, potentially resulting in a life-threatening tension pneumothorax.
Required Actions
If a patient or caregiver observes any concerning changes, such as new or increased continuous bubbling, or a sudden stop in expected bubbling, they should immediately notify a nurse or physician. It is important never to clamp the chest tube when continuous bubbling is present without explicit instruction from a medical professional, as this action can trap the air and cause the dangerous pressure accumulation. Keeping the drainage system below the level of the chest and ensuring the tube is free of kinks are important actions to maintain system function and patient safety.