The observation of bubbling in a chest drainage system’s water seal chamber can be a source of confusion or concern. This system is commonly employed to manage conditions affecting the pleural space, such as a collapsed lung or fluid accumulation. Understanding when this bubbling is an expected part of the healing process and when it signals a potential problem requiring prompt attention is important. This article clarifies these distinctions, explaining normal and abnormal bubbling in the water seal chamber.
Purpose of the Water Seal Chamber
The water seal chamber serves as a component of a chest drainage system, acting as a one-way valve to permit air and fluid to exit the pleural space while preventing atmospheric air from re-entering the chest cavity. This mechanism is achieved by submerging the end of the chest tube in a column of sterile water, creating a seal. As air or fluid drains from the patient’s chest, it passes through this water seal. The system is designed to restore and maintain the negative pressure within the pleural space, which aids proper lung expansion. Without this one-way valve, air could be drawn back into the chest with each inhalation, hindering lung re-expansion and potentially leading to complications.
When Bubbling is Normal
Intermittent bubbling in the water seal chamber is a normal finding, indicating that air is successfully escaping from the pleural space and correlating with the patient’s respiratory efforts, appearing during exhalation, coughing, or sneezing. The increase in intrathoracic pressure during these actions forces air out of the chest and through the water seal. This fluctuation in the water seal fluid level with respiration is known as “tidaling”. Tidaling signifies that the chest tube remains open and connected to the pleural space, reflecting the normal pressure changes within the chest cavity. Gentle, occasional bubbling, particularly in a patient who has recently had a chest tube inserted for a pneumothorax (collapsed lung), is a positive sign that trapped air is being removed.
When Bubbling Indicates a Problem
Conversely, continuous bubbling in the water seal chamber indicates an air leak within the chest drainage system. This persistent stream of bubbles, often more pronounced than intermittent bubbling, suggests that air is constantly entering the system from an unintended source. An air leak can originate from various points, including a loose connection between the chest tube and the drainage unit, a crack in the drainage system itself, or a persistent leak from the patient’s lung. An air leak from the lung, such as a bronchopleural fistula, can also manifest as continuous bubbling, where air escapes from the airways into the pleural space and then into the drainage system. Distinguishing continuous bubbling from normal intermittent tidaling is important, as this bubbling warrants further investigation to identify and resolve the source of the air leak.
Steps to Take
If continuous bubbling is observed, assess for potential issues by visually inspecting the external components of the chest drainage system for problems like loose connections or kinks. Ensuring all connections are secure and the tubing is free of obstructions can sometimes resolve the issue. Avoid clamping the chest tube without instructions from a healthcare professional. Clamping the tube when an air leak is present can lead to a buildup of air in the pleural cavity, potentially causing a tension pneumothorax. If continuous bubbling persists after checking external connections, or if there are any concerns about the patient’s respiratory status, contact a healthcare professional immediately for assessment and intervention.