What is Tube Clogging?
About Chest Tubes
Traditional
chest tubes are long, semi-stiff, clear plastic tubes that are inserted
into the chest so that they can drain collections of fluids or air from
the space between the pleura or within the mediastinum or pericardial
space. The chest tubes are connected to a closed drainage system that
is placed on suction. This drainage system is made up of a tubing
coupler, which couples the chest tube to the drainage tubing that leads
to the drainage canister. Because the pressure is lower in the closed
suction drainage system than in the chest, the blood, fluid and air
travel into the tubes and out to the drainage system.
When a
surgeon selects a chest tube, the biggest question they have to address
is what size is the internal diameter of the tube. Chest tubes come in
a variety of internal diameters sizes, ranging from 14 F to 40F or
larger. The term French or (FR) is the measurement of the diameter of
the tube. A 14 French tube is fairly small about ¼ inch in diameter. A
48 French chest tube is about ¾ inch in diameter. One French is
approximately 1/3 of a millimeter .013 inch. A 36 F chest tube is
nearly 11 mm in diameter, or the size of tip of your index finger.
After most heart operation, one or more 36 F chest tube are used to
drain the chest. Many patients refer to having a 36F chest tube being
akin to having a “garden hose” go through the chest wall, as this is a
major source of pain in the post operative period.
Selecting a Chest Tube
For the surgeon considering a chest tube, chest tube internal size selection is all about potential for clogging. Choosing a chest tube diameter size is up to the physician inserting the tube and the choice is always impacted by the surgeon’s perception of the risk of clogging. The higher the risk perceived, the bigger the diameter of the tube chosen. If a surgeon is simply draining a small amount of air, a small diameter tube can be chosen (20F).
Complications from Clogging
Ongoing production of more viscous fluids such as blood or even pus, particularly if being generated rapidly, requires a larger bore tube (36F or 40F). Even though larger sized tubes are clearly associated with more pain, physicians generally err on the side of caution to avoid clogging, and insert tubes with larger tube diameters. The downside of this approach is the effect of large tube diameter size on patient discomfort. Chest tube pain is directly related to the size of the chest tube.
Any tube used to drain a body space after surgery can become clogged. This usually happens in the setting of bleeding. Bleeding and clotting in the tube in this circumstance can be life threatening for two reasons. First, the amount of blood that comes out is very carefully monitored as a measure of the seriousness of the amount of bleeding. If blood pools in the chest, for example, unnoticed because it is not coming out of the tubes, the patient can loose a large volume of blood untreated. This can have severe consequences hemodynamically, including death. Second, if blood pools in the pericardial space, it can compress the structures of the heart, impairing the return of blood to the heart, and thus the ability of the ventricle to fill and empty. This condition, known as pericardial tamponade, likewise can be fatal. In the case of pulmonary surgery, when air is leaking, a clogged tube can lead to pneumothorax (lung collapse) or leakage of air outside of the chest (subcutaneous emphysema). Any time a tube is needed it is imperative that it function properly. If it doesn’t, the ensuing problems can be serious.