The Sengstaken-Blakemore (SB)tube is a red tube used to stop or slow bleeding from the esophagus and stomach. The bleeding is typically caused by gastric or esophageal varices, which are veins that have swollen from obstructed blood flow. A variation of the SB tube, called the Minnesota tube, can also be used to decompress or drain the stomach to avoid insertion of a second tube called a nasogastric tube.
The SB tube has three ports at one end, each with a different function:
- esophageal balloon port, which inflates a small balloon in the esophagus
- gastric aspiration port, which removes fluid and air out of the stomach
- gastric balloon port, which inflates a balloon in the stomach
At the other end of the SB tube are two balloons. When inflated, these balloons put pressure on the areas that are bleeding to stop blood flow. The tube is typically inserted through the mouth, but it can also be inserted through the nose to reach the stomach. Doctors will remove it once the bleeding has stopped.
The SB tube is used as an emergency technique to control bleeding from swollen esophageal veins. Esophageal and gastric veins often swell from portal hypertension or vascular congestion. The more the veins swell, the more likely the veins will rupture, causing excessive bleeding or shock from losing too much blood. If left untreated or treated too late, excessive blood loss can cause death.
Before choosing to use the SB tube, doctors will exhaust all other measures to slow or stop bleeding. These techniques might include endoscopic variceal banding and glue injections. If a doctor chooses to use the SB tube, it will work only temporarily.
In the following cases, doctors advise against using the SB tube:
- Variceal bleeding stops or slows down.
- The patient recently had surgery involving the esophagus or stomach muscles.
- The patient has a blocked or narrowed esophagus.
A doctor can insert the SB tube through the nose, but it’s more likely to be inserted through the mouth. Prior to inserting the tube, you would usually be intubated and mechanically ventilated to control your breathing. You’re also given IV fluids to maintain blood circulation and volume.
The doctor then checks for air leaks in the esophageal and gastric balloons found at the end of the tube. To do this, they inflate the balloons and place them in water. If there are no air leaks, the balloons will be deflated.
The doctor also needs to insert a Salem sump tube for this procedure to drain the stomach.
The doctor measures these two tubes to ensure accurate placement in the stomach. First, the SB tube must be properly positioned in the stomach. They next measure the Salem sump tube against the SB tube and mark it at the desired point.
After measuring, the SB tube must be lubricated to ease the insertion process. The tube is inserted until the mark made by the doctor is at your gums or opening of your mouth.
To ensure the tube reaches your stomach, the doctor inflates the gastric balloon with a small amount of air. They then use an X-ray to confirm proper placement. If the inflated balloon is positioned correctly in the stomach, they inflate it with additional air to reach the desired pressure.
Once they insert the SB tube, the doctor connects it to a weight for traction. The added resistance may cause the tube to stretch. In this case, they need to mark the new point where the tube leaves your mouth. The doctor also needs to pull the tube gently until they feel resistance. This indicates the balloon is properly inflated and applying pressure to the bleeding.
After feeling resistance and measuring the SB tube, the doctor inserts the Salem sump tube. Both the SB tube and the Salem sump tube are secured after placement to prevent movement.
The doctor applies suction to the SB aspiration port and the Salem sump to remove any blood clots. If bleeding continues, they may increase the inflation pressure. It’s important not to overinflate the esophageal balloon so it doesn’t pop.
Once the bleeding has stopped, the doctor performs these steps to remove the SB tube:
- Deflate the esophageal balloon.
- Remove traction from the SB tube.
- Deflate the gastric balloon.
- Remove the SB tube.
There are a few risks associated with using the SB tube. You can expect some discomfort from the procedure, specifically a sore throat if the tube was inserted through the mouth. If placed incorrectly, the SB tube can affect your ability to breathe.
Other complications from incorrectly positioning this tube or ruptured balloons include:
- recurrent bleeding
- aspiration pneumonia, an infection that occurs after you breathe food, vomit, or saliva into the lungs
- esophageal ulceration, when painful ulcers form in the lower portion of the esophagus
- mucosal ulceration, or ulcers that form on mucous membranes
- acute laryngeal obstruction, or a blockage in your airways that restricts oxygen intake
An SB tube is a device used to stop bleeding in your esophagus and stomach. It’s typically used in emergency situations and only for short periods of time. This and similar endoscopic procedures have a high success rate.
If you have questions about this procedure or have experienced complications, discuss your concerns with a doctor.