A Salem sump tube is a nasogastric (NG) tube inserted through the nose and down into the stomach, primarily used to drain stomach contents through suction. Its most common purpose is gastric decompression, removing air, fluid, and other material that has built up in the stomach after surgery or during a bowel obstruction. It can also be used for feeding, hydration, and delivering medication directly to the stomach.
How the Double Lumen Design Works
What sets a Salem sump apart from a standard single-lumen NG tube is its two-channel design. The larger main channel connects to a suction source and draws out stomach contents. The smaller channel, which ends in a visible blue “pigtail” vent outside the body, serves a critical safety role: it allows air to flow into the tube and equalize vacuum pressure inside the stomach once contents have been emptied.
Without this second channel, continuous suction could pull the stomach lining directly against the tube’s drainage holes, causing tissue damage. The air vent prevents that by breaking the vacuum. This makes the Salem sump safer for prolonged suction compared to single-lumen alternatives like the Levin tube.
When a Salem Sump Is Used
The most frequent reason for placing a Salem sump is gastric decompression. After abdominal surgery, the digestive system often slows down or temporarily stops moving (a condition called ileus). Gas and fluid accumulate in the stomach, causing nausea, vomiting, bloating, and pain. The tube relieves that pressure by continuously or intermittently suctioning out the buildup.
Beyond post-surgical care, Salem sump tubes are placed for:
- Bowel obstruction: When a blockage prevents stomach and intestinal contents from moving forward, the tube keeps the stomach decompressed and reduces the risk of aspiration (inhaling stomach contents into the lungs).
- Gastric lavage: In cases of poisoning or certain types of bleeding, the tube can be used to wash out the stomach with fluid.
- Feeding and medication delivery: Newer Salem sump models with updated connectors are approved for delivering liquid nutrition, hydration, and medications when a patient cannot eat or swallow safely.
Sizes and Who Gets Them
Salem sump tubes come in sizes ranging from 6 French to 18 French (French is a unit measuring the tube’s outer diameter, where each French equals roughly one-third of a millimeter). Adults typically receive a 12 to 18 French tube, while smaller sizes between 6 and 10 French are reserved for infants and children. The right size depends on the patient’s anatomy and the reason for placement.
How Placement Is Confirmed
Once the tube is threaded through the nose, down the esophagus, and into the stomach, its position needs to be verified before use. Historically, clinicians listened with a stethoscope while pushing air through the tube, but this method proved unreliable and led to frequent misplacements going undetected.
X-ray imaging is the current standard. Chest X-rays have traditionally been preferred, though recent clinical discussion has pushed for abdominal X-rays or a combined imaging approach, since these can more reliably confirm the tube tip is sitting in the stomach rather than coiled in the esophagus or accidentally placed in the airway.
Suction Settings
Salem sump tubes are typically connected to wall suction set at low pressure, generally between 40 and 60 mmHg, and no higher than 80 mmHg. Higher suction increases the risk of pulling the stomach lining against the tube’s drainage holes, even with the air vent in place. Suction can be set to run continuously or intermittently depending on the clinical situation and how much fluid the stomach is producing.
Caring for the Blue Pigtail Vent
The blue pigtail is the most maintenance-sensitive part of the Salem sump, and keeping it functional is essential for the tube to work properly. A few key rules apply. Fluid should never be flushed through the blue vent. Only air goes through it. After each time the main lumen is irrigated or flushed, air should be injected through the blue pigtail to clear it: 15 to 30 mL for adults, 5 to 10 mL for children, and 1 to 3 mL for newborns.
The vent typically has an anti-reflux valve attached to prevent stomach contents from leaking out. If that valve gets wet or soiled, it needs to be replaced because a blocked valve will stop the tube from decompressing the stomach effectively. If gastric secretions start appearing in the blue vent lumen, that signals an obstruction. The main tube needs to be flushed (through the primary lumen, not the vent), suction settings checked, and air re-injected through the pigtail once the blockage clears.
Who Should Not Get One
Salem sump tubes are not appropriate for everyone. Nasogastric tubes of any type are contraindicated when there is a blockage in the nasal passages or esophagus, severe facial trauma (particularly fractures of the midface or skull base, where a tube could enter the brain cavity), or uncorrected bleeding disorders that raise the risk of uncontrolled bleeding during insertion. Esophageal varices, the swollen veins in the esophagus common in liver disease, were long considered a reason to avoid NG tubes, but current evidence does not clearly support this as a firm contraindication.
What It Feels Like for the Patient
Having a Salem sump tube placed is uncomfortable. The tube passes through the nostril and the back of the throat, which triggers a strong gag reflex in most people. Patients are usually asked to swallow sips of water during insertion to help guide the tube into the esophagus rather than the airway. Once in place, the tube causes a persistent sensation of something in the throat, mild soreness in the nostril, and sometimes a dry or scratchy throat. These discomforts are manageable but real, and they persist for as long as the tube stays in, which can range from hours to several days depending on the reason for placement.
The tube is secured to the nose with tape or a specialized bridle device to prevent it from shifting. Patients can typically talk and move around with the tube in place, though eating by mouth is often restricted while the tube is connected to suction.