Should an NG (Nasogastric) tube be set to low or intermittent suction?

Nasogastric Tube Suction: Low vs. Intermittent

For nasogastric tubes, intermittent suction is preferred over low continuous suction as it causes less gastric mucosal damage while maintaining equivalent effectiveness in gastric decompression. 1

Suction Mode Selection

• Intermittent air injection suction systems (IAIS) produce significantly fewer gastric ulcers compared to continuous suction while maintaining equivalent effectiveness in removing gastric contents 1
• Continuous suction can lead to suction-induced gastric mucosal damage when mucosa gets pulled into the holes of the NG tube 1
• Intermittent suction allows the gastric mucosa to recover between suction cycles, reducing the risk of mucosal injury 1

Clinical Considerations for NG Tube Management

Placement and Monitoring

• Fine bore (5-8 French gauge) nasogastric tubes should be used unless there's a need for repeated gastric aspiration or administration of high viscosity feeds/drugs 2
• Position must be confirmed before use, typically using pH testing prior to each use 2
• NG tubes should be changed every 4-6 weeks, alternating nostrils 2

Duration of Use

• NG tubes should not be used routinely in the postoperative period and should be removed as soon as possible 3
• Daily evaluation of the necessity for NG decompression is recommended 3
• Routine nasogastric decompression should be avoided as it increases risk of complications including fever, atelectasia, and pneumonia 3

Evidence on Complications

• Studies show that patients with NG decompression have significantly increased risk of pneumonia and respiratory failure 4
• Patients with NG tubes have longer time to resolution and increased hospital length of stay compared to those without 4
• Routine use of NG suction as adjunctive therapy following abdominal operations is not supported by evidence 5
• The total number of complications (high temperature, atelectasis) is significantly higher in patients with NG tubes compared to those without 5

Special Considerations

• In cases of inadvertent NG tube removal during the first 7-10 days after gastrostomy placement, management consists of NG suction, broad-spectrum antibiotics, and repeat gastrostomy placement in 7-10 days 2
• For patients with severe reflux, vomiting, or risk of aspiration, nasojejunal feeding may be preferred over nasogastric feeding 2
• In neonates with epidermolysis bullosa, experienced staff should insert lubricated NG tubes to reduce friction on internal mucosa 2

Practical Algorithm for NG Tube Suction Management

1. Initial Assessment:

   • Determine if NG tube is absolutely necessary; avoid routine use 3, 4
   • Consider patient's condition, risk of aspiration, and expected duration of use 3

2. Suction Mode Selection:

   • Choose intermittent suction as the default option 1
   • Use intermittent air injection suction if available to minimize mucosal damage 1
   • Apply low suction levels (around 20 mm Hg) rather than high suction 1

3. Monitoring:

   • Assess daily for continued need of NG tube 3
   • Monitor for complications including respiratory issues and mucosal damage 4, 1
   • Check tube position before each use 2

4. Removal Criteria:

   • Remove as soon as clinically feasible 3
   • Consider removal when patient can tolerate oral intake 3
   • Monitor for signs of intolerance after removal (nausea, vomiting, distension) 3