Will gastric juices be aspirated out when a nasogastric (NG) tube is hooked to suction if it's in the correct position?

Nasogastric Tube Function and Gastric Juice Aspiration

Yes, gastric juices will come out when a properly positioned nasogastric tube is hooked to suction, confirming correct placement in the stomach. 1

Confirming Proper NG Tube Placement

Proper placement of a nasogastric tube is critical for patient safety and effective treatment. When a tube is correctly positioned in the stomach and connected to suction, you should observe:

1. Gastric contents/juices: The aspiration of gastric contents is the most reliable indicator of correct NG tube placement 2

   • Appearance: Yellow-green or clear fluid with mucus
   • pH: Typically acidic (pH < 5.5)

2. Warning signs of improper placement:

   • Inability to aspirate gastric contents
   • Absence of gastric juices when suction is applied
   • Resistance when attempting to aspirate

Verification Methods for Tube Placement

The guidelines recommend multiple verification methods to ensure proper placement:

1. Radiographic confirmation: Gold standard for initial verification 1, 3

   • Essential before initiating any feeding or medication administration
   • Required after blind bedside placement

2. Bedside verification techniques (less reliable, but useful for ongoing monitoring):

   • Aspiration of gastric contents and pH testing 4
   • Point-of-care ultrasound (POCUS) 3
   • CO₂ detection (capnography) to rule out respiratory placement 3

3. Unreliable methods to avoid:

   • Auscultation alone ("whooshing" sound when air is injected) 1
   • Direct palpation of the tube during surgery 2
   • Observing bubbling when the tube is placed in water

Clinical Implications and Pitfalls

1. Complications of improper placement:

   • Pulmonary aspiration if feeding through misplaced tube
   • Pneumothorax, tracheobronchial perforation 3
   • Intracranial insertion (rare but serious) 3

2. Common reasons for inability to aspirate gastric contents:

   • Tube misplacement (most serious concern)
   • Tube against gastric wall
   • Tube clogging (12.5% of cases) 5
   • Empty stomach

3. Tube management considerations:

   • Proper fixation is crucial (40-80% of NG tubes become dislodged when not secured) 6
   • Regular position checks before each use
   • Monitoring for tube dislodgement (occurs in 48.5% of cases) 5

Algorithm for NG Tube Function Assessment

1. Connect NG tube to suction
2. If gastric juices appear → tube likely in correct position
3. If no gastric juices appear:
   • Reposition patient (turn to left side)
   • Advance or withdraw tube slightly (1-2 cm)
   • Flush with 10-20 ml of air and reattempt aspiration
   • If still unsuccessful → obtain radiographic confirmation
   • Never proceed with feeding or medication without confirmed placement

Remember that the absence of gastric aspirate should always raise suspicion of improper placement 2, and radiographic confirmation remains the definitive method to verify tube position before use.