What is the recommended depth for nasogastric tube (NGT) placement in adults?

From the Guidelines

The recommended depth for nasogastric tube (NGT) placement in adults is typically 50-60 cm from the nostril, as measured from the xiphisternum to the nose via the earlobe 1. This measurement is a general guideline and may need to be individualized based on patient anatomy.

Key Considerations for NGT Placement

• The patient should be positioned upright with the head level during insertion, and the tube should be advanced as the patient swallows to help guide it into the stomach 1.
• The tube should be lubricated externally with gel or water and internally with water if a guidewire is present, and the guidewire should be checked to ensure it moves freely 1.
• Nasal patency should be checked by having the patient sniff with each nostril occluded in turn, and the clearer nostril can be sprayed with lignocaine to minimize discomfort 1.
• The tube should be secured to the nose after confirmation of correct placement to prevent displacement.

Verification of NGT Placement

• Proper placement of the NGT must be confirmed before use, as improper positioning can lead to serious complications 1.
• Verification methods include checking the position of the tube before use, which does not usually require an X-ray 1.
• It is essential to document tube insertion in the patient's notes and to check the position of the tube before every use 1.
• pH testing of aspirate can also be used to verify placement, with a pH less than 5.5 suggesting gastric placement 1.

From the Research

Recommended Depth for Nasogastric Tube Placement in Adults

The recommended depth for nasogastric tube (NGT) placement in adults can be determined using various methods, including:

• The tip of the nose-earlobe-xiphoid distance (NEX) + 10 cm, with a mean of 59.9-60.7 cm 2
• The formula (NEX × 0.38696) + 30.37 + 6 cm, with a mean of 56.6-56.7 cm 2
• The distance from xiphisternum to earlobe to nose + 10 cm, which provided the best estimate of the internal length in one study 3
• The formula ((Distance from tip of nose to earlobe to xiphisternum-50 cm)/2) + 50 cm, which has been shown to provide a 91% confidence level of tube tip placement in the stomach 4

Comparison of Methods

Different studies have compared the accuracy of various methods for determining the internal length of NGT in adults, including:

• A systematic review that found the NEX + 10 cm and (NEX × 0.38696) + 30.37 + 6 cm methods to be potentially accurate 2
• An integrative review that suggested the [gender-weight and nose-umbilicus-flat] method to be safer 5
• An observational study that found the distance from xiphisternum to earlobe to nose + 10 cm to provide the best estimate of the internal length 3

Key Findings

Key findings from the studies include:

• The importance of accurate determination of the internal length of NGT to achieve correct gastric positioning and prevent complications 2
• The need for additional verification of tube tip positioning, as blind placement using any method cannot be considered safe 2
• The variation in accuracy of different methods, with some studies finding certain methods to be more accurate than others 5, 3