Accuracy of the corrected nose-earlobe-xiphoid distance formula for determining nasogastric feeding tube insertion length in intensive care unit patients: A prospective observational study

Abstract

Background: As nasogastric feeding tube insertion is a frequently applied, non-risk-free nursing technique, a high level of evidence-based nursing care is required. Little evidence is available regarding the accurate determination of the insertion length of nasogastric feeding tubes. The method of using the nose-earlobe-xiphoid distance as measurement is inadequate and not supported by evidence. Findings from a recent randomized trial led to an alternative calculation: the corrected nose-earlobe-xiphoid distance formula: (nose-earlobe-xiphoid distance × 0.38696) + 30.37 + 6 cm.

Objectives: To test the accuracy of the corrected nose-earlobe-xiphoid distance formula for determining the required nasogastric feeding tube insertion length in adults admitted on an intensive care unit and to investigate the probability to successfully obtain gastric aspirate for pH measurement.

Design: Prospective, single-center observational study.

Participants and methods: Adult intensive care unit patients in a general hospital (N = 218) needing a small-bore nasogastric feeding tube were included between March and September 2018. Correct tip positioning was defined as a tube tip located > 3 cm under the lower esophageal sphincter. Tip positioning was verified using X-ray.

Results: All nasogastric feeding tube tips were correctly positioned > 3 cm under the lower esophageal sphincter. The chance of successfully obtaining gastric aspirate within 2 h after placement of the tube was 77.9%.

Conclusions: With all tips positioned > 3 cm in the stomach and zero tubes migrating back into the esophagus, the corrected nose-earlobe-xiphoid distance formula can be considered a more accurate method to determine nasogastric feeding tube insertion length.

Keywords: Adult; Enteral nutrition; Evidence-based nursing; Gastrointestinal intubation; Patient safety; X-rays.