Swallow Studies

Why choose Blue for Swallow Studies?
The most important consideration when deciding on a color contrast to add to your arsenal of diagnostic bedside tools is impact. What is going to be most indicative of gross aspiration?


Nothing in the human body resembles the color blue. Even veins near to the mucosal surface as sometimes seen in Fiberoptic Endoscopic Evaluation of Swallowing (FEES) are not distinctive enough to mistake for the blue of a color contrast.

Other than the use of endoscopy, very little at bedside is truly definitive. But blue is a powerful tool and occasionally a definitive measure — especially when noted immediately in tracheal secretions or around the tracheal phalange.

Immediate return of blue in tracheal secretions has impact and can aid in the identification and understanding of the implications of prandial aspiration across care providers.

Why Use All-Natural PhageinBlue for Swallow Studies?

  • PhageinBlue is a natural product made from the extracts of vegetables —not an artificial petroleum- or coal-based colorant like the FD&C Blue No. 1 and No. 2
  • PhageinBlue is comprised of  anthocyanins & phycocyanins derived from fruit/vegetable juice and Spirulina
  • PhageinBlue is  packaged  into individual, sterile units that are intended for one-time, one-patient use. Individual packaging increases patient safety by decreasing the risk of bacterial and viral contamination that may occur when using multi-use, multi-patient bottles.

Synthetic Colorant Controversy
There has been concern over the use of synthetic blue food colorings such as methylene blue and FD&C Blue No.1 in swallow studies after instances of toxicity and mortality following maximal exposure studies conducted via enteral tube feedings to assess for non- or postprandial aspiration. This should not be confused with the limited-exposure swallow studies conducted by speech pathologists to assess for prandial aspiration.

False Positives and Negatives
The reliability of blue dye bedside swallow studies has been called into question due to reports of false negatives and false positives. False negatives were indicated when there was no blue dye return in tracheal secretions at bedside but where frank aspiration was noted on video-fluorographic swallowing study (VFSS). Fewer cases of false positives were indicated when there was blue dye return in tracheal secretions but where there was no frank aspiration on VFSS.

These studies have not definitively linked immediate deep suctioning as a cause of the false positives, but have strongly suggested this as a possibility. It is always important to have patients cough before initiating deep suctioning. If blue is seen before deep suctioning, blue return due to deep suctioning can be ruled out.

Blue is a Powerful Diagnostic Tool
The use of blue color contrast in bedside swallow studies is a tool, and like all other diagnostic tools, requires adequate education and training of the care provider to ensure its appropriate use and interpretation.

Whether you use a synthetic colorant or an all-natural one such as PhageinBlue, it is always a good idea for the trans-disciplinary medical team to discuss diagnostic plans and contraindications including medical and respiratory status, aspiration risk, gut perforation or permeability before commencing evaluation of the patient’s swallow.

More Information
For more information regarding swallow studies and the use of synthetic colorants click on the links in sidebar.