Gatorade Is a Good Substitute for Normal Saline in Multichannel Intraluminal Impedance and Manometry

Abstract

Purpose: Multichannel intraluminal impedance and manometry (MII-EM) is a method evaluating esophageal motility and bolus transit. Patients swallow 5 ml of normal saline during their swallow assessment. Due to the taste of normal saline, patients quite often complain. Normal saline was initially chosen as the liquid challenge medium for swallowing because of its high electrolyte contents which is needed for good electrical conductance for the MII part of the test. Gatorade is also rich in electrolytes, thought less than normal saline. The aim of this study was to evaluate the usage of Gatorade as a substitute for normal saline in MII-EM. Methods: 15 patients (3 males; 12 females) scheduled for esophageal function testing were studied with an MII-EM catheter: 4 impedance measuring segments (5, 10, 15 and 20 cm above LES (lower esophageal sphincter)) and 5 solid state pressure transducers (within the LES and 5, 10 15 and 20 cm above LES). Each subject was given 10 swallows of 5 ml of normal saline and 10 swallows of 5 ml of Gatorade. The studies were assessed and results were compared using PRISM statistical software. Results: In the normal saline study, 14 patients had normal manometry and 1 patient had nutcracker esophagus. In the Gatorade study, 12 patients had normal manometry, 2 patients had ineffective esophageal motility and 1 patient had nutcracker esophagus. The patient with nutcracker esophagus had the same diagnosis using both saline and Gatorade. Thus there is an 87% concordance between the two studies. All the normal saline as well as the Gatorade studies had complete bolus transit, as defined by at least 80% complete swallows on MII. Both studies had a statistically significant correlation in distal esophageal amplitude (P < 0.001, pearson r = 0.95) and total bolus transit time (P < 0.001, pearson r = 0.92). Conclusion: This initial study indicates that Gatorade may be a good substitute to normal saline in MII-EM as it provides similar results. Furthermore, it is more palatable for most patients. Further testing will be needed to confirm these results.