title: Effect of Feeding and Suction on Gastric Impedance Spectroscopy Measurements.
abstract: A specific device and system has been developed and tested for clinical monitoring of gastric mucosal reactance in the critically ill as an early warning of splanchnic hypoperfusion associated with shock and sepsis. This device has been proven effective in clinical trials and is expected to become commercially available next year. The system uses a combination nasogastric tube and impedance spectroscopy probe as a single catheter. Because this device has a double function, the question is: Does enteral feeding or suction affect the gastric reactance measurements? This study was designed to evaluate the effect of feeding and suction on the measurement of gastric impedance spectroscopy in healthy volunteers. Impedance spectra were obtained from the gastric wall epithelia of 18 subjects. The spectra were measured for each of the following conditions: postinsertion of gastric probe, during active suction, postactive suction, and during enteral feeding (236 ml of nutritional supplement). Impedance spectra were reproducible in all volunteers under all conditions tested. There was a slight increase in impedance parameters after suction, and a decrease in impedance after feeding; however, these observed differences were insignificant compared to patient-to-patient variability, and truly negligible compared with previously observed changes associated with splanchnic ischemia in critically ill patients. Our results demonstrate that suction or feeding when using the impedance spectro-metry probe/nasogastric tube does not significantly interfere with gastric impedance spectrometer measurements.
authors.affiliation: Nohra E. Beltran, PhD, is Professor and Researcher, Process and Technology Department, Universidad Autonoma Metropolitana-Cuajimalpa, Mexico City, Mexico. Gustavo Sánchez-Miranda, MD, MSc, is Coronary Unit Chief and Cardiology Associate Professor, ABC Medical Center, Mexico City, Mexico. Emilio Sacristan, PhD, is Professor and Researcher, National Center for Medical Instrumentation and Imaging Research, Department of Electrical Engineering, Universidad Autonoma Metropolitana-Iztapalapa, Mexico City, Mexico.
authors.forename: Nohra E
authors.initials: NE
authors.lastname: Beltran
authors.forename: Gustavo
authors.initials: G
authors.lastname: Sánchez-Miranda
authors.forename: Emilio
authors.initials: E
authors.lastname: Sacristan
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D016001:Confidence Intervals; D058266:Dielectric Spectroscopy / Q000379:methods*; D017097:Electric Impedance; D004750:Enteral Nutrition / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005753:Gastric Mucosa / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012494:Sampling Studies; D013396:Suction / Q000009:adverse effects / Q000379:methods; D055815:Young Adult