Validation of the RightLevelpH Detector for Monitoring Gastric pH.
BACKGROUND
The RightLevelpH indicator is a new device designed to measure the pH of gastric aspirate obtained via a nasogastric tube while minimizing exposure of the operator.


OBJECTIVE
To validate the RightLevelpH indicator in vivo and in vitro.


METHODS
With general anesthesia, 20 patients had placement of a nasogastric tube and a gastric pH electrode catheter after endotracheal intubation. Direct intragastric pH was recorded simultaneously with gastric aspirate pH by using the RightLevelpH indicator and by using an external pH electrode. Measurements were made every 30 minutes until removal of the nasogastric tube as indicated clinically. In vitro validation of the RightLevelpH indicator was performed by using standard buffer solutions.


RESULTS
The pH of clear buffer solutions was linearly related to pH determined by the RightLevelpH indicator (R(2) = 0.99; P < .001). The pH of gastric aspirate determined with an external pH electrode was linearly related to the gastric aspirate pH determined by using the RightLevelpH indicator (R(2) = 0.92; P < .001). Intragastric pH determined with the catheter electrode was also linearly related but more loosely correlated with gastric aspirate pH determined by using an external pH electrode (R(2) = 0.52; P < .001) and by the RightLevelpH indicator (R(2) = 0.55; P < .001).


CONCLUSIONS
The RightLevelpH indicator provides accurate measurements of the pH of gastric aspirate in patients.
Charles R. Lambert is the medical director of Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute, Tampa, Florida, and professor of medicine, Division of Cardiovascular Medicine, University of Florida, Gainesville, Florida. David Varlotta is a staff anesthesiologist, Marjorie Posey and Jadie L. Heberlein are clinical research nurses, and Janice M. Shirley is administrative director of research, Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute. Charles.lambert@ahss.org.
Charles R
CR
Lambert
Charles R. Lambert is the medical director of Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute, Tampa, Florida, and professor of medicine, Division of Cardiovascular Medicine, University of Florida, Gainesville, Florida. David Varlotta is a staff anesthesiologist, Marjorie Posey and Jadie L. Heberlein are clinical research nurses, and Janice M. Shirley is administrative director of research, Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute.
David
D
Varlotta
Charles R. Lambert is the medical director of Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute, Tampa, Florida, and professor of medicine, Division of Cardiovascular Medicine, University of Florida, Gainesville, Florida. David Varlotta is a staff anesthesiologist, Marjorie Posey and Jadie L. Heberlein are clinical research nurses, and Janice M. Shirley is administrative director of research, Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute.
Marjorie
M
Posey
Charles R. Lambert is the medical director of Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute, Tampa, Florida, and professor of medicine, Division of Cardiovascular Medicine, University of Florida, Gainesville, Florida. David Varlotta is a staff anesthesiologist, Marjorie Posey and Jadie L. Heberlein are clinical research nurses, and Janice M. Shirley is administrative director of research, Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute.
Jadie L
JL
Heberlein
Charles R. Lambert is the medical director of Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute, Tampa, Florida, and professor of medicine, Division of Cardiovascular Medicine, University of Florida, Gainesville, Florida. David Varlotta is a staff anesthesiologist, Marjorie Posey and Jadie L. Heberlein are clinical research nurses, and Janice M. Shirley is administrative director of research, Florida Hospital Tampa Pepin Heart Institute and the Dr Kiran C. Patel Research Institute.
Janice M
JM
Shirley
D000328:Adult; D003422:Critical Care; D005750:Gastric Juice / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007441:Intubation, Gastrointestinal; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D015203:Reproducibility of Results