Home parenteral nutrition use in palliative care: A retrospective study to identify potential prognostic indicators

Abstract

Using pH indicators to measure nasogastric tube aspirate is subjective. Accuracy relies on the reproducibility of results. Colour of solution tested and method of use could also affect the results. This in-vitro study aimed to assess the effect of these variables on the reliability of pH indicators. 250 non buffered fluids (140 clear, 110 coloured) were assessed. pH was measured by 1 rater with 10 pH indicators and compared against values from a calibrated pH meter. 100 samples were tested twice with each indicator. In the first test the solution was dropped onto the indicator. In the second the indicator was immersed in the solution. 100 samples were tested twice (same method) at 2 separate intervals. Pearson's correlation coefficient of the samples compared with those from the pH meter, and the % paired samples in agreement per method of testing and test-retest are shown below.