Effect of an indwelling nasogastric tube on gastric emptying rates of liquids in horses.

The research article investigates how the presence of a nasogastric tube, a medical device inserted through the nose and down into the stomach, affects the rate at which horses’ stomachs empty of liquids. Despite an apparent difference in gastric emptying times after outliers were removed, there was overall no major difference detected between horses with the nasogastric tube and those without it over an 18 hour period.

Methods

• The study employed a randomized block crossover design, in which 9 adult horses of sound health were alternated between treatment and control groups.
• In the treatment group, horses were implanted with a nasogastric tube left in place for the duration of the 18 hour experiment. These horses were then given acetaminophen, a common pain killer.
• In the control group, horses also received a nasogaic tube and were given acetaminophen but then had the tube immediately removed.
• Blood samples were taken 15 minutes prior and subsequently following the administration of acetaminophen in order to measure its concentration in the horses’ serum. This was accomplished by utilizing fluorescence polarization immunoassay, a laboratory technique used to measure the concentration of chemical substances in a sample.
• The key variables in this experiment were the time to maximum acetaminophen concentration (Tmax) and the appearance constant for acetaminophen (Kapp). These values were compared between the treatment and control horse groupings.

Results and Conclusions

• The results indicated no significant difference either in the Tmax or in the Kapp between horses with extended nasogastric tube placement and those without.
• The data analysis was also performed after removal of possible outlier values from one horse. This reanalysis revealed a significant difference in Tmax between horses with prolonged nasogastric tube placement and those without it.
• Despite this, the overall conclusion drawn was that there appeared to be no clinically significant impact of nasogastric intubation over an 18 hour period on the gastric emptying time in healthy horses.
• The study provides useful information for the veterinary field, helping to inform best practices when threading a nasogastric tube is required in horses.