Quality Improvement: Diagnostic accuracy of mainstream versus sidestream capnography in detecting airway intubation of small-bore styleted nasoenteric feeding tubes in dogs and cats
Quality improvement: Diagnostic accuracy of mainstream versus sidestream capnography in detecting airway intubation of small-bore styleted nasoenteric feeding tubes in dogs and cats

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In our edition of: Oct 2025
In our categories of: small animals
our summary:
Bechtold, M.A. et al. (2025) Quality Improvement: Diagnostic accuracy of mainstream versus sidestream capnography in detecting airway intubation of small‐bore styleted nasoenteric feeding tubes in dogs and cats. Journal of Veterinary Emergency and Critical Care, 35 (3), pp 239-245.
The aim of this prospective study was to evaluate whether capnography (sidestream or mainstream) is able to accurately detect airway intubation of nasoenteric (NE) feeding tubes in dogs and cats of various sizes, in order to identify tracheobronchial misplacement.
Client-owned dogs and cats undergoing general anesthesia for elective surgical procedures at a university teaching hospital in the United States were enrolled in the study. An NE feeding tube attached to a handheld sidestream (dogs and cats) then mainstream capnograph (dogs) was inserted into the patient’s endotracheal (ET) tube. Respiratory rate, end-tidal carbon dioxide (ETCO2), and time to ETCO2 waveform were recorded.
Ten dogs and ten cats were included in the study. For the canine patients, sidestream capnography accurately detected respiratory rate, ETCO2, and capnogram waveform within four seconds of the NE tube insertion. While detection of an ETCO2 waveform initially did not occur in the smallest dog (2.37 kg), once the side port on the NE tube was closed, a waveform was detected in three seconds. Mainstream capnography failed to detect any of the same readings in all canine patients.
For the feline patients, sidestream capnography accurately detected respiratory rate, ETCO2, and capnogram waveform within one second. Mainstream capnography was not assessed in cats.
Limitations of the study include its small sample size and the difficulty of assessing the risk of bias based on the methodological data provided. The study only assessed placement in anaesthetised animals, placement in a non-anaesthetised patient may introduce complexities that could reduce the effectiveness of this technique.
This study provides some evidence that sidestream capnography, but not mainstream capnography can be used to detect misplacement of nasoenteric tubes in anaesthetised canine and feline patients. This information could be of use to practices where the insertion of feeding tubes is a frequent procedure.
The following may also be of interest:
inFOCUS: Comparison of 4 point-of-care techniques to detect correct positioning of nasogastric tubes in dogs (2020–2021). [RCVS Knowledge] [Online] Available from: https://infocus.rcvsknowledge.org/comparison-of-4-point-of-care-techniques-to-detect-correct-positioning-of-nasogastric-tubes-in-dogs-2020-2021/ [Accessed 17 October 2025
inFOCUS: Complication rates associated with nasoesophageal versus nasogastric feeding tube placement in dogs and cats: a randomised controlled trial. [RCVS Knowledge] [Online] Available from: https://infocus.rcvsknowledge.org/complication-rates-associated-with-nasoesophageal-versus-nasogastric-feeding-tube-placement-in-dogs-and-cats-a-randomised-controlled-trial/ [Accessed 17 October 2025]
WSAVA Nutritional Assessment Guidelines Task Force (2011), WSAVA Nutritional Assessment Guidelines. Journal of Small Animal Practice, 52 (7), pp. 385-396. https://doi.org/10.1111/j.1748-5827.2011.01079.x
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