Output list
Thesis
Published 2025
Respiratory complications are a major cause of post-anaesthetic mortality in dogs. Its
pathophysiology is poorly understood due to the limitations of traditional monitoring
technologies. The thesis aimed to i) develop an electrode belt that accommodates dogs of
different breeds and thoracic conformations, and ii) to quantify respiratory changes using
electrical impedance tomography (EIT) via the constructed belt in the post-anaesthetic period
in dogs.
In the first study, a canine-specific 32-electrode belt was developed. Its performance was
assessed in 18 dogs. In the second study, EIT data was collected via the constructed belt in 8
dogs in the post-anaesthetic period after neutering. The EIT data collected included global
variables: tidal impedance variation (TIV), minute TIV (MTIV) and end-expiratory lung
impedance (EELI), which describes lung volumes; and regional variables: centre of
ventilation, region of interests and silent spaces, which describes ventilation distribution.
These variables were statistically and descriptively compared at time points from the end of
anaesthesia to 15 minutes post-extubation.
In the first study, the constructed belt obtained optimal signals in 15/18 (83 %) of dogs of
varying breeds and thoracic conformations. Reasons of failure included computer issue and
failed signal acquisition from thick hair coat. The second study showed an overall
improvement in respiratory function in 7/8 (87.5 %) of dogs based on an increase in MTIV
and EELI at 15 minutes post-extubation. Inter-individual variations were observed, with
many showed temporary improvement in respiratory function at the time of extubation with
subsequent deterioration. The study was limited by the small sample size and lack of preanaesthetic baseline. It is unknown if respiratory function were normalised by 15 minutes
post-extubation.
The use of EIT via the constructed belt provided insight of the mechanisms and timings of
post-anaesthetic pulmonary complications. The need for vigilant, individualised monitoring
during recovery is highlighted.