Simultaneous visual inspection for barometric whole-body plethysmography waveforms during pulmonary function testing in client-owned cats

Abstract

Visual inspection for BWBP waveforms in real time can reliably identify stable breathing signals in client-owned cats. The obtained results were significantly different when the SVI method was used in addition to AE. In the interpretation of BWBP parameters or comparison of measurements among studies, whether an SVI methodology was applied should be considered.

Influence of acclimatization time on parameters of barometric whole-body plethysmography in healthy adult cats

“…Except for the parameter TV/BW, all other parameters changed significantly. In previous studies in cats, acclimatization times were not standardized or no information was given about the time cats spent in the measuring chamber before measurement started [ 4 – 6 , 22 , 26 – 28 ]. However, it is possible that in studies where the acclimatization time was not specified, it was individually adjusted to the behaviour of each cat to choose time periods for measurement, when animals seemed calm and relaxed.…”

“…However, this is usually not possible in clinical trials in companion animals. In different studies in cats the acclimatization time varied from 1–20 minutes [ 6 , 22 , 26 , 27 ] or no information was given at all [ 4 , 5 , 28 ]. In addition, it makes a difference for respiratory parameters whether cats are evaluated at home or in a hospital setting [ 29 , 30 ].…”

Assessing breathing effort by barometric whole‐body plethysmography and its relationship with prognosis in client‐owned cats with respiratory distress

“…The BWBP system was calibrated before each use by injecting 50 mL of air into the chamber, according to the manufacturer's instructions (Buxco Electronics, Wilmington, NC). The cat was placed in the BWBP chamber (length: 51 cm, width: 30 cm, and height: 25 cm) without any restraint, and an acclimation period (until the cat sat or laid down in a comfortable position with stable breathing signals) based on each cat's status was allowed before recording the signals, as previously described 14,19 . A bias flow of 6 L per minute was provided throughout the assessment to prevent carbon dioxide accumulation in the chamber, with temperature and humidity monitoring.…”

“…Conventional BWBP variables were calculated from breath‐by‐breath analysis of box flow waveforms by the software (Biosystem XA 2.11.0 software; Buxco Electronics), including RR (breaths/min), tidal volume per kg body weight (TV/BW; mL/kg), MV per kg BW (MV/BW; mL/kg; calculated by multiplying TV/BW by RR), inspiratory and expiratory times (Ti and Te; s), peak inspiratory and expiratory flow per kg BW (PIF/BW and PEF/BW; mL/s/BW), relaxation time (RT; s; time point when 65% of TV is expired), pause (unitless; [Te‐ RT]/RT), and enhanced pause (Penh; unitless; [PEF/PIF] × pause). Artifactual signals from nonbreathing activities (eg, posture change or vocalization) were excluded by applying both the automatic rejection settings of the software (TV < 10 mL, Ti < 0.15 s, Te > 10 s, or a difference in inspiratory and expiratory volume > 20%) and manual methodology (manually deleting time periods that were not free of artifacts based on simultaneous inspection) 19 . Considering that the nature of the pseudo‐volume differs from that of the true volume, the level of increase in MV was also expressed as a fold increase relative to the normal median value of the control group, with the aim of facilitating future applications in different systems.…”

“…14,19 A bias flow of 6 L per minute was provided throughout the assessment to prevent carbon dioxide accumulation in the chamber, with temperature and humidity monitoring. Analog breathing signals detected using a differential pressure transducer were amplified 19 Considering that the nature of the pseudo-volume differs from that of the true volume, the level of increase in MV was also expressed as a fold increase relative to the normal median value of the control group, with the aim of facilitating future applications in different systems.…”