The effect of body position, sedation, and thoracic bandaging onfunctional residual capacity in healthy deep-chested dogs

摘要

The objective of this study was to determine the effect of body position, chest wrap, and sedation on functional residual capacity(FRC) in 6 healthy dogs. Functional residual capacity was determined by helium dilution (re-breathing) whilst in differentclinically relevant conditions. These conditions included the standing (sternal) and lateral positions in unsedated dogs andthen again both standing and lateral following chest bandaging, and sedation with acepromazine, IV and butorphanol, IV. Themean FRC at each measurement point was determined, as was the change in FRC (delta FRC) from one measurement point toanother. Analysis of variance (ANOVA) with repeated measures with Fisher’s LSD post hoc test was used to evaluate the effectof interventions. The differences in delta FRC were evaluated using a t-test or Wilcoxon rank-sum test. P < 0.05 was consideredsignificant. The mean FRC at baseline, defined as standing, unsedated and unwrapped, was 75.3 +- 23.8 mL/kg. Body positionor sedation had the most profound effect on FRC with right lateral recumbency lowering FRC by a median of 20.4 mL/kg andsedation lowering FRC by a median of 19.8 mL/kg. Common clinical procedures and positioning result in lowered FRC inhealthy deep-chested dogs. In critically ill or injured dogs, the iatrogenic loss of FRC through chest bandaging, sedation, orbody position may be clinically relevant.