Abstract: Background - Urodynamics including cystometrogram (CMG) and urethral pressure profile (UPP) should accurately represent the function of the bladder and urethra. Patient cooperation is required for urinary catheter placement and accurate pressure recordings. Any sedation protocol should have minimal effect on urodynamic variables. Previous studies by Rawlings (2001), Richter (1985) and Byron (2003) highlight some of these issues. Hypotheses - Low-dose propofol bolus will allow urinary catheterization.The detrusor reflex will be maintained, and CMGs will be comparable between repetitions.The protocol will permit cooperation for a satisfactory UPP to be recorded. Animals - Six healthy four-year-old female sexually intact research colony Beagles. Methods - A prospective interventional study recording urodynamics in each dog after low-dose propofol, then repeated after a five-week interval. 2mg/kg propofol was administered intravenously and urinary catheterization attempted. Recovery from sedation, defined as the ability to maintain sternal recumbency and at least 10 minutes from drug administration, was required before commencing CMG. The bladder was filled until either a detrusor reflex or an intravesical pressure of 40cmH2O was achieved. This was followed by UPP measurements. Results - Successful urinary catheterization and sufficient cooperation in all dogs was achieved. Detrusor reflex activity was recorded in 2/12 CMG procedures. Threshold volume varied. A satisfactory UPP tracing was recorded in 5/12 procedures. Conclusions and clinical importance – Although low-dose protocol produced satisfactory patient cooperation, maintenance of a detrusor reflex was unreliable and urodynamic measurements were variable, which may impact clinical assessment of bladder and urethral function.
