EXPRESS: Effect of Intraoperative Positioning on Anesthetic Variables in Cats Undergoing a Perineal Urethrostomy

ObjectivesCats undergoing perineal urethrostomy (PU) often have acute kidney injury (AKI). Minimizing additional kidney injury during anesthesia is critical to prevent exacerbation of AKI. The impact of surgical positioning for PU on anesthetic variables is unknown. This study evaluated pre-, intra- and postoperative variables in cats undergoing PU in sternal (SR) or dorsal (DR) recumbency. We hypothesized there would not be a significant difference in anesthetic complications and postoperative serum creatinine (SCr) concentrations in cats positioned in SR as compared with those positioned in DR.MethodsMedical records of 97 client-owned cats undergoing PU in SR (n=55) or DR (n=42) were retrospectively reviewed. Cats undergoing procedures in addition to PU were excluded. Data collection included signalment, number of preoperative obstructive episodes, pre- and postoperative SCr, surgical and anesthetic duration, drugs in the anesthetic regimen, and presence and duration of intraoperative hypotension, hypertension, bradycardia, tachycardia, hypoventilation, and hypothermia. Data were compared using Mann-Whitney U or Fisher's exact tests.ResultsA significant difference was detected in the number of preoperative obstructive episodes in cats undergoing PU in SR compared to DR (SR median episodes=2 [range=0-5]; DR median episodes=2 [range=1-6]; P=0.0074). No other differences were identified in preoperative or intraoperative variables. Postoperative SCr and change from preoperative SCr did not differ between groups.Conclusion and relevanceAnalysis of these data demonstrate no measurable differences in anesthetic parameters or postoperative outcomes in cats undergoing PU in SR or DR. The statistical difference between groups relative to preoperative obstructive episodes does not appear to be clinically relevant. Thus, we accept our hypothesis and conclude SR or DR positioning should not be a consideration in establishing an optimized anesthetic experience for cats with urethral obstruction associated AKI. Surgeon preference should continue to be the driving force on positioning for a PU in cats.