Upper urinary tract surgical disease (Proceedings)
Careful consideration of preoperative, intraoperative, and postoperative management techniques will assist in preventing complications related to anesthesia and surgery in patients with urinary tract surgical disease. Hospital acquired renal insufficiency is common in humans, seemingly less so in animals but caution is advised. Hypotension of any cause is a potential predisposing cause to renal failure.
Potential Causes of Hypotension
1. Hypovolemia and electrolyte imbalance corrected PRIOR to definitive surgery. Maintenance of a normovolemic state and NORMAL urine production (0.5-1.0 ml/kg/hr) during the anesthetic episode is a goal.
2. Administration of crystalloid fluids (LR or other balanced electrolyte solution) at rates of 10 ml/kg/hour in the normal healthy patient is routine, HIGHER rates if there is preexisting disease.
3. Measuring urine production may be advantageous and requires nothing more than an indwelling u-cath and a closed system.
AIDS if patient is oliguric (choose one or more)
Anemia may be associated with chronic renal failure (CRF) or secondary to specific surgical procedures such as Urethrostomy which may result in excessive bleeding. Consider Packed cells or whole blood for those animals needing surgery who have a PCV below 25.
Surgical Exposure/Anatomy- Depends Upon Which Portion Of The Urinary Tract One Wants To Expose;
Use of the duodenum & mesoduodenum on the right side and the colon and mesocolon on the left side as anatomic retractors will help you in exposing the kidney/ureter on the respective side.
Renal Surgical Disease
***Functional status of an individual kidney can be difficult to determine. Excretory urography is a qualitative study of kidney filtration but is not a quantitative study. If no contrast is excreted by a kidney no function is present but if contrast is excreted we can't determine how much function is present. 2-3 mm of functional cortex is enough to consider salvage of a kidney. Renal scintigraphy is the only non-invasive technique for measuring glomerular filtration but is not widely available.