ABSTRACT
A DIAGNOSIS often has to wait. In cases of complete urinary retention, the bladder must be emptied by catheterization (see 89-101) or centesis (see 112) to prevent secondary vesical problems. There are a number of experimental papers detailing the effects of obstruction on the bladder and some are listed in the Further Reading section at the end of this book. Clinically recognizable problems include urothelial sloughing, deeper ischaemic damage and paralysis (see 2 and 135). The metabolic effects of uraemia, acidosis and hyperkalaemia should be corrected using intravenous fluids, bladder drainage and, if uroperitoneum is present, abdominocentesis and peritoneal dialysis (see 113, 114). There is some argument about the use of intravenous Hartmann’s solution (compound sodium lactate) in such cases. Although Hartmann’s solution contains potassium, and thus might be expected to make the hyperkalaemia worse, it also tends to correct the acidosis. The author’s approach is to use fluids without potassium initially (normal saline or dextrose saline) and then, once the potassium levels enter the upper end of the normal range, to change to Hartmann’s, since many animals that were initially hyperkalaemic may become hypokalaemic as acid-base balance is restored. If the animal is severely acidotic, bicarbonate can be added to the initial fluids.
