Electrolyte and acid base imbalance in patients with rectosigmoid bladder

Area of Science:

• Urology
• Nephrology
• Gastroenterology

Background:

• Rectosigmoid bladder (RSB) is increasingly used after cystectomy due to lower complication rates compared to ureterosigmoidostomy (USS).
• Systemic metabolic consequences of RSB require thorough investigation.

Purpose of the Study:

• To investigate the systemic metabolic consequences of rectosigmoid bladder (RSB) operations.
• To compare metabolic acidosis, electrolyte balance, and renal function between RSB and ureterosigmoidostomy (USS) patients.

Main Methods:

• Studied acid-base balance, serum electrolytes, and renal function in 22 RSB and 25 USS patients.
• Analyzed urine from RSB patients and urine-feces mixture from USS patients.

Main Results:

• Metabolic acidosis occurred in 86% of RSB patients and 80% of USS patients, but was significantly less severe in the RSB group (pH 7.34 vs. 7.29).
• RSB patients exhibited lower intestinal loss of HCO3- compared to USS patients.
• Hyperchloremia was rare; increased anion gap was surprisingly common in both groups.

Conclusions:

• Metabolic acidosis can occur even after RSB, indicating reduced colonic mucosa contact is insufficient to prevent it.
• RSB generally leads to asymptomatic metabolic alterations and offers good functional results.
• RSB is a satisfactory option for patients requiring cystectomy, but requires ongoing clinical and metabolic surveillance.