Fluid absorption during percutaneous nephrolithotomy: does it matter?

Large amounts of irrigating fluid are used during percutaneous nephrolithotomy (PCNL). This use may be associated with migrating calculus debris, infection, and fluid absorption. This study evaluated the presence of fluid absorption during PCNL, its clinical and biochemical significance, and maneuvers to reduce it.

Fluid absorption during PCNL was evaluated in 148 patients by estimating the expired breath ethanol concentration. Factors thought to affect the amount of fluid absorbed were studied, including the amount of irrigating fluid used, the number of nephrostomy tracts, the presence of a low-pressure system, the presence of existing tracts, and complications such as bleeding or perforation of the pelvicaliceal wall.

Fluid absorption was evident in all patients, although no patient had any clinical or biochemical evidence of intraoperative or postoperative electrolyte imbalance. Creating a low-pressure system by using an Amplatz sheath, reducing the amount of irrigating fluid used, and staging the procedure significantly reduced the amount of fluid absorbed.

Fluid absorption does take place during PCNL. This may be clinically significant in patients with compromised cardiorespiratory or renal status and in pediatric patients, leading to fluid overload. Using a low-pressure system, reducing the nephroscopy time and the amount of irrigating fluid used, and staging the procedure for large renal stone burdens, especially in the presence of complications such as perforation of the pelvicaliceal system, reduces fluid absorption and avoids volume overload. Fluid absorption may also be associated with both infective and noninfective pyrexia, necessitating adequate preoperative control of urinary infection.