During peritoneal washings, what is the typical volume of normal saline used?

• A. 50 mL
• B. 100 mL
• C. 500 mL
• D. 1000 mL

Answer: (B)

Peritoneal washings aim to collect a representative cellular sample from the peritoneal surfaces without diluting it excessively or compromising visualization. A volume around 100 mL of normal saline is enough to rinse the area and yield an adequate aspirate for cytology, while remaining practical to perform during laparoscopy. Too little saline, like 50 mL, may not rinse all surfaces well and could reduce diagnostic yield. Much larger volumes, such as 500–1000 mL, are used for irrigation rather than washing, as they flood the cavity and dilute cells, making cytology less reliable and harder to manage.