Can intravenous pain killers+ 500ml normal saline twice a day aggrevate ascites condition for a liver cancer patient?

Yes. Which ones?: Which IV pain killers are you referring to? Ofirmev, in particular, can harm the liver. If someone has liver cancer, they often have liver cirrhosis which leads to less protein (albumin) in the blood & the inability to hold blood volume in the vessels. In those situations, extra fluid can leak out into the abdomen & worsen ascites. However, sometimes fluid is needed to support blood pressure. TTYD