Hello,
I'm not sure if you mean a
liver biopsy or plain removal of fluid from the abdomen.
If you meant a liver biopsy then this is a relatively safe procedure provided she does not have significant blood coagulation problems. A needle (somewhat larger than the ones we use to draw blood) is inserted under the skin into the liver and a little piece of the liver is removed for testing.
The liver is a very sensitive organ. If it starts bleeding it can be difficult to stop. Thankfully serious bleeding happens only rarely.
Very rare complications include also:
pneumothorax (injury to the lung),
peritonitis (invasion of bacteria into the
peritoneal cavity) and injury to surrounding tissues (including - but not limited to - the
gallbladder).
Liver biopsy in the awake patient needs very good cooperation between the doctor and the patient. If by "bad tempered to put it mildly" you implied that she does not have a rational behavior - which may happen in patients with advanced uncompensated
cirrhosis - then this might pose a problem for the procedure to be performed safely.
If you meant peritoneal
paracentesis that is removal of fluid from the abdomen then this is a even safer procedure. A needle is inserted into the abdomen (into a 'safe' location) and fluid is drawn with a large syringe. The fluid ends up in a plastic bag. Inserting the needle into the intestine or internal organs is a possible danger but it is not that easy to happen. I would rather say it's almost impossible if the doctor is careful.
I wish you the best for your friend!
Kind Regards!