Can contrast instilled through a displaced PEG tube that extravasates into the abdomen cause acute kidney injury?

That's an interesting question. Gastrografin (diatrizoate), used for gastrointestinal (GI) imaging, is poorly absorbed from the GI tract. Nonetheless, low levels of renal excretion of Gastrografin can be seen in some normal individuals and in patients with losses of GI mucosal integrity. Leakage of Gastrografin into the peritoneum would allow prompt absorption of this ionic iodinated contrast material into the circulation and increased kidney exposure. I do not recall ever seeing a patient devel...

I doubt it, unlikely there is any literature on it. My understanding of contrast nephropathy is that the transient increase in serum osmolality is toxic to the kidney tubules. I don't believe we will get that with contrast in the abdominal cavity. Of course, if it leads to sepsis and hypotension, then all bets are off.