clonus

SuperNurse please guide me in for a landing. My pt 32 M alcoholic pancreatitis with sepsis, staf positive, abdomen like having twins, 4 drains plus wound vac, open abdomen, multiple debridements, intubated, VS stable, bladder pressure 9-13, I find clonus in lower extremities. ***** I know clonus can occur with CNS problems like surgery or injury, but a medical problem? Help? Is this from abd pressure on spinal nerves, metablolic derangement, CNS disturbance or what? My first experience, reported to surgery, no big interest, just want to understand the patho, any help appreciated.