MRCP2-0702

A 69-year-old man is admitted to the unit with an exacerbation of severe pain around his abdomen. He describes it as a tight band like pain which is burning in character. He has a past medical history of metastatic prostate cancer. His drug history includes morphine modified release (100mg, twice daily), duloxetine (60mg, twice daily), pregabalin (200mg, three times per day). He states that the pain initially responded well to the analgesics he is on however over the past few weeks it has got progressively worse and culminated in a severe attack of pain today.

Suspecting severe neuropathic pain secondary to spinal metastases, the pain is now poorly controlled with a large dose of opioids and two neuropathic agents. The consultant decides to start him on ketamine. What acute complication should be monitored for?