Why did this healthy boy develop hearing loss after routine surgery?

A 12-year-old boy has undergone a routine appendectomy and woken up with unilateral hearing loss, in a landmark report published to raise awareness of the unusual complication.
The otherwise fit and well Scottish boy attended his local children’s hospital with a history of worsening abdominal pain, diagnosed as appendicitis, report otolaryngologists from NHS Lothian in Edinburgh and Livingston, UK.
He was given IV antibiotics and subsequently underwent a laparoscopic appendicectomy.
But after emerging from general anaesthesia the boy, who had no previous otological or significant family history, reported difficulty hearing from his right ear, the doctors write in BMJ Case Reports.