Bosses at United Christian Hospital on Friday said a patient there died last week after nurses failed to check on him regularly as instructed by a doctor.

An 89-year-old man was found dead last Thursday, two days after he had been admitted with a high temperature and repeated vomiting.

It's thought he may have choked to death on his vomit.

Dr Sunny Wong, chief of service of the department of medicine at the hospital, said a nurse failed to input a doctor's instruction into a computer system that the man's vital signs should be checked every four hours.

The patient's heart rate, blood pressure and blood oxygen level were only checked once after he was taken to a different ward on Wednesday.

"She [the nurse] carried out nearly every other order that the doctor instructed, like giving intravenous fluid, antibiotics and also checking the blood sugar regularly for this patient," Wong said.

"But it's just this single point that the nurse actually did not enter into the system... So probably because of her busy work, the nurse had to deal with several tasks and maybe we can really say she just forgot to do this one."

The general manager of nursing at the hospital, Tang Siu-keung, said an "e-vital" system was put in place in the medicine ward in January and staff may not be familiar with it.

Tang said more training on the system will be offered.

Wong said the death has been reported to the coroner, adding that the hospital has explained to the man's family what happened, and has apologised to them.

The Hospital Authority said it is setting up a committee to look into the incident and to come up with measures to repeat the same mistake from happening again.