A scandal-hit hospital in Saitama Prefecture is suspected of having used an unnecessary intravenous feeding method on its patients, local government officials said Saturday.
Prefectural authorities monitored Asakura Hospital's operations for a year from November 1999 and found that of the 77 patients who died at the hospital in the period, 70 underwent intravenous hyperalimentation (IVH).
About half of the deceased are known to have died from circulatory organ failure.
Intravenous hyperalimentation is a feeding method in which a slender tube is inserted, usually below the collarbone, into veins near the heart to deliver essential nutrients to patients unable to feed themselves.
But the officials said IVH can cause circulatory organ failure if carried out in an improper manner that allows bacteria to enter patients.
The alleged practice came to light after a former nurse at the hospital in the town of Showa reported in April that the hospital was conducting unnecessary IVH, according to the officials.
They quoted the nurse as saying the hospital had also demanded medical service fees for fictitious checkups.
There are also unconfirmed reports the hospital has ordered nurses to randomly select patients to receive IVH.
Investigations to unravel the hospital's management system are underway.
Hospital officials have so far refused to comment.
In November, authorities ordered the hospital to take corrective action after they found that staff had violated the mental health and welfare law by tying patients in the psychiatric ward to their beds in order to restrain them.