The editors of 16 international medical journals have retracted "unethical" research carried out by a German doctor on drugs known as colloids, which boost blood volume in patients having surgery.
Joachim Boldt, an anesthesiologist at the center of an investigation into allegations that he may have forged up to 90 studies, was sacked from Klinikum Ludwigshafen, the German hospital where he worked, late last year.
British surgeons' organizations said they were withdrawing and reviewing their guidelines on the use of colloids following the retractions, although experts said there was little risk to patients.
In an open letter, 16 editors of various medical journals, including the U.S.-based Anesthesia & Analgesia, the European Journal of Anesthesiology and the British Journal of Anesthesia, said 89 of 102 studies published by Boldt had so far been found not to have had approval from an ethics body known as the institutional review board (IRB).
"At this stage we can't say it's fraud, all we can say is that the studies were not conducted with ethical approval and should therefore not have been published," Charles Reilly, editor-in-chief of the British Journal of Anesthesia (BJA), told Reuters.
"The most important point is that there are no immediate safety concerns for patients because these studies are small and they are not fundamental to how doctors use intravenous fluid in clinical practice," said Rupert Pearse, a consultant in intensive care medicine at Barts and The London Medical School.
"The wider issue is research fraud, which is rare but very serious," he added in an emailed statement. "As doctors, we must continue our efforts to ensure the integrity of our research."
The Association of Surgeons of Great Britain and Ireland (ASGBI) said it had been made aware that Boldt was "at the center of a criminal investigation following allegations about his research."
"Whilst these investigations take place the ASGBI has withdrawn the document entitled 'British consensus guidelines on intravenous fluid therapy for adult surgical patients' from its website," ASGBI president John MacFie said in a statement.
"The guidelines are being rewritten and will not be placed back on the website until we are assured of their accuracy."
In their open letter, the 16 editors said they were retracting the papers, some of which date back to 1999, because "the research was unethical" and because "IRB approval for the research was misrepresented in the published article."
"It does not mean the research results per se are fraudulent," they said.
The Anesthesia & Analgesia journal said in a statement on its website that it had received notification from the Rheinland State Medical
Board, Landesaerztekammer Rheinland-Pfalz, that there was no IRB approval for 89 articles by Boldt, including 22 published in its journal between 1999 and 2009.
"All 22 articles have now been retracted," it said. "An ongoing investigation at Klinikum Ludwigshafen is comparing the results in Dr. Boldt's research to patient and laboratory records to determine the veracity of his published findings."