The practice of restricting IV fluids after surgery has been shown to increase a patient's risk of severe kidney damage.
The intravenous saline drip stuck in the arm for surgery can be annoying, but a landmark trial has proven just how vital it is to a patient's recovery.
Used to hydrate patients, the IV is a mainstay of hospital treatment after a major surgical procedure, but there has been contention among medical experts over how much fluid a patient needs.
In the last 10 to 15 years there was a move to restrict, by almost a half, the amount to fluids given to prevent complications.
But a six year Australian-led global trial involving 3000 abdominal surgery patients in 47 hospitals found the restrictive practice led to a "doubling" of severe kidney damage.
"This is people that actually have what we would label as quite severe renal damage, so much so that a proportion of them had to have dialysis in the first few weeks or months after surgery," said lead investigator Professor Myles, Director of Anaesthesia and Perioperative Medicine at The Alfred hospital and Monash University.
Published in the New England Journal of Medicine on Thursday, the trial also found IV fluid restriction was linked to a greater risk of severe wound infection.
"We have certainly dispelled the belief that it improves disability-free survival, so therefore it's not helpful," said Professor Myles.
The RELIEF trial (restrictive versus liberal fluid therapy) showed patients had fewer complications and recovered more quickly after their operation if they were given more IV fluids rather than less.
"The results of this international trial were clear-cut and very reassuring - a more liberal amount of IV fluids protects against kidney damage and reduces the risk of wound infection after surgery."
The impact of the findings is expected to be immediate and immense for hospitals, said Professor Myles.
The Alfred in Melbourne, where an estimated 28,000 operations are performed every year, will be among the first to implement the evidence-based change in practice.
"The care of all of those people is now going to be that much better as of tomorrow," said Professor Myles.
The findings of the RELIEF trial were released at the Australian and New Zealand College of Anaesthetists' (ANZCA) annual scientific meeting in Sydney.