Enhanced protein during critical illness shows no benefit

Critically ill patients often experience substantial and rapid muscle loss, leading to poor recovery. Researchers from the University of Adelaide have been exploring the impact of high protein nutritional formula in a new trial, aimed at improving outcomes.

As part of the TARGET Protein Trial, 3397 patients from eight intensive care units across Australia and New Zealand were involved in the randomised delivery of a higher protein (100g/L) nutritional formula and a lower protein (63g/L) formula.

In a 12-month open-label crossover trial, patients in an ICU were given one nutrition formula via a feeding tube (also known as enteral nutrition) for three months, before changing over to the alternate formula for the next three months.

The University’s ICU Research Dietitian and PhD Candidate Matthew Summers and Senior ICU Dietitian and Research Fellow Associate Professor Lee-anne Chapple, from Adelaide Medical School and the Centre for Research Excellence in Translating Nutritional Science to Good Health, published their findings in the journal JAMA.

“Increased protein delivery has the potential to attenuate muscle loss, but current international guidelines are based on low-quality evidence,” said Mr Summers, who is the first author on the paper.

“We found the addition protein didn’t increase the time the patients had outside of hospital, or have any impact on their status after the three-month mark.

“There was also no sign of improvement in our secondary measurements which included the duration of ventilation or ICU stay, incidences of tracheostomy insertion and new kidney replacement therapy, and hospital discharge destination.”

Mr Summers said the higher protein formula was more likely to cause harmful outcomes in patients with acute kidney failure when they were admitted to ICU.

“This means that augmenting enteral protein in critical illness did not improve patient outcomes, and caution should be applied when providing higher amounts of protein to patients, particularly those with a kidney injury,” he said.

Co-first author Associate Professor Chapple said the results were surprising, but would lead to more research.

“While no benefit was found with higher protein delivery early in critical illness, this does not preclude the potential that higher protein delivery could be beneficial for patients during the recovery phase of critical illness,” she said.

“Finding the appropriate time in a patient’s recovery course to provide a protein intervention is the focus of future research for the intensive care nutrition research program at the University of Adelaide and Royal Adelaide Hospital, with the aim of improving long term recovery from critical illness.”