Doctors warn against fluid therapy approach in surgery after global trial

The results from the large international trial have been published in the BMJ.  

Researchers found using a type of fluid therapy during major planned gut surgery did not reduce infections afterwards. It did, however, increase the risk of arrhythmias (abnormal heart rhythms). Due to these results, they recommend avoiding routine use of this technique for these patients.

The trial involved almost 2,500 patients from 11 countries. It was led by Professor Rupert Pearse from Queen Mary University of London. Professor Mark Edwards from University Hospital Southampton (UHS) helped lead the trial and co-ordinated the BMJ publication. 

Major surgeries 

More than 300 million major surgeries are performed around the globe each year. High-risk surgeries can lead to short or long-term medical problems. In the UK, more than 50,000 patients aged over 50 are reported to undergo major gut surgery every year. After surgery, around one third of these patients develop a hospital acquired infection. Many of these patients will die within a few months of surgery. 

Previous smaller studies had suggested that a fluid therapy approach using advanced cardiac monitoring might reduce complications after major surgery. This global clinical trial aimed to either recommend the treatment if it was beneficial, or withdraw it from routine use if ineffective or harmful. 

Large-scale research  

The trial was known as OPTIMISE II. Patients undergoing major planned operations on their gut took part at 55 hospitals worldwide. They were all over 65 years of age, with long term conditions that can increase the risks from surgery. Half were randomly assigned to receive the treatment, during and four hours after surgery. The other half received usual care, without cardiac output monitoring, for comparison. 

Those who had the treatment were given fluids into their veins using a drip, alongside a low-dose inotrope infusion. Their heart was constantly monitored, and the amount of blood being pumped was used to guide how much fluid they were given. Inotropes are medicines that alter how strongly the heart muscle contracts, and are used to regulate blood flow. Complications such as infections, heart problems or kidney issues were tracked for 30 days after they joined. 

Highlighting safety concerns 

This trial found the more advanced treatment approach made no difference to the risk of infection following major planned gut surgery. However, it did find that more patients in the treatment group had abnormal heart rhythms just after surgery, presumably due to the inotrope treatment. The researchers therefore state that routine use of this technique in this circumstance should be avoided. 

Professor Rupert Pearse, a Consultant in Intensive Care Medicine at Queen Mary, was Chief Investigator for the trial. He said: "We are delighted to complete this international trial which brings to closes a decades long and controversial debate among doctors about how to care for patients having major surgery. Our findings will guide treatment for tens of thousands of patients each year.” 

Professor Edwards is a Consultant in Anaesthesia and Perioperative Medicine at UHS and a researcher at the NIHR Southampton Biomedical Research Centre. He said: “This was an amazing international effort to get high quality evidence on this intervention, following decades of uncertainty. Although the approach we trialled was unfortunately not found to be beneficial, we now have clear information that could support practice recommendations impacting many thousands of patients having surgery every year.”