New clinical trial explores early nutritional support for emergency abdominal surgery patients
The NIHR-funded trial will be one of the first and largest nutritional emergency surgery trials of its kind.
A major new UK-wide clinical trial led by the University of Birmingham will investigate whether early nutritional support can improve recovery and reduce complications in patients undergoing emergency abdominal surgery.
The TONIC Trial (Timing Of Nutritional Intervention after emergency laparotomy/laparoscopy) will evaluate whether providing early Parenteral Nutrition (PN), or nutritional supplementation delivered directly into the bloodstream, within the first 48 hours after surgery can lead to better outcomes than current standard care.
Each year, approximately 21,000 patients in England and Wales undergo emergency abdominal operations such as laparotomy to treat life‑threatening conditions. Although survival rates have improved over the past decade, national data show that 90‑day mortality has plateaued at around 9.6% since 2021, highlighting the need for innovative approaches to support recovery.
Why nutrition matters after emergency surgery
Many patients struggle to eat in the days following major abdominal surgery, putting them at significant risk of malnutrition, which can slow wound healing, increase infection risk, and prolong hospital stay.
Evidence from critical care settings suggests that tailored early nutritional support can reduce complications and improve survival, but there is currently limited research on its benefits specifically for emergency surgical patients. Existing guidelines acknowledge the potential value of early intervention yet stop short of recommending a clear approach for this high‑risk group.
Hospitals currently manage [emergency bowel surgery risk] very differently, with some starting nutritional support early and others waiting. We simply do not know which approach is safest. TONIC is designed to answer that question.
Chief Investigator Mr Matthew Lee, BHP Clinician Scientist and Honorary Consultant Colorectal Surgeon at the University of Birmingham, said: “Emergency bowel surgery is one of the highest-risk operations performed in the NHS. Even when the operation itself is successful, many patients struggle to recover because their bodies are under extreme stress and they are unable to eat for several days.
Hospitals currently manage this very differently, with some starting nutritional support early and others waiting. We simply do not know which approach is safest. TONIC is designed to answer that question. By understanding when to provide nutritional support, we hope to reduce complications, help patients recover faster and get home sooner after serious emergency illness.”
About the TONIC trial
TONIC is a multi‑centre, two‑arm, randomised controlled trial involving 25 NHS hospitals across the UK. Neither emergency surgery trials nor nutrition trials in surgery are particularly common, making TONIC the first major trial of its kind.
A total of 898 adult patients undergoing National Emergency Laparotomy Audit (NELA)-eligible urgent or emergency laparotomy or laparoscopy will be recruited. Participants will be randomly allocated to one of two groups:
- Early Parenteral Nutrition (Intervention): PN delivered within 48 hours of surgery
- Standard Care (Control): Usual nutritional management, which may include oral supplements, nasoenteric feeding, or later PN (after 5 days unless clinically required)
The study’s primary outcome is the rate and severity of complications up to hospital discharge. Secondary outcomes will assess:
- Complications at 30 and 90 days
- Infectious complications such as surgical site infection and pneumonia
- Function and quality of life
- Readmission rates
- Cost‑effectiveness from an NHS and societal perspective
- Patient‑reported outcomes, including recovery measures and satisfaction
An internal pilot across six sites will run for the first six months to assess feasibility, recruitment rates, intervention delivery, and data completeness before the full trial rollout. The trial will be delivered with the support of the Birmingham Clinical Trials Unit.
Aiming to transform emergency surgical care
Emergency abdominal surgery places a considerable burden on patients, families, and healthcare services. By determining whether early nutrition improves outcomes and delivers value for the NHS, TONIC has the potential to reshape national guidelines and enhance recovery pathways for thousands of patients each year.
The trial is supported by the National Institute for Health Research (NIHR) Health Technology Assessment Programme.