The clinical context explains why timing matters so much. Large tumours of the oral cavity often leave what surgeons call volume defects, gaps in tissue that must be reconstructed with flap transfers, in which a segment of tissue, sometimes with its own blood supply, is moved to rebuild the affected area. After such operations, patients cannot eat normally while the wounds and swallowing musculature heal. Roughly 60 percent of head and neck cancer patients are already malnourished at presentation, and poor nutrition is an independent risk factor for surgical complications, morbidity and mortality. Every additional day of fasting therefore compounds an existing problem, deepening the metabolic stress that major surgery already imposes on the body.

Enhanced recovery after surgery, or ERAS, is the modern framework designed to counter that stress. These multimodal perioperative pathways combine early mobilisation, standardised anaesthetic and analgesic regimens, and careful nutritional optimisation, and they have been shown to shorten hospital stays and reduce costs. A central ERAS principle is avoiding prolonged fasting: solids are permitted up to six hours before anaesthesia, and fluids, including carbohydrate-loading drinks, up to two hours before. The ERAS Society consensus guidelines for head and neck surgery recommend that postoperative tube feeding should begin within 24 hours of surgery in patients who cannot yet tolerate oral intake. The most recent guidance from ESPEN, the European Society of Parenteral and Enteral Nutrition, goes further, stating that oral or tube feeding should start as soon as possible within the first few hours after surgery in conscious and haemodynamically stable patients.

The physiological rationale is well established. Prolonged preoperative fasting raises the risk of hyperglycaemia, metabolic stress and insulin resistance, the hallmark of the catabolic response to injury. Carbohydrate loading before surgery has been shown to blunt postoperative insulin resistance, reduce protein and nitrogen losses, improve muscle function and shorten length of stay. Early postoperative nutrition works in the same direction, limiting nitrogen and muscle loss during the critical healing window. Evidence from gastrointestinal surgery, where most of this research has been conducted, has found no benefit to keeping patients nil-by-mouth, and a Cochrane review concluded that early enteral nutrition reduced hospital stay by almost two days, with no differences in complications, including pneumonia, and only weak evidence of increased vomiting.

What remained unclear was whether these findings translate to head and neck flap surgery, where the airway, the swallow and a freshly transplanted flap all sit in close proximity. Few studies have examined the timing of tube feeding in this population, and a gap existed specifically around feeding earlier within the 24-hour window, including on the same day as surgery. The UCLH team, led by head and neck dietitian Florence Cook together with oral and maxillofacial surgeons and perioperative medicine consultants, set out to close that gap using the Plan-Do-Study-Act cycle, the four-stage improvement model, borrowed from industrial engineering, in which a change is planned, tested, studied and then adapted or adopted.

The planning stage revealed both an opportunity and a hidden inefficiency. Although the unit’s existing ERAS protocol already required feeding within 24 hours, the usual practice was to wait until the morning surgical review before commencing feeds. Discussions among stakeholders noted that operating finish times had improved, with midnight finishes now uncommon, making same-day feeding more feasible. Patient and public involvement feedback added that earlier feeding might support the energy levels patients need to mobilise the next day. The team also spotted that many patients were being sent for a chest x-ray to confirm nasogastric tube position before anyone attempted a pH aspirate test, contrary to national guidance that specifies pH testing first. Five of seven consultants agreed to trial early enteral nutrition; two declined, citing concerns about the risk-benefit ratio and nausea or vomiting. High-risk patients, such as those at risk of vomiting or delayed gastric emptying, were excluded at the operating surgeon’s discretion.

The protocol that emerged after three rounds of revision was deliberately conservative in one respect: the feed itself did not change. Patients received the established starter regimen, a 1.5 kcal/ml standard polymeric formula beginning at 20 ml per hour and increasing in 30 ml per hour steps as long as gastric aspirates stayed below 200 ml, with target rates scaled to body weight. A pre-written electronic record template ensured feeding instructions were consistent. The protocol was approved through clinical governance and rolled out on 27 May 2025, with prospective data collected over six months on fasting times, nutritional intake, complications graded by the Clavien-Dindo system, length of stay and weight change.

The results were striking. Of 45 included patients, 23 received early enteral nutrition and 22 received usual care. The early group’s median perioperative fasting time was 0.7 days compared with 1.3 days in the usual group, and feeding began a median of 4.3 hours after surgery versus 18.5 hours, differences that were highly statistically significant. Within the first 24 hours, the early group received a median of 215 ml of feed, delivering 322.5 kcal and 13.5 g of protein, while the usual-care group received nothing. Weight loss at discharge was also markedly lower in the early group, a median of 1 percent versus 5.6 percent. Crucially, safety signals were reassuring: there were no significant differences in Clavien-Dindo complications of grade three or above, in vomiting during the first 24 or 72 hours, or in gastric aspirates. Length of stay was similar between groups, and 96 percent of all patients met the ERAS target of feeding within 24 hours, an adherence rate higher than reported in previous studies.

The authors are careful about what these numbers can and cannot show. The project was a non-randomised, single-centre quality improvement exercise with a small sample and a short timeframe, so causation cannot be established and the findings may not generalise to every unit. Six patients recommended for early feeding did not receive it, for reasons including an immediate return to theatre and displaced feeding tubes, and the usual-care group contained more sarcoma cases. Even so, the pattern aligns with a growing international literature: a Japanese before-and-after study found early feeding on postoperative day one was safe and feasible without increased complications, and a randomised trial of feeding started during the operation itself reported no excess adverse events or flap failure, with some indication of enhanced wound regeneration.

The practical consequences of the project extend beyond the feeding schedule. In the Act phase of the cycle, the findings were presented to the wider surgical team, who agreed to establish early enteral nutrition as an option in the local ERAS protocol. The audit also exposed the overuse of chest x-rays for tube position checking: only 16 percent of patients had a pH aspirate attempted first, and the early-feeding group needed fewer x-rays overall, 53 versus 73, prompting further improvement cycles. The team now calls for high-quality randomised trials to confirm the safety and potential metabolic benefits of very early feeding in head and neck surgery, and for a mapping exercise of current practice, noting that as fast-track protocols become usual care, such trials may become difficult to run. For now, the message for patients facing flap reconstruction is a simple one: the era of waiting until the morning after surgery for the first calories may be coming to an end.

Subject of Research: Timing of early enteral nutrition after reconstructive head and neck flap surgery

Article Title: Early enteral feeding following flap surgery for head and neck defects: a quality improvement project using the Plan-Do-Study-Act cycle

Article References: Cook, F., Niemann, A., Ambler, G., Sahovaler, A., & Ward, P. (2026). Early enteral feeding following flap surgery for head and neck defects: a quality improvement project using the Plan-Do-Study-Act cycle. Supportive Care in Cancer, 34(10), Article 1008. https://doi.org/10.1007/s00520-026-11231-7

Image Credits: AI Generated

DOI: 10.1007/s00520-026-11231-7

Keywords: head and neck cancer, flap reconstruction, enteral nutrition, ERAS, enhanced recovery, quality improvement, Plan-Do-Study-Act, nasogastric feeding, perioperative nutrition, fasting, Clavien-Dindo complications, Supportive Care in Cancer