Nutritional considerations for patients undergoing major surgery

Patients undergoing major surgery can experience distinct metabolic and nutritional challenges that require early, individualized planning. The 2025 European Society for Clinical Nutrition and Metabolism (ESPEN) guideline on clinical nutrition in surgery identifies these patients—particularly those undergoing complex or cancer-related procedures—as being at increased nutritional risk across the perioperative period.

Rather than applying a uniform approach, ESPEN emphasizes aligning nutrition support with surgical stress, baseline nutritional status, and gastrointestinal function. Within this framework, the guideline provides specific recommendations that inform the use of nutrition support, including parenteral nutrition (PN), across the surgical care pathway.

Integrating nutrition across the surgical care pathway

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Early nutrition risk assessment

Identify malnutrition or risk
of malnutrition
Anticipate perioperative
nutrition needs

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Timely nutrition planning

Resume oral intake or tube
feeding/enteral nutrition when
clinically appropriate
Evaluate adequacy of intake

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Nutrition route selection

Oral or enteral nutrition
when feasible
PN when oral or enteral intake
is not possible or sufficient

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Ongoing reassessment

Monitor tolerance and
nutritional adequacy
Transition to oral or enteral
nutrition as gastrointestinal
function improves

Within this pathway-based approach, ESPEN highlights several considerations that are especially relevant for patients undergoing major surgery.

Elevated nutritional risk in major and cancer surgery

Major surgery induces an inflammatory and catabolic response that can increase protein and energy requirements while limiting intake. ESPEN notes that patients undergoing extensive procedures, including cancer surgery, are particularly vulnerable due to factors such as preexisting malnutrition, reduced intake before surgery, and delayed recovery of gastrointestinal function.

Because nutritional deficits may already be present at the time of surgical planning—especially in oncology populations—the guideline emphasizes early and proactive nutritional assessment rather than reactive intervention.

When oral and enteral nutrition are insufficient

While oral and enteral nutrition remain preferred whenever feasible, ESPEN acknowledges that these routes may not adequately meet nutritional needs in patients with gastrointestinal tract resections. Gastrointestinal dysfunction, postoperative ileus, surgical resections, or intolerance may limit intake during critical periods.

In these situations, the guideline supports the use of PN to help ensure adequate nutrient delivery when insufficient oral or enteral intake is anticipated for a prolonged duration.

Supplemental PN and short-term peripheral PN use

Recommendation #13 supports the use of supplemental peripheral PN when PN is required for a short duration (less than 7 days) and when central venous access is not indicated or available. This recommendation highlights peripheral PN as a practical option for short-term nutritional support in appropriate patients.

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If the expected duration of supplementary PN is below seven days, nutrition can be delivered parenterally via peripheral access. (Grade 0; strong consensus 100%.)

This guidance reinforces the role of PN across a spectrum of surgical needs, including short-term supplementation when oral or enteral intake alone is insufficient.

PN in malnourished surgical patients

Recommendation #20 notes that PN in malnourished patients is supported by evidence demonstrating significantly lower mortality, with a tendency toward lower infection rates, compared with no PN. This recommendation is informed by a meta-analysis of randomized controlled trials and underscores the importance of addressing malnutrition proactively in surgical populations.

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Patients with severe malnutrition and/or high metabolic risk shall receive nutritional therapy preoperatively (A), even if it postpones surgery. A period of 10–14 days should be considered (B). (Grade A/B; strong consensus 93%.)

Importantly, the guideline situates these findings within the context of patient selection, reinforcing that the benefits observed apply specifically to malnourished patients, rather than broadly to all surgical populations.

Increased protein and energy requirements

ESPEN highlights that the metabolic response to major surgery is associated with increased protein and energy demands. Nutrition therapy should be designed to meet these requirements and adjusted as the patient’s condition evolves.

When PN is indicated, it should be tailored to individual needs and integrated into a broader nutrition plan that reflects changes in tolerance and recovery.

Preoperative PN in high-risk patients

Recommendation #27 notes that preoperative PN may be beneficial in malnourished patients and/or patients at high metabolic risk in whom oral/enteral nutrition is not feasible. ESPEN cites evidence from a large Cochrane analysis showing a reduction in noninfectious complications in patients with gastrointestinal tract resections receiving preoperative PN compared with standard care.

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Only in those patients with severe malnutrition and/or at high metabolic risk in whom oral/enteral nutrition is not feasible, preoperative PN shall be provided (A). A period of 10–14 days with a minimum of seven days can be recommended (GPP). (Grade A/GPP; strong consensus 100%.)

This recommendation reinforces the importance of considering nutrition support earlier in the surgical timeline for patients at high nutritional risk.

Considerations in cancer surgery

For patients undergoing cancer surgery, ESPEN emphasizes the importance of nutrition support within complex oncologic care pathways. Tumor-related symptoms, prior treatments, and surgical burden may contribute to prolonged periods of inadequate intake.

In malnourished patients or those at high nutritional risk, PN may play a role when oral or enteral routes cannot sufficiently meet nutritional requirements.

Nutrition as a core element of surgical care

Together, these insights from the ESPEN 2025 guideline on clinical nutrition in surgery reinforce a consistent theme: nutrition should be integrated early and deliberately across the surgical care pathway. From risk assessment through recovery, timely and individualized nutrition support—including PN when indicated—remains a foundational component of comprehensive perioperative care.