An operational framework with bedside indicators for early acute illness, stabilization/prolonged ICU care, and post-ICU recovery is proposed, which contextualizes existing recommendations and requires prospective validation.
Abstract
Precision nutrition in critical illness should be understood as a longitudinal clinical strategy rather than a fixed prescription for calorie and protein delivery. This structured narrative review used PubMed/MEDLINE as the primary database and supplemented the search through Web of Science Core Collection and Google Scholar. Publications from January 2020 to January 2026 were prioritized, while earlier landmark trials, guidelines, and consensus papers were retained when relevant. Evidence from 73 references, including guidelines, randomized trials, systematic reviews, and relevant observational or mechanistic studies, was synthesized. We propose an operational framework with bedside indicators for early acute illness, stabilization/prolonged ICU care, and post-ICU recovery. During early acute instability, safe initiation and tolerance-based progression are favored over immediate completion of calculated targets. During stabilization and recovery, greater emphasis is placed on correcting persistent deficits, preserving lean mass, and supporting rehabilitation. Feeding intolerance is interpreted as gastrointestinal dysfunction, avoidable interruption, aspiration risk, or persistent inability to sustain enteral nutrition. Post-pyloric feeding and supplemental parenteral nutrition are selective escalation strategies, with safeguards against overfeeding and metabolic complications. After ICU discharge, quantified intake, swallowing function, muscle mass, functional trajectory, and participation in rehabilitation should guide continued support. The framework contextualizes existing recommendations and requires prospective validation.
INTRODUCTION
Survivorship after critical illness is frequently complicated by muscle wasting and gastrointestinal (GI) dysfunction, driving prolonged functional impairment. Nutrition is a modifiable determinant across the intensive care unit (ICU)-to-home continuum, yet delivery is commonly limited by feeding intolerance and fragmented transitions of care.
AREAS COVERED
This expert opinion review synthesizes evidence identified via a narrative search of MEDLINE/PubMed and key guideline/reference screening, focusing on GI dysfunction as a barrier to enteral nutrition (EN) in the ICU, phase-adapted energy and protein provision, and strategies to restore intake during ward recovery and after discharge, including high-energy, protein-dense oral nutritional supplements (ONS).
EXPERT OPINION
Nutrition should be delivered as a structured pathway rather than a single ICU intervention. Early EN with proactive, symptom-targeted management of GI dysfunction, coupled with stepwise protein escalation aligned to metabolic phase and organ function, may help reduce avoidable deficits. The early post-ICU period is an anabolic 'window of opportunity' that warrants intake monitoring, deliberate tapering of tube feeds only once oral intake is reliable, and routine post-discharge ONS for patients at nutritional risk. Research should prioritize pragmatic trials of phase-specific targets and transition-of-care models.
A. V. van Zanten, Pavel Kohout, Elisabeth de Waele et al.· Expert Review of Gastroenter...· 0 citations
Clinicians should recognize the post-ICU hospitalization period as a potential 'metabolic danger zone', requiring a shift from acute-phase restrictive feeding toward strategies prioritizing functional recovery and lean mass preservation.
O. Leemans, Zenzi Rosseel, C. Pichard et al.· Current Opinion in Critical...· 0 citations
Background Hyperglycemia is a common complication in critically ill patients receiving enteral nutrition (EN). This review synthesizes evidence on its mechanisms, epidemiology, clinical implications, and nursing management to support precision glycemic care. Methods A systematic literature search identified 45 eligible studies, including randomized trials, retrospective studies, reviews, guidelines, and expert consensus statements. Given the lack of a universally accepted definition, enteral nutrition-related hyperglycemia was pragmatically defined as blood glucose ≥7.8 mmol/L occurring within 24−72 h after initiation of enteral nutrition. Results Reported incidence varies widely, from approximately 30−47% in general ICU populations to 60−80% following cardiac surgery, reflecting differences in definitions, patient characteristics, timing, and nutritional protocols. Based on thematic integration of existing evidence, we propose a six-level conceptual cascade framework, linking metabolic vulnerability, stress-hormone activation, exogenous substrate load, enteroinsular axis dysfunction, inflammation-mediated insulin resistance, and microbiota dysbiosis. Corresponding nursing strategies include diabetes-specific formulas, optimized feeding regimens, continuous glucose monitoring, and individualized insulin protocols within multidisciplinary care. These strategies may improve glycemic control; however, evidence for clinical outcome benefits remains limited and heterogeneous. Conclusion Further prospective studies are needed to validate the model and refine precision nursing strategies.
Jiani Qian, Quanquan He, Maoyun Miao et al.· Frontiers in Nutrition· 0 citations
PURPOSE OF REVIEW
The pathogenesis of critical illness drives a dynamic cascade of clinical, metabolic, and immunologic abnormalities through the course of disease. Recent randomized trials show that early full-dose feeding for critically ill patients is ineffective and potentially harmful compared to trophic feeding. The aim of this review is to propose a response-contingent phase-specific strategy of nutrition therapy appropriate for this patient population.
RECENT FINDINGS
Barriers to delivering effective nutritional therapy exist, ranging from bioenergetic failure related to mitochondrial dysfunction and gastrointestinal dysmotility with feeding intolerance, to microbial dysbiosis and impaired substrate utilization characterized by inefficient energy production and futile substrate cycling. Emerging concepts are helping to design more appropriate regimens, including estimation of potential benefit from nutritional therapy based on disease severity, risk of net harm, and determination of the stage of enteral nutrition responsiveness, which can be conceptualized as the capacity for achieving phase-specific goals within the constraints of physiologic state, metabolic capacity, safety, and feasibility.
SUMMARY
Calibrating goals, dosage, monitoring strategies, and expectations from nutritional therapy is required to overcome barriers imposed by the underlying pathophysiology and to optimize support, as these complex patients transition through the acute phase of critical illness towards recovery and rehabilitation.
Stephen A McClave, R. Martindale, Jayshil J. Patel· Current Opinion in Critical...· 0 citations
In the acute phase of critical illness, adults have severe catabolism, inflammation, muscle loss, and gut dysfunction, all of which shape nutritional requirements. Early enteral nutrition supports gut integrity and microbiome health, but trials have shown that early short-term parenteral nutrition is a safe alternative when enteral feeding is not possible. Large trials have shown that early full-dose energy delivery offers no benefit over restrictive dosing and may increase gastrointestinal and metabolic complications, findings that support a restrictive nutrition strategy, especially in patients who have circulatory shock or are at risk for refeeding syndrome. Similarly, large trials have shown no advantage of high-dose over standard-dose protein and suggest harm in patients with acute kidney injury. Because adverse events are common with enteral nutrition, safe nutrition delivery requires gradual advancement, strategies for prevention of refeeding syndrome, glycemic control, and avoidance of routine gastric residual volume monitoring. Patient heterogeneity underscores the need for precise, biomarker-guided, phase-specific nutrition to preserve lean muscle mass and improve recovery.
Jayshil J. Patel, Stephen A McClave· New England Journal of Medic...· 0 citations
PURPOSE
Patients with obesity who are admitted to an ICU bring specific challenges for rehabilitation during and after critical illness. This narrative review explores impact of differences in body compositions and pathophysiology on outcomes to summarise interprofessional, patient-centred rehabilitation strategies across the trajectory of recovery.
METHODS
The interprofessional expert panel reviewed major trials and guidelines, integrating their clinical expertise with the current evidence.
RESULTS
Three distinct phenotypes potentially influence outcomes for survivors. Whilst patients with preserved muscle mass may have a survival advantage, the phenotypes characterised by ectopic visceral fat or sarcopenia are frequently complicated by multimorbidity and polypharmacy, likely increasing the risk of adverse effects such as suboptimal sedation, prolonged ventilation and immobilisation, malnutrition, and impaired recovery. Targeted respiratory interventions, including secretion-clearance techniques and appropriate patient positioning to prevent atelectasis, reduce the work of breathing. Optimisation of communication and swallowing function is an essential component for facilitating safe oral intake and promoting active patient participation in rehabilitation. Concurrently, targeted nutrition strategies combined with early, targeted, progressive mobilisation might mitigate ICU acquired weakness and support functional recovery. The availability of appropriate weight‑based equipment is fundamental to ensuring safe mobilisation for both patients and healthcare professionals.
CONCLUSION
Interprofessional collaboration is central to optimising outcomes and should extend beyond the ICU to structured post-ICU follow-up to address persistent, worsening, or newly emerging health impairments. Early rehabilitation in critically ill patients with obesity should integrate physiological, logistical, and psychosocial considerations to support equitable and functional recovery.
Sabrina Eggmann, Danielle E. Bear, Richard S. Bourne et al.· Intensive Care Medicine· 0 citations