Nurse-led glycemic control protocols in intensive care units: a scoping review

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Acute Crit Care. 2026;41(1):58-67

Publication date (electronic) : 2025 December 19

doi : https://doi.org/10.4266/acc.003225

Eugene Han¹, Eunhye Park², Eui Geum Oh^,3

¹Yonsei University College of Nursing and Intensive Care Unit, Division of Nursing, Severance Hospital, Yonsei University Health System, Seoul, Korea

²Yonsei University College of Nursing and Division of Cardiovascular Surgery, Division of Nursing, Severance Hospital, Yonsei University Health System, Seoul, Korea

³Yonsei University College of Nursing, Mo-Im Kim Nursing Research Institute, Seoul, Korea

Corresponding author: Eui Geum Oh Yonsei University College of Nursing, Mo-Im Kim Nursing Research Institute, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea Tel: +82-2-2228-3256, Fax: +82-2-2227-8304, E-mail: euigeum@yuhs.ac

Received 2025 August 16; Revised 2025 September 22; Accepted 2025 October 8.

Abstract

Infographics

INTRODUCTION

Critically ill patients experience hyperglycemia regardless of a prior diagnosis of diabetes. This phenomenon, known as stress-induced hyperglycemia, results from various pathophysiological factors, such as acute illness, pharmacologic interventions, surgical stress, systemic inflammation, and altered insulin sensitivity [1]. Furthermore, such patients have an increased risk of developing hypoglycemia compared with the general patient population [2]. In the intensive care unit (ICU), glycemic instability is further compounded by frequent interruptions in nutritional support, impaired recognition of hypoglycemia resulting from sedation, and the overall complexity of glycemic management. Hypoglycemia and glycemic variability are particularly detrimental, being strongly associated with increased infection rates, prolonged mechanical ventilation, extended hospital stays, and high mortality [1-3]. However, glycemic control is often considered a lower priority in critical care settings, frequently overshadowed by more immediate life-sustaining interventions [4].

To address this limitation, nurse-led glycemic control protocols have emerged as a pragmatic and effective approach. These protocols enable bedside nurses to initiate and manage insulin therapy, which enhances the timeliness and consistency of glycemic control interventions [2]. Nurse-led glycemic control protocols have been demonstrated to effectively manage hyperglycemia, enhance clinical outcomes, and reduce the incidence of hypoglycemia [2,5].

Recent developments in critical care practice have shown a shift from deep toward minimal sedation while maintaining patients’ consciousness level [6]. Furthermore, the increasing adoption of Enhanced Recovery After Surgery protocols—standardized, multidisciplinary approaches that include nutritional management—together with growing evidence for the benefits of early oral feeding, has led to a steady increase in attempts to initiate oral nutrition in critically ill patients [7-9]. Moreover, technologies such as continuous glucose monitoring, decision-support systems (DSSs), and insulin dose calculators have been introduced and implemented to increase management efficiency and reduce cognitive workload among nurses [10-12]. Updating protocols to reflect emerging technologies is crucial to optimize patient care and reduce the cognitive and documentation burdens on nursing staff [13-15]. Within this context, it is necessary to determine whether recently reported nurse-led glycemic control protocols reflect these evolving treatment strategies and clinical environments and whether they contribute to the advancement of evidence-based nursing practice.

A comprehensive examination of current research is crucial to support the refinement of nursing practice based on up-to-date evidence and evolving clinical contexts. Previous studies, including a systematic review, have shown the efficacy of nurse-led insulin infusion protocols; however, they were limited to literature published up to 2021 and predominantly included studies conducted before 2017 [16]. More recently, a scoping review investigated insulin infusion protocols in ICUs, but solely focused on protocol typologies and indicators, excluding broader aspects of glycemic care or non-infusion strategies [5]. These limitations highlight the need for a more comprehensive and current synthesis of the literature encompassing the full spectrum of nurse-led glycemic control practices in critical care settings. Building on these findings, this study conducts a scoping review to comprehensively map nurse-led glycemic control protocols in adult ICUs. This scoping review aims to identify nurse-led glycemic control protocols implemented in ICUs and analyze their components—including target blood glucose ranges, monitoring intervals, and implementation methods—along with associated clinical outcomes.

MATERIALS AND METHODS

This study did not involve human participants or identifiable personal data and therefore did not require institutional review board approval or informed consent.

RESULTS

Search Results

Through systematic database searches, 969 studies were identified. After removing 123 duplicate records, 846 articles remained for title and abstract screening. Of these, 814 were excluded for the following reasons: irrelevance to glucose management or nurse-led interventions, conducted outside of ICUs, and involving non-adult populations. The full texts of the 32 studies were reviewed, which led to the exclusion of 25 studies due to the absence of intervention implementation or the use of ineligible comparison groups. Ultimately, seven studies were included in final analysis. Figure 1 illustrates the comprehensive selection process.

Figure 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram. ICU: intensive care unit.

The methodological quality of the seven included studies was evaluated using the revised JBI critical appraisal tool [19]. Quality appraisal indicated that most studies demonstrated validity in terms of temporal precedence, participant selection and allocation, outcome measure validity and reliability, appropriate statistical analyses, and follow-up completeness. However, certain limitations were identified in some studies, particularly regarding the control of confounding variables and the methods used for assigning comparison groups. Despite these limitations, all seven studies were deemed to meet the inclusion criteria and were thus classified as “included” in the final selection. The detailed results of the quality appraisal are presented in Table 1.

Table 1.

Results of critical appraisal using the revised JBI critical appraisal tool for quasi-experimental studies (n=7)

General Characteristics of the Included Studies

This review included seven studies: two conducted in Korea [20,21], two in the United States [22,23], two in Spain [24,25], and one in Germany [26]. All studies employed quasi-experimental designs and were conducted across various ICUs, including four surgical ICUs [20,21,23,24], one medical ICU [26], and two mixed medical-surgical ICUs [22,25]. With regard to the interventions, five studies implemented continuous intravenous insulin infusion [20,21,24-26] and two focused on hypoglycemia management [22,23]. Table 2 presents a summary of these findings.

Table 2.

Summary of the study characteristics of nurse-led glycemic control protocols in ICUs (n=7)

Characteristics of Nurse-Led Glycemic Control Protocols

The target blood glucose range across the included studies was set at 100–180 mg/dl. The frequency of blood glucose monitoring varied depending on the protocol used: in insulin infusion protocols, measurements were performed at intervals ranging from 30 minutes to 4 hours, whereas in hypoglycemia management protocols, monitoring was conducted every 15 minutes. All protocols were applied to patients who were either fasting or receiving continuous enteral nutrition. Patients on oral diets or intermittent enteral feeding were excluded. With regard to the mode of protocol implementation, four studies adopted paper-based protocols, in which nurses manually calculated and adjusted insulin doses according to printed guidelines [20,22,23,26]. The remaining three studies used DSSs that automatically recommended insulin doses and corresponding actions through computerized calculators [21,24,25]. Table 3 presents a summary of these findings.

Table 3.

Components of nurse-led glycemic control protocols in ICUs (n=7)

Outcomes of Nurse-Led Glycemic Control Protocols

Of the seven studies, the three that evaluated glycemic variability reported significantly lower variability in the nurse led glycemic control protocol group [20-22]. Six studies reported the incidence of hypoglycemia [20,21,23-26], of which four indicated a significantly lower incidence in the nurse led group [20,21,23,26]. Hyperglycemia incidence was assessed in four studies [20,21,25,26], with one reporting a significantly lower incidence in the nurse-led group [20]. The remaining two yielded mixed results across different blood glucose ranges [21,25]. Table 4 presents a summary of these findings.

Table 4.

Summary of the study outcomes of nurse-led glycemic control protocols in ICUs (n=7)

DISCUSSION

This scoping review explored recent literature on nurse-led glycemic control management in ICUs. It aimed to identify the outcomes of these interventions and the key characteristics of their protocol components. A total of seven studies met the inclusion criteria. This review highlighted four key findings: (1) nurse-led glycemic control protocols contribute to the enhancement of critical care, (2) guidance for patients on oral nutrition is lacking, (3) efforts to tailor protocols according to specific disease or treatment characteristics is limited, and (4) implementation methods have evolved, particularly with the adoption of decision-support technologies.

The findings of this scoping review suggest that nurse led glycemic control protocols contribute meaningfully to the improvement of glycemic management in critical care settings. Among the included studies, groups applying nurse led protocols yielded more favorable outcomes, particularly with regard to reduced glycemic variability and lower hypoglycemia incidence. These findings suggest that nurse led interventions can support more stringent and safer glucose control, which is a crucial aspect of outcome optimization in critically ill patients. These results partially align with the findings of a previous systematic review, which reported that nurse led protocols appear to control glycemia within predefined ranges and prevent hyper- and hypoglycemia episodes at levels comparable to those of control groups [16]. Taken together, these findings indicate the potential of nurse led glycemic control protocols to advance evidence based nursing practice in critical care. Encouraging nurses to implement standardized protocols may enhance patient outcomes.

None of the included studies considered patients receiving oral nutrition. Most interventions were applied to critically ill patients who were fasting or receiving continuous enteral nutrition, and patients on oral diets or receiving intermittent enteral feeding were either explicitly excluded or not mentioned. This represents a considerable gap, given the clinical relevance of nutritional intake in glycemic control. The Korean Diabetes Association (KDA) stated that oral hypoglycemic agents are generally not recommended during hospitalization due to several factors, such as fasting status, diagnostic procedures involving contrast agents, and potential adverse effects [27]. In contrast, the American Diabetes Association (ADA) recommend transition protocols, whereby intravenous insulin doses are converted to basal insulin combined with pre-meal rapid-acting insulin subcutaneously administered [28].

Across the studies, target blood glucose range was set between 100 and 180 mg/dl. This aligns with previous studies [5,16]. Notably, our finding that disease specific tailoring was largely absent suggests that current recommendations to incorporate differentiation by disease categories or patient specific metabolic requirements [29] have not yet been fully reflected in clinical practice. However, some studies have attempted to adjust target ranges based on patient-specific factors including disease characteristics and surgical status. The protocols applied in surgical ICUs tended to set lower upper limits (e.g., 150–160 mg/dl), potentially to mitigate the risk of postoperative infection associated with hyperglycemia. In contrast, studies that allowed an upper target of 180 mg/dl [21,25] reported higher frequencies of mild hyperglycemia (180–200 mg/dl) in the intervention groups compared with controls. The ADA and KDA recommend individualized target glucose levels, suggesting a range of 140–180 mg/dl for most critically ill patients [27,28]. Stricter control, within the range of 110–140 mg/dl, is cautiously advised in selected cases requiring stringent glycemic management, such as in postoperative care [27,30].

A notable trend in recent studies is the integration of technology-based tools, including glucose calculators and DSSs. The most recently published studies included in this review used computerized DSSs to facilitate nurse-led glycemic control [21,24,25]. Moreover, current clinical guidelines recommend glycemic management through paper-based and computerized protocols [27,28]. DSSs have been shown to enhance nurses’ clinical decision-making, improve safety and accuracy in clinical practice, promote standardization of care, and contribute to better patient outcomes [13-15].

Our results indicate that nurses play a pivotal role as implementers of glycemic control in ICUs; however, there remains a need to broaden protocol design to reflect nutritional diversity and disease specific tailoring. When situated within the broader literature, our findings align with those of previous reviews that examined nurse led protocols for glycemic management in critical care [5,16]. This highlights the importance of further empowering nurses as leaders in the development and implementation of such protocols.

This scoping review had some limitations. First, only studies published in English or Korean were included, which may have introduced language bias and led to the exclusion of relevant research published in other languages. Second, the review focused solely on quasi-experimental designs, which, although informative, may limit the generalizability of the findings due to potential biases inherent in nonrandomized study designs.

CONCLUSIONS

The findings of this study highlight the need to review and update current glycemic management protocols across healthcare settings. The implementation of an evidence-based approach through multidisciplinary collaboration is crucial. We recommend developing standardized protocols that incorporate the nutritional diversity of patients in the ICU, including specific guidance for those on oral diets. In addition, the integration of practical tools such as insulin dosage calculators and electronic medical record–linked protocols into clinical practice is needed to enhance glycemic control in critical care.

KEY MESSAGES

SUPPLEMENTARY MATERIALS

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