A practical approach to hyperglycemia management in the intensive care unit: evaluation of an intensive insulin infusion protocol

Nurse led protocols for control of glycaemia in critically ill patients: A systematic review

BACKGROUND

Blood glucose control in critically ill patients is challenging and can affect clinical outcomes. Several manual as well as automated approaches have been proposed over the time, however nursing staff still covers the key-role for optimization of glycemia throughout adjustment of insulin infusion and administration.

AIM

Systematic review to compare the efficacy/the effects of nurse led insulin infusion protocols versus standard approaches in patients admitted in the intensive care unit.

METHODS

All relevant studies evaluating nurse directed protocols for insulin administration in critically ill adults. Data was independently extracted and collected through a dedicated electronic form. The following outcomes have been recorded: the number (or percentage) of glycaemia measurements within the target range; the number of hypo- and hyper-glycaemic events, separately; the mean glycaemia; the lowest and highest glycemia values recorded; the time to reach the glycaemia target; the ICU length of stay and the ICU and the long-term (>30 days) mortality. Statistical analysis was conducted on the summary statistics of the selected articles (eg, means, medians, proportions). Unpaired nonparametric continuous data were compared through the Mann-Whitney U-test.

RESULTS

Glycaemic control as well as ICU length of stay and mortality are similar in both patients' groups. Specifically, the group of patients treated with standard modalities include those treated with doctors led protocols, paper charts or software-based approaches.

CONCLUSION

Overall, nurse led insulin protocols can effectively control blood glucose level among critically ill patients.

Association Between Perioperative Hyperglycemia or Glucose Variability and Postoperative Acute Kidney Injury After Liver Transplantation: A Retrospective Observational Study

BACKGROUND

Glucose control can be difficult in the intraoperative and immediate postoperative period of liver transplantation. Hyperglycemia and glucose variability have been associated with acute kidney injury (AKI) in critically ill patients. We performed a retrospective study to test the hypothesis that perioperative glucose levels represented by time-weighted average glucose levels and glucose variability are independently associated with the incidence of postoperative AKI in patients undergoing liver transplantation.

METHODS

On the basis of blood glucose levels during liver transplantation and the initial 48 hours postoperatively, adult liver transplant recipients were classified into 4 groups according to their time-weighted average glucose: normoglycemia (80-200 mg/dL), mild hyperglycemia (200-250 mg/dL), moderate hyperglycemia (250-300 mg/dL), and severe hyperglycemia (>300 mg/dL) group. Patients were also classified into quartiles depending on their glucose variability, defined as the standard deviation of glucose measurements. The primary outcome was postoperative AKI.

RESULTS

AKI after liver transplantation was more common in the patients with greater perioperative glucose variability (first versus third quartile; OR, 2.47 [95%CI, 1.22-5.00], P = .012; first versus fourth quartile; OR, 2.16 [95% CI, 1.05-4.42], P = .035).

CONCLUSIONS

Our study suggests that increased perioperative glucose variability, but not hyperglycemia, is independently associated with increased risk of postoperative AKI in liver transplantation recipients.

International multidisciplinary consensus conference on multimodality monitoring: ICU processes of care

There is an increased focus on evaluating processes of care, particularly in the high acuity and cost environment of intensive care. Evaluation of neurocritical-specific care and evidence-based protocol implementation are needed to effectively determine optimal processes of care and effect on patient outcomes. General quality measures to evaluate intensive care unit (ICU) processes of care have been proposed; however, applicability of these measures in neurocritical care populations has not been established. A comprehensive literature search was conducted for English language articles from 1990 to August 2013. A total of 1,061 articles were reviewed, with 145 meeting criteria for inclusion in this review. Care in specialized neurocritical care units or by neurocritical teams can have a positive impact on mortality, length of stay, and in some cases, functional outcome. Similarly, implementation of evidence-based protocol-directed care can enhance outcome in the neurocritical care population. There is significant evidence to support suggested quality indicators for the general ICU population, but limited research regarding specific use in neurocritical care. Quality indices for neurocritical care have been proposed; however, additional research is needed to further validate measures.

Guidelines for the use of an insulin infusion for the management of hyperglycemia in critically ill patients

OBJECTIVE

To evaluate the literature and identify important aspects of insulin therapy that facilitate safe and effective infusion therapy for a defined glycemic end point.

METHODS

Where available, the literature was evaluated using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to assess the impact of insulin infusions on outcome for general intensive care unit patients and those in specific subsets of neurologic injury, traumatic injury, and cardiovascular surgery. Elements that contribute to safe and effective insulin infusion therapy were determined through literature review and expert opinion. The majority of the literature supporting the use of insulin infusion therapy for critically ill patients lacks adequate strength to support more than weak recommendations, termed suggestions, such that the difference between desirable and undesirable effect of a given intervention is not always clear.

RECOMMENDATIONS

The article is focused on a suggested glycemic control end point such that a blood glucose ≥ 150 mg/dL triggers interventions to maintain blood glucose below that level and absolutely <180 mg/dL. There is a slight reduction in mortality with this treatment end point for general intensive care unit patients and reductions in morbidity for perioperative patients, postoperative cardiac surgery patients, post-traumatic injury patients, and neurologic injury patients. We suggest that the insulin regimen and monitoring system be designed to avoid and detect hypoglycemia (blood glucose ≤ 70 mg/dL) and to minimize glycemic variability.Important processes of care for insulin therapy include use of a reliable insulin infusion protocol, frequent blood glucose monitoring, and avoidance of finger-stick glucose testing through the use of arterial or venous glucose samples. The essential components of an insulin infusion system include use of a validated insulin titration program, availability of appropriate staffing resources, accurate monitoring technology, and standardized approaches to infusion preparation, provision of consistent carbohydrate calories and nutritional support, and dextrose replacement for hypoglycemia prevention and treatment. Quality improvement of glycemic management programs should include analysis of hypoglycemia rates, run charts of glucose values <150 and 180 mg/dL. The literature is inadequate to support recommendations regarding glycemic control in pediatric patients.

CONCLUSIONS

While the benefits of tight glycemic control have not been definitive, there are patients who will receive insulin infusion therapy, and the suggestions in this article provide the structure for safe and effective use of this therapy.

A retrospective cohort study of a nurse-driven computerized insulin infusion program versus a paper-based protocol in critically ill patients

BACKGROUND

There is variability in the extent of outcome achievement between computerized insulin infusion programs (CIIPs) and paper-based protocols (PBPs). This reported variability may be improved by intensive CIIP training prior to implementation. The objective was to evaluate the impact of a CIIP following intensive nurse training versus a PBP in a critical care setting.

METHODS

A retrospective cohort study was performed on patients admitted to a mixed intensive care unit comparing glucose control between the CIIP following intensive training and a PBP. Consecutive patients on each protocol were assessed to obtain glucose concentrations and outcomes. The primary measure was the percentage of blood glucose values within target range (90-130 mg/dL). Patient glucose values were pooled and assessed using the χ(2) test for independence.

RESULTS

In total, 61 patients with 5,495 glucose tests were included in the PBP group, and 51 patients with 5,645 glucose tests in the CIIP group. A greater percentage of glucose tests was within target range in the CIIP group (68.4% vs. 36.5%, P<0.001). In the CIIP group, time-to-target (median [interquartile range] 5 [3-8] h vs. 7 [4-20] h, P=0.02) and severe hypoglycemic events were reduced (26 vs. 6, P<0.0001).

CONCLUSIONS

The nurse-driven CIIP led to a higher percentage of glucose values within target range, faster achievement of target glucose values, and a reduction in the number of severe hypoglycemic events. This improved outcome achievement compared with previous reports may be associated with intensive user training.

Insulin therapy in critically ill patients

Hyperglycemia frequently occurs with acute medical illness, especially among patients with cardiovascular disease, and has been linked to increased morbidity and mortality in critically ill patients. Even patients who are normoglycemic can develop hyperglycemia in response to acute metabolic stress. An expanding body of literature describes the benefits of normalizing hyperglycemia with insulin therapy in hospitalized patients. As a result, both the American Diabetes Association and the American College of Endocrinology have developed guidelines for optimal control of hyperglycemia, specifically targeting critically ill, hospitalized patients. Conventional blood glucose values of 140–180 mg/dL are considered desirable and safely achievable in most patients. More aggressive control to <110 mg/dL remains controversial, but has shown benefits in certain patients, such as those in surgical intensive care. Intravenous infusion is often used for initial insulin administration, which can then be transitioned to subcutaneous insulin therapy in those patients who require continued insulin maintenance. This article reviews the data establishing the link between hyperglycemia and its risks of morbidity and mortality, and describes strategies that have proven effective in maintaining glycemic control in high-risk hospitalized patients.

The role of hyperglycemia in burned patients: evidence-based studies

Severely burned patients typically experience a systemic response expressed as increased metabolism, inflammation, alteration of cardiac and immune function, and associated hyperglycemia. Hyperglycemia has been associated with an increased risk of morbidity and mortality in critically ill patients. Until recently and for many years, hyperglycemia has been expectantly managed and considered a normal and desired response of an organism to stress. However, findings reported from recent studies now suggest beneficial effects of intensive insulin treatment of critically ill patients. The literature on the management of hyperglycemia in severely burned patients is sparse, with most of the available studies involving only small numbers of burned patients. The purpose of this article is to describe the pathophysiology of hyperglycemia after severe burns and to review the available literature on the outcome of intensive insulin treatment and other anti-hyperglycemic modalities in burned patients in an evidence-based medical approach.

Delay in blood glucose monitoring during an insulin infusion protocol is associated with increased risk of hypoglycemia in intensive care units

BACKGROUND

Hypoglycemia during insulin infusion therapy is a major problem. We investigated whether a delay in blood glucose (BG) monitoring during an insulin infusion protocol (IIP) in the intensive care unit (ICU) is associated with hypoglycemia.

METHODS

Data were collected for 50 consecutive patients treated with Brigham and Women's Hospital's IIP. Point-of-care BG values were obtained from the bedside paper flow sheets and the exact times of individual measurements were ascertained from an internet-based glucose meter download program. Data were carefully studied for protocol time violations, defined as a delay of >10 minutes after the recommended time for BG measurement.

RESULTS

A total of 2309 BG values were evaluated for time violation. A total of 1474 (63.9%) measurements had been obtained at the recommended time or earlier; 835 (36.1%) measurements had been obtained >10 minutes after the recommended time for measurement. There were a significantly higher proportion of BG values <80 mg/dL following the time violation as compared to no time violation (17.8% versus 11.6%; P < 0.001).

CONCLUSION

We conclude that the risk of hypoglycemia during insulin infusion therapy is higher after a delay in BG measurement.

Hyperglycemia during acute coronary syndrome: a nurse-managed insulin infusion protocol for stricter and safer control

BACKGROUND

Diabetic patients with acute coronary syndromes (ACS) might benefit from tight glycemic control by means of insulin infusion. Nurse-implemented insulin infusion protocols (IIP) are available but none validated in patients with ACS admitted to a coronary care unit (CCU).

AIMS

To assess feasibility, effectiveness and safety of a new nurse-managed IIP (Desio Diabetes Diagram, DDD) for intensive glucose control in patients with suspected ACS and known diabetes or blood glucose (BG) >200 mg/dL.

METHODS AND RESULTS

To reach and maintain a target BG level of 100-139 mg/dL we adopted a nomogram based on the percent changes in the insulin infusion rate according to the current BG value and the percent change from previous BG level. Ninety-one consecutive patients (53 men, mean age 69.7+/-11.2 years) were treated with DDD IIP. Baseline BG was 202.2+/-86.8 mg/dL. The median time to achieve the target was 3 h (Q1-Q3 2-5 h). Afterwards target BG levels were maintained for 70.4+/-15.9% of the time. During 5004 h of insulin infusion BG never fell below 40 mg/dL.

CONCLUSIONS

The nurse-managed DDD IIP was easily implemented in our CCU and permitted strict and safe glycemic control in hyperglycemic patients with ACS.

Safety and Efficacy of Intensive Insulin Therapy in Patients with Thermal Injury

Purpose

To evaluate the safety and efficacy of intensive insulin therapy (IIT) versus traditional corrective insulin management (CIM) for the treatment of hyperglycemia in adult patients with thermal injury who are under intensive care.

Methods

Using a searchable pharmacy database, a retrospective, observational chart review was conducted of adult patients who were admitted to the surgical burn service intensive care unit (ICU) at the University of North Carolina Hospitals (UNCH) from January 2004 through December 2005 and who had received insulin therapy.

Results

Seventy-one patients qualified for analysis. The average morning serum blood glucose value while patients were receiving IIT, defined as 80 to 110 mg/dL, was 107 mg/dL compared with 124 mg/dL while patients were receiving CIM ( P < 0.001). Of morning serum blood glucose values taken, 49% were within the target range in patients receiving IIT compared with 34% in patients receiving CIM ( P < 0.001). No significant differences were found between the 2 groups with regard to mortality, ICU stay, or hospital stay. More patients experienced hypoglycemia (blood glucose value less than 50 mg/dL) while receiving IIT compared with CIM (36.4% vs 31.3%; P = 0.732); however, none of the patients had symptomatic hypoglycemia. There was a significantly higher rate of hypoglycemia among nonsurvivors compared with survivors (66.7% vs 26.4%; P = 0.006).

Conclusion

IIT lowers average morning blood glucose in the thermal injury population when compared with CIM. Differences in hypoglycemic events were observed in this review; however, none of the episodes were symptomatic. Although further study is needed, IIT appears to be a safe and effective method of controlling serum blood glucose values in this specialized population.

A systematic review on quality indicators for tight glycaemic control in critically ill patients: need for an unambiguous indicator reference subset

Introduction

The objectives of this study were to systematically identify and summarize quality indicators of tight glycaemic control in critically ill patients, and to inspect the applicability of their definitions.

Methods

We searched in MEDLINE^® for all studies evaluating a tight glycaemic control protocol and/or quality of glucose control that reported original data from a clinical trial or observational study on critically ill adult patients.

Results

Forty-nine studies met the inclusion criteria; 30 different indicators were extracted and categorized into four nonorthogonal categories: blood glucose zones (for example, 'hypoglycaemia'); blood glucose levels (for example, 'mean blood glucose level'); time intervals (for example, 'time to occurrence of an event'); and protocol characteristics (for example, 'blood glucose sampling frequency'). Hypoglycaemia-related indicators were used in 43 out of 49 studies, acting as a proxy for safety, but they employed many different definitions. Blood glucose level summaries were used in 41 out of 49 studies, reported as means and/or medians during the study period or at a certain time point (for example, the morning blood glucose level or blood glucose level upon starting insulin therapy). Time spent in the predefined blood glucose level range, time needed to reach the defined blood glucose level target, hyperglycaemia-related indicators and protocol-related indicators were other frequently used indicators. Most indicators differ in their definitions even when they are meant to measure the same underlying concept. More importantly, many definitions are not precise, prohibiting their applicability and hence the reproducibility and comparability of research results.

Conclusions

An unambiguous indicator reference subset is necessary. The result of this systematic review can be used as a starting point from which to develop a standard list of well defined indicators that are associated with clinical outcomes or that concur with clinicians' subjective views on the quality of the regulatory process.

Designing and implementing insulin infusion protocols and order sets

Influential trials and guidelines supporting the value of glucose control in hospital settings, particularly in the intensive care and postoperative settings, has led to the widespread adoption of intravenous infusions of human regular insulin. As groups have attempted to study the outcomes or to explore improved methods for improved glucose control, a number of insulin infusion protocols (IIPs) have been reported and validated. Now, many institutions are attempting to translate this experience into clinical practice in a systematic manner. The intent of this discussion is to highlight the authors' practical view of best practices in development and use of IIPs. As the implementation of IIPs has progressed, it has become apparent that this is not a simple process. It requires a carefully planned, inclusive, and continuous effort striving to attain effective glucose control while avoiding severe hypoglycemia. Whereas there are limitations in the literature comparing the IIPs, we identify design elements and implementation methods that increase the chances for staff acceptance and safe attainment of glycemic goals. Most importantly, this must be a team effort with attention to the numerous potential pitfalls that can disrupt the process and place patients at risk. In many cases, it is best to start more conservatively and methodically intensify the protocol. Continuous assessment of protocol errors, adverse events, staff satisfaction, and outcomes is vital to overall success.

Tight glucose control in intensive care units: an update with an emphasis on nutritional issues

PURPOSE OF REVIEW

Tight glucose control in ICU patients is now regarded as a goal of successful care. Some challenge this on the basis that it produces no benefit and may cause harm. We review the recent literature with an emphasis on nutritional aspects.

RECENT FINDINGS

Since 2001, several randomized controlled trials have examined the effect of tight glucose control in ICU patients, but only one showed an overall survival benefit. Glucose potassium insulin infusions have also produced variable results, and sometimes cause falls in plasma phosphate with potential consequences. Several studies have shown tight glucose control is labour-intensive and increases the incidence of hypoglycaemia, which could have profound effects, especially if cerebral perfusion is poor. Nutritional intake during tight glucose control has generally been poorly defined. Unintentional cessation of nutrition has been identified as a risk factor for hypoglycaemia. No difference in glucose control has been found between parenteral and enteral feeding.

SUMMARY

Without knowledge of nutrition provision in terms of carbohydrate, total energy intake and route of administration, some studies are difficult to interpret. It is currently difficult to recommend routine use of tight glucose control in the ICU. Many clinicians have adopted regimes to control glucose between 5.0-9.0 mmol/l.

Inpatient insulin therapy

PURPOSE OF REVIEW

In a 2001 report from a surgical intensive care unit in Leuven, Belgium, intravenous insulin infusion targeting blood glucose 80-110 mg/dl reduced patient mortality and morbidities. Subsequent research has failed to define glycemic targets necessary or sufficient for attainment of desired health outcomes in other inpatient settings, but a large body of evidence suggests hospital outcomes are related to hyperglycemia.

RECENT FINDINGS

Recent literature describes observational evidence for hypoglycemia as an independent predictor of mortality in a general medical intensive care unit; superiority of performance of computerized intravenous insulin algorithms in comparison to earlier manual algorithms; acceptability of early transition to scheduled basal prandial correction subcutaneous insulin analog therapy for maintenance of glycemic targets after induction of euglycemia by intravenous insulin infusion, among cardiothoracic surgery patients; inferiority of sliding scale insulin compared to basal prandial correction therapy; and feasibility of diabetes patient self-management in the hospital setting.

SUMMARY

With development of improved insulin administration strategies problems of hypoglycemia and variability of glycemic control are reduced. Investigators and care providers need to achieve glycemic targets to optimize patient outcomes.

Intensive insulin therapy in the critically ill geriatric patient

Tight glucose control can significantly improve outcomes of critically ill geriatric patients in the critical care unit (CCU). In the past, blood glucose levels were managed by a point-of-care testing every 4 to 6 hours and using a sliding scale of insulin therapy. This article explores the need for more intensive intravenous insulin therapies. Studies have shown that patient outcomes improve by having a specific set of standing orders, a well-defined algorithm, and empowering the CCU nurses with these tools. Methods for initiating intensive intravenous insulin therapies are discussed along with some of the biggest challenges faced by CCU nurses at the bedside.

Differential temporal profile of lowered blood glucose levels (3.5 to 6.5 mmol/l versus 5 to 8 mmol/l) in patients with severe traumatic brain injury

INTRODUCTION

Hyperglycaemia is detrimental, but maintaining low blood glucose levels within tight limits is controversial in patients with severe traumatic brain injury, because decreased blood glucose levels can induce and aggravate underlying brain injury.

METHODS

In 228 propensity matched patients (age, sex and injury severity) treated in our intensive care unit (ICU) from 2000 to 2004, we retrospectively evaluated the influence of different predefined blood glucose targets (3.5 to 6.5 versus 5 to 8 mmol/l) on frequency of hypoglycaemic and hyperglycaemic episodes, insulin and norepinephrine requirement, changes in intracranial pressure and cerebral perfusion pressure, mortality and length of stay on the ICU.

RESULTS

Mortality and length of ICU stay were similar in both blood glucose target groups. Blood glucose values below and above the predefined levels were significantly increased in the 3.5 to 6.5 mmol/l group, predominantly during the first week. Insulin and norepinephrine requirements were markedly increased in this group. During the second week, the incidences of intracranial pressure exceeding 20 mmHg and infectious complications were significantly decreased in the 3.5 to 6.5 mmol/l group.

CONCLUSION

Maintaining blood glucose within 5 to 8 mmol/l appears to yield greater benefit during the first week. During the second week, 3.5 to 6.5 mmol/l is associated with beneficial effects in terms of reduced intracranial hypertension and decreased rate of pneumonia, bacteraemia and urinary tract infections. It remains to be determined whether patients might profit from temporally adapted blood glucose limits, inducing lower values during the second week, and whether concomitant glucose infusion to prevent hypoglycaemia is safe in patients with post-traumatic oedema.

Adaptive closed-loop control provides blood-glucose regulation using dual subcutaneous insulin and glucagon infusion in diabetic Swine

BACKGROUND

In order to stave off deleterious complications of the disease, the ultimate task for people with diabetes is to maintain their blood glucose in euglycemic range. Despite technological advancements, conventional open-loop therapy often results in prolonged hyperglycemia and episodic hypoglycemia, in addition to necessitating carbohydrate counting, frequent glucose monitoring, and drug administration. The logical conclusion in the evolution of exogenous insulin therapy is to develop an automated closed-loop control system.

METHODS

Eleven closed-loop control experiments were conducted in four anesthetized diabetic pigs, with carbohydrate loads simulated by intravenous glucose administration through ear-vein catheters. Type 1 diabetes-like pathology was induced using intravenous administration of cytotoxin streptozotocin. The augmented model-predictive control algorithm accounts for the accumulation of subcutaneous insulin, which is critical in avoiding excessive insulin dosing.

RESULTS

Control results consistently showed successful blood-glucose regulation to euglycemic range within 80-120 minutes after intravenous glucose loads, with no incidence of hypoglycemia. This is consistent with a negative oral glucose tolerance test for diabetes and is the optimal postprandial regulation that can be achieved with subcutaneous insulin administration. Results also demonstrated the potency of subcutaneous glucagon in staving off episodic hypoglycemia and revealed efficacy of the control algorithm in coping with a twofold variation in subject weights, while simultaneously overlooking erratic blood-glucose fluctuations.

CONCLUSIONS

Using an automated adaptive glucose-control system, we show successful blood-glucose regulation in vivo and establish, definitively, the plausibility and practicality of closed-loop blood-glucose control using subcutaneous insulin and glucagon infusion in type 1 diabetes. The control system strikes an intricate balance between tight blood-glucose control and optimal drug consumption, while simultaneously maintaining emphasis on simplicity and reliability.