Insulin Therapy and In-Hospital Mortality in Critically Ill Patients: Systematic Review and Meta-analysis of Randomized Controlled Trials

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

Preadmission Insulin-Treated Type 2 Diabetes Mellitus Patients Had Increased Mortality in Intensive Care Units

AIM

To explore the clinical outcomes among preadmission insulin-treated type 2 diabetes mellitus (T2DM) in intensive care units (ICU).

PATIENTS AND METHODS

In this retrospective observational study, 578 T2DM patients admitted to ICU were recruited from March 2011 to February 2021, which were composed of 528 patients treated with insulin after ICU admission (including 300 preadmission non-insulin-treated and 228 preadmission insulin-treated patients) and 50 patients treated without insulin before and after ICU admission. Clinical outcomes were compared between the groups. Variables of age (± 10 years), gender, blood glucose >10 mmol/l on ICU admission, and original comorbidities were used for matching to get the 1:1 matched cohort. The Kaplan-Meier survival curves were graphed to describe the survival trend and Cox regression analysis was performed to get adjusted hazard ratio (HR).

RESULTS

Compared with the preadmission non-insulin-treated T2DM patients, preadmission insulin-treated T2DM patients had higher incidence of hypoglycemia [14.5% (33/228) vs 8.7% (26/300); p = 0.036]. In the 1:1 matched cohort, the preadmission insulin-treated T2DM patients had significantly increased mortality rate [30.0% (45/150) vs (16.0% (24/150)); adjusted HR, 1.68 (1.01-2.80)] than preadmission non-insulin-treated T2DM patients. Compared with T2DM patients treated without insulin before and after ICU admission, preadmission insulin-treated T2DM patients had higher mortality and longer length of ICU stay (all p < 0.05).

CONCLUSION

Preadmission insulin treatment was associated with increased mortality rate and longer length of ICU stay among T2DM patients in ICU. Preadmission insulin-treated T2DM patients might have worse clinical outcomes when they are critically ill.

[Risk factors for post stroke epilepsy]

Stroke is the leading cause of death and disability in the world. The prevalence of post-stroke epilepsy increases with the increase in the number of stroke cases. Epilepsy may develop in 10% of post-stroke cases and first-diagnosed seizures may develop in 55%. Most often they occur in people who have had intracerebral or subarachnoid haemorrhage. A huge number of factors influence the development of post-stroke seizures and epilepsy. The role of some of them is not in doubt. However, in most cases, the influence of a factor remains controversial and participation in the development of post-stroke epilepsy is not fully proven. The management of post-stroke epilepsy is of great clinical importance, since patients with seizures after a stroke have a higher mortality and disability than those without seizures. Attacks worsen the quality of life of patients, can slow the recovery of functions damaged as a result of a stroke, and aggravate cognitive impairment. Social consequences of post-stroke epilepsy play an important role as well.

Effects and mechanisms of glucose-insulin-potassium on post-procedural myocardial injury after percutaneous coronary intervention

OBJECTIVE

To evaluate the effects and mechanisms of glucose-insulin-potassium (GIK) on post-procedural myocardial injury (PMI) after percutaneous coronary intervention (PCI).

METHODS

A total of 200 non-diabetic patients with documented coronary heart disease (CHD) were divided into the Group GIK and Group G, with 100 patients in each group. Patients in Group G were given intravenous infusion of glucose solution 2 hours before PCI. As compared, patients in Group GIK were given GIK.

RESULTS

Both post-procedural creatine phosphokinase isoenzyme MB (CK-MB; 62.1 ± 47.8 vs. 48.8 ± 52.6 U/L, P = 0.007) and cTnI (0.68 ± 0.83 vs. 0.19 ± 0.24 ng/mL, P < 0.001) in Group GIK were significantly higher than those in Group G. In Group G, 9.0% and 4.0% of patients had post-procedural increases in CK-MB 1-3 times and > 3 times, which were significantly lower than those in Group GIK (14.0% and 7.0%, respectively; all P values < 0.01); 13.0% and 7.0% of patients had post-procedural increases in cTnI 1-3 times and > 3 times, which were also significantly lower than those in Group GIK (21.0% and 13.0%, respectively; all P < 0.001). Pre-procedural (10.2 ± 4.5 vs. 5.1 ± 6.3, P < 0.001) and post-procedural rapid blood glucose (RBG) levels (8.9 ± 3.9 vs. 5.3 ± 5.6, P < 0.001) in Group G were higher than those in Group GIK. In adjusted logistic models, usage of GIK (compared with glucose solution) remained significantly and independently associated with higher risk of post-procedural increases in both CK-MB and cTnI levels > 3 times. Furthermore, pre-procedural RBG levels < 5.0mmol/L were significantly associated with higher risk of post-procedural increases in both CK-MB and cTnI levels.

CONCLUSIONS

In non-diabetic patients with CHD, the administration of GIK may increase the risk of PMI due to hypoglycemia induced by GIK.

Autophagy: should it play a role in ICU management?

PURPOSE OF REVIEW

This review is to discuss the role of autophagy in the critically ill patient population. As the understanding of autophagy continues to expand and evolve, there are certain controversies surrounding whether intensivist should allow the benefit of autophagy to supersede gold standard of insulin therapy or early nutritional support.

RECENT FINDINGS

The review is relevant as the current literature seems to support under-feeding patients, and perhaps the reason these studies were positive could be prescribed to the mechanisms of autophagy. It is well understood that autophagy is a physiologic response to stress and starvation, and that the inducible form could help patients with end-organ dysfunction return to homeostasis.

SUMMARY

The jury is still out as to how autophagy will play into clinical practice as we review several gold standard therapies for the critically ill.

Update on glucose in critical care

The aim of this review is to summarize recent developments on the mechanisms involved in stress hyperglycemia associated with critical illness. Different aspects of the consequences of stress hyperglycemia as well as the therapeutic approaches tested so far are discussed: the physiological regulations of blood glucose, the mechanisms underlying stress hyperglycemia, the clinical associations, and the results of the prospective trials and meta-analyses to be taken into consideration when interpreting the available data. Current recommendations, challenges, and technological hopes for the future are be discussed.

More Harm Than Benefit of Perioperative Dexamethasone on Recovery Following Reconstructive Head and Neck Cancer Surgery: A Prospective Double-Blind Randomized Trial

PURPOSE

Prospective studies on the effect of dexamethasone after microvascular reconstructive head and neck surgery are sparse despite the widespread use of dexamethasone in this setting. The aim of this study was to clarify whether perioperative use of dexamethasone would improve the quality and speed of recovery. The authors hypothesized that dexamethasone would enhance recovery and diminish pain and nausea.

MATERIALS AND METHODS

Ninety-three patients with oropharyngeal cancer and microvascular reconstruction were included in this prospective double-blinded randomized controlled trial. Patients in the study group (n = 51) received dexamethasone 60 mg over 3 perioperative days; 42 patients did not receive dexamethasone and served as controls. Patient rehabilitation, postoperative opioid and insulin consumption, postoperative nausea and vomiting (PONV), and C-reactive protein (CRP), leukocyte, and lactate levels were recorded.

RESULTS

There was significantly less pain in the study group (P = .030) and the total oxycodone dose for 5 days postoperatively was lower (P = .040). Dexamethasone did not significantly lessen PONV for 5 days postoperatively (P > .05). There were no differences between groups in intensive care unit or hospital stay or in other clinical measures of recovery. Patients receiving dexamethasone required significantly more insulin compared with patients in the control group (P < .001). Lactate and leukocyte levels were significantly higher (P < .001) and CRP levels were significantly lower in the study group.

CONCLUSION

The only benefit of perioperative dexamethasone use was lower total oxycodone dose; however, the disadvantages were greater. Because dexamethasone can have adverse effects on the postoperative course, routine use of dexamethasone as a pain or nausea medication during reconstructive head and neck cancer surgery is not recommended.

Association of the -1031T>C polymorphism and soluble TNF-α levels with Acute Coronary Syndrome

INTRODUCTION

Inflammation has gained a pivotal role in the pathophysiology of Acute Coronary Syndrome (ACS). TNF-α is a pro-inflammatory cytokine that could be a potential biomarker in ACS due to its multiple functions. The rs1799964 TNFA polymorphism (-1031T>C) has been associated with a decrease in gene transcription and cytokine levels.

OBJECTIVE

To determine the association of rs1799964 TNFA polymorphism and TNF-α soluble levels in ACS.

METHODS

A total of 251 patients diagnosed with ACS and 164 individuals without cardiovascular diseases classified as the reference group (RG), were included. The rs1799964 polymorphism was genotyped by PCR-RFLP. Soluble protein levels were determined by ELISA. Statistical analyses were performed using chi square and U-Mann Whitney tests.

RESULTS

The genotype and allele frequencies were different between ACS and RG (OR=0.317, p=0.01; OR=0.688, p=0.03 respectively). ACS patients had higher soluble TNF-α levels compared with the RG (31.08 vs 23.00pg/mL, p<0.001); according genotype significant differences were observed (T/T: 24.06 vs T/C: 34.95pg/mL, p=0.0001) in patients. In the RG, T/T carriers showed discrete lower levels than C/C genotype (22.14 vs 27.83pg/mL, p=0.04).

CONCLUSIONS

The -1031C allele of the TNFA polymorphism confers protection for the development of ACS. The T/C genotype carriers had higher TNF-α serum levels compared to the T/T genotype in ACS. In addition, the -1031T>C TNFA polymorphism was associated with dyslipidemia in ACS in a Western Mexican population.

In search of the perfect glucose concentration for hospitalized patients: a brief review of the meta-analyses

In hospitalized patients, the optimal target blood glucose concentration is controversial. Numerous studies have examined clinical use of glucose control in various patient populations. In the present review, we briefly discuss corresponding meta-analyses. We electronically searched MEDLINE, EMBASE and CINAHL for meta-analyses relevant to the subject. Fifteen meta-analyses were identified that analyzed effects of a targeted glucose control. Twelve meta-analyses examined studies performed in critically ill patients. Included studies in this review varied in terms of the type of nutritional support, the efficacy of glucose control, the kind of glucose measurement, clinical end points (hospital or intensive care unit mortality, or 28-, 90- or 180-d mortality, or mortality 30 d after discharge), and the intensity of glucose control (moderate, tight, very tight). Four meta-analyses also including studies with a less stringent glucose control (glucose target <200 mg/dL) showed a beneficial effect on mortality. This effect disappeared when analyzing studies with a tighter glucose control (glucose target <150 mg/dL or <110/120 mg/dL, n = 5), with a very tight glucose control (glucose target <110/120 mg/dL, n = 2), or with a more precise definition of clinical endpoints (28-d mortality, n = 2). Eight meta-analyses showed that, despite the intensity of glucose control, the frequency of hypoglycemic episodes increased. The residual heterogeneity of individual studies incorporated into the various meta-analyses prevents a valid conclusion regarding potential benefits of a specific glucose target. A glucose concentration <200 mg/dL appears preferable.

Management of hyperglycemia in a hospitalized patient with diabetes mellitus and cardiovascular disease

Hyperglycemia in patients with and without known diabetes is a common finding in patients hospitalized with cardiovascular disease, and is associated with poor outcomes. Investigators have been examining the role of insulin to treat patients with acute myocardial infarction since the 1960's. Until the 1990's most studies evaluated fixed doses of glucose-insulin-potassium (GIK) infusions. The Diabetes Mellitus Insulin-Glucose Infusion in Acute Myocardial Infarction (DIGAMI) trial, published in 1995, evaluated the role of adjustable-dose insulin infusion to lower blood glucose. Its promising results spurred further interest and a number of trials evaluating the use of insulin to lower blood glucose in hospitalized patients - many of which included patients with cardiovascular disease - have been conducted over the last two decades with conflicting results. This manuscript reviews the epidemiology and pathophysiology of hyperglycemia in hospitalized patients, summarizes the evidence for benefits and harms of using insulin to treat hyperglycemic patients hospitalized with cardiovascular disease, and offers some practical management considerations.

Higher Blood Glucose within the Normal Range Is Associated with More Severe Strokes

Background. Higher fasting blood glucose (FBG) concentrations in the hyperglycemic range are associated with more severe strokes. Whether this association also extends into patients with FBG in the normoglycemic range is unclear. We studied the association of stroke severity and FBG in normoglycemic patients with ischemic stroke in a median of 7 days after stroke when the initial glycemic stress response has resolved. Method and Material. Included were 361 nondiabetic ischemic stroke patients with admission fasting blood glucose within 70–130 mg/dL admitted into an acute stroke rehabilitation unit in a median of 7 days after stroke. Data including neuroimaging, vital signs, cardiovascular risk factors, and admission functional independence measure (AFIM) were recorded prospectively. Results. FBG correlated with stroke severity in the normoglycemic 70–130 mg/dL range (FBG-AFIM correlation coefficient −0.17; P = 0.003). Odds ratio for more severe injury (below average AFIM score) was 2.02 for patients with FBG 110–130 mg/dL compared to FBG 70–90 mg/dL (95% confidence interval 1.10–3.73, P = 0.022). Each mg/dL increase in FBG was associated with an average decrease of 0.25 FIM points. In a multiple linear regression model, FBG was associated with more severe stroke (P = 0.002). Conclusion. One week after ischemic stroke, FBG within the normoglycemic range was associated with stroke severity.

Hyperglycemia during chemotherapy for hematologic and solid tumors is correlated with increased toxicity

BACKGROUND

Few data are available concerning how glycemic control can affect outcomes in cancer patients treated with chemotherapy.

METHODS

Charts of non-Hodgkin lymphoma (NHL) and prostate cancer (PC) patients treated at Moffitt Cancer Center between January 1999 and September 2006 were reviewed, and patients who received cyclophosphamide, doxoruicin, vincristine, prednisone, rituximab or Docetaxel plus steroids were eligible. Demographics, vitals, comorbidity, laboratory parameters including baseline and average glucose level during chemotherapy, G4 hematological toxicity (HemT), and G3-G4 non-hematological toxicity (NHemT), progression, and death dates were recorded.

RESULTS

A total of 349 patients were eligible (NHL/PC: 162/187). G4 HemT was experienced by 76 (47%) NHL and 9 (5%) PC patients. Seventy-nine NHL and 90 PC patients had G3-G4 NHemT. The most frequent NHemT were as follows: neuropathy (25.3%), fever (non-neutropenic, 18.9%), fatigue (15.2%), for NHL; and fatigue (22.1%), thromboembolic events (11.6%), and diarrhea (9.3%) for PC. For NHL patients, G3-G4 NHemT was associated with baseline hyperglycemia (P = 0.0384, Wilcoxon Rank-Sum test) as well as with average glycemia during chemotherapy (P = 0.0048), whereas there was no significant correlation for HemT. For PC patients, a positive correlation was found between baseline hyperglycemia and G4 HemT (P = 0.0241), while univariate correlations between average glycemia during chemotherapy and G4 HemT and between both baseline and average glycemia with NHemT were not significant, multivariate correlation between average glycemia during chemotherapy and overall severe toxicity was significant at 0.05 level.

CONCLUSIONS

In NHL patients, hyperglycemia correlates with NHemT, and a similar although less clear pattern is suggested in PC patients. Prospective studies are needed to assess whether a better glycemic control during chemotherapy can improve toxicity and outcomes.

International recommendations for glucose control in adult non diabetic critically ill patients

INTRODUCTION

The purpose of this research is to provide recommendations for the management of glycemic control in critically ill patients.

METHODS

Twenty-one experts issued recommendations related to one of the five pre-defined categories (glucose target, hypoglycemia, carbohydrate intake, monitoring of glycemia, algorithms and protocols), that were scored on a scale to obtain a strong or weak agreement. The GRADE (Grade of Recommendation, Assessment, Development and Evaluation) system was used, with a strong recommendation indicating a clear advantage for an intervention and a weak recommendation indicating that the balance between desirable and undesirable effects of an intervention is not clearly defined.

RESULTS

A glucose target of less than 10 mmol/L is strongly suggested, using intravenous insulin following a standard protocol, when spontaneous food intake is not possible. Definition of the severe hypoglycemia threshold of 2.2 mmol/L is recommended, regardless of the clinical signs. A general, unique amount of glucose (enteral/parenteral) to administer for any patient cannot be suggested. Glucose measurements should be performed on arterial rather than venous or capillary samples, using central lab or blood gas analysers rather than point-of-care glucose readers.

CONCLUSIONS

Thirty recommendations were obtained with a strong (21) and a weak (9) agreement. Among them, only 15 were graded with a high level of quality of evidence, underlying the necessity to continue clinical studies in order to improve the risk-to-benefit ratio of glucose control.

Molecular mechanisms behind clinical benefits of intensive insulin therapy during critical illness: glucose versus insulin

High blood glucose levels have been associated with morbidity and poor outcome in critically ill patients, irrespective of underlying pathology. In a large, randomised, controlled study the use of insulin therapy to maintain normoglycaemia for at least a few days improved survival and reduced morbidity of patients who are in a surgical intensive care unit (ICU). Since the publication of this landmark study, several other investigators have provided support for, whereas others have questioned, the beneficial effects of intensive insulin therapy. In this review, we discuss the investigated potential molecular mechanisms behind the clinical benefits of intensive insulin therapy. We first describe the molecular origin of hyperglycaemia and the impact of the therapy on insulin sensitivity. Next, the molecular basis of glucose toxicity in critical illness and the impact of intensive insulin therapy hereon are described, as well as other non-glucose-toxicity-related metabolic effects of intensive insulin therapy.

How to weigh the current evidence for clinical practice

This article presents a template for judging trials of tight glucose control in critically ill patients. It reviews threats to both internal validity and generalisability using examples from the current literature. When judging internal validity, it is important to consider factors specific to trials of glucose control (particularly the methods of glucose control, measurement and reporting) in addition to factors common to all randomised controlled trials (such as treatment allocation, losses to follow-up and protocol violations). Judging generalisability requires the identification of differences between the trial population and the population for whom the intervention is being considered. These may relate to the setting, the patients or the practical delivery of tight glucose control or other interventions. Once identified, a judgement must be made for each difference of whether it is likely to modify the effect of tight glucose control.

Increasing intravenous glucose load in the presence of normoglycemia: effect on outcome and metabolism in critically ill rabbits

OBJECTIVES

Endocrine disturbances and a feeding-resistant wasting syndrome, characterized by a negative protein balance, promote delayed recovery and poor outcome of critical illness. Parenteral nutrition alone cannot counteract the hypercatabolic state, possibly in part as a result of aggravation of the hyperglycemic response to illness. In critically ill rabbits, we investigated the impact of varying amounts of intravenous glucose while maintaining normoglycemia on mortality, organ damage, and markers of catabolism/anabolism.

DESIGN

Prospective, randomized laboratory investigation.

SETTING

University animal and molecular laboratory.

SUBJECTS

Three-month-old male rabbits.

INTERVENTIONS

Critically ill rabbits were randomized into a fasting group, a standard parenteral nutrition group, and two groups receiving either intermediate or high additional physiological amounts of intravenous glucose while maintained normoglycemic with insulin. These groups were compared with a hyperglycemic group and healthy rabbits. Protein and lipid load was equal for all fed groups.

MEASUREMENTS AND MAIN RESULTS

Varying intravenous glucose load did not affect mortality or organ damage provided hyperglycemia was prevented. Fasted critically ill rabbits lost weight, which was attenuated by increasing intravenous glucose load. As compared with healthy rabbits, mRNA expression and/or activity of several ubiquitin-proteasome pathway components, cathepsin-L and calpain-1, was elevated in skeletal muscle of fasted critically ill rabbits. Intravenous feeding was able to counteract this response. Excessive glucose load and/or hyperglycemia, however, reduced the protective effect of feeding. Genes investigated in the diaphragm and myocardium revealed roughly a similar response. Except in the normoglycemic group with intermediate glucose load, circulating thyroid hormone and insulin-like growth factor-1 levels decreased, most pronounced in hyperglycemic rabbits.

CONCLUSIONS

Increasing intravenous glucose infusion within the physiological range, while maintaining normoglycemia, was safe for organ function and survival of critically ill rabbits. Concomitantly, it reduced the catabolic responses as compared with fasting. Whether this has a beneficial effect on muscle function and mass remains to be investigated.

Hyperglycemia-related mortality in critically ill patients varies with admission diagnosis

OBJECTIVES

Hyperglycemia during critical illness is common and is associated with increased mortality. Intensive insulin therapy has improved outcomes in some, but not all, intervention trials. It is unclear whether the benefits of treatment differ among specific patient populations. The purpose of the study was to determine the association between hyperglycemia and risk- adjusted mortality in critically ill patients and in separate groups stratified by admission diagnosis. A secondary purpose was to determine whether mortality risk from hyperglycemia varies with intensive care unit type, length of stay, or diagnosed diabetes.

DESIGN

Retrospective cohort study.

SETTING

One hundred seventy-three U.S. medical, surgical, and cardiac intensive care units.

PATIENTS

Two hundred fifty-nine thousand and forty admissions from October 2002 to September 2005; unadjusted mortality rate, 11.2%.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A two-level logistic regression model determined the relationship between glycemia and mortality. Age, diagnosis, comorbidities, and laboratory variables were used to calculate a predicted mortality rate, which was then analyzed with mean glucose to determine the association of hyperglycemia with hospital mortality. Hyperglycemia was associated with increased mortality independent of illness severity. Compared with normoglycemic individuals (70-110 mg/dL), adjusted odds of mortality (odds ratio, [95% confidence interval]) for mean glucose 111-145, 146-199, 200-300, and >300 mg/dL was 1.31 (1.26-1.36), 1.82 (1.74-1.90), 2.13 (2.03-2.25), and 2.85 (2.58-3.14), respectively. Furthermore, the adjusted odds of mortality related to hyperglycemia varied with admission diagnosis, demonstrating a clear association in some patients (acute myocardial infarction, arrhythmia, unstable angina, pulmonary embolism) and little or no association in others. Hyperglycemia was associated with increased mortality independent of intensive care unit type, length of stay, and diabetes.

CONCLUSIONS

The association between hyperglycemia and mortality implicates hyperglycemia as a potentially harmful and correctable abnormality in critically ill patients. The finding that hyperglycemia-related risk varied with admission diagnosis suggests differences in the interaction between specific medical conditions and injury from hyperglycemia. The design and interpretation of future trials should consider the primary disease states of patients and the balance of medical conditions in the intensive care unit studied.

Persistent outpatient hyperglycemia is independently associated with survival, recurrence and malignant degeneration following surgery for hemispheric low grade gliomas

OBJECTIVE

Hyperglycemia has been shown to augment tumor growth in vitro. However, the effects of persistent hyperglycemia on survival, recurrence and malignant degeneration in patients undergoing surgery for low grade gliomas remain unknown.

METHODS

All patients who underwent a craniotomy for hemispheric low grade glioma (WHO grade II) from 1996 to 2006 at a single institution were retrospectively reviewed. Persistent hyperglycemia was defined as serum glucose >180 microg/dl occurring three or more times between 1 and 3 months post-operatively. The independent association of outpatient glucose levels and recorded clinical and treatment variables with overall survival, tumor recurrence and malignant degeneration was assessed via separate multivariate proportional-hazards regression analyses.

RESULTS

In this study, 182 patients (89 fibrillary astrocytomas, 82 oligodendrogliomas and 11 mixed gliomas) were available for analysis. Eighteen (10%) patients experienced persistent hyperglycemia. Patients experiencing persistent hyperglycemia were older (44 +/- 16 versus 34 +/- 15) and more frequently diabetic [3 (17%) versus 4 (2%)]. All other clinical and treatment variables were not significantly different between the two cohorts. After adjusting for inter-group differences including age and diabetes and variables associated with survival and recurrence, persistent hyperglycemia was independently associated with decreased survival (p=0.001), increased recurrence (p=0.0001) and increased malignant degeneration (p<0.0001). This remained true after excluding all patients with diabetes and those on continued steroid administration. Five-year overall survival, progression-free survival and malignancy-free survival for persistent hyperglycemia versus relatively euglycemic cohorts were 43% versus 84%, 16% versus 46% and 46% versus 77%, respectively.

DISCUSSION

These findings may provide useful insight for increasing survival, decreasing tumor recurrence and decreasing malignant degeneration in patients undergoing surgery for low grade gliomas.

Blood glucose in acute stroke

Blood glucose is often elevated in acute stroke, and higher admission glucose levels are associated with larger lesions, greater mortality and poorer functional outcome. In patients treated with thrombolysis, hyperglycemia is associated with an increased risk of hemorrhagic transformation of infarcts. For a number of years, tight glycemic control has been regarded as beneficial in critically illness, but recent research has been unable to support this notion. The only completed randomized study on glucose-lowering therapy in stroke has failed to demonstrate effect, and concerns relating to the risk of inducing potentially harmful hypoglycemia has been raised. Still, basic and observational research is overwhelmingly in support of a causal relationship between blood glucose and stroke outcome and further research on glucose-lowering therapy in acute stroke is highly warranted.

[Repercussions and management of perioperative hyperglycemia in cardiac surgery]

Surgery produces a neuroendocrine stress response that affects resistance to insulin, reduces insulin secretion, and increases the release of glucose from the liver. This situation can trigger hyperglycemia in both diabetics and nondiabetics. Hyperglycemia has been linked to an increase in the morbidity and mortality among patients who undergo cardiac surgery, and the benefits of correcting hyperglycemia in this setting by means of intensive insulin therapy are well documented. This review discusses various aspects of hyperglycemia, particularly the evidence supporting stricter control of this condition in patients undergoing cardiac surgery. Furthermore, based on the available data and recommendations, and our clinical experience, we suggest therapeutic strategies to improve the control of hyperglycemia in these patients.

Cleveland Clinic cardiovascular intensive care unit insulin conversion protocol

BACKGROUND

The importance of near-normal blood glucose in the immediate postoperative period is generally accepted and is best achieved in the perioperative period with a constant intravenous (IV) infusion of insulin. This requires intensive nursing only achievable in an intensive care unit (ICU) setting. Glucose management after transfer to a regular nursing floor (RNF) has not been studied systematically. In August 2006, the Cleveland Clinic began using long-acting insulin glargine as the insulin infusion was terminated in the ICU.

METHODS

This prospective analysis examined all patients receiving IV insulin infusion after cardiothoracic surgery in a 1 month period. The analyses evaluated the safety and efficacy of a protocol using a transition to subcutaneous insulin glargine of 50% of the calculated 24 h requirement at the end of the ICU insulin infusion protocol in preparation for transfer to the RNF.

RESULTS

Only 1 patient in 99 developed hypoglycemia, and no patient suffered severe hypoglycemia (glucose < 40 mg/dl), while the majority (70%) had euglycemia (glucose between 70 and 150 mg/dl).

CONCLUSIONS

This approach was both safe-as there was very little hypoglycemia (1 patient in 99)-and effective, as blood sugar was well controlled in most subjects. Efficacy for achieving euglycemia was 70%. Efficacy was likely reduced because of the upper limit of insulin glargine dosage imposed by some providers as a safety consideration. Although there was a physician option to override, the maximum protocol dose of 30 U was rarely exceeded, leading to inadequate dosing in some subjects who required high insulin infusion rates in the ICU.

[Glycemic control in sepsis and septic shock: friend or foe?]

INTRODUCTION

Intensive care patients commonly suffer from hyperglycemia. Evidence is growing that strictly maintaining normoglycemia by intensive insulin therapy (IIT) ameliorates outcome in these patients. Whether or not this also holds true for patients with sepsis and septic shock is the issue of this post-hoc analysis of the database (2,748 patients) of 2 recent prospective clinical trials.

MATERIAL AND METHODS

A total of 950 patients suffering from sepsis were identified and of these 462 fulfilled the diagnostic criteria of septic shock upon admission to the intensive care unit (ICU). Patients were treated by either IIT [mean glycemia 5.88 mmol/l (106 mg/dl)] or conventional glucose management [mean glycemia 8.44 mmol/l (152 mg/dl)].

RESULTS

Under IIT the mortality of patients treated for more than 3 days in the ICU was lowered by 7.6% (p=0.03) in septic patients and by 8.7% (p=0.08) in septic shock patients. Polyneuropathy occurred less frequently under IIT compared to conventional glucose management (sepsis -9.8%, septic shock -14%; p<0.001). The incidence of acute renal failure was not affected by either treatment regimen (sepsis -3.3%, septic shock -3.1%; p<0.25). Intensive insulin therapy was associated with an increased risk of hypoglycemia (sepsis +16.7%, septic shock +18.8; p<0.0001) which did not, however, directly affect morbidity nor mortality.

CONCLUSIONS

These data suggest that IIT improves outcome of patients with sepsis or septic shock. Hypoglycemia is a frequent complication, but its clinical relevance remains to be defined.

Hyperglycemia is associated with morbidity in critically ill children with meningococcal sepsis

OBJECTIVE

To determine the association between hyperglycemia and outcome in children ventilated for meningococcal sepsis.

DESIGN

Retrospective case notes review.

SETTING

Eight bedded pediatric intensive care unit in London.

PATIENTS

Consecutive children ventilated for meningococcal sepsis 2001-2004.

INTERVENTIONS

None.

MEASUREMENTS

Peak glucose for the entire admission was determined and mean glucose was calculated for the following three epochs: 1) first 24 hrs, 2) second 24 hrs, and 3) the entire pediatric intensive care unit admission. Patients were also grouped according to whether their blood glucose rose to >7 mmol/L (126 mg/dL), >10 mmol/L (180 mg/dL), or remained below these levels during the pediatric intensive care unit admission. Outcome measures were predicted mortality (based on pediatric risk of mortality score), ventilator free days at 30 days, nosocomial infection, use of renal replacement therapy, use of inotropes, and skin necrosis.

MAIN RESULTS

Ninety-seven patients were identified with a median age of 2.1 yrs and a median length of stay of 4 days. Four patients died. Peak glucose significantly correlated with predicted mortality and negatively correlated with ventilator free days at 30 days (p < 0.001 and p < 0.001, respectively). Patients who received renal replacement therapy or inotropic support, or developed a nosocomial infection or skin necrosis had significantly higher peak glucose than those who did not (p = 0.006, p < 0.0001, p = 0.022, and p < 0.0001, respectively). Patients who received renal replacement therapy or who developed skin necrosis had significantly higher mean blood glucose in the second 24 hrs of admission (p = 0.017 and p = 0.004, respectively). However, mean blood glucose in the first 24 hrs and over the entire admission did not correlate with outcome. Patients defined as hyperglycemic with blood glucose either >7 mmol/L or >10 mmol/L also had a significantly worse outcome than those who maintained blood glucose below these levels.

CONCLUSIONS

There was a significant association between hyperglycemia and outcome. Our results support a trial of tight glycemic control in this group of critically ill children.

Intensive insulin therapy: enhanced Model Predictive Control algorithm versus standard care

OBJECTIVE

To investigate the effectiveness of an enhanced software Model Predictive Control (eMPC) algorithm for intravenous insulin infusion, targeted at tight glucose control in critically ill patients, over 72 h, in two intensive care units with different management protocols.

DESIGN

Comparison with standard care in a two center open randomized clinical trial.

SETTING

Two adult intensive care units in University Hospitals.

PATIENTS AND PARTICIPANTS

Thirty-four critically ill patients with hyperglycaemia (glucose >120 mg/dL) or already receiving insulin infusion.

INTERVENTIONS

Patients were randomized, within each ICU, to intravenous insulin infusion advised by eMPC algorithm or the ICU's standard insulin infusion administration regimen.

MEASUREMENTS AND RESULTS

Arterial glucose concentration was measured at study entry and when advised by eMPC or measured as part of standard care. Time-weighted average glucose concentrations in patients receiving eMPC advised insulin infusions were similar [104 mg/dL (5.8 mmol/L)] in both ICUs. eMPC advised glucose measurement interval was significantly different between ICUs (1.1 vs. 1.8 h, P < 0.01). The standard care insulin algorithms resulted in significantly different time-weighted average glucose concentrations between ICUs [128 vs. 99 mg/dL (7.1 vs. 5.5 mmol/L), P < 0.01].

CONCLUSIONS

In this feasibility study the eMPC algorithm provided similar, effective and safe tight glucose control over 72 h in critically ill patients in two different ICUs. Further development is required to reduce glucose sampling interval while maintaining a low risk of hypoglycaemia.

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.

Tight glucose control: should we move from intensive insulin therapy alone to modulation of insulin and nutritional inputs?

The report by Chase and coworkers in the previous issue of Critical Care describes the implementation into clinical practice of the Specialized Relative Insulin Nutrition Table (SPRINT) for tight glycaemic control in critically ill patients. SPRINT is a simple, wheel-based system that modulates both insulin rate and nutritional inputs. It achieved a better glycaemic control in a severely ill critical cohort than their previous method for glycaemic control in a matched historical cohort. Reductions in mortality were also observed.

Early versus late intravenous insulin administration in critically ill patients

OBJECTIVE

To investigate whether timing of intensive insulin therapy (IIT) after intensive care unit (ICU) admission influences outcome.

DESIGN AND SETTING

Single-center prospective cohort study in the 14-bed medical ICU of a 1,171-bed tertiary teaching hospital.

PATIENTS

The study included 127 patients started on ITT within 48 h of ICU admission (early group) and 51 started on ITT thereafter (late group); the groups did not differ in age, gender, race, BMI, APACHE III, ICU steroid use, admission diagnosis, or underlying comorbidities.

MEASUREMENTS AND RESULTS

The early group had more ventilator-free days in the first 28 days after ICU admission (median 12 days, IQR 0-24, vs. 1 day, 0-11), shorter ICU stay (6 days, IQR 3-11, vs. 11 days, vs. 7-17), shorter hospital stay (15 days, IQR 9-30, vs. 25 days, 13-43), lower ICU mortality (OR 0.48), and lower hospital mortality (OR 0.27). On multivariate analysis, early therapy was still associated with decreased hospital mortality (ORadj 0.29). The strength and direction of association favoring early IIT was consistent after propensity score modeling regardless of method used for analysis.

CONCLUSIONS

Early IIT was associated with better outcomes. Our results raise questions about the assumption that delayed administration of IIT has the same benefit as early therapy. A randomized study is needed to determine the optimal timing of therapy.

Effect of perioperative insulin infusion on surgical morbidity and mortality: systematic review and meta-analysis of randomized trials.7

OBJECTIVE

To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of perioperative insulin infusion on outcomes important to patients.

PATIENTS AND METHODS

We used 6 search strategies including an electronic database search of MEDLINE, EMBASE, and Cochrane CENTRAL, from their inception up to May 1, 2006, and included RCTs of perioperative insulin infusion (with or without glucose targets) measuring outcomes in patients undergoing any surgery. Pairs of reviewers working independently assessed the methodological quality and characteristics of included trials and abstracted data on perioperative outcomes (ie, outcomes that occurred during hospitalization or within 30 days of surgery).

RESULTS

We identified 34 eligible trials. In the 14 trials that assessed mortality, there were 68 deaths among 2192 patients randomized to insulin infusion compared with 98 deaths among 2163 patients randomized to control therapy (random-effects pooled relative risk, 0.69; 95% confidence interval [CI], 0.51-0.94; 99% CI, 0.46-1.04; I2, 0%; 95% CI, 0.0%-47.4%). Hypoglycemia increased in the intensively treated group (20 trials, 119/1470 patients in insulin infusion vs 48/1476 patients in control group; relative risk, 2.07; 95% CI, 1.29-3.32; 99% CI, 1.09-3.88; I2, 31.5%; 95% CI, 0.0%-59.0%). No significant effect was seen in any other outcomes. The available mortality data represent only 40% of the optimal information size required to reliably detect a plausible treatment effect; potential methodological and reporting biases weaken inferences.

CONCLUSION

Perioperative insulin infusion may reduce mortality but increases hypoglycemia in patients who are undergoing surgery; however, mortality results require confirmation in large and rigorous RCTs.

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.

Pharmacogenomics and end-organ susceptibility to injury in the perioperative period

Genomic medicine has provided new mechanistic understanding for many complex diseases over the last 5-10 years. More recently genomic approaches have been applied to the perioperative paradigm, facilitating identification of patients at high risk for adverse events, as well as those who will respond better/worse to specific pharmacologic therapies. The consistent biological theme emerging is that while inflammation is important in healing from surgical trauma, patients who are too robustly proinflammatory appear to be at higher risk for adverse perioperative events. Precise predictors of each adverse event are being elucidated so that corrective therapeutics can be instituted to improve outcomes in high-risk patients. While the field of perioperative genomics could be considered in its infancy, such approaches are the wave of the future.

Type B lactic acidosis and insulin-resistant hyperglycemia in an adolescent following cardiac surgery

OBJECTIVE

To report the presence of type B lactic acidosis and insulin-resistant hyperglycemia following cardiopulmonary bypass in a pediatric patient.

DESIGN

Case report.

SETTING

Tertiary referral children's hospital pediatric intensive care unit.

PATIENT

Fourteen-year-old child with hyperlactatemia and hyperglycemia following cardiac surgery.

INTERVENTIONS AND RESULTS

We report a patient who following cardiopulmonary bypass for repair of his congenital heart disease developed type B lactic acidosis and hyperglycemia resistant to insulin therapy. Resolution of his hyperlactatemia and hyperglycemia occurred approximately 24 hrs postoperatively without apparent ill effect.

CONCLUSIONS

Type B lactic acidosis is a phenomenon that may occur in the pediatric population in conjunction with insulin-resistant hyperglycemia. We observed that its resolution corresponded to improvement in the patient's hyperglycemia.

Causes and consequences of hyperglycemia in critical illness

PURPOSE OF REVIEW

This article reviews recent epidemiologic and intervention studies addressing the impact of hyperglycemia on morbidity and mortality in critically ill patients. It also discusses a growing body of literature examining why elevated blood glucose occurs in hospitalized patients without previously recognized diabetes.

RECENT FINDINGS

Hyperglycemia is highly prevalent in the intensive care unit. Numerous observational studies have demonstrated the association between hyperglycemia and adverse outcomes, independent of pre-existing diabetes. Intervention trials of insulin therapy are limited but overall demonstrate that glucose lowering significantly improves outcomes. The ideal target for blood glucose and the population that would benefit most from intervention remain controversial. Less frequently studied than the consequences, the causes of hyperglycemia occurring during critical illness remain unclear. Although glucose abnormalities in hospitalized patients have traditionally been explained by mediators of stress, a growing body of evidence has examined whether underlying defects in glucose metabolism may also be important contributors.

SUMMARY

In general, evidence suggests that hyperglycemia is a potentially correctable abnormality that has deleterious effects in critically ill individuals. Hyperglycemic patients without previously recognized diabetes appear to be particularly vulnerable, and thus further examination of the mechanisms underlying the development of elevated blood glucose is warranted.

Effect of nutritional support on glucose control

PURPOSE OF REVIEW

There is evidence that maintaining a normal glycemia level in critically ill patients has beneficial effects on outcome. Strategies aimed at lowering glycemia are based on the understanding of mechanisms regulating glucose metabolism.

RECENT FINDINGS

Activation of AMP protein kinase in skeletal muscle and in the liver leads to a reduction in glucose production, a stimulation of glucose uptake, and a lowering of glycemia. These mechanisms appear to be activated during exercise, or by the endogenous adipokine adiponectin. Alterations in adiponectin concentrations during critical illness may thus play a role in the metabolic stress responses. In addition, AMP-activated protein kinase is the target for drugs (metformin, thazolidinediones), which may be of interest in the intensive care unit. Besides insulin, plasma glucose concentrations may be lowered by hypocaloric feeding, or by feeding 'diabetic' formula with low glucose content and supplemented with fructose. Whether such approaches lead to beneficial effects comparable to those observed with insulin remains to be established.

SUMMARY

Recent findings regarding the molecular mechanisms underlying glucose transport and metabolism are summarized, and potential strategies other than insulin are outlined which may contribute to lowering glycemia in critically ill patients.

Practical aspects of intensive insulinization in the intensive care unit

PURPOSE OF REVIEW

Strategies used for intensive insulin therapy of critically ill patients and differences of approach according to medical condition are reviewed.

RECENT FINDINGS

Acceptance of proposed glycemic targets for critically ill patients has been tempered by uncertainties about benefit of strict glycemic control for specific target subpopulations, differences between treatment centers, optimal timing and duration of intervention, and safety. Present-day intravenous insulin infusion protocols may perform well only for restricted populations. Assessment of protocol performance requires knowledge of algorithm behavior on or near the narrow target range and, using the patient as unit of observation, examination of glycemic variability. Systems of the future will permit adjustment of algorithm parameters to meet individual- or population-specific targets and match carbohydrate exposure.

SUMMARY

Attainment and preservation of glycemic control among critically ill patients are best attempted with intravenous insulin infusion. Advances in the design of decision support and insulin delivery systems, and progress in the technology of continuous blood glucose monitoring, are likely to reduce the risk of hypoglycemia, without compromise of target range control, such that the patient outcomes enjoyed by experienced centers in the future will prove generalizable to others through the extension of new technologies.

Glycaemic control in critically ill patients with cardiovascular disease

PURPOSE OF REVIEW

The role of hyperglycaemia in the pathogenesis of myocardial damage during cardiac surgery or patients with acute coronary syndromes has been the subject of increasing interest over the past few years. Several further trials and meta-analyses investigating the role of insulin treatment, either aimed at tight control of blood glucose concentration or as part of a regimen including glucose and potassium, have been reported recently and are the subject of this review.

RECENT FINDINGS

Good control of blood glucose has been demonstrated to improve outcomes for diabetic patients undergoing cardiac surgery and following acute myocardial infarction. In surgical intensive care patients, tight glucose control improved mortality--a finding that is awaiting confirmation in multicentre studies. The use of glucose-insulin-potassium regimens does not improve outcomes in patients with acute myocardial infarction who have undergone reperfusion therapy, but may be beneficial during cardiac surgery.

SUMMARY

Tight control of blood glucose has been shown to be beneficial in several patient groups. The optimal target glucose concentration and glucose and insulin regimens remain to be confirmed or determined in each clinical situation.

Intensive insulin therapy in intensive care: an example of the struggle to implement evidence-based medicine

Schultz and colleagues discuss the factors hindering implementation of intensive insulin therapy.