What's new in glucose control in the ICU?

The Role of the Insulin/Glucose Ratio in the Regulation of Pathogen Biofilm Formation

During the management of patients in acute trauma the resulting transient hyperglycemia is treated by administration of insulin. Since the effect of insulin, a quorum sensing compound, together with glucose affects biofilm formation in a concentration-specific manner, we hypothesize that the insulin/glucose ratio over the physiologic range modulates biofilm formation potentially influencing the establishment of infection through biofilm formation.

METHODS

A variety of Gram-positive and Gram-negative bacteria were grown in peptone (1%) yeast nitrogen base broth overnight in 96-well plates with various concentrations of glucose and insulin. Biofilm formation was determined by the crystal violet staining procedure. Expression of insulin binding was determined by fluorescent microscopy (FITC-insulin). Controls were buffer alone, insulin alone, and glucose alone.

RESULTS

Overall, maximal biofilm levels were measured at 220 mg/dL of glucose, regardless of insulin concentration (10, 100, 200 µU/mL) of the organism tested. In general, insulin with glucose over the range of 160-180 mg/dL exhibited a pattern of biofilm suppression. However, either above or below this range, the presence of insulin in combination with glucose significantly modulated (increase or decrease) biofilm formation in a microbe-specific pattern. This modulation appears for some organisms to be reflective of the glucose-regulated intrinsic expression of bacterial insulin receptor expression.

CONCLUSION

Insulin at physiologic levels (normal and hyperinsulinemic) in combination with glucose can affect biofilm formation in a concentration-specific and microbe-specific manner. These findings may provide insight into the importance of co-regulation of the insulin/glucose ratio in patient management.

Blood glucose control in the intensive care unit: Where is the data?

Blood glucose control, including hyperglycemia correction, maintaining glucose at optimal level and avoiding hypoglycemia, is a challenge clinicians face every day in intensive care units (ICUs). If managed inadequately, its related mortality can increase. Prior to 2001, no relevant data from randomized, controlled studies assessing glucose control in the ICU were available. In the past 18 years, however, many clinical trials have defined criteria for managing abnormal blood glucose levels, as well as provided suggestions for glycemic monitoring. Point-of-care blood glucose monitors have become the preferred bedside technology to aid in glycemic management. In addition, in some institutions, continuous glucose monitoring is now available. Cost-effectiveness of adequate glycemic control in the ICU must be taken into consideration when addressing this complex issue. Newer types of glycemic monitoring may reduce nursing staff fatigue and shorten times for the treatment of hyperglycemia or hypoglycemia. There are a variety of glycemic care protocols available. However, not all ICU clinicians are aware of them. The following minireview describes some of these concepts.

Insulin therapy in organ donation and transplantation

Hyperglycaemia is common in hospitalized individuals, and is often caused by physiological stress associated with critical illness or major surgery. Insulin therapy is an established treatment for hyperglycaemia and acute hyperkalaemia, and has also been used for myocardial dysfunction resistant to inotropic support. Insulin is commonly used in both organ donors and transplant recipients for hyperglycaemia, but the underlying knowledge base supporting its use remains limited. Insulin therapy plays an important yet poorly understood role in both organ donation and transplantation. Tight glycaemic control has been extensively studied in critical care over the past 15 years; however, this has not yet translated into the field of transplantation, where patients are more unwell and where improved outcomes remain an ongoing challenge. Insulin therapy and optimization of glycaemic control represent important areas for future hypothesis-driven research into organ donation and transplantation, such as amelioration of ischaemia-reperfusion injury, rejection and infection.

Pathophysiological changes after lipopolysaccharide-induced acute inflammation in a type 2 diabetic rat model versus normal controls

AIMS

The present study aimed to explore the mechanism of a potential beneficial effect of pre-existing diabetes in acute hyperglycemia during critical illness.

METHODS

Pathophysiological changes including blood glucose variability, changes of inflammatory and oxidative stress responses after lipopolysaccharide (LPS)-induced acute infection were compared between type 2 diabetic rat model (GK rats) and normal controls (Wistar rats).

RESULTS

After LPS injection, Wistar rats showed serious infective symptoms while GK rats did not. Blood glucose (BG) levels were significantly elevated in both GK and Wistar rats; however, compared to Wistar rats, GK rats had lower BG variability, smaller increases in the serum tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels, a larger increase in the serum IL-10 level, and a smaller decrease in the IκB-α protein level of lung tissue. Serum malondialdehyde (MDA) levels increased and serum total antioxidant capacity (T-AOC) levels decreased for both GK and Wistar rats.

CONCLUSIONS

We found diabetes was associated with adaptive changes at the cellular level that might actually be protective in acute hyperglycemia-mediated damage during sepsis. Chronic exposure to hyperglycemia potentially reduced the acute deleterious effects of acute hyperglycemia on septic mortality by decreasing BG variability, blunting the pro-inflammatory response and elevating the anti-inflammatory response.

Prevention of acute kidney injury and protection of renal function in the intensive care unit: update 2017 : Expert opinion of the Working Group on Prevention, AKI section, European Society of Intensive Care Medicine

BACKGROUND

Acute kidney injury (AKI) in the intensive care unit is associated with significant mortality and morbidity.

OBJECTIVES

To determine and update previous recommendations for the prevention of AKI, specifically the role of fluids, diuretics, inotropes, vasopressors/vasodilators, hormonal and nutritional interventions, sedatives, statins, remote ischaemic preconditioning and care bundles.

METHOD

A systematic search of the literature was performed for studies published between 1966 and March 2017 using these potential protective strategies in adult patients at risk of AKI. The following clinical conditions were considered: major surgery, critical illness, sepsis, shock, exposure to potentially nephrotoxic drugs and radiocontrast. Clinical endpoints included incidence or grade of AKI, the need for renal replacement therapy and mortality. Studies were graded according to the international GRADE system.

RESULTS

We formulated 12 recommendations, 13 suggestions and seven best practice statements. The few strong recommendations with high-level evidence are mostly against the intervention in question (starches, low-dose dopamine, statins in cardiac surgery). Strong recommendations with lower-level evidence include controlled fluid resuscitation with crystalloids, avoiding fluid overload, titration of norepinephrine to a target MAP of 65-70 mmHg (unless chronic hypertension) and not using diuretics or levosimendan for kidney protection solely.

CONCLUSION

The results of recent randomised controlled trials have allowed the formulation of new recommendations and/or increase the strength of previous recommendations. On the other hand, in many domains the available evidence remains insufficient, resulting from the limited quality of the clinical trials and the poor reporting of kidney outcomes.

Effects of short-term manipulation of serum FFA concentrations on left ventricular energy metabolism and function in patients with heart failure: no association with circulating bio-markers of inflammation

BACKGROUND AND AIMS

We wanted to assess the effects of short-term changes in serum free fatty acids (FFAs) on left ventricular (LV) energy metabolism and function in patients with heart failure and whether they correlated with circulating markers of inflammation.

METHODS AND RESULTS

LV function and phosphocreatine (PCr)/ATP ratio were assessed using MR imaging (MRI) and 31P magnetic resonance spectroscopy (MRS) in 11 men with chronic heart failure in two experimental conditions 7 days apart. Study 1: MRI and 31P-MRS were performed before and 3-4 h after i.v. bolus + continuous heparin infusion titrated to achieve a serum FFA concentration of 1.20 mM. Study 2: The same protocol was performed before and after the oral administration of acipimox titrated to achieve a serum FFA concentration of 0.20 mM. Serum concentrations of IL6, TNF-α, PAI-1, resistin, visfatin and leptin were simultaneously assessed. Serum glucose and insulin concentrations were not different between studies. The PCr/ATP ratio (percent change from baseline: +6.0 ± 16.9 and -16.6 ± 16.1 % in Study 1 and Study 2, respectively; p = 0.005) and the LV ejection fraction (-1.5 ± 4.0 and -6.9 ± 6.3 % in Study 1 and Study 2, respectively; p = 0.044) were reduced during low FFA when compared to high FFA. Serum resistin was higher during Study 1 than in Study 2 (p < 0.05 repeated measures ANOVA); meanwhile, the other adipocytokines were not different.

CONCLUSION

FFA deprivation, but not excess, impaired LV energy metabolism and function within hours. Cautions should be used when sudden iatrogenic modulation of energy substrates may take place in vulnerable patients.

Admission blood glucose helps predict 1 year, but not 2 years, mortality in an unselected cohort of acute general medical admissions

AIM

We previously showed that hyperglycaemia in newly hospitalised medical inpatients is associated with longer length of hospital stay, higher 28-day readmission rates and increased 28-day mortality. We aimed to assess whether a single blood glucose measurement taken at the time of admission could help to predict 1 and 2 years mortality.

METHODS

We retrospectively reviewed data from all 1502 patients admitted to our Acute Medical Unit during February 2010.

RESULTS

By using a blood glucose range of 6.5-7.0 mmol/l as the comparator, an admission blood glucose between 9.1 and 20 mmol/l was associated with an increased risk of death at 1 year (p < 0.05). In addition, those people with admission glucose readings of < 6.5 mmol/l showed a strong trend towards a higher mortality (p = 0.053) at 1 year.

CONCLUSION

Thus admission blood glucose can be used to help predict the risk of 1 year mortality in an unselected cohort of general medical admissions.

Hyper/hypoglycemia and acute kidney injury in critically ill patients

BACKGROUND & AIMS

Abnormalities of blood glucose (BG) concentration (hyper- and hypoglycemia), now referred to with the cumulative term of dysglycemia, are frequently observed in critically ill patients, and significantly affect their clinical outcome. Acute kidney injury (AKI) may further complicate glycemic control in the same clinical setting. This narrative review was aimed at describing the pathogenesis of hyper- and hypoglycemia in the intensive care unit (ICU), with special regard to patients with AKI. Moreover, the complex relationship between AKI, glycemic control, hypoglycemic risk, and outcomes was analyzed.

METHODS

An extensive literature search was performed, in order to identify the relevant studies describing the epidemiology, pathogenesis, treatment and outcome of hypo- and hyperglycemia in critically ill patients with AKI.

RESULTS AND CONCLUSION

Patients with AKI are at increased risk of both hyper-and hypoglycemia. The available evidence does not support a protective effect on the kidney by glycemic control protocols employing Intensive Insulin Treatment (IIT), i.e. those aimed at maintaining normal BG concentrations (80-110 mg/dl). Recent guidelines taking into account the high risk for hypoglycemia associated with IIT protocols in critically ill patients, now suggest higher BG concentration targets (<180 mg/dl or 140-180 mg/dl) than those previously recommended (80-110 mg/dl). Notwithstanding the limited evidence available, it seems reasonable to extend these indications also to ICU patients with AKI.

The clinical value of whole blood point-of-care biomarkers in large animal emergency and critical care medicine

OBJECTIVE

To summarize the current medical literature and provide a clinical perspective of whole blood point-of-care (POC) biomarkers in large animal emergency and critical care practice.

DATA SOURCES

Original studies, reviews, and textbook chapters in the human and veterinary medical fields.

SUMMARY

POC biomarkers are tests used to monitor normal or disease processes at or near the patient. In both human and veterinary medicine these tools are playing an increasingly important role in the management of critical diseases. The most important whole blood POC biomarkers available for veterinary practitioners include l-lactate, cardiac troponin I, serum amyloid A, triglyceride, creatinine, and glucose, although many other tests are available or on the horizon.

CONCLUSION

Whole blood POC biomarkers enable clinicians to provide improved management of critical diseases in large animals. These tools are especially useful for establishing a diagnosis, guiding therapy, and estimating disease risk and prognosis.

Recent advances in multidisciplinary critical care

The intensive care unit is a work environment where superior dedication is crucial for optimizing patients' outcomes. As this demanding commitment is multidisciplinary in nature, it requires special qualities of health care workers and organizations. Thus research in the field covers a broad spectrum of activities necessary to deliver cutting-edge care. However, given the numerous research articles and education activities available, it is difficult for modern critical care clinicians to keep up with the latest progress and innovation in the field. This article broadly summarizes new developments in multidisciplinary intensive care. It provides elementary information about advanced insights in the field via brief descriptions of selected articles grouped by specific topics. Issues considered include care for heart patients, mechanical ventilation, delirium, nutrition, pressure ulcers, early mobility, infection prevention, transplantation and organ donation, care for caregivers, and family matters.

Short acting insulin analogues in intensive care unit patients

Blood glucose control in intensive care unit (ICU) patients, addressed to actively maintain blood glucose concentration within defined thresholds, is based on two major therapeutic interventions: to supply an adequate calories load and, when necessary, to continuously infuse insulin titrated to patients needs: intensive insulin therapy (IIT). Short acting insulin analogues (SAIA) have been synthesized to improve the chronic treatment of patients with diabetes but, because of the pharmacokinetic characteristics that include shorter on-set and off-set, they can be effectively used also in ICU patients and have the potential to be associated with a more limited risk of inducing episodes of iatrogenic hypoglycemia. Medical therapies carry an intrinsic risk for collateral effects; this can be more harmful in patients with unstable clinical conditions like ICU patients. To minimize these risks, the use of short acting drugs in ICU patients have gained a progressively larger room in ICU and now pharmaceutical companies and researchers design drugs dedicated to this subset of medical practice. In this article we report the rationale of using short acting drugs in ICU patients (i.e., sedation and treatment of arterial hypertension) and we also describe SAIA and their therapeutic use in ICU with the potential to minimize iatrogenic hypoglycemia related to IIT. The pharmacodynamic and pharmachokinetic characteristics of SAIA will be also discussed.

Glycaemic control and long-term outcomes following transition from modified intensive insulin therapy to conventional glycaemic control

This retrospective observational cohort study compared glycaemic control and long-term outcomes following transition from a modified intensive insulin therapy (mIIT) regimen to conventional glycaemic control (CGC) in adult patients admitted to a tertiary adult general intensive care unit, during two 24-month periods, before and after the publication of the Normoglycemia in Intensive Care Evaluation and Surviving Using Glucose Algorithm Regulation (NICE-SUGAR) trial. The before NICE-SUGAR cohort received mIIT (target glycaemic ranges 4.4 to 7.0 mmol/l), while the after NICE-SUGAR cohort received CGC (target glycaemic range 7.1 to 9.0 mmol/l). A total of 5202 patients were included in the study. With transition from mIIT to CGC, the mean time-weighted glucose increased from 6.94 mmol/l to 8.2 mmol/l (P <0.0001). A similar increase was observed in other glycaemic indices (mean, highest and lowest glucose values, P <0.0001 for all). The adjusted 90-day odds ratio for mortality decreased by 47% with transition from mIIT to CGC (odds ratio 1.47 (95% confidence interval, 1.22 to 1.78) (P <0.0001). The rate of severe and moderate hypoglycaemia also decreased from 1.2 to 0.4% (P=0.004) and from 23.3 to 5.9% (P <0.0001), respectively. mIIT was associated with an increased risk of moderate and severe hypoglycaemia compared to CGC (odds ratio 3.1 (1.51 to 6.39) (P=0.002), 6.29 (5.1 to 7.75) (P <0.0001)). Changes in recommended glycaemic control were translated into practice, with increased glycaemic indices and decreased rates of severe and moderate hypoglycaemia after the introduction of CGC. The associated decrease in 90-day mortality suggests mIIT was not superior to CGC, despite a lower hypoglycaemia rate than in previous IIT trials. Our findings support the continued use of CGC.

Tight computerized versus conventional glucose control in the ICU: a randomized controlled trial

PURPOSE

The blood glucose target range and optimal method to reach this range remain a matter of debate in the intensive care unit (ICU). A computer decision support system (CDSS) might improve the outcome of ICU patients through facilitation of a tighter blood glucose control.

METHODS

We conducted a multi-center randomized trial in 34 French ICU. Adult patients expected to require treatment in the ICU for at least 3 days were randomly assigned without blinding to undergo tight computerized glucose control with the CDSS (TGC) or conventional glucose control (CGC), with blood glucose targets of 4.4-6.1 and <10.0 mmol/L, respectively. The primary outcome was all-cause death within 90 days after ICU admission.

RESULTS

Of the 2,684 patients who underwent randomization to the TGC and CGC treatment groups, primary outcome was available for 1,335 and 1,311 patients, respectively. The baseline characteristics of these treatment groups were similar in terms of age (61 ± 16 years), SAPS II (51 ± 19), percentage of surgical admissions (40.0%) and proportion of diabetic patients (20.3%). A total of 431 (32.3%) patients in the TGC group and 447 (34.1%) in the CGC group had died by day 90 (odds ratio for death in the TGC 0.92; 95% confidence interval 0.78-1.78; p = 0.32). Severe hypoglycemia (<2.2 mmol/L) occurred in 174 of 1,317 patients (13.2%) in the TGC group and 79 of 1,284 patients (6.2%) in the CGC group (p < 0.001).

CONCLUSIONS

Tight computerized glucose control with the CDSS did not significantly change 90-day mortality and was associated with more frequent severe hypoglycemia episodes in comparison with conventional glucose control.