Range Of Blood Glucose Concentrations Research Articles

Engineering of graphene-based composites with hexagonal boron nitride and PEDOT:PSS for sensing applications.

A unique nanomaterial has been developed for sweat analysis, including glucose level monitoring. Simple resusable low-cost sensors from composite materials based on graphene, hexagonal boron nitride, and conductive PEDOT:PSS (poly(3,4-ethylenedioxythiophene)polystyrene sulfonate) polymer have been developed and fabricated via 2D printing on flexible substrates. The sensors were tested as biosensors using different water-based solutions. A strong increase in the current response (several orders of magnitude) was observed for aqua vapors or glucose solution vapors. This property is associated with the sorption capacity of graphene synthesized in a volume of plasma jets and thus having many active centers on the surface. The structure and properties of graphene synthesized in a plasma are different from those of graphene created by other methods. As a result, the current response for a wearable sensor is 3-5 orders of magnitude higher for the reference blood glucose concentration range of 4-14 mM. It has been found that the most promising sensor with the highest response was fabricated based on the graphene:PEDOT:PSS composite. The graphene:h-BN:PEDOT:PSS (h-BN is hexagonal boron nitride) sensors demonstrated a longer response and the highest response after the functionalization of the sensors with a glucose oxidase enzyme. The reusable wearable graphene:PEDOT:PSS glucose sensors on a paper substrate demonstrated a current response of 10-10 to 10-5 A for an operating voltage of 0.5 V and glucose range of 4-10 mM.

Mesoporous Silica-Based Metal Oxide Electrode for a Nonenzymatic Glucose Sensor at a Physiological pH.

To construct an electrochemical biosensing platform, we propose a glucose sensor whose electrode interface was modified by mesoporous silica (MPSi) as an electronic signal transmission interface between a biomarker and an electrochemical device. We develop an enzyme-free glucose sensor using an MPSi-coated Ta2O5 electrode in an actual biological fluid such as blood serum. MPSi includes a phenylboronic acid (PBA) molecule, in which glucose binds to a synthesized PBA-silane compound in an ca. 150 nm thick MPSi nanolayer, which changes the density of molecular charges of the PBA/glucose complex on the surface of MPSi. The charge changes derived from the equilibrium reaction of PBA with glucose lead to changes in surface potential of the Ta2O5 electrode, and the surface potential changes depending on glucose concentration were measured by a potentiometric detector. As a result, a remarkable surface potential response was observed in the vicinity of neutral pH. Kd = 6.0 mM and Vmax = 194 mV were obtained from the fitting curve of the Langmuir adsorption isotherm. Finally, we confirmed the glucose response of the PBA-MPSi-coated Ta2O5 substrate in human serum by considering the influence of various contaminants. Although the surface potential change was suppressed by approximately one-third of that in the buffer system, it was suggested that it could be applied to measurements in the blood glucose concentration range. From the results of this study, it was clarified that blood-level glucose response could be monitored using a PBA-MPSi-coated Ta2O5 substrate, which suggests the possibility of using a nonenzymatic glucose sensor as an alternative to the existing enzyme sensor.

Noninvasive in vivo glucose detection in human finger interstitial fluid using wavelength-modulated differential photothermal radiometry.

We present a noninvasive and noncontacting biosensor using Wavelength Modulated Differential Photothermal Radiometry (WM-DPTR) to monitor blood glucose concentration (BGC) through interstitial fluid (ISF) probing in human middle fingers. WM-DPTR works in the interference-free mid-infrared range with differential wavelengths at the peak and baseline of the fundamental glucose molecule absorption band, giving rise to high glucose sensitivity and specificity. In vivo WM-DPTR measurements and simultaneous finger pricking BGC reference measurements were performed on diabetic and nondiabetic volunteers during oral glucose tolerance testing. The measurement results demonstrated high resolution and large dynamic range (~80 deg) change in phase signal in the normal-to-hyperglycemia BGC range (5 mmol/L to higher than 33.2 mmol/L), which were supported by negative control measurements. The immunity to temperature variation of WM-DPTR yields precise and accurate noninvasive glucose measurements in the ISF.

A Noninvasive Measurement of Blood Glucose Concentration by UWB Microwave Spectrum

A noninvasive blood glucose measurement method based on ultrawideband (UWB) microwave detecting technique is proposed for monitoring the patients' blood glucose level. With this method, a noninvasive measurement for the blood glucose determination can be realized by analyzing the received UWB microwave signals. This method is very convenient and is harmless to the patients. The time-frequency features are used to analyze the received signals. The correctness of the method is testified by successfully obtaining the regularity of the energy of the received signals with the range of blood glucose concentration 0-4000 mg/dl in the dispersion case of the configuration. The reliability of the method is also confirmed by obtaining the regularity of the energy of experimental signals at 6.5 GHz for the realistic earlobe phantom with the step of 50 mg/dl in the range of human blood glucose concentration 0-400 mg/dl. The results verify the sensitivity and efficiency of this method.

Discrete Blood Glucose Control in Diabetic Göttingen Minipigs

Despite continuous research effort, patients with type 1 diabetes mellitus (T1D) experience difficulties in daily adjustments of their blood glucose concentrations. New technological developments in the form of implanted intravenous infusion pumps and continuous blood glucose sensors might alleviate obstacles for the automatic adjustment of blood glucose concentration. These obstacles consist, for example, of large time-delays and insulin storage effects for the subcutaneous/interstitial route. Towards the goal of an artificial pancreas, we present a novel feedback controller approach that combines classical loop-shaping techniques with gain-scheduling and modern H ∞ -robust control approaches. A disturbance rejection design is proposed in discrete frequency domain based on the detailed model of the diabetic Göttingen minipig. The model is trimmed and linearised over a large operating range of blood glucose concentrations and insulin sensitivity values. Controller parameters are determined for each of these operating points. A discrete H ∞ loop-shaping compensator is designed to increase robustness of the artificial pancreas against general coprime factor uncertainty. The gain scheduled controller uses subcutaneous insulin injection as a control input and determines the controller input error from intravenous blood glucose concentration measurements, where parameter scheduling is achieved by an estimator of the insulin sensitivity parameter. Thus, only one controller stabilises a family of animal models. The controller is validated in silico with a total number of five Göttingen Minipig models, which were previously obtained by experimental identification procedures. Its performance is compared with an experimentally tested switching PI-controller.

Metaheuristic Patient Estimation Based Patient-Specific Fuzzy Aggregated Artificial Pancreas Design

Patient-specific artificial pancreas design has been receiving increasing attention lately. In this article, using the chaotic bat algorithm (CBA), Hovorka–Wilinska (H–W) model parameters are estimated from nominal H–W virtual patient data. Using this identified H–W model for the virtual patient, multiple empirical second-order plus delay time (SOPDT) models representing glucose–insulin dynamics are derived for the range of blood glucose concentrations (BGCs) considered. Clustering of these models using the k-means algorithm yields three distinct clusters. Implicitly enumerated multiparametric model predictive controllers (mpMPCs) are designed using the cluster representatives. A fuzzy logic aggregation (FLA) of prediction and control improves the design parsimony. An insulin on board (IOB) safety trigger is designed using FLA of multiple full-order linearized CBA-estimated H–W models. The FLA-based mpMPC along with IOB and meal estimation are implemented on an embedded platform and by hardware-in-the-loo...

Nutrition Support Team-Led Glycemic Control Program for Critically Ill Patients.

Glycemic control is an important component of the metabolic management of the critically ill patient. Nutrition support teams are frequently challenged by complicated patients who exhibit multiple concurrent etiologies for hyperglycemia. Nutrition support teams can serve in a pivotal role in the development and evaluation of safe and effective techniques for achieving glycemic control. This review describes the efforts of a nutrition support team in achieving safe and effective glycemic control at their institution. Identification of target blood glucose concentration range, development, initiation, monitoring of a continuous intravenous insulin infusion algorithm, nursing adherence to the algorithm, modification of the algorithm based on the presence of conditions that alter insulin metabolism and glucose homeostasis, and transition of the patient who receives continuous enteral nutrition from a continuous intravenous insulin infusion to intermittent subcutaneous insulin therapy are discussed.

Evaluation of enzyme-based tear glucose electrochemical sensors over a wide range of blood glucose concentrations

Miniature enzyme-based amperometric and coulometric glucose sensors were fabricated and applied to measure tear glucose concentrations in anesthetized rabbits. Without perturbing the eyeball, 3µL of tear fluid was sampled from the marginal conjunctiva under the lower eyelid of anesthetized rabbits at various time points via a microliter glass capillary tube, and the miniature sensors were then inserted into the volume of collected tear fluids within the capillaries for detection. Intravenous bolus doses of insulin were administrated to the rabbits to lower the elevated blood glucose concentrations caused by anesthesia over the 7h test periods. A significant correlation was found between tear and blood glucose levels for multiple rabbits, suggesting that electrochemical sensor-based tear glucose measurements may be a potential supplementary method for point-of-care glucose monitoring.

Microfluidic fabrication of monodisperse microcapsules for glucose-response at physiological temperature

Hydrogel-based hollow microcapsules with good monodispersity and repeated glucose-response under physiological temperature and glucose concentration conditions have been fabricated by a simple emulsion-template approach. Double emulsions from microfluidic devices are used as templates to synthesize the monodisperse glucose-responsive microcapsules. In the poly(N-isopropylacrylamide-co-3-aminophenylboronic acid-co-acrylic acid) (P(NIPAM-co-AAPBA-co-AAc)) hydrogel shell of the microcapsules, the thermo-responsive PNIPAM network and the glucose-responsive AAPBA moiety are respectively used for actuation and glucose response, and the AAc moiety is used for adjusting the volume phase transition temperature of the shell. Glucose-responsive microcapsules prepared with 2.4 mol% AAc exhibit reversible and repeated swelling/shrinking response to glucose concentration changes within the physiological blood glucose concentration range (0.4–4.5 g L−1) at 37 °C. Rhodamine B and fluorescein-isothiocyanate-labeled insulin are used as model molecules and model drugs to demonstrate the potential application of the microcapsules for glucose-responsive controlled release. The microcapsules provide a promising and feasible model for developing glucose-responsive sensors and self-regulated delivery systems for diabetes and cancer therapy. Moreover, the microfluidic fabrication approach and research results presented here provide valuable guidance for the design and fabrication of monodisperse glucose-responsive microcapsules.

Improving IV Insulin Administration in a Community Hospital

Diabetes mellitus is a major independent risk factor for increased morbidity and mortality in the hospitalized patient, and elevated blood glucose concentrations, even in non-diabetic patients, predicts poor outcomes. The 2008 consensus statement by the American Association of Clinical Endocrinologists (AACE) and the American Diabetes Association (ADA) states that "hyperglycemia in hospitalized patients, irrespective of its cause, is unequivocally associated with adverse outcomes." It is important to recognize that hyperglycemia occurs in patients with known or undiagnosed diabetes as well as during acute illness in those with previously normal glucose tolerance. The Normoglycemia in Intensive Care Evaluation-Survival Using Glucose Algorithm Regulation (NICE-SUGAR) study involved over six thousand adult intensive care unit (ICU) patients who were randomized to intensive glucose control or conventional glucose control. Surprisingly, this trial found that intensive glucose control increased the risk of mortality by 14% (odds ratio, 1.14; p = 0.02). In addition, there was an increased prevalence of severe hypoglycemia in the intensive control group compared with the conventional control group (6.8% vs. 0.5%, respectively; p < 0.001). From this pivotal trial and two others, Wyoming Medical Center (WMC) realized the importance of controlling hyperglycemia in the hospitalized patient while avoiding the negative impact of resultant hypoglycemia. Despite multiple revisions of an IV insulin paper protocol, analysis of data from usage of the paper protocol at WMC shows that in terms of achieving normoglycemia while minimizing hypoglycemia, results were suboptimal. Therefore, through a systematical implementation plan, monitoring of patient blood glucose levels was switched from using a paper IV insulin protocol to a computerized glucose management system. By comparing blood glucose levels using the paper protocol to that of the computerized system, it was determined, that overall, the computerized glucose management system resulted in more rapid and tighter glucose control than the traditional paper protocol. Specifically, a substantial increase in the time spent within the target blood glucose concentration range, as well as a decrease in the prevalence of severe hypoglycemia (BG < 40 mg/dL), clinical hypoglycemia (BG < 70 mg/dL), and hyperglycemia (BG > 180 mg/dL), was witnessed in the first five months after implementation of the computerized glucose management system. The computerized system achieved target concentrations in greater than 75% of all readings while minimizing the risk of hypoglycemia. The prevalence of hypoglycemia (BG < 70 mg/dL) with the use of the computer glucose management system was well under 1%.

Improving IV Insulin Administration in a Community Hospital

Diabetes mellitus is a major independent risk factor for increased morbidity and mortality in the hospitalized patient, and elevated blood glucose concentrations, even in non-diabetic patients, predicts poor outcomes.1-4 The 2008 consensus statement by the American Association of Clinical Endocrinologists (AACE) and the American Diabetes Association (ADA) states that "hyperglycemia in hospitalized patients, irrespective of its cause, is unequivocally associated with adverse outcomes."5 It is important to recognize that hyperglycemia occurs in patients with known or undiagnosed diabetes as well as during acute illness in those with previously normal glucose tolerance. The Normoglycemia in Intensive Care Evaluation-Survival Using Glucose Algorithm Regulation (NICE-SUGAR) study involved over six thousand adult intensive care unit (ICU) patients who were randomized to intensive glucose control or conventional glucose control.6 Surprisingly, this trial found that intensive glucose control increased the risk of mortality by 14% (odds ratio, 1.14; p=0.02). In addition, there was an increased prevalence of severe hypoglycemia in the intensive control group compared with the conventional control group (6.8% vs. 0.5%, respectively; p<0.001). From this pivotal trial and two others,7,8 Wyoming Medical Center (WMC) realized the importance of controlling hyperglycemia in the hospitalized patient while avoiding the negative impact of resultant hypoglycemia. Despite multiple revisions of an IV insulin paper protocol, analysis of data from usage of the paper protocol at WMC shows that in terms of achieving normoglycemia while minimizing hypoglycemia, results were suboptimal. Therefore, through a systematical implementation plan, monitoring of patient blood glucose levels was switched from using a paper IV insulin protocol to a computerized glucose management system. By comparing blood glucose levels using the paper protocol to that of the computerized system, it was determined, that overall, the computerized glucose management system resulted in more rapid and tighter glucose control than the traditional paper protocol. Specifically, a substantial increase in the time spent within the target blood glucose concentration range, as well as a decrease in the prevalence of severe hypoglycemia (BG < 40 mg/dL), clinical hypoglycemia (BG < 70 mg/dL), and hyperglycemia (BG > 180 mg/dL), was witnessed in the first five months after implementation of the computerized glucose management system. The computerized system achieved target concentrations in greater than 75% of all readings while minimizing the risk of hypoglycemia. The prevalence of hypoglycemia (BG < 70 mg/dL) with the use of the computer glucose management system was well under 1%.

Altered blood glucose concentration is associated with risk of death among patients with community-acquired Gram-negative rod bacteremia

BackgroundAltered blood glucose concentration is commonly observed in patients with sepsis, even among those without hypoglycemic treatments or history of diabetes mellitus. These alterations in blood glucose are potentially detrimental, although the precise relationship with outcome in patients with bacteremia has not been yet determined.MethodsA retrospective cohort study design for analyzing patients with Gram negative rod bacteremia was employed, with the main outcome measure being in-hospital mortality. Patients were stratified in quintiles accordingly deviation of the blood glucose concentration from a central value with lowest mortality. Cox proportional-hazards regression model was used for determining the relationship of same day of bacteremia blood glucose and death.ResultsOf 869 patients identified 63 (7.4%) died. Same day of bacteremia blood glucose concentration had a U-shaped relationship with in-hospital mortality. The lowest mortality (2%) was detected in the range of blood glucose concentration from 150 to 160 mg/dL. Greater deviation of blood glucose concentration from the central value of this range (155 mg/dL, reference value) was directly associated with higher risk of death (p = 0.002, chi for trend). The low-risk group (quintile 1) had a mortality of 3.3%, intermediate-risk group (quintiles 2, 3 and 4) a mortality of 7.1%, and the high-risk group (quintile 5) a mortality of 12.05%. In a multivariable Cox regression model, the hazard ratio for death among patients in the intermediate-risk group as compared with that in the low risk group was 2.88 (95% confidence interval, 1.01 to 8.18; P = 0.048), and for the high risk group it was 4.26 (95% confidence interval, 1.41 to 12.94; P = 0.01).ConclusionsSame day of bacteremia blood glucose concentration is related with outcome of patients with Gram-negative rod bacteremia. Lowest mortality is detected in patients with blood glucose concentration in an interval of 150-160 mg/dL. Deviations from these values are associated with an increased risk of death.

Performance of the Ascensia ENTRUST glucose meter for determination of blood glucose concentration in rats

The Ascensia ENTRUST blood glucose meter is intended for self-monitoring of blood glucose by diabetic patients. Use of such a glucometer would minimize blood volume requirements for the measurement of glucose in small laboratory animals. The purpose of this study was to assess the performance of the Ascensia ENTRUST for measuring glucose in whole blood from Wistar rats by evaluating the effect of anticoagulant and sample processing delay and comparing normalized results with plasma glucose concentration. Blood samples were collected from the retroorbital sinus of 30 male Wistar rats with a wide range of blood glucose concentrations. Glucose concentration was measured with the Ascensia ENTRUST in nonheparinized (NH) and heparinized samples immediately after collection (Hep-0) and in heparinized samples after a 15 min delay at 23-28 degrees C (Hep-15). Heparinized samples were centrifuged and glucose concentration was determined in plasma using an automated chemistry analyzer. Results were compared to assess the effect of anticoagulant (NH vs Hep-0) and time (Hep 0 vs Hep 15), and to compare normalized Hep-15 results with plasma glucose concentration. Glucose concentration was not significantly different between NH and Hep-0 samples. Glucose concentration was lower in Hep-15 (77+/-36.9 mg/dL) than Hep-0 (88+/-39.7 mg/dL) samples, but the difference was not significant. With normalization, Hep-15 glucose concentration correlated well (r>or=.98) with plasma glucose concentration but was lower by 6.0+/-16.7 mg/dL, with a positive bias at low glucose concentrations and a negative bias at high concentrations. The Ascensia ENTRUST may be adequate for repeated blood glucose measurements in rats, but its results do not accurately predict plasma glucose concentrations measured by an automated clinical chemistry analyzer.

Glycemic Control during Critical Illness: Tight or Not?

Nutrition Support Pharmacist features issues pertinent to the practice of clinical pharmacy in the area of metabolic support. In this review, a critical analysis of six current major intensive insulin therapy trials (Leuven I, Leuven II, Leuven III, NICE-SUGAR, VISEP, and Glucontrol) for critically ill surgical and medical patients is provided. Practical suggestions for managing hyperglycemia, defining an effective target blood glucose concentration range, avoiding hypoglycemia, and designing a safe and effective insulin infusion algorithm are given.

Scientific Knowledge Gaps and Clinical Research Priorities for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Identified During the 2005 International Consensus Conference on ECC and CPR Science With Treatment Recommendations

Scientific Knowledge Gaps and Clinical Research Priorities for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Identified During the 2005 International Consensus Conference on ECC and CPR Science With Treatment Recommendations

Hospital protocols for targeted glycemic control: Development, implementation, and models for cost justification

Evolving elements of best practices for providing targeted glycemic control in the hospital setting, clinical performance measurement, basal-bolus plus correction-dose insulin regimens, components of standardized subcutaneous (s.c.) insulin order sets, and strategies for implementation and cost justification of glycemic control initiatives are discussed. Best practices for targeted glycemic control should address accurate documentation of hyperglycemia, initial patient assessment, management plan, target blood glucose range, blood glucose monitoring frequency, maintenance of glycemic control, criteria for glucose management consultations, and standardized insulin order sets and protocols. Establishing clinical performance measures, including desirable processes and outcomes, can help ensure the success of targeted hospital glycemic control initiatives. The basal-bolus plus correction-dose regimen for insulin administration will be used to mimic the normal physiologic pattern of endogenous insulin secretion. Standardized insulin order sets and protocols are being used to minimize the risk of error in insulin therapy. Components of standardized s.c. insulin order sets include specification of the hyperglycemia diagnosis, finger stick blood glucose monitoring frequency and timing, target blood glucose concentration range, cutoff values for excessively high or low blood glucose concentrations that warrant alerting the physician, basal and prandial or nutritional (i.e., bolus) insulin, correction doses, hypoglycemia treatment, and perioperative or procedural dosage adjustments. The endorsement of hospital administrators and key physician and nursing leaders is needed for glycemic control initiatives. Initiatives may be cost justified on the basis of the billings for clinical diabetes management services and/or the return- on-investment accrued to reductions in hospital length of stay, readmissions, and accurate documentation and coding of unrecognized or uncontrolled diabetes, and diabetes complications. Standardized insulin order sets and protocols may minimize risk of insulin errors. The endorsement of these protocols by administrators, physicians, nurses, and pharmacists is also needed for success.

Part 13: Neonatal Resuscitation Guidelines

The following guidelines are intended for practitioners responsible for resuscitating neonates. They apply primarily to neonates undergoing transition from intrauterine to extrauterine life. The recommendations are also applicable to neonates who have completed perinatal transition and require resuscitation during the first few weeks to months following birth. Practitioners who resuscitate infants at birth or at any time during the initial hospital admission should consider following these guidelines. The terms newborn and neonate are intended to apply to any infant during the initial hospitalization. The term newly born is intended to apply specifically to an infant at the time of birth. Approximately 10% of newborns require some assistance to begin breathing at birth. About 1% require extensive resuscitative measures. Although the vast majority of newly born infants do not require intervention to make the transition from intrauterine to extrauterine life, because of the large number of births, a sizable number will require some degree of resuscitation. Those newly born infants who do not require resuscitation can generally be identified by a rapid assessment of the following 4 characteristics: If the answer to all 4 of these questions is “yes,” the baby does not need resuscitation and should not be separated from the mother. The baby can be dried, placed directly on the mother’s chest, and covered with dry linen to maintain temperature. Observation of breathing, activity, and color should be ongoing. If the answer to any of these assessment questions is “no,” there is general agreement that the infant should receive one or more of the following 4 categories of action in sequence:

Insulin infusion protocol for critical care units

An insulin infusion protocol for critical care units is described. Evidence that aggressive glycemic control improves outcomes led physicians, nurses, dietitians, and pharmacists at a trauma center to develop an insulin infusion protocol. Before the protocol, elevated blood glucose concentrations were often not treated until they reached 200 mg/dL or higher. Insulin infusions were underutilized and were often not started until capillary blood glucose concentrations were greater than 350 mg/dL for 12 or more hours. When orders for an insulin infusion were written, they did not include directions for dosage adjustment, and the goal blood glucose range varied. A preliminary protocol was drafted allowing adjustments in insulin administration to be based on changes in capillary blood glucose values since the previous blood glucose measurement. The protocol was presented to a multidisciplinary team and further refined. The targeted blood glucose concentration range was 80-130 mg/dL. After the targeted range was achieved for a patient, if the blood glucose level continued to decrease over three consecutive measurements, the infusion rate was decreased by 0.5 or 1 unit/hr, depending on the capillary blood glucose level. Data for the first 30 patients were collected from September 2003 to August 2004. It took 2-36 hours (mean, 12.6 hours) to bring the capillary blood glucose concentration to less than 130 mg/dL. Among 2,845 capillary blood glucose measurements, there were 15 cases of hypoglycemia (0.4%) requiring treatment with 50% dextrose injection. A multidisciplinary effort resulted in the development of an insulin infusion protocol for use in critical care units.

Comparison of two insulin protocols for diabetic dogs undergoing cataract surgery

Objective To evaluate the effectiveness of two insulin doses to maintain an acceptable range of blood glucose concentrations (70–200 mg dL−1) in the peri-operative period in diabetic dogs.Animals Twenty-four diabetic dogs with a median weight of 20.6 kg and a median age of 8 years old.Methods The dogs were randomly assigned to receive either 25 or 100% of their normal insulin dose subcutaneously on the morning of surgery. The anesthetic and feeding protocols were standardized. On the day before surgery, venous blood was collected for measurement of β-hydroxybutyrate, cholesterol, glucose, glycosylated hemoglobin, hematocrit, total plasma protein and urea nitrogen. On the day of surgery, blood glucose concentrations were measured prior to anesthesia, prior to the start of surgery, 1 and 2 hours after beginning of surgery, 1 hour after extubation, at 16 : 00 hours and at 20 : 00 hours. β-hydroxybutyrate concentrations were measured at 20 : 00 hours that day. At 08 : 00 hours the following day, β-hydroxybutyrate and glucose concentrations were measured. The significance of differences between groups was tested with Wilcoxon's two-tailed rank-sum test, Chi-square test and Fisher's exact test.Results There were no differences in insulin treatments, clinical signs, concurrent diseases and most clinicopathological parameters between the two groups of dogs at entry to the study. The 25% dose group had blood glucose values of 296 (102–601) mg dL−1 at 16 : 00 hours and 429 (97–595) mg dL−1 at 20 : 00 hours on the day of surgery. The 100% insulin dose group had lower corresponding values of 130 (55–375) mg dL−1 (p = 0.04) and 185 (51–440) mg dL−1 (p = 0.004). No other differences (p < 0.05) were detected between the two groups.Conclusions The administration of a full dose of insulin is only marginally advantageous for reducing glucose to normal (70–120 mg dL−1) after anesthesia but neither dose consistently induced glycemic values in an acceptable range (70–200 mg dL−1) or normoketonemia.Clinical relevance Blood glucose should be measured immediately before anesthesia and periodically throughout the peri-operative period in all diabetic dogs because presurgical subcutaneous administration of 25 or 100% of the normal insulin dose resulted in unpredictable blood glucose concentrations.

Glycaemic threshold for changes in electroencephalograms during hypoglycaemia in patients with insulin dependent diabetes

The relation between blood glucose concentration, the symptoms and signs of hypoglycaemia, and electroencephalographic changes in diabetic patients is not known. The effect of hypoglycaemia on brain function was studied in 13 patients with insulin dependent diabetes. During a gradual fall in blood glucose concentration induced by a bolus injection of insulin followed by an intravenous infusion of insulin, during 60 minutes of biochemical hypoglycaemia, and after restoration of normoglycaemia with intravenous glucose electroencephalograms were evaluated continuously by period-amplitude analysis; blood samples were taken every 10 minutes throughout. No changes were seen in electroencephalograms when the blood glucose concentration was above 3 mmol/l. At a median blood glucose concentration of 2.0 (95% confidence interval 1.7 to 2.3) mmol/l alpha activity decreased abruptly in the electroencephalograms concomitant with an increase in theta activity, reflecting neuronal dysfunction in the cortex. When the blood glucose concentration was further lowered changes were observed in the electroencephalograms indicating that deeper brain structures were affected. A normal electroencephalogram was re-established at a blood glucose concentration of 2.0 (1.8 to 2.1) mmol/l. There was no significant correlation between the blood glucose concentration at the onset of changes in the electroencephalograms and age, duration of diabetes, insulin dose, haemoglobin A1c concentration, initial blood glucose concentration, rate of fall in blood glucose concentration, and appearance of symptoms and signs of hypoglycaemia. Changes in electroencephalograms during hypoglycaemia appear and disappear at such a narrow range of blood glucose concentrations that the term threshold blood glucose concentration for the onset of such changes seems justified.