Relative Hypoglycemia in Diabetic Patients With Critical Illness

Association of Relative Dysglycemia With Hospital Mortality in Critically Ill Patients: A Retrospective Study

OBJECTIVES

Relative dysglycemia has been proposed as a clinical entity among critically ill patients in the ICU, but is not well studied. This study aimed to clarify associations of relative hyperglycemia and hypoglycemia during the first 24 hours after ICU admission with in-hospital mortality and the respective thresholds.

DESIGN

A single-center retrospective study.

SETTING

An urban tertiary hospital ICU.

PATIENTS

Adult critically ill patients admitted urgently between January 2016 and March 2022.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Maximum and minimum glycemic ratio (GR) was defined as maximum and minimum blood glucose values during the first 24 hours after ICU admission divided by hemoglobin A1c-derived average glucose, respectively. Of 1700 patients included, in-hospital mortality was 16.9%. Nonsurvivors had a higher maximum GR, with no significant difference in minimum GR. Maximum GR during the first 24 hours after ICU admission showed a J-shaped association with in-hospital mortality, and a mortality trough at a maximum GR of approximately 1.12; threshold for increased adjusted odds ratio for mortality was 1.25. Minimum GR during the first 24 hours after ICU admission showed a U-shaped relationship with in-hospital mortality and a mortality trough at a minimum GR of approximately 0.81 with a lower threshold for increased adjusted odds ratio for mortality at 0.69.

CONCLUSIONS

Mortality significantly increased when GR during the first 24 hours after ICU admission deviated from between 0.69 and 1.25. Further evaluation will necessarily validate the superiority of personalized glycemic management over conventional management.

Association Between Individualized Versus Conventional Blood Glucose Thresholds and Acute Kidney Injury After Cardiac Surgery: A Retrospective Observational Study

OBJECTIVES

This study was designed to compare individualized and conventional hyperglycemic thresholds for the risk of acute kidney injury (AKI) after cardiac surgery.

DESIGN

This was an observational study.

SETTING

The study took place in a single-center tertiary teaching hospital.

PARTICIPANTS

Adult patients who underwent cardiac surgery between January 2012 and November 2021 were enrolled.

MEASUREMENTS AND MAIN RESULTS

Two blood glucose thresholds were used to define intraoperative hyperglycemia. While the conventional hyperglycemic threshold (CHT) was 180 mg/dL in all patients, the individualized hyperglycemic threshold (IHT) was calculated based on the preoperative hemoglobin A1c level. Various metrics of intraoperative hyperglycemia were calculated using both thresholds: any hyperglycemic episode, duration of hyperglycemia, and area above the thresholds. Postoperative AKI associations were compared using receiver operating characteristic curves and logistic regression analysis. Among the 2,427 patients analyzed, 823 (33.9%) developed AKI. The C-statistics of IHT-defined metrics (0.58-0.59) were significantly higher than those of the CHT-defined metrics (all C-statistics, 0.54; all p < 0.001). The duration of hyperglycemia (adjusted odds ratio, 1.09; 95% confidence interval, 1.02-1.16) and area above the IHT (1.003; 1.001-1.004) were significantly associated with the risk of AKI, except for the presence of any hyperglycemic episode. None of the CHT-defined metrics were significantly associated with the risk of AKI.

CONCLUSIONS

Individually defined intraoperative hyperglycemia better predicted postcardiac surgery AKI than universally defined hyperglycemia. Intraoperative hyperglycemia was significantly associated with the risk of AKI only for the IHT. Target blood glucose levels in cardiac surgical patients may need to be individualized based on preoperative glycemic status.

Predicting hypoglycemia in ICU patients: a machine learning approach

BACKGROUND

The current study sets out to develop and validate a robust machine-learning model utilizing electronic health records (EHR) to forecast the risk of hypoglycemia among ICU patients in Jordan.

RESEARCH DESIGN AND METHODS

The present study drew upon a substantial cohort of 13,567 patients admitted 26,248 times to the intensive care unit (ICU) over 10 years from July 2012 to July 2022. The primary outcome of interest was the occurrence of any hypoglycemic episode during the patient's ICU stay. Developing and testing predictor models was conducted using Python machine-learning libraries.

RESULTS

A total of 1,896 were eligible to participate in the study, 206 experienced at least one hypoglycemic episode. Eight machine-learning models were trained to predict hypoglycemia. All models showed predicting power with a range of 74.53-99.69 for AUROC. Except for Naive Bayes, the six remaining models performed distinctly better than the basic logistic regression usually used for prediction in epidemiological studies. CatBoost model was consistently the best performer with the highest AUROC (0.99), accuracy and precision, sensitivity and specificity, and recall.

CONCLUSIONS

We used machine learning to anticipate the likelihood of hypoglycemia, which can significantly decrease hypoglycemia incidents and enhance patient outcomes.

Malglycemia in the critical care setting. Part III: Temporal patterns, relative potencies, and hospital mortality

INTRODUCTION

The relationship between critical care mortality and combined impact of malglycemia remains undefined.

METHODS

We assessed the risk-adjusted relationship (n = 4790) between hospital mortality with malglycemia, defined as hypergycemia (hours Glycemic Ratio ≥ 1.1, where GR is quotient of mean ICU blood glucose (BG) and estimated average BG), absolute hypoglycemia (hours BG < 70 mg/dL) and relative hypoglycemia (excursions GR < 0.7 in those with HbA1c ≥ 8%).

RESULTS

Each malglycemia was independently associated with mortality - hyperglycemia (OR 1.0020/h, 95%CI 1.0009-1.0031, p = 0.0004), absolute hypoglycemia (OR 1.0616/h, 95%CI 1.0190-1.1061, p = 0.0043), and relative hypoglycemia (OR 1.2813/excursion, 95%CI 1.0704-1.5338, p = 0.0069). Absolute (7.4%) and relative hypoglycemia (6.7%) exposure dominated the first 24 h, decreasing thereafter. While hyperglycemia had lower risk association with mortality, it was persistently present across the length-of-stay (68-76% incidence daily), making it the dominant form of malglycemia. Relative contributions in the first five days from hyperglycemia, absolute hypoglycemia and relative hypoglycemia were 60%, 21% and 19% respectively.

CONCLUSIONS

Absolute and relative hypoglycemia occurred largely in the first 24 h. Relative to all hypoglycemia, the associated mortality from the seemingly less potent but consistently more prevalent hyperglycemia steadily accumulated with increasing length-of-stay. This has important implications for interpretation of study results.

Tight Versus Liberal Blood Glucose Control in Patients With Diabetes in the ICU: A Meta-Analysis of Randomized Controlled Trials

Introduction: Glycemia is an important factor among critically ill patients in the intensive care unit (ICU). There is conflicting evidence on the preferred strategy of blood glucose control among patients with diabetes in the ICU. We aimed to conduct a meta-analysis comparing tight with liberal blood glucose in critically ill patients with diabetes in the ICU. Methods: We systematically searched PubMed, Embase, and Cochrane Central for randomized controlled trials (RCTs) comparing tight versus liberal blood glucose control in critically ill patients with diabetes from inception to December 2023. We pooled odds-ratios (OR) and 95% confidence intervals (CI) with a random-effects model for binary endpoints. We used the Review Manager 5.17 and R version 4.3.2 for statistical analyses. Risk of bias assessment was performed with the Cochrane tool for randomized trials (RoB2). Results: Eight RCTs with 4474 patients were included. There was no statistically significant difference in all-cause mortality (OR 1.11; 95% CI 0.95-1.28; P = .18; I² = 0%) between a tight and liberal blood glucose control. RoB2 identified all studies at low risk of bias and funnel plot suggested no evidence of publication bias. Conclusion: In patients with diabetes in the ICU, there was no statistically significant difference in all-cause mortality between a tight and liberal blood glucose control. PROSPERO registration: CRD42023485032.

Society of Critical Care Medicine Guidelines on Glycemic Control for Critically Ill Children and Adults 2024

RATIONALE

Maintaining glycemic control of critically ill patients may impact outcomes such as survival, infection, and neuromuscular recovery, but there is equipoise on the target blood levels, monitoring frequency, and methods.

OBJECTIVES

The purpose was to update the 2012 Society of Critical Care Medicine and American College of Critical Care Medicine (ACCM) guidelines with a new systematic review of the literature and provide actionable guidance for clinicians.

PANEL DESIGN

The total multiprofessional task force of 22, consisting of clinicians and patient/family advocates, and a methodologist applied the processes described in the ACCM guidelines standard operating procedure manual to develop evidence-based recommendations in alignment with the Grading of Recommendations Assessment, Development, and Evaluation Approach (GRADE) methodology. Conflict of interest policies were strictly followed in all phases of the guidelines, including panel selection and voting.

METHODS

We conducted a systematic review for each Population, Intervention, Comparator, and Outcomes question related to glycemic management in critically ill children (≥ 42 wk old adjusted gestational age to 18 yr old) and adults, including triggers for initiation of insulin therapy, route of administration, monitoring frequency, role of an explicit decision support tool for protocol maintenance, and methodology for glucose testing. We identified the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the GRADE approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak or as a good practice statement. In addition, "In our practice" statements were included when the available evidence was insufficient to support a recommendation, but the panel felt that describing their practice patterns may be appropriate. Additional topics were identified for future research.

RESULTS

This guideline is an update of the guidelines for the use of an insulin infusion for the management of hyperglycemia in critically ill patients. It is intended for adult and pediatric practitioners to reassess current practices and direct research into areas with inadequate literature. The panel issued seven statements related to glycemic control in unselected adults (two good practice statements, four conditional recommendations, one research statement) and seven statements for pediatric patients (two good practice statements, one strong recommendation, one conditional recommendation, two "In our practice" statements, and one research statement), with additional detail on specific subset populations where available.

CONCLUSIONS

The guidelines panel achieved consensus for adults and children regarding a preference for an insulin infusion for the acute management of hyperglycemia with titration guided by an explicit clinical decision support tool and frequent (≤ 1 hr) monitoring intervals during glycemic instability to minimize hypoglycemia and against targeting intensive glucose levels. These recommendations are intended for consideration within the framework of the patient's existing clinical status. Further research is required to evaluate the role of individualized glycemic targets, continuous glucose monitoring systems, explicit decision support tools, and standardized glycemic control metrics.

Differential Association between Blood Glucose Levels and Nonrelapse Mortality after Allogeneic Hematopoietic Cell Transplantation Based on Presence or Absence of Preexisting Diabetes

Malglycemia, defined as hyperglycemia, hypoglycemia, or increased glycemic variability, has been associated with increased mortality after allogeneic hematopoietic cell transplantation (HCT). Among critically ill non-HCT recipients with diabetes and poor glycemic control, compared to those without diabetes, stringent blood glucose control has been associated with increased mortality. This study investigated whether a pre-HCT diagnosis of diabetes and the type of pre-HCT diabetes treatment modulate the previously reported negative impact of malglycemia on post-HCT nonrelapse mortality (NRM). We performed a single-institution retrospective analysis of mortality outcomes after allogeneic HCT as a function of post-HCT blood glucose levels, pre-HCT diagnosis of diabetes, and type of pre-HCT diabetes treatment (insulin, no insulin). A total of 1062 patients who underwent allogeneic HCT between 2015 and 2020 were included in this study. Among these patients, 84 (8%) had a pre-HCT diagnosis of diabetes, of whom 38 (4%) used insulin and 46 (4%) used a noninsulin antiglycemic agent. Post-HCT blood glucose values measured within 100 days from HCT, modeled as a continuous nonlinear time-varying covariate, were associated with day-200 NRM, with both lower and higher glycemic values associated with higher NRM compared to normoglycemic values (adjusted P < .0001). The association between post-HCT blood glucose and NRM varied, however, depending on the presence or absence of a pre-HCT diagnosis of diabetes; that is, there was evidence of a statistical interaction between blood glucose levels and diabetes (adjusted P = .008). In particular, the detrimental impact of hyperglycemic values was more pronounced in patients without a pre-HCT diagnosis of diabetes compared to those with a pre-HCT diagnosis of diabetes. As reported previously, higher and lower blood glucose levels measured within 100 days after allogeneic HCT were associated with an increased risk of NRM; however, this association was more pronounced among patients without a pre-HCT diagnosis of diabetes compared to those with a pre-HCT diagnosis of diabetes, suggesting that patients with diabetes are relatively protected from the downstream effects of hyperglycemia. These data support the notion that patients with pre-HCT diabetes may need a different approach to blood glucose management after transplantation compared to those without diabetes. © 2024 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Tight versus liberal blood-glucose control in the intensive care unit: special considerations for patients with diabetes

Stress hyperglycaemia, hypoglycaemia, and diabetes are common in critically ill patients and related to clinical endpoints. To avoid complications related to hypoglycaemia and hyperglycaemia, it is recommended to start insulin therapy for the majority of critically ill patients with persistent blood glucose concentrations higher than 10·0 mmol/L (>180 mg/dL), targeting a range of 7·8-10·0 mmol/L (140-180 mg/dL). However, management and evidence-based targets for blood glucose control are under debate, particularly for patients with diabetes. Recent randomised controlled clinical trials now challenge current recommendations. In this Personal View, we aim to highlight these developments and the important differences between critically ill patients with and without diabetes, taking into account the considerable heterogeneity in this patient group. We critically discuss evidence from prospective randomised controlled trials and observational studies on the safety and efficacy of glycaemic control, specifically in the context of patients with diabetes in intensive care units.

Impact of Insulin-Induced Relative Hypoglycemia on Vascular Insulin Sensitivity and Central Hemodynamics in Prediabetes

CONTEXT

Relative hypoglycemia (RH) is linked to sympathetic responses that can alter vascular function in individuals with type 2 diabetes. However, less is known about the role of RH on hemodynamics or metabolic insulin sensitivity in prediabetes.

OBJECTIVE

Determine if RH alters peripheral endothelial function or central hemodynamics to a greater extent in those with prediabetes (PD) versus normoglycemia (NG).

METHODS

Seventy adults with obesity were classified using ADA criteria as PD (n=34 (28F); HbA1c=6.02±0.1%) or NG (n=36 (30F); HbA1c=5.4±0.0%). Brachial artery endothelial function, skeletal muscle capillary perfusion, and aortic waveforms were assessed at 0 and 120min of a euglycemic clamp (40 mU/m2/min, 90 mg/dl). Plasma nitrate/nitrite and endothelin-1 (ET-1) were measured as surrogates of nitric oxide-mediated vasodilation and vasoconstriction, respectively. RH was defined as the drop in glucose (%) from fasting to clamp steady state.

RESULTS

There were no differences in age, weight, or VO2max between groups. PD had higher HbA1c (P<0.01) and a greater drop in glucose in response to insulin (14 vs. 8%; P=0.03). Further, heart rate (HR) increased in NG compared to PD (P<0.01), while forward wave (Pf) decreased in PD (P=0.04). Insulin also tended to reduce arterial stiffness (cfPWV) in NG versus PD (P=0.07), despite similar increases in pre-occlusion diameter (P=0.02), blood flow (P=0.02), and lower augmentation index (AIx75) (P≤0.05).

CONCLUSION

Compared with NG, insulin-induced RH corresponded with a blunted rise in HR and drop in Pf during insulin infusion in adults with PD, independent of changes in peripheral endothelial function.

The Glycemic Ratio Is Strongly and Independently Associated With Mortality in the Critically Ill

BACKGROUND

Interventional studies investigating blood glucose (BG) management in intensive care units (ICU) have been inconclusive. New insights are needed. We assessed the ability of a new metric, the Glycemic Ratio (GR), to determine the relationship of ICU glucose control relative to preadmission glycemia and mortality.

METHODS

Retrospective cohort investigation (n = 4790) in an adult medical-surgical ICU included patients with minimum four BGs, hemoglobin (Hgb), and hemoglobin A1c (HbA1c). The GR is the quotient of mean ICU BGs (mBG) and estimated preadmission BG, derived from HbA1c.

RESULTS

Mortality displayed a J-shaped curve with GR (nadir GR 0.9), independent of background glycemia, consistent for HbA1c <6.5% vs >6.5%, and Hgb >10 g/dL vs <10 g/dL and medical versus surgical. An optimal range of GR 0.80 to 0.99 was associated with decreased mortality compared with GR above and below this range. The mBG displayed a linear relationship with mortality at lower HbA1c but diminished for HbA1c >6.5%, and dependent on preadmission glycemia. In adjusted analysis, GR remained associated with mortality (odds ratio = 2.61, 95% confidence interval = 1.48-4.62, P = .0012), but mBG did not (1.004, 1.000-1.009, .059). A single value on admission was not independently associated with mortality.

CONCLUSIONS

The GR provided new insight into malglycemia that was not apparent using mBG, or an admission value. Mortality was associated with acute change from preadmission glycemia (GR). Further assessment of the impact of GR deviations from the nadir in mortality at GR 0.80 to 0.99, as both relative hypo- and hyperglycemia, and as duration of exposure and intensity, may further define the multifaceted nature of malglycemia.

Malglycemia in the critical care setting. Part II: Relative and absolute hypoglycemia

INTRODUCTION

The relationship between critical care mortality and hypoglycemia, both relative (>30% below average preadmission glycemia) and absolute (blood glucose (BG) <70 mg/dL (<10 mmol/L)) requires further definition.

METHODS

We assessed the risk-adjusted relationship between hospital mortality with relative hypoglycemia using the Glycemic Ratio (GR), and with absolute hypoglycemia using BG in a retrospective cohort investigation (n = 4790).

RESULTS

Relative hypoglycemia excursions below GR 0.7 with a of 24-h non-exposure period between excursions in those with HbA1c ≥ 8% were independently associated with mortality (n = 373, OR 2.49, 95% CI 1.54-4.04, p = 0.0002) but not those with HbA1c < 8% (n = 4417, OR 0.98 95% CI 0.89-1.08, p = 0.70). Hours below GR 0.7 (1.0037, 0.9995-1.0080, 0.0846) or minimum GR (0.0896, 0.0030-2.6600, 0.1632) were not independently associated with outcome. Absolute hypoglycemia occurred across the HbA1c spectrum in a U-shaped pattern. There was no difference in mortality associated with exposure to BG < 70 mg/dL for HbA1c ≥ 6.5% vs <6.5% (29.7% vs 24.3%, p = 0.77). Hours below 70 mg/dL demonstrated strongest association with outcome, while minimum BG, and excursions below 70 mg/dL were also independently associated.

CONCLUSIONS

Relative hypoglycemia represented by excursions below GR 0.7 in those with HbA1c ≥ 8% occurred commonly and was independently associated with mortality. Absolute hypoglycemia had similar association with mortality regardless of HbA1c.

The association of hypoglycemia with outcome of critically ill children in relation to nutritional and blood glucose control strategies

BACKGROUND

Withholding parenteral nutrition (PN) until one week after PICU admission facilitated recovery from critical illness and protected against emotional and behavioral problems 4 years later. However, the intervention increased the risk of hypoglycemia, which may have counteracted part of the benefit. Previously, hypoglycemia occurring under tight glucose control in critically ill children receiving early PN did not associate with long-term harm. We investigated whether hypoglycemia in PICU differentially associates with outcome in the context of withholding early PN, and whether any potential association with outcome may depend on the applied glucose control protocol.

METHODS

In this secondary analysis of the multicenter PEPaNIC RCT, we studied whether hypoglycemia in PICU associated with mortality (N = 1440) and 4-years neurodevelopmental outcome (N = 674) through univariable comparison and multivariable regression analyses adjusting for potential confounders. In patients with available blood samples (N = 556), multivariable models were additionally adjusted for baseline serum NSE and S100B concentrations as biomarkers of neuronal, respectively, astrocytic damage. To study whether an association of hypoglycemia with outcome may be affected by the nutritional strategy or center-specific glucose control protocol, we further adjusted the models for the interaction between hypoglycemia and the randomized nutritional strategy, respectively, treatment center. In sensitivity analyses, we studied whether any association with outcome was different in patients with iatrogenic or spontaneous/recurrent hypoglycemia.

RESULTS

Hypoglycemia univariably associated with higher mortality in PICU, at 90 days and 4 years after randomization, but not when adjusted for risk factors. After 4 years, critically ill children with hypoglycemia scored significantly worse for certain parent/caregiver-reported executive functions (working memory, planning and organization, metacognition) than patients without hypoglycemia, also when adjusted for risk factors including baseline NSE and S100B. Further adjustment for the interaction of hypoglycemia with the randomized intervention or treatment center revealed a potential interaction, whereby tight glucose control and withholding early PN may be protective. Impaired executive functions were most pronounced in patients with spontaneous or recurrent hypoglycemia.

CONCLUSION

Critically ill children exposed to hypoglycemia in PICU were at higher risk of impaired executive functions after 4 years, especially in cases of spontaneous/recurrent hypoglycemia.

Brain Glucose Sensing and the Problem of Relative Hypoglycemia

"Relative hypoglycemia" is an often-overlooked complication of diabetes characterized by an increase in the glycemic threshold for detecting and responding to hypoglycemia. The clinical relevance of this problem is linked to growing evidence that among patients with critical illness, higher blood glucose in the intensive care unit is associated with higher mortality among patients without diabetes but lower mortality in patients with preexisting diabetes and an elevated prehospitalization HbA1c. Although additional studies are needed, the cardiovascular stress associated with hypoglycemia perception, which can occur at normal or even elevated glucose levels in patients with diabetes, offers a plausible explanation for this difference in outcomes. Little is known, however, regarding how hypoglycemia is normally detected by the brain, much less how relative hypoglycemia develops in patients with diabetes. In this article, we explore the role in hypoglycemia detection played by glucose-responsive sensory neurons supplying peripheral vascular beds and/or circumventricular organs. These observations support a model wherein relative hypoglycemia results from diabetes-associated impairment of this neuronal glucose-sensing process. By raising the glycemic threshold for hypoglycemia perception, this impairment may contribute to the increased mortality risk associated with standard glycemic management of critically ill patients with diabetes.

Case-control Investigation of Previously Undiagnosed Diabetes in the Critically Ill

Context

The outcome of patients requiring intensive care can be influenced by the presence of previously undiagnosed diabetes (undiagDM).

Objective

This work aimed to define the clinical characteristics, glucose control metrics, and outcomes of patients admitted to the intensive care unit (ICU) with undiagDM, and compare these to patients with known DM (DM).

Methods

This case-control investigation compared undiagDM (glycated hemoglobin A1c [HbA1c] ≥ 6.5%, no history of diabetes) to patients with DM. Glycemic ratio (GR) was calculated as the quotient of mean ICU blood glucose (BG) and estimated preadmission glycemia, based on HbA1c ([28.7 × HbA1c] - 46.7 mg/dL). GR was analyzed by bands: less than 0.7, 0.7 to less than or equal to 0.9, 0.9 to less than 1.1, and greater than or equal to 1.1. Risk-adjusted mortality was represented by the Observed:Expected mortality ratio (OEMR), calculated as the quotient of observed mortality and mortality predicted by the severity of illness (APACHE IV prediction of mortality).

Results

Of 5567 patients 294 (5.3%) were undiagDM. UndiagDM had lower ICU mean BG (P < .0001) and coefficient of variation (P < .0001) but similar rates of hypoglycemia (P = .08). Mortality and risk-adjusted mortality were similar in patients with GR less than 1.1 comparing undiagDM and DM. However, for patients with GR greater than or equal to 1.1, mortality (38.5% vs 10.3% [P = .0072]) and risk-adjusted mortality (OEMR 1.18 vs 0.52 [P < .0001]) were higher in undiagDM than in DM.

Conclusion

These data suggest that DM patients may develop tolerance to hyperglycemia that occurs during critical illness, a protective mechanism not observed in undiagDM, for whom hyperglycemia remains strongly associated with higher risk of mortality. These results may shed light on the natural history of diabetes.

Acute and Chronic Glucose Control in Critically Ill Patients With Diabetes: The Impact of Prior Insulin Treatment

BACKGROUND

Emerging data highlight the interactions of preadmission glycemia, reflected by admission HbA1c levels, glycemic control during critical illness, and mortality. The association of preadmission insulin treatment with outcomes is unknown.

METHODS

This observational cohort study includes 5245 patients admitted to the medical-surgical intensive care unit of a university-affiliated teaching hospital. Three groups were analyzed: patients with diabetes with prior insulin treatment (DM-INS, n = 538); patients with diabetes with no prior insulin treatment (DM-No-INS, n = 986); no history of diabetes (NO-DM, n = 3721). Groups were stratified by HbA1c level: <6.5%; 6.5%-7.9% and >8.0%.

RESULTS

Among the three strata of HbA1c, mean blood glucose (BG), coefficient of variation (CV), and hypoglycemia increased with increasing HbA1c, and were higher for DM-INS than for DM-No-INS. Among patients with HbA1c < 6.5%, mean BG ≥ 180 mg/dL and CV > 30% were associated with lower severity-adjusted mortality in DM-INS compared to patients with mean BG 80-140 mg/dL and CV < 15%, (P = .0058 and < .0001, respectively), but higher severity-adjusted mortality among DM-No-INS (P = .0001 and < .0001, respectively) and NON-DM (P < .0001 and < .0001, respectively). Among patients with HbA1c ≥ 8.0%, mean BG ≥ 180 mg/dL was associated with lower severity-adjusted mortality for both DM-INS and DM-No-INS than was mean BG 80-140 mg/dL (p < 0.0001 for both comparisons).

CONCLUSIONS

Significant differences in mortality were found among patients with diabetes based on insulin treatment and HbA1c at home and post-admission glycemic control. Prospective studies need to confirm an individualized approach to glycemic control in the critically ill.

Association between time in range of relative normoglycemia and in-hospital mortality in critically ill patients: a single-center retrospective study

The aim of this single-center retrospective study was to investigate the association between the time in range (TIR) of relative normoglycemia (RN) and in-hospital mortality. We defined RN as measured blood glucose in the range of 70–140% of A1C-derived average glucose and absolute normoglycemia (AN) as 70–140 mg/dL. We conducted multivariate logistic regression analyses to examine the association between TIR of RN > 80% or TIR of AN > 80% up to 72 h after ICU admission and in-hospital mortality (Model 1 and Model 2, respectively). The discrimination of the models was assessed using the area under the receiver operating characteristic curve (AUROC). Among 328 patients, 35 died in hospital (11%). Model 1 showed that TIR of RN > 80% was associated with reduced in-hospital mortality (adjusted OR 0.16; 95% CI 0.06–0.43; P < 0. 001); however, Model 2 showed that the TIR of AN > 80% was not. The AUROC of Model 1 was significantly higher than that of Model 2 (0.84 [95% CI 0.77–0.90] vs. 0.79 [0.70–0.87], P = 0.008).Our findings provide a foundation for further studies exploring individualized glycemic management in ICUs.

Association between stress hyperglycemia on admission and unfavorable neurological outcome in OHCA patients receiving ECPR

BACKGROUND

Stress hyperglycemia is a normal response to stress and has been associated with outcomes in out-of-hospital cardiac arrest (OHCA) patients. However, this association remained unknown in OHCA patients receiving extracorporeal cardiopulmonary resuscitation (ECPR). This study aimed to examine the association between degree of stress hyperglycemia on admission and neurological outcomes at discharge in OHCA patients receiving ECPR.

PATIENTS AND METHODS

This was a retrospective cohort study of adult OHCA patients receiving ECPR between 2011 and 2021. Patients were classified into three groups: absence of stress hyperglycemia (blood glucose level on admission < 200 mg/dL), moderate stress hyperglycemia (200-299 mg/dL), and severe stress hyperglycemia (≥ 300 mg/dL). The primary outcome was unfavorable neurological outcome (Cerebral Performance Category: 3-5) at discharge.

RESULTS

This study included 160 patients; unfavorable neurological outcomes totaled 79.4% (n = 127). There were 23, 52, and 85 patients in the absence, moderate, and severe stress hyperglycemia groups, respectively. Of each group, unfavorable neurological outcomes constituted 91.3%, 71.2%, and 81.2%, respectively. Multivariable analysis showed that, compared with moderate stress hyperglycemia, absence of stress hyperglycemia on admission was significantly associated with unfavorable neurological outcome at discharge (odds ratio [OR], 4.70; 95% confidence interval [CI], 1.07-33.35; p = 0.039).

CONCLUSION

Compared with moderate stress hyperglycemia on admission, absence of stress hyperglycemia showed significant association with unfavorable neurological outcome at discharge in OHCA patients receiving ECPR.

Novel insights in endocrine and metabolic pathways in sepsis and gaps for future research

Sepsis is defined as any life-threatening organ dysfunction caused by a dysregulated host response to infection. It remains an important cause of critical illness and has considerable short- and long-term morbidity and mortality. In the last decades, preclinical and clinical research has revealed a biphasic pattern in the (neuro-)endocrine responses to sepsis as to other forms of critical illness, contributing to development of severe metabolic alterations. Immediately after the critical illness-inducing insult, fasting- and stress-induced neuroendocrine and cellular responses evoke a catabolic state in order to provide energy substrates for vital tissues, and to concomitantly activate cellular repair pathways while energy-consuming anabolism is postponed. Large randomized controlled trials have shown that providing early full feeding in this acute phase induced harm and reversed some of the neuro-endocrine alterations, which suggested that the acute fasting- and stress-induced responses to critical illness are likely interlinked and benefical. However, it remains unclear whether, in the context of accepting virtual fasting in the acute phase of illness, metabolic alterations such as hyperglycemia are harmful or beneficial. When patients enter a prolonged phase of critical illness, a central suppression of most neuroendocrine axes follows. Prolonged fasting and central neuroendocrine suppression may no longer be beneficial. Although pilot studies have suggested benefit of fasting-mimicking diets and interventions that reactivate the central neuroendocrine suppression selectively in the prolonged phase of illness, further study is needed to investigate patient-oriented outcomes in larger randomized trials.

Insulin therapy associated relative hypoglycemia during critical illness

PURPOSE

In critically ill diabetes patients, relative hypoglycemia (RH) (a decrease in glucose ≥30% below pre-admission levels, as estimated by HbA1c) is associated with greater mortality and absolute hypoglycemia. We investigated the epidemiology and outcomes of RH when it was associated with insulin therapy.

METHODS

We performed retrospective analysis of a cohort of critically ill patients with diabetes who received insulin in the intensive care units (ICUs) of a tertiary hospital. The primary outcome was 28-day mortality with respect to insulin therapy associated relative hypoglycemia (ITARH).

RESULTS

ITARH occurred in 184 (42%) of insulin-treated patients. ITARH was associated with a higher HbA1c (8.6% vs 6.6%, p < 0.001), a higher glycemic variability index (121 vs 75.1 mmol²/L²/h/week, p < 0.001) and more absolute hypoglycemia (18.5% vs 3.94%, p < 0.001). Its frequency peaked about 5 h after initiation of insulin therapy. ITARH was associated with a greater risk of subsequent hypoglycemia (adjusted HR 3.5, 95% CI 1.7-6.8) but not mortality (HR 1.2, 95% CI 0.7-2.2).

CONCLUSIONS

ITARH is common in insulin treated critically ill diabetes patients and associated with poorer glycemic control. Unlike reports of RH in general, it is not associated with mortality, suggesting that the prognostic implications of RH differ according to its context.

Relative Hypoglycemia and Lower Hemoglobin A1c-Adjusted Time in Band Are Strongly Associated With Increased Mortality in Critically Ill Patients

OBJECTIVES

To determine the associations of relative hypoglycemia and hemoglobin A1c-adjusted time in blood glucose (BG) band (HA-TIB) with mortality in critically ill patients.

DESIGN

Retrospective cohort investigation.

SETTING

University-affiliated adult medical-surgical ICU.

PATIENTS

Three thousand six hundred fifty-five patients with at least four BG tests and hemoglobin A1c (HbA1c) level admitted between September 14, 2014, and November 30, 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were stratified for HbA1c bands of <6.5%; 6.5-7.9%; greater than or equal to 8.0% with optimal affiliated glucose target ranges of 70-140, 140-180, and 180-250 mg/dL, respectively. HA-TIB, a new glycemic metric, defined the HbA1c-adjusted time in band. Relative hypoglycemia was defined as BG 70-110 mg/dL for patients with HbA1c ≥ 8.0%. Further stratification included diabetes status-no diabetes (NO-DM, n = 2,616) and preadmission treatment with or without insulin (DM-INS, n = 352; DM-No-INS, n = 687, respectively). Severity-adjusted mortality was calculated as the observed:expected mortality ratio (O:EMR), using the Acute Physiology and Chronic Health Evaluation IV prediction of mortality. Among NO-DM, mortality and O:EMR, decreased with higher TIB 70-140 mg/dL (p < 0.0001) and were lowest with TIB 90-100%. O:EMR was lower for HA-TIB greater than or equal to 50% than less than 50% and among all DM-No-INS but for DM-INS only those with HbA1 greater than or equal to 8.0%.Among all patients with hba1c greater than or equal to 8.0% And no bg less than 70 mg/dl, mortality was 18.0% For patients with relative hypoglycemia (bg, 70-110 mg/dl) (p < 0.0001) And was 0.0%, 12.9%, 13.0%, And 34.8% For patients with 0, 0.1-2.9, 3.0-11.9, And greater than or equal to 12.0 Hours of relative hypoglycemia (p < 0.0001).

CONCLUSIONS

These findings have considerable bearing on interpretation of previous trials of intensive insulin therapy in the critically ill. Moreover, they suggest that BG values in the 70-110 range may be deleterious for patients with HbA1c greater than or equal to 8.0% and that the appropriate target for BG should be individualized to HbA1c levels. These conclusions need to be tested in randomized trials.

Relative Hypoglycemia is Associated with Delirium in Critically Ill Patients with Diabetes: A Cohort Study

PURPOSE

Critically ill patients with premorbid diabetes can suffer from relative hypoglycemia (RHG), falling below the normal blood glucose (BG) target. However, these events have not been well defined or studied. In the present study, we aimed to explore the incidence and clinical significance of RHG events in critically ill patients with diabetes.

PATIENTS AND METHODS

Patients with a history of diabetes who stayed in the intensive care unit (ICU) for more than three days with at least 12 BG recordings were retrospectively included in the study. A BG level > 30% below the estimated average according to patient hemoglobin A1c measured at admission was defined as a single RHG event. Outcomes were compared between patients with and those without RHG events.

RESULTS

In total, 113 patients were included in the final analysis. RHG was detected in 73 patients (64.6%). Those who experienced RHG events had a significantly higher incidence of ICU delirium. They also had a higher risk of 28-day mortality, but this was not statistically significant. However, patients with a higher frequency of RHG events did have a significantly higher risk of overall mortality (57.1% for more than four events vs 15.4% for three to four events, P=0.006 and 15.1% for one to two events, P=0.003).

CONCLUSION

In conclusion, RHG is a common finding in critically ill patients with diabetes and is associated with mortality and the occurrence of delirium.

Individualised versus conventional glucose control in critically-ill patients: the CONTROLING study-a randomized clinical trial

Purpose

Hyperglycaemia is an adaptive response to stress commonly observed in critical illness. Its management remains debated in the intensive care unit (ICU). Individualising hyperglycaemia management, by targeting the patient’s pre-admission usual glycaemia, could improve outcome.

Methods

In a multicentre, randomized, double-blind, parallel-group study, critically-ill adults were considered for inclusion. Patients underwent until ICU discharge either individualised glucose control by targeting the pre-admission usual glycaemia using the glycated haemoglobin A1c level at ICU admission (IC group), or conventional glucose control by maintaining glycaemia below 180 mg/dL (CC group). A non-commercial web application of a dynamic sliding-scale insulin protocol gave to nurses all instructions for glucose control in both groups. The primary outcome was death within 90 days.

Results

Owing to a low likelihood of benefit and evidence of the possibility of harm related to hypoglycaemia, the study was stopped early. 2075 patients were randomized; 1917 received the intervention, 942 in the IC group and 975 in the CC group. Although both groups showed significant differences in terms of glycaemic control, survival probability at 90-day was not significantly different (IC group: 67.2%, 95% CI [64.2%; 70.3%]; CC group: 69.6%, 95% CI [66.7%; 72.5%]). Severe hypoglycaemia (below 40 mg/dL) occurred in 3.9% of patients in the IC group and in 2.5% of patients in the CC group (p = 0.09). A post hoc analysis showed for non-diabetic patients a higher risk of 90-day mortality in the IC group compared to the CC group (HR 1.3, 95% CI [1.05; 1.59], p = 0.018).

Conclusion

Targeting an ICU patient’s pre-admission usual glycaemia using a dynamic sliding-scale insulin protocol did not demonstrate a survival benefit compared to maintaining glycaemia below 180 mg/dL.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06526-8.

The paradox of the glycemic gap: Does relative hypoglycemia exist in critically ill patients?

BACKGROUND & AIMS

Elevated glycemic gap, as the differences between measured glucose and hemoglobin A1c (HbA1c)-derived average glucose (ADAG) levels, is a marker of stress-induced hyperglycemia and is a predictor of mortality in critically ill patients. Whether low glycemic gaps are associated with outcomes in critically ill patients remains unclear. We investigated the association of different glycemic gaps on mortality in critically ill patients.

METHODS

Totally 935 patients admitted to intensive care units (ICUs) were enrolled retrospectively after the exclusion of patients with absolute hypoglycemia, extreme hyperglycemia, and incomplete glycemic records. Patients were divided into 3 groups according to their glycemic gaps (<-29.7, -29.7-40, ≧40 mg/dL) at the time of ICU admission. The patients were followed for 1 year or until death.

RESULTS

Patients with low glycemic gap (glycemic gap < -29.7 mg/dL), which implied relative hypoglycemia, had lower serum glucose levels, higher HbA1c levels, and greater disease severity. Compared with medium group (glycemic gap -29.7-40 mg/dL), both the low and the high glycemic gap (glycemic gap ≧40 mg/dL) groups had significantly greater 30-day (log-rank p = 0.0464) and 1-year mortality (log-rank p = 0.0016). However, only the low glycemic gap group was independently associated with greater in-hospital mortality after adjusting for comorbidities (adjusted OR 1.78, 95% CI 1.00-3.16, p = 0.048).

CONCLUSION

This study revealed the presence of a U-shaped relationship between the glycemic gap and mortality in critically ill patients. Low glycemic gaps suggested relative hypoglycemia at the time of ICU admission, and were associated independently with greater in-hospital mortality.

Incidence, Risk Factors, and Attributable Mortality of Catheter-Related Bloodstream Infections in the Intensive Care Unit After Suspected Catheters Infection: A Retrospective 10-year Cohort Study

INTRODUCTION

Catheter management strategies for suspected catheter-related bloodstream infection (CRBSI) remain a major challenge in intensive care units (ICUs). The objective of this study was to determine the incidence, risk factors, and mortality attributable to CRBSIs in those patients.

METHODS

A population-based surveillance on suspected CRBSI was conducted from 2009 to 2018 in a tertiary care hospital in China. We used the results of catheter tip culture to identify patients with suspected CRBSIs. Demographics, systemic inflammatory response syndrome (SIRS) criteria, interventions, and microorganism culture results were analysed and compared between patients with and without confirmed CRBSIs. Univariate and multivariate analyses identified the risk factors for CRBSIs, and attributable mortality was evaluated with a time-varying Cox proportional hazard model.

RESULTS

In total, 686 patients with 795 episodes of suspected CRBSIs were included; 19.2% (153/795) episodes were confirmed as CRBSIs, and 17.4% (119/686) patients died within 30 days. The multifactor model shows that CRBSIs were associated with fever, hypotension, acute respiratory distress syndrome, hyperglycaemia and the use of continuous renal replacement therapy. The AUC was 77.0% (95% CI 73.3%-80.7%). The population attributable mortality fraction of CRBSI in patients was 18.2%, and mortality rate did not differ significantly between patients with and without CRBSIs (95% CI 0.464-1.279, P = 0.312).

CONCLUSIONS

This initial model based on the SIRS criteria is relatively better at identifying patients with CRBSI but only in domains of the sensitivity. There were no significant differences in attributable mortality due to CRBSI and other causes in patients with suspected CRBSI, which prompt catheter removal and re-insertion of new catheter may not benefit patients with suspected CRBSIs.

TRIAL REGISTRATION

China Clinical Trials Registration number; ChiCTR1900022175.

Elevation of blood glucose level predicts worse outcomes in hospitalized patients with COVID-19: a retrospective cohort study

INTRODUCTION

With intense deficiency of medical resources during COVID-19 pandemic, risk stratification is of strategic importance. Blood glucose level is an important risk factor for the prognosis of infection and critically ill patients. We aimed to investigate the prognostic value of blood glucose level in patients with COVID-19.

RESEARCH DESIGN AND METHODS

We collected clinical and survival information of 2041 consecutive hospitalized patients with COVID-19 from two medical centers in Wuhan. Patients without available blood glucose level were excluded. We performed multivariable Cox regression to calculate HRs of blood glucose-associated indexes for the risk of progression to critical cases/mortality among non-critical cases, as well as in-hospital mortality in critical cases. Sensitivity analysis were conducted in patient without diabetes.

RESULTS

Elevation of admission blood glucose level was an independent risk factor for progression to critical cases/death among non-critical cases (HR=1.30, 95% CI 1.03 to 1.63, p=0.026). Elevation of initial blood glucose level of critical diagnosis was an independent risk factor for in-hospital mortality in critical cases (HR=1.84, 95% CI 1.14 to 2.98, p=0.013). Higher median glucose level during hospital stay or after critical diagnosis (≥6.1 mmol/L) was independently associated with increased risks of progression to critical cases/death among non-critical cases, as well as in-hospital mortality in critical cases. Above results were consistent in the sensitivity analysis in patients without diabetes.

CONCLUSIONS

Elevation of blood glucose level predicted worse outcomes in hospitalized patients with COVID-19. Our findings may provide a simple and practical way to risk stratify COVID-19 inpatients for hierarchical management, particularly where medical resources are in severe shortage during the pandemic.