A Patient-Level Meta-Analysis of Intensive Glucose Control in Critically Ill Adults.

BACKGROUND: Whether intensive glucose control reduces mortality in critically ill patients remains uncertain. Patient-level meta-analyses can provide more precise estimates of treatment effects than are currently available. METHODS: We pooled individual patient data from randomized trials investigating intensive glucose control in critically ill adults. The primary outcome was in-hospital mortality. Secondary outcomes included survival to 90 days and time to live cessation of treatment with vasopressors or inotropes, mechanical ventilation, and newly commenced renal replacement. Severe hypoglycemia was a safety outcome. RESULTS: Of 38 eligible trials (n=29,537 participants), 20 (n=14,171 participants) provided individual patient data including in-hospital mortality status for 7059 and 7049 participants allocated to intensive and conventional glucose control, respectively. Of these 1930 (27.3%) and 1891 (26.8%) individuals assigned to intensive and conventional control, respectively, died (risk ratio, 1.02; 95% confidence interval [CI], 0.96 to 1.07; P=0.52; moderate certainty). There was no apparent heterogeneity of treatment effect on in-hospital mortality in any examined subgroups. Intensive glucose control increased the risk of severe hypoglycemia (risk ratio, 3.38; 95% CI, 2.99 to 3.83; P<0.0001). CONCLUSIONS: Intensive glucose control was not associated with reduced mortality risk but increased the risk of severe hypoglycemia. We did not identify a subgroup of patients in whom intensive glucose control was beneficial. (Funded by the Australian National Health and Medical Research Council and others; PROSPERO number CRD42021278869.).

Intensive glucose control in critically ill adults: a protocol for a systematic review and individual patient data meta-analysis / Controle intensivo da glicose em adultos em estado grave: um protocolo de revisão sistemática e metanálise de dados individuais de pacientes

ABSTRACT Objective: The optimal target for blood glucose concentration in critically ill patients is unclear. We will perform a systematic review and meta-analysis with aggregated and individual patient data from randomized controlled trials, comparing intensive glucose control with liberal glucose control in critically ill adults. Data sources: MEDLINE®, Embase, the Cochrane Central Register of Clinical Trials, and clinical trials registries (World Health Organization, clinical trials.gov). The authors of eligible trials will be invited to provide individual patient data. Published trial-level data from eligible trials that are not at high risk of bias will be included in an aggregated data meta-analysis if individual patient data are not available. Methods: Inclusion criteria: randomized controlled trials that recruited adult patients, targeting a blood glucose of ≤ 120mg/dL (≤ 6.6mmol/L) compared to a higher blood glucose concentration target using intravenous insulin in both groups. Excluded studies: those with an upper limit blood glucose target in the intervention group of > 120mg/dL (> 6.6mmol/L), or where intensive glucose control was only performed in the intraoperative period, and those where loss to follow-up exceeded 10% by hospital discharge. Primary endpoint: In-hospital mortality during index hospital admission. Secondary endpoints: mortality and survival at other timepoints, duration of invasive mechanical ventilation, vasoactive agents, and renal replacement therapy. A random effect Bayesian meta-analysis and hierarchical Bayesian models for individual patient data will be used. Discussion: This systematic review with aggregate and individual patient data will address the clinical question, 'what is the best blood glucose target for critically ill patients overall?' Protocol version 0.4 - 06/26/2023 PROSPERO registration: CRD42021278869

RESUMO Objetivo: Não está claro qual é a meta ideal de concentração de glicose no sangue em pacientes em estado grave. Realizaremos uma revisão sistemática e uma metanálise com dados agregados e de pacientes individuais de estudos controlados e randomizados, comparando o controle intensivo da glicose com o controle liberal da glicose em adultos em estado grave. Fontes de dados: MEDLINE®, Embase, Cochrane Central Register of Clinical Trials e registros de ensaios clínicos (Organização Mundial da Saúde, clinical trials.gov). Os autores dos estudos qualificados serão convidados a fornecer dados individuais de pacientes. Os dados publicados em nível de ensaio qualificado que não apresentem alto risco de viés serão incluídos em uma metanálise de dados agregados se os dados individuais de pacientes não estiverem disponíveis. Métodos: Critérios de inclusão: ensaios clínicos controlados e randomizados que recrutaram pacientes adultos, com meta de glicemia ≤ 120mg/dL (≤ 6,6mmol/L) comparada a uma meta de concentração de glicemia mais alta com insulina intravenosa em ambos os grupos. Estudos excluídos: aqueles com meta de glicemia no limite superior no grupo de intervenção > 120mg/dL (> 6,6mmol/L), ou em que o controle intensivo de glicose foi realizado apenas no período intraoperatório, e aqueles em que a perda de seguimento excedeu 10% até a alta hospitalar. Desfecho primário: Mortalidade intra-hospitalar durante a admissão hospitalar. Desfechos secundários: Mortalidade e sobrevida em outros momentos, duração da ventilação mecânica invasiva, agentes vasoativos e terapia de substituição renal. Utilizaremos metanálise bayesiana de efeito randômico e modelos bayesianos hierárquicos para dados individuais de pacientes. Discussão: Essa revisão sistemática com dados agregados e de pacientes individuais abordará a questão clínica: Qual é a melhor meta de glicose no sangue de pacientes graves em geral? Protocolo versão 0.4 - 26/06/2023 Registro PROSPERO: CRD42021278869

Intensive glucose control in critically ill adults: a protocol for a systematic review and individual patient data meta-analysis.

OBJECTIVE: The optimal target for blood glucose concentration in critically ill patients is unclear. We will perform a systematic review and meta-analysis with aggregated and individual patient data from randomized controlled trials, comparing intensive glucose control with liberal glucose control in critically ill adults. DATA SOURCES: MEDLINE®, Embase, the Cochrane Central Register of Clinical Trials, and clinical trials registries (World Health Organization, clinical trials.gov). The authors of eligible trials will be invited to provide individual patient data. Published trial-level data from eligible trials that are not at high risk of bias will be included in an aggregated data meta-analysis if individual patient data are not available. METHODS: Inclusion criteria: randomized controlled trials that recruited adult patients, targeting a blood glucose of ≤ 120mg/dL (≤ 6.6mmol/L) compared to a higher blood glucose concentration target using intravenous insulin in both groups. Excluded studies: those with an upper limit blood glucose target in the intervention group of > 120mg/dL (> 6.6mmol/L), or where intensive glucose control was only performed in the intraoperative period, and those where loss to follow-up exceeded 10% by hospital discharge. PRIMARY ENDPOINT: In-hospital mortality during index hospital admission. Secondary endpoints: mortality and survival at other timepoints, duration of invasive mechanical ventilation, vasoactive agents, and renal replacement therapy. A random effect Bayesian meta-analysis and hierarchical Bayesian models for individual patient data will be used. DISCUSSION: This systematic review with aggregate and individual patient data will address the clinical question, 'what is the best blood glucose target for critically ill patients overall?'Protocol version 0.4 - 06/26/2023PROSPERO registration:CRD42021278869.

A randomised controlled trial and cost-effectiveness analysis of high-frequency oscillatory ventilation against conventional artificial ventilation for adults with acute respiratory distress syndrome. The OSCAR (OSCillation in ARDS) study.

BACKGROUND: Patients with the acute respiratory distress syndrome (ARDS) require artificial ventilation but this treatment may produce secondary lung damage. High-frequency oscillatory ventilation (HFOV) may reduce this damage. OBJECTIVES: To determine the clinical benefit and cost-effectiveness of HFOV in patients with ARDS compared with standard mechanical ventilation. DESIGN: A parallel, randomised, unblinded clinical trial. SETTING: UK intensive care units. PARTICIPANTS: Mechanically ventilated patients with a partial pressure of oxygen in arterial blood/fractional concentration of inspired oxygen (P : F) ratio of 26.7 kPa (200 mmHg) or less and an expected duration of ventilation of at least 2 days at recruitment. INTERVENTIONS: Treatment arm HFOV using a Novalung R100(®) ventilator (Metran Co. Ltd, Saitama, Japan) ventilator until the start of weaning. Control arm Conventional mechanical ventilation using the devices available in the participating centres. MAIN OUTCOME MEASURES: The primary clinical outcome was all-cause mortality at 30 days after randomisation. The primary health economic outcome was the cost per quality-adjusted life-year (QALY) gained. RESULTS: One hundred and sixty-six of 398 patients (41.7%) randomised to the HFOV group and 163 of 397 patients (41.1%) randomised to the conventional mechanical ventilation group died within 30 days of randomisation (p = 0.85), for an absolute difference of 0.6% [95% confidence interval (CI) -6.1% to 7.5%]. After adjustment for study centre, sex, Acute Physiology and Chronic Health Evaluation II score, and the initial P : F ratio, the odds ratio for survival in the conventional ventilation group was 1.03 (95% CI 0.75 to 1.40; p = 0.87 logistic regression). Survival analysis showed no difference in the probability of survival up to 12 months after randomisation. The average QALY at 1 year in the HFOV group was 0.302 compared to 0.246. This gives an incremental cost-effectiveness ratio (ICER) for the cost to society per QALY of £88,790 and an ICER for the cost to the NHS per QALY of £ 78,260. CONCLUSIONS: The use of HFOV had no effect on 30-day mortality in adult patients undergoing mechanical ventilation for ARDS and no economic advantage. We suggest that further research into avoiding ventilator-induced lung injury should concentrate on ventilatory strategies other than HFOV. TRIAL REGISTRATION: Current Controlled Trials ISRCTN10416500.

Pulmonary retention of primed neutrophils: a novel protective host response, which is impaired in the acute respiratory distress syndrome.

RATIONALE: Acute respiratory distress syndrome (ARDS) affects over 200000 people annually in the USA. Despite causing severe, and often refractory, hypoxaemia, the high mortality and long-term morbidity of ARDS results mainly from extra-pulmonary organ failure; however the mechanism for this organ crosstalk has not been determined. METHODS: Using autologous radiolabelled neutrophils we investigated the pulmonary transit of primed and unprimed neutrophils in humans. Flow cytometry of whole blood samples was used to assess transpulmonary neutrophil priming gradients in patients with ARDS, sepsis and perioperative controls. MAIN RESULTS: Unprimed neutrophils passed through the lungs with a transit time of 14.2 s, only 2.3 s slower than erythrocytes, and with <5% first-pass retention. Over 97% of neutrophils primed ex vivo with granulocyte macrophage colony-stimulating factor were retained on first pass, with 48% still remaining in the lungs at 40 min. Neutrophils exposed to platelet-activating factor were initially retained but subsequently released such that only 14% remained in the lungs at 40 min. Significant transpulmonary gradients of neutrophil CD62L cell surface expression were observed in ARDS compared with perioperative controls and patients with sepsis. CONCLUSIONS: We demonstrated minimal delay and retention of unprimed neutrophils transiting the healthy human pulmonary vasculature, but marked retention of primed neutrophils; these latter cells then 'deprime' and are re-released into the systemic circulation. Further, we show that this physiological depriming mechanism may fail in patients with ARDS, resulting in increased numbers of primed neutrophils within the systemic circulation. This identifies a potential mechanism for the remote organ damage observed in patients with ARDS.

Clinical review: Consensus recommendations on measurement of blood glucose and reporting glycemic control in critically ill adults.

The management reporting and assessment of glycemic control lacks standardization. The use of different methods to measure the blood glucose concentration and to report the performance of insulin treatment yields major disparities and complicates the interpretation and comparison of clinical trials. We convened a meeting of 16 experts plus invited observers from industry to discuss and where possible reach consensus on the most appropriate methods to measure and monitor blood glucose in critically ill patients and on how glycemic control should be assessed and reported. Where consensus could not be reached, recommendations on further research and data needed to reach consensus in the future were suggested. Recognizing their clear conflict of interest, industry observers played no role in developing the consensus or recommendations from the meeting. Consensus recommendations were agreed for the measurement and reporting of glycemic control in clinical trials and for the measurement of blood glucose in clinical practice. Recommendations covered the following areas: How should we measure and report glucose control when intermittent blood glucose measurements are used? What are the appropriate performance standards for intermittent blood glucose monitors in the ICU? Continuous or automated intermittent glucose monitoring - methods and technology: can we use the same measures for assessment of glucose control with continuous and intermittent monitoring? What is acceptable performance for continuous glucose monitoring systems? If implemented, these recommendations have the potential to minimize the discrepancies in the conduct and reporting of clinical trials and to improve glucose control in clinical practice. Furthermore, to be fit for use, glucose meters and continuous monitoring systems must match their performance to fit the needs of patients and clinicians in the intensive care setting.

Diabetic status and the relation of the three domains of glycemic control to mortality in critically ill patients: an international multicenter cohort study.

INTRODUCTION: Hyperglycemia, hypoglycemia, and increased glycemic variability have each been independently associated with increased risk of mortality in critically ill patients. The role of diabetic status on modulating the relation of these three domains of glycemic control with mortality remains uncertain. The purpose of this investigation was to determine how diabetic status affects the relation of hyperglycemia, hypoglycemia, and increased glycemic variability with the risk of mortality in critically ill patients. METHODS: This is a retrospective analysis of prospectively collected data involving 44,964 patients admitted to 23 intensive care units (ICUs) from nine countries, between February 2001 and May 2012. We analyzed mean blood glucose concentration (BG), coefficient of variation (CV), and minimal BG and created multivariable models to analyze their independent association with mortality. Patients were stratified according to the diagnosis of diabetes. RESULTS: Among patients without diabetes, mean BG bands between 80 and 140 mg/dl were independently associated with decreased risk of mortality, and mean BG bands>or=140 mg/dl, with increased risk of mortality. Among patients with diabetes, mean BG from 80 to 110 mg/dl was associated with increased risk of mortality and mean BG from 110 to 180 mg/dl with decreased risk of mortality. An effect of center was noted on the relation between mean BG and mortality. Hypoglycemia, defined as minimum BG<70 mg/dl, was independently associated with increased risk of mortality among patients with and without diabetes and increased glycemic variability, defined as CV>or=20%, was independently associated with increased risk of mortality only among patients without diabetes. Derangements of more than one domain of glycemic control had a cumulative association with mortality, especially for patients without diabetes. CONCLUSIONS: Although hyperglycemia, hypoglycemia, and increased glycemic variability is each independently associated with mortality in critically ill patients, diabetic status modulates these relations in clinically important ways. Our findings suggest that patients with diabetes may benefit from higher glucose target ranges than will those without diabetes. Additionally, hypoglycemia is independently associated with increased risk of mortality regardless of the patient's diabetic status, and increased glycemic variability is independently associated with increased risk of mortality among patients without diabetes.

High-frequency oscillation for acute respiratory distress syndrome.

BACKGROUND: Patients with the acute respiratory distress syndrome (ARDS) require mechanical ventilation to maintain arterial oxygenation, but this treatment may produce secondary lung injury. High-frequency oscillatory ventilation (HFOV) may reduce this secondary damage. METHODS: In a multicenter study, we randomly assigned adults requiring mechanical ventilation for ARDS to undergo either HFOV with a Novalung R100 ventilator (Metran) or usual ventilatory care. All the patients had a ratio of the partial pressure of arterial oxygen (PaO) to the fraction of inspired oxygen (FiO) of 200 mm Hg (26.7 kPa) or less and an expected duration of ventilation of at least 2 days. The primary outcome was all-cause mortality 30 days after randomization. RESULTS: There was no significant between-group difference in the primary outcome, which occurred in 166 of 398 patients (41.7%) in the HFOV group and 163 of 397 patients (41.1%) in the conventional-ventilation group (P=0.85 by the chi-square test). After adjustment for study center, sex, score on the Acute Physiology and Chronic Health Evaluation (APACHE) II, and the initial PaO:FiO ratio, the odds ratio for survival in the conventional-ventilation group was 1.03 (95% confidence interval, 0.75 to 1.40; P=0.87 by logistic regression). CONCLUSIONS: The use of HFOV had no significant effect on 30-day mortality in patients undergoing mechanical ventilation for ARDS. (Funded by the National Institute for Health Research Health Technology Assessment Programme; OSCAR Current Controlled Trials number, ISRCTN10416500.).

The metrics of glycaemic control in critical care.

INTRODUCTION: Trials of tight glucose control have compared measures of central tendency, such as average blood glucose, and yielded conflicting results. Other metrics, such as standard deviation, reflect different properties of glucose control and are also associated with changes in outcome. It is possible, therefore, that the conflicting results from interventional studies arise from effects on glycaemic control that have not been reported. METHODS: Using glucose measurements from patients admitted to four adult intensive care units in one UK hospital, we sought to identify metrics of glycaemic control, examine the relationship between them and identify the metrics that are both independently and most strongly associated with outcome. RESULTS: We examined nine previously described metrics and identified a further four. Cluster analysis classified these metrics into two families, namely, those reflecting measures of central tendency and those reflecting measures of dispersion. A measure of minimum glucose was also identified but related to neither family. Plots of the quintiles of these metrics against hospital mortality revealed population-specific relationships. Areas under receiver-operating characteristic curves could not identify an optimum metric of central tendency or dispersion. Using odds ratios, we were able to show that the effect of these metrics is independent of one another. CONCLUSION: Our results suggest that glycaemic control is associated with outcome on the basis of three independent metrics, reflecting measures of central tendency, measures of dispersion and a measure of minimum glucose.

Blast injuries to the lung: epidemiology and management.

Lung injury is frequently a component of the polytrauma sustained by military personnel surviving blast on the battlefield. This article describes a case series of the military casualties admitted to University Hospital Birmingham's critical care services (role 4 facility), during the period 1 July 2008 to 15 January 2010. Of the 135 casualties admitted, 107 (79.2%) were injured by explosive devices. Plain chest films taken soon after arrival in the role 4 facility were reviewed in 96 of the 107 patients. In 55 (57.3%) films a tracheal tube was present. One or more radiological abnormalities was present in 66 (68.75%) of the films. Five patients met the consensus criteria for the definition of adult respiratory distress syndrome (ARDS). The majority of casualties with blast-related lung injury were successfully managed with conventional ventilatory support employing a lung protective strategy; only a small minority received non-conventional support at any time in the form of high-frequency oscillatory ventilation. Of those casualties who survived to be received by the role 4 facility, none subsequently died as a consequence of lung injury.

Successful salvage right upper lobectomy and flap repair of trachea-esophageal fistula due to severe necrotizing pneumonia.

A 55-year-old previously well man developed a severe pneumonia. Endoscopy found tracheal and esophageal fistulae communicating with the right lung and pleural space. Bilateral main bronchi intubation was required. Emergency surgery was performed with a latissimus dorsi and serratus anterior muscle flap to close the tracheal and esophageal fistulae. The right upper lobe was found to be destroyed and resected. It was possible to salvage the patient who was discharged home despite challenging anesthetic and surgical circumstances.

C-reactive protein concentrations during bacteraemia: A comparison between patients with and without liver dysfunction.

OBJECTIVE: To evaluate the value of serum C-reactive protein (CRP) concentrations as a marker of sepsis in patients with biochemical evidence of liver dysfunction. DESIGN: A retrospective case-control comparison of serum CRP concentrations between patients with and those without liver dysfunction (prothrombin time over 18 s and serum bilirubin > or = 20 micromol/l) during their first episode of bacteraemia. SETTING: The neurosciences and general adult intensive care units of a university teaching hospital. PATIENTS: Any patient from the above settings with a first episode of bacteraemia (first isolate of pathogenic bacteria from blood cultures) over a 3-year period. MEASUREMENTS AND RESULTS: After exclusions 126 first episodes of bacteraemia were identified, of which 33 were in patients with liver dysfunction. Serum CRP concentrations were significantly lower in patients with liver dysfunction (median 103 mg/l, IQR 29-204) than in those without (146 mg/l, 74, > 250). CONCLUSIONS: Patients with biochemical evidence of liver disease generate significantly lower serum CRP concentrations during bacteraemia than patients without liver dysfunction. Serum CRP concentrations should be interpreted with caution in patients with liver disease to diagnose and monitor bacterial sepsis.

Hypoglycemia and cardiac arrest in a critically ill patient on strict glycemic control.

Glycemic control in critically ill patients has become a subject of considerable interest since the publication of studies showing reduced morbidity and mortality in patients when blood glucose was maintained within a relatively low and narrow range (4.4 to 6.1 mM/L). We describe a patient who developed cardiac asystole while being given a concentrated glucose solution to treat severe hypoglycemia after administration of insulin. The mechanism in this patient appears to be hyperkalemia from the rapid administration of a concentrated glucose solution.