Endocrine aspects of critical illness

Association between circadian body temperature rhythm during the first 24 hours of ICU stay and 28-day mortality in elderly critically ill patients: A retrospective cohort study

Disrupted circadian temperature rhythm is commonly observed in elderly patients in the intensive care unit (ICU), but the association between circadian temperature rhythm and mortality in elderly patients is unclear. Adult patients with a relatively complete record of body temperature (BT) during the first 24 hours of ICU stay in the Multi-parameter Intelligent Monitoring in Intensive Care IV (MIMIC-IV) database were included in this retrospective cohort study. The circadian rhythm of body temperature was blunted as a ratio of the maximum BT between 12:00 and 24:00 divided by the minimum BT between 0:00 and 12:00, and we defined it as BT fluctuation ratio. The associations of BT fluctuation ratio with 28-day mortality were assessed separately using Cox proportional hazards model in elderly patients and non-elderly patients. The overall cohort comprised 12 767 patients. After adjusting for covariates, the analysis showed that the BT fluctuation ratio (%) was significantly associated with mortality at 28 days in total patients (hazard ratio: 1.044; 95% CI 1.001-1.088; P = 0.042), and still significantly in elderly patients (hazard ratio 1.055, 95% CI as 1.004-1.109, p = 0.035), but not significantly in non-elderly patients. The implementation of restricted cubic splines demonstrated a nonlinear correlation between the ratio of BT fluctuation and the hazard ratio of 28-day mortality, indicating that increased diurnal temperature fluctuations are linked to elevated risk of mortality. This study revealed that the augmented amplitude of the circadian rhythm of body temperature in the elderly patients constitutes a risk factor for the rise of 28-day mortality. Additionally, the circadian body temperature rhythm may facilitate the early detection of critically ill elderly patients.

Pneumonia in endangered aquatic mammals and the need for developing low-coverage vaccination for their management and conservation

Anthropogenic activities can lead to several devastating effects on the environment. The pollutants, which include the discharge of effluents, runoffs in the form of different lethal and sub-lethal concentrations of pesticides, heavy metals, and other contaminants, can harm exposed fauna and flora. The aquatic environment is the ultimate destination for many pollutants which negatively affect aquatic biodiversity and even can cause a species to become extinct. A pollutant can directly affect the behavior of an animal, disrupt cellular systems, and impair the immune system. This harm can be reduced and even mitigated by adopting proper approaches for the conservation of the target biota. Among aquatic organisms, cetaceans, such as the Yangtze finless porpoise, Irrawaddy dolphin, Ganges River dolphin, Amazon River dolphin, and Indus River dolphin, are at a higher risk of extinction because of lack of knowledge and research, and thus insufficient information with respect to their conservation status, management, and policies. Pneumonia is one of the leading causes of mass mortalities of cetaceans. This article reviews the limited research reported on stress and pneumonia induced by pollution, stress-induced pneumonia and immunosuppression, pneumonia-caused mass mortalities of aquatic mammals, and vaccination in wildlife with a specific focus on aquatic mammals, the role of genomics in vaccine development and vaccination, and the major challenges in vaccine development for biodiversity conservation.

Nocturnal Mean Arterial Pressure Rising Is Associated With Mortality in the Intensive Care Unit: A Retrospective Cohort Study

Background

Disrupted circadian rhythm of blood pressure is commonly observed in patients in the intensive care unit (ICU). This study assessed the association of nocturnal mean arterial pressure rising (NMAPR) with short‐ and long‐term mortality in critically ill adult patients.

Methods and Results

Adult patients with a complete record of mean arterial pressure monitoring during the first 24 hours of ICU stay in the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC‐II) database were included in this retrospective cohort study. All patients were divided into the non‐NMAPR group (≤1) or the NMAPR group (>1), according to the value of mean nighttime divided by daytime mean arterial pressure. The associations of NMAPR with ICU, hospital, 28‐day, and 1‐year mortality were assessed using multivariable logistic regression or a Cox proportional hazards model. Interaction and subgroup analyses were performed for those patients who had a first Sequential Organ Failure Assessment (SOFA) score of ≥8 or <8. The overall cohort comprised 5185 patients. The patients with NMAPR (n=1865) had higher ICU, hospital, 28‐day, and 1‐year mortality than the non‐NMAPR group (n=3320). After adjusting for covariates, the analysis showed that NMAPR was significantly associated with mortality in the ICU (odds ratio: 1.34; 95% CI, 1.10–1.65), in the hospital (odds ratio: 1.35; 95% CI, 1.12–1.63), at 28 days (hazard ratio: 1.27; 95% CI, 1.10–1.48), and at 1 year (hazard ratio: 1.24; 95% CI, 1.10–1.40). All results of the interaction analysis had no statistical significance, and similar results persisted in the patients with different SOFA scores.

Conclusions

NMAPR may aid in the early identification of critically ill patients at high risk of ICU, hospital, 28‐day, or 1‐year mortality.

Time-dependent association of glucocorticoids with adverse outcome in community-acquired pneumonia: a 6-year prospective cohort study

Background

The hypothalamic-pituitary-adrenal stress axis plays a crucial role in community-acquired pneumonia (CAP), with high cortisol being associated with disease severity and corticosteroid treatment resulting in earlier time to recovery. Our aim in the present study was to compare different glucocorticoid hormones, including cortisol, 11-deoxycortisol, cortisone, and corticosterone, regarding their association with short- and long-term adverse outcomes in a well-defined CAP cohort.

Methods

We prospectively followed 285 patients with CAP from a previous Swiss multicenter trial for a median of 6.1 years and measured different admission glucocorticoid serum levels by liquid chromatography coupled with tandem mass spectrometry. We used adjusted Cox regression models to investigate associations between admission hormone levels and all-cause mortality at different time points.

Results

Mortality was 5.3% after 30 days and increased to 47.3% after 6 years. High admission cortisol was associated with adverse outcome after 30 days (adjusted OR 3.85, 95% CI 1.10–13.49, p = 0.035). In the long term (i.e.,), however, high admission cortisol was associated with better survival (adjusted HR after 3 years 0.53, 95% CI 0.32–0.89, p = 0.017; adjusted HR after 6 years 0.57, 95% CI 0.36–0.90, p = 0.015). Compared with 11-deoxycortisol, cortisone, and corticosterone, cortisol showed the highest association with mortality.

Conclusions

Among different glucocorticoid hormones, cortisol showed the highest association with mortality in CAP. Whereas a more pronounced glucocorticoid stress response on hospital admission was associated with higher short-term adverse outcome, long-term outcome was favorable in these patients. These data should support the correct interpretation of glucocorticoid blood data.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1656-7) contains supplementary material, which is available to authorized users.

Neuron-Specific Enolase Is Correlated to Compromised Cerebral Metabolism in Patients Suffering from Acute Bacterial Meningitis; An Observational Cohort Study

Introduction

Patients suffering from acute bacterial meningitis (ABM) with a decreased level of consciousness have been shown to have an improved clinical outcome if treated with an intracranial pressure (ICP) guided therapy. By using intracranial microdialysis (MD) to monitor cerebral metabolism in combination with serum samples of biomarkers indicating brain tissue injury, S100B and Neuron Specific Enolase (NSE), additional information might be provided. The aim of this study was to evaluate biomarkers in serum and MD parameters in patients with ABM.

Methods

From a prior study on patients (n = 52) with a confirmed ABM and impaired consciousness (GCS ≤ 9, or GCS = 10 combined with lumbar spinal opening pressure > 400 mmH₂O), a subgroup of patients (n = 21) monitored with intracerebral MD and biomarkers was included in the present study. All patients were treated in the NICU with intracranial pressure (ICP) guided therapy. Serum biomarkers were obtained at admission and every 12 hours. The MD parameters glucose, lactate, pyruvate and glycerol were analyzed. Outcome was assessed at 12–55 months after discharge from hospital. Mann-Whitney U-Test and Wilcoxon matched-pairs signed rank test were applied.

Results

The included patients had a mean GCS of 8 (range, 3–10) on admission and increased ICP (>20 mmHg) was observed in 62% (n = 13/21) of the patients. Patients with a lactate:pyruvate ratio (LPR) >40 (n = 9/21, 43%) had significantly higher peak levels of serum NSE (p = 0.03), with similar, although non-significant observations made in patients with high levels of glycerol (>500 μmol/L, p = 0.11) and those with a metabolic crisis (Glucose <0.8 mmol/L, LPR >25, p = 0.09). No associations between serum S100B and MD parameters were found. Furthermore, median MD glucose levels decreased significantly between day 1 (0–24h) and day 3 (48–72h) after admission to the NICU (p = 0.0001). No correlation between MD parameters or biomarkers and outcome was found.

Conclusion

In this observational cohort study, we were able to show that cerebral metabolism is frequently affected in patients with ABM. Furthermore, patients with high LPR (LPR>40) had significantly higher levels of NSE, suggesting ongoing deterioration in compromised cerebral tissue. However, the potential clinical impact of MD and biomarker monitoring in ABM patients will need to be further elaborated in larger clinical trials.

Relationship among stress, depression, cardiovascular and metabolic changes and physical exercise

Abstract Introduction: Stress is considered one of the most significant health problems in modern society. It can be characterized as any changes in the homeostasis of an individual that require an adaptive response. An imbalance in the secretion of the primary stress mediators may be responsible for the onset and development of several diseases. Thus, chronic stress has been recognized as a risk factor for depression as well as cardiovascular and metabolic diseases. Given the pathophysiological mechanisms associated with chronic stress and related cardiovascular and metabolic changes, it is necessary to implement measures to prevent, control and/or avoid their development. Physical exercise is a non-pharmacological resource that is widely used for this purpose. Its beneficial effects include the improvement of the emotional state as well as lipid and glycemic control. Objective: The aim of this review is to discuss the relationship between stress, depression, cardiovascular and metabolic changes, and highlight the importance of physical exercise in the prevention and treatment of resulting disorders. Materials and Methods: We searched MEDLINE and SCIELO from 2000 through 2012, using the terms chronic stress, mood disorders, depression, cardiovascular and metabolic changes, and exercise. Results: Most of the studies found in our literature search have shown that exercise can attenuate and/or reverse the deleterious effects of chronic stress. Conclusion: Regular physical exercise is useful for maintaining health, especially with respect to improving mood and mental stress.

Systematic review regarding metabolic profiling for improved pathophysiological understanding of disease and outcome prediction in respiratory infections

Metabolic profiling through targeted quantification of a predefined subset of metabolites, performed by mass spectrometric analytical techniques, allows detailed investigation of biological pathways and thus may provide information about the interaction of different organic systems, ultimately improving understanding of disease risk and prognosis in a variety of diseases. Early risk assessment, in turn, may improve patient management in regard to cite-of-care decisions and treatment modalities. Within this review, we focus on the potential of metabolic profiling to improve our pathophysiological understanding of disease and management of patients. We focus thereby on lower respiratory tract infections (LRTI) including community-acquired pneumonia (CAP) and chronic obstructive pulmonary disease (COPD), an important disease responsible for high mortality, morbidity and costs worldwide. Observational data from numerous clinical and experimental studies have provided convincing data linking metabolic blood biomarkers such as lactate, glucose or cortisol to patient outcomes. Also, identified through metabolomic studies, novel innovative metabolic markers such as steroid hormones, biogenic amines, members of the oxidative status, sphingo- and glycerophospholipids, and trimethylamine-N-oxide (TMAO) have shown promising results. Since many uncertainties remain in predicting mortality in these patients, further prospective and retrospective observational studies are needed to uncover metabolic pathways responsible for mortality associated with LRTI. Improved understanding of outcome-specific metabolite signatures in LRTIs may optimize patient management strategies, provide potential new targets for future individual therapy, and thereby improve patients' chances for survival.

Serum levels of procalcitonin as a biomarker for differentiating between sepsis and systemic inflammatory response syndrome in the neurological intensive care unit

We explored the value of procalcitonin (PCT) to differentiate sepsis from systemic inflammatory response syndrome (SIRS), and determine sepsis severity in the neurological intensive care unit (NICU). Blood samples were measured for C-reactive protein (CRP) and PCT levels upon NICU admission, on the day of diagnosis of SIRS or sepsis, and at 3 and 7 days after diagnosis. We found that there were significant differences in serum levels of CRP and PCT as well as Glasgow Coma Scale (GCS) score upon admission between the SIRS and sepsis groups (p<0.05). CRP and white blood cell levels were not significantly different when attempting to differentiate sepsis severity (p>0.05). Multiple comparisons showed that significant differences in serum PCT levels were observed between sepsis and severe sepsis groups, as well as sepsis and septic shock groups (p<0.05). We obtained the highest sensitivity and specificity for SIRS and sepsis with cut-off values of 2 ng/mL for PCT, 44 mg/dL for CRP, and 4 for the GCS. There were no differences in CRP and PCT levels between cerebrovascular disease and non-cerebrovascular disease groups (p>0.05). No differences were found between viral and bacterial meningitis groups (p>0.05). PCT levels are valuable in discriminating sepsis from SIRS and determining sepsis severity in critically ill patients with neurological disease.

The Utility of Procalcitonin in Diagnosis of H1N1 Influenza in Intensive Care Patients

Procalcitonin (PCT) has been reported to differentiate between bacterial and viral causes of respiratory tract infections. We aimed to assess its ability to discriminate between viral and bacterial infection during the H1N1 pandemic of 2009. The design of this study was a retrospective single centre case series review. Subjects were 17 adult patients admitted to the intensive care unit with suspected or confirmed isolated H1N1 influenza infection, from whom a PCT level was assessed within 24 hours of admission. All patients were admitted during the H1N1 pandemic in Queensland from 6 July 2009 to 2 August 2009.

The relationship between PCT levels and H1N1 status was measured by a Wilcoxon rank sum test. Patients were proven to have isolated H1N1 infection as judged by Polymerase Chain Reaction, with no bacterial super-infection. Of this number, 37% had a PCT <1 μg/l, and 63% of patients had an indeterminate PCT between 1 and 10 μg/l.

The demographics of all 17 patients were mean age 48.2 years (SD 13.6 years); 59% female; mean Acute Physiological and Chronic Health Evaluation II score 20.3 (SD 5.8); mean intensive care unit 477.5 hours (SD 330.0 hours); 82% of cases required mechanical ventilation; 24% of cases required extracorporeal membrane oxygenation and 94% of cases were alive at intensive care unit discharge.

PCT was neither sensitive nor specific in determining isolated H1N1 infection in this series of patients. The use of PCT to assist in isolation triage of patients suspected of infection with H1N1 influenza in the intensive care unit should be made with caution. A larger study may be required.

Procalcitonin in sepsis and systemic inflammation: a harmful biomarker and a therapeutic target

The worldwide yearly mortality from sepsis is substantial, greater than that of cancer of the lung and breast combined. Moreover, its incidence is increasing, and its response to therapy has not appreciably improved. In this condition, the secretion of procalcitonin (ProCT), the prohormone of calcitonin, is augmented greatly, attaining levels up to thousands of fold of normal. This hypersecretion emanates from multiple tissues throughout the body that are not traditionally viewed as being endocrine. The serum values of ProCT correlate with the severity of sepsis; they recede with its improvement and worsen with exacerbation. Accordingly, as highlighted in this review, serum ProCT has become useful as a biomarker to assist in the diagnosis of sepsis, as well as related infectious or inflammatory conditions. It is also a useful monitor of the clinical course and prognosis, and sensitive and specific assays have been developed for its measurement. Moreover, it has been demonstrated that the administration of ProCT to septic animals greatly increases mortality, and several toxic effects of ProCT have been elucidated by in vitro experimental studies. Antibodies have been developed that neutralize the harmful effects of ProCT, and their use markedly decreases the symptomatology and mortality of animals that harbour a highly virulent sepsis analogous to that occurring in humans. This therapy is facilitated by the long duration of serum ProCT elevation, which allows for a broad window of therapeutic opportunity. An experimental groundwork has been established that suggests a potential applicability of such therapy in septic humans.

Glycemic control and the injured brain

The interaction between glycemic control and critical neurologic illness and injury is complex. Hyperglycemia can be either the cause or the result of severe brain injury. Hyperglycemia in acute neurologic injury is associated with worse neurologic outcomes. Demographic patterns, including an aging population and shifts in racial and ethnic representation, contribute to the increasing prevalence of hyperglycemia and diabetes among victims of the most common neurologic emergencies. This article reviews the epidemiology of the problem, relevant pathophysiology, the use of tight glycemic control therapy in other populations, and the potential for tight glycemic control as a way to improve outcomes after acute neurologic illness and injury.

Serum procalcitonin at the time of admission to the ICU as a predictor of short-term mortality

OBJECTIVE

This purpose of this study was to determine if serum procalcitonin (PCT) concentration at the time of admission to the ICU is a predictor of all-cause short-term mortality.

DESIGN AND METHODS

This prospective cross-sectional study was conducted over a 16-month period with 86 consecutive critically ill patients. The semi-quantitative PCT-Q test was performed and APACHE II scores and C-reactive protein (CRP) concentrations were determined within 24 h of admission.

RESULTS

PCT-Q test value was a better predictor of all-cause short-term mortality than CRP value or APACHE II score. PCT > or = 10 ng/mL was highly and independently correlated with mortality. Use of PCT-Q > or = 10 ng/mL was superior to use of APACHE II > or = 25 or CRP > or = 10 mg/dL as a predictor of poor outcome.

CONCLUSIONS

A PCT-Q value > or = 10 ng/mL obtained at the time of admission to the ICU is a strong predictor of short-term mortality.