Predictive value of ionized calcium in critically ill patients: an analysis of a large clinical database MIMIC II

Serum calcium and mortality in pediatric pneumonia patients admitted to the PICU: a retrospective cohort study

This study investigates serum calcium's prognostic value in pediatric pneumonia, focusing on its correlation with PICU mortality, to enhance understanding and treatment approaches in this field. Data from 414 pediatric pneumonia patients (2010-2019) admitted to the intensive care units at the Children's Hospital, Zhejiang University School of Medicine were analyzed. The study utilized restricted cubic spline analysis, Cox proportional hazard regression, and Kaplan-Meier survival curve analysis to assess the relationship between serum calcium levels at admission and PICU mortality risk. After adjusting for multivariate factors, for each 1 mmol/dL increase in serum calcium, the risk of mortality decreased by 24% (HR: 0.76, 95% CI 0.67-0.87). Among the three levels of serum calcium groups, higher serum calcium levels were linked to a 63% reduction in the mortality rate compared to lower levels (HR: 0.37, 95% CI 0.16-0.84). The cumulative hazard estimates of mortality significantly differed across serum calcium groups (log-rank P = 0.032). This association was consistent across diverse subgroups (P for interaction > 0.05). Higher serum calcium levels are associated with decreased PICU mortality in pediatric pneumonia, highlighting its potential as a prognostic marker.

Calcium supplementation during trauma resuscitation: a propensity score-matched analysis from the TraumaRegister DGU®

BACKGROUND

In major trauma patients, hypocalcemia is associated with increased mortality. Despite the absence of strong evidence on causality, early calcium supplementation has been recommended. This study investigates whether calcium supplementation during trauma resuscitation provides a survival benefit.

METHODS

We conducted a retrospective analysis using data from the TraumaRegister DGU® (2015-2019), applying propensity score matching to balance demographics, injury severity, and management between major trauma patients with and without calcium supplementation. 6 h mortality, 24 h mortality, and in-hospital mortality were considered as primary outcome parameters.

RESULTS

Within a cohort of 28,323 directly admitted adult major trauma patients at a European trauma center, 1593 (5.6%) received calcium supplementation. Using multivariable logistic regression to generate propensity scores, two comparable groups of 1447 patients could be matched. No significant difference in early mortality (6 h and 24 h) was observed, while in-hospital mortality appeared higher in those with calcium supplementation (28.3% vs. 24.5%, P = 0.020), although this was not significant when adjusted for predicted mortality (P = 0.244).

CONCLUSION

In this matched cohort, no evidence was found for or against a survival benefit from calcium supplementation during trauma resuscitation. Further research should focus on understanding the dynamics and kinetics of ionized calcium levels in major trauma patients and identify if specific conditions or subgroups could benefit from calcium supplementation.

Investigating Potential Correlations between Calcium Metabolism Biomarkers and Periprocedural Clinical Events in Major Cardiovascular Surgeries: An Exploratory Study

Background: There is emerging but conflicting evidence regarding the association between calcium biomarkers, more specifically ionized calcium and the prognosis of intensive care unit (ICU) postoperative cardiac patients. Methods: Our study investigated the relationship between ionized calcium, vitamin D, and periprocedural clinical events such as cardiac, neurologic and renal complications, major bleeding, vasoactive-inotropic score (VIS), and length of ICU and hospitalization. Results: Our study included 83 consecutive subjects undergoing elective major cardiac surgery requiring cardiopulmonary bypass. The mean age of the participants was 64.9 ± 8.5 years. The majority of procedures comprised isolated CABG (N = 26, 31.3%), aortic valve procedures (N = 26, 31.3%), and mitral valve procedures (N = 12, 14.5%). A difference in calcium levels across all time points (p < 0.001) was observed, with preoperative calcium being directly associated with intraoperative VIS (r = 0.26, p = 0.016). On day 1, calcium levels were inversely associated with the duration of mechanical ventilation (r = -0.30, p = 0.007) and the length of hospital stay (r = -0.22, p = 0.049). At discharge, calcium was inversely associated with length of hospital stay (r = -0.22, p = 0.044). All calcium levels tended to be lower in those who died during the 1-year follow-up (p = 0.054). Preoperative vitamin D levels were significantly higher in those who experienced AKI during hospitalization (median 17.5, IQR 14.5-17.7, versus median 15.3, IQR 15.6-20.5, p = 0.048) Conclusion: Fluctuations in calcium levels and vitamin D may be associated with the clinical course of patients undergoing cardiac surgery. In our study, hypocalcemic patients exhibited a greater severity of illness, as evidenced by elevated VIS scores, and experienced prolonged mechanical ventilation time and hospital stays. Additional larger-scale studies are required to gain a deeper understanding of their impact on cardiac performance and the process of weaning from cardiopulmonary bypass, as well as to distinguish between causal and associative relationships.

Small vs. Large Library Docking for Positive Allosteric Modulators of the Calcium Sensing Receptor

Drugs acting as positive allosteric modulators (PAMs) to enhance the activation of the calcium sensing receptor (CaSR) and to suppress parathyroid hormone (PTH) secretion can treat hyperparathyroidism but suffer from side effects including hypocalcemia and arrhythmias. Seeking new CaSR modulators, we docked libraries of 2.7 million and 1.2 billion molecules against transforming pockets in the active-state receptor dimer structure. Consistent with simulations suggesting that docking improves with library size, billion-molecule docking found new PAMs with a hit rate that was 2.7-fold higher than the million-molecule library and with hits up to 37-fold more potent. Structure-based optimization of ligands from both campaigns led to nanomolar leads, one of which was advanced to animal testing. This PAM displays 100-fold the potency of the standard of care, cinacalcet, in ex vivo organ assays, and reduces serum PTH levels in mice by up to 80% without the hypocalcemia typical of CaSR drugs. Cryo-EM structures with the new PAMs show that they induce residue rearrangements in the binding pockets and promote CaSR dimer conformations that are closer to the G-protein coupled state compared to established drugs. These findings highlight the promise of large library docking for therapeutic leads, especially when combined with experimental structure determination and mechanism.

Predictive value of serum albumin and calcium levels in burn patients with Pseudomonas aeruginosa infection: A comprehensive analysis of clinical outcomes

In the ongoing challenge to reduce burn-associated mortality rates, this study explores the predictive capacity of clinical factors in burn patients, focusing on vitamin D, calcium, and serum albumin levels during hospitalisation in cases with Pseudomonas aeruginosa infection. Our research involves a comprehensive analysis of 100 burn patients, encompassing crucial clinical parameters such as the burn severity index, serum albumin, vitamin D, and calcium levels at admission. Data were meticulously entered into IBM Statistics SPSS software version 28 and subjected to statistical analysis. The study reveals an average patient age of 39.75 years and a notable 34% mortality rate. Additionally, the average lengths of hospital and intensive care unit (ICU) stays are determined to be 11.33 and 7.79 days, respectively. Significantly, a correlation between calcium and albumin variables and treatment outcomes is established, showcasing their potential to predict variable changes in patient mortality rates. Furthermore, a noteworthy association is observed between serum calcium levels and the duration of ICU hospitalisation. In conclusion, albumin and calcium variables emerge as sensitive and specific indicators for predicting outcomes in burn patients. Importantly, the independence of these factors from the physician's experience and diagnosis reduces human error and thus increases the accuracy of mortality prediction in this patient population.

Can Patients with Electrolyte Disturbances Be Safely and Effectively Treated in a Hospital-at-Home, Telemedicine-Controlled Environment? A Retrospective Analysis of 267 Patients

BACKGROUND

Morbidities indicated for hospital-at-home (HAH) treatment include infectious diseases and exacerbations of chronic conditions. Electrolyte disturbances are not included per se. However, their rate is high. We aimed to describe our experience via the monitoring and treatment of such patients.

METHODS

This was a retrospective analysis of patients in the setting of telemedicine-controlled HAH treatment. We collected data from the electronic medical records of patients who presented electrolyte disturbances.

RESULTS

For 14 months, we treated 267 patients in total in HAH settings, with a mean age of 72.2 + 16.4, 44.2% for males. In total, 261 (97.75%) patients were flagged with electrolyte disturbances, of whom 149 had true electrolyte disturbances. Furthermore, 67 cases (44.96%) had hyponatremia, 9 (6.04%) had hypernatremia after correction for hyperglycemia, 20 (13.42%) had hypokalemia and 27 (18.12%) had hyperkalemia after the exclusion of hemolytic samples. Ten (6.09%) patients had hypocalcemia and two (1.34%) had hypercalcemia corrected to albumin levels. Thirteen (8.72%) patients had hypomagnesemia and one (0.67%) had hypermagnesemia. Patients with electrolyte disturbances suffered from more chronic kidney disease (24.2% vs. 12.2%; p = 0.03) and malignancy (6.3% vs. 0.6%; p = 0.006), and were more often treated with diuretics (12.6% vs. 4.1%; p = 0.016). No patient died or suffered from clinically significant cardiac arrhythmias.

CONCLUSIONS

The extent of electrolyte disturbances amongst HAH treatment patients is high. The monitoring and treatment of such patients can be conducted safely in this setting.

Effect Modification of Kidney Function on the Non-linear Association Between Serum Calcium Levels and Cardiovascular Mortality in Korean Adults

OBJECTIVES

This study aimed to evaluate the potential interaction between kidney function and the non-linear association between serum calcium levels and cardiovascular disease (CVD) mortality.

METHODS

This study included 8927 participants enrolled in the Dong-gu Study. Albumin-corrected calcium levels were used and categorized into 6 percentile categories: <2.5th, 2.5-25.0th, 25.0-50.0th, 50.0-75.0th, 75.0-97.5th, and >97.5th. Restricted cubic spline analysis was used to examine the non-linear association between calcium levels and CVD mortality. Cox proportional hazard regression was used to estimate hazard ratios (HRs) for CVD mortality according to serum calcium categories. All survival analyses were stratified by the estimated glomerular filtration rate.

RESULTS

Over a follow-up period of 11.9±2.8 years, 1757 participants died, of whom 219 died from CVD. A U-shaped association between serum calcium and CVD mortality was found, and the association was more evident in the low kidney function group. Compared to the 25.0-50.0th percentile group for serum calcium levels, both low and high serum calcium tended to be associated with CVD mortality (<2.5th: HR, 6.23; 95% confidence interval [CI], 1.16 to 33.56; >97.5th: HR, 2.56; 95% CI, 0.76 to 8.66) in the low kidney function group. In the normal kidney function group, a similar association was found between serum calcium levels and CVD mortality (<2.5th: HR, 1.37; 95% CI, 0.58 to 3.27; >97.5th: HR, 1.65; 95% CI, 0.70 to 3.93).

CONCLUSIONS

We found a non-linear association between serum calcium levels and CVD mortality, suggesting that calcium dyshomeostasis may contribute to CVD mortality, and kidney function may modify the association.

Hypocalcemia is associated with adverse outcomes in patients hospitalized with COVID-19

PURPOSE

Calcium ions are involved in the regulation of several cellular processes and may also influence viral replication. Hypocalcemia has been frequently reported during infectious diseases and in critically ill patients, including also COVID-19 patients, significantly related with the pro-inflammatory state and mortality. The aim of this study is to investigate the prevalence of hypocalcemia at admission in patients hospitalized for COVID-19 (Coronavirus disease 2019) and to evaluate association of hypocalcemia with in-hospital COVID-19 outcomes.

METHODS

Retrospective analysis on 118 consecutive patients, hospitalized for COVID-19 between March and May 2020. Clinical characteristics, inflammation markers, biochemical routine and mineral metabolism parameters at admission were collected. Hypocalcemia was defined as total serum calcium <2.2 mmol/L. Population was stratified by tertiles of total serum calcium. Primary outcome was the composite of in-hospital death or admission to intensive care unit (ICU). Secondary outcomes included in-hospital death, admission to ICU and need for non-invasive ventilation as separate events. Associations were tested by logistic regression and Cox-regression analysis with survival curves.

RESULTS

Overall prevalence of hypocalcemia was 76.6%, with just 6.7% of patients reporting levels of 25-(OH)-vitamin D > 30 ng/ml. Total serum calcium was inversely related with selected inflammatory biomarkers (p < 0.05) and poorer outcome of COVID-19 during hospitalization. Lower tertile of total calcium (≤2.02 mmol/L) had increased risk of in-hospital mortality (HR 2.77; 1.28-6.03, p = 0.01) compared with other groups.

CONCLUSION

Total serum calcium detected on admission is inversely related with proinflammatory biomarkers of severe COVID-19 and is useful to better define risk stratification for adverse in-hospital outcome.

Serum Calcium, Magnesium, and Phosphorus Levels in Patients with COVID-19: Relationships with Poor Outcome and Mortality

In this retrospective study to assess the impact of serum corrected calcium (CorrCa), magnesium (Mg) and phosphorus (P) levels, all adult patients with laboratory-confirmed COVID-19 hospitalized during 2020 were included. Poor outcome was considered in patients who presented need for mechanical ventilation, intensive care unit (ICU) admission, or in-hospital mortality. We analyzed 2473 patients (956 females) aged (mean±SD) 63.4±15.9 years. During admission, 169 patients (6.8%) required mechanical ventilation, 205 (8.3%) were admitted to the ICU, and 270 (10.9%) died. Composite variable of poor outcome, defined as need for mechanical ventilation, ICU admission or death, was present in 434 (17.5%) patients. In univariate analysis, the need for mechanical ventilation was positively related to Mg levels (OR 8.37, 95% CI 3.62-19.33; p<0.001); ICU admission was related to CorrCa (OR 0.49, 95% CI 0.25-0.99; p=0.049) and Mg levels (OR 5.81, 95% CI 2.74-12.35; p<0.001); and in-hospital mortality was related to CorrCa (OR 1.73, 95% CI 1.14-2.64; p=0.011). The composite variable of poor outcome was only related to Mg (OR 2.68, 95% CI 1.54-4.68; p=0.001). However, in multivariate analysis only CorrCa was significantly related to the need for mechanical ventilation (OR 0.19, 95% CI 0.05-0.72; p=0.014) and ICU admission (OR 0.25; 95% CI 0.09-0.66; p=0.005), but not with in-hospital mortality or the composite variable. In conclusion, CorrCa can be used as a simple and reliable marker of poor outcome in patients with COVID-19, although not to predict the risk of in-hospital mortality.

Risk Factor Analysis and Prediction of Severe Hypocalcemia after Total Parathyroidectomy without Auto-Transplantation in Patients with Secondary Hyperparathyroidism

OBJECTIVE

Our study aimed to develop and validate a nomogram to predict severe hypocalcemia (SH) before total parathyroidectomy (TPTX) without auto-transplantation in patients with secondary hyperparathyroidism.

METHODS

A total of 299 consecutive patients who underwent TPTX without transplantation for secondary hyperparathyroidism were selected from the General Hospital of Northern Theater Command between January 2013 and December 2021. Of these, patients who underwent surgery between January 2013 and December 2020 formed the training cohort (n = 208) to develop a nomogram, and those who underwent surgery thereafter formed the validation cohort (n = 91) to validate the performance of this nomogram. Univariate and multivariate logistic regression analyses were used to identify the risk factors associated with SH, and then, a nomogram was constructed.

RESULTS

The incidence of postoperative SH was 27.9% and 35.2% in the training and validation cohorts, respectively. The preoperative factors associated with SH were younger age, lower serum calcium (Ca) level, higher intact parathyroid hormone (iPTH) level, and higher serum alkaline phosphatase (ALP) level. Incorporating these 4 factors, the nomogram achieved good concordance indexes of 0.866 (95%CI, 0.816-0.916) and 0.867 (95% CI, 0.793-0.941) in predicting SH in the training and validation cohorts, respectively, and had well-fitted calibration curves. The positive predictive values of the nomogram were 64.7% (54.1%-78.4%) and 75.0% (58.6%-88.5%), and negative predictive values of the nomogram were 90.0% (82.9%-93.6%) and 86.4% (73.5%-94.0%) for the training and validation cohorts, respectively.

CONCLUSIONS

We developed and validated a nomogram for the prediction of SH in patients who underwent TPTX without auto-transplantation for secondary hyperparathyroidism. Our nomogram may facilitate the identification of high-risk SH in patients after TPTX and optimization of preoperative decision-making.

Predictive Value of Ionized Calcium for Prognosis of Sepsis in Very Low Birth Weight Infants

Purpose

Previous studies have shown that ionized calcium (iCa) is strongly correlated with critical illnesses, including sepsis. However, there are few studies on the association of iCa levels and sepsis in very low birth weight infants (VLBWI). Therefore, the aim of this study was to investigate the role of iCa in assessing the severity of sepsis and in predicting the prognosis of sepsis in VLBWI.

Patients and Methods

249 eligible VLBWI with sepsis were included in the present study and were divided into good and poor prognosis groups according to prognosis. We collected complete laboratory and clinical data. The lowest iCa measured during the first 24h from sepsis onset was recorded, and the Pediatric Risk of Mortality (PRISM III) score was calculated for each newborn.

Results

Neonatal mortality was higher in the hypocalcemia group (32.80% vs 12.80%, P < 0.001), and iCa levels were negatively correlated with PRISM III scores (r= −0.819, P < 0.001). The result of multiple logistic regression analysis showed that iCa was an independent predictor of poor prognosis (odds ratio [OR]= 0.558, 95% confidence interval [CI], 0.406–0.768, P < 0.001). Furthermore, our data demonstrated that iCa was also an independent predictor for the occurrence of death in VLBWI with sepsis who have a poor prognosis (OR= 0.659, 95% CI, 0.445–0.977, P =0.038). ROC curve analysis showed that iCa had good discriminatory power in predicting the poor prognosis (AUC=0.739, 95% CI, 0.664–0.813, P <0.001) in VLBWI with sepsis.

Conclusion

iCa levels correlate with the severity of sepsis and can be an independent predictor of poor prognosis in VLBWI with sepsis.

Trauma-induced hypocalcemia

BACKGROUND

Trauma-induced hypocalcemia is an underappreciated complication of severe injury but is well known to result in the derangement of an array of physiological regulatory mechanisms. Existing literature provides a compelling link between hypocalcemia and worse trauma-induced coagulopathy and increased mortality after injury.

STUDY DESIGN AND METHODS

This narrative review evaluates available data related to the risk factors, mechanisms, and treatment of hypocalcemia after severe injury. The authors did not perform a systemic review or meta-analysis.

RESULTS AND DISCUSSION

The interplay of acidosis, hypothermia, and coagulopathy with hypocalcemia potentiates the bloody vicious cycle of hemorrhagic shock which has been the paradigm of trauma resuscitation for over half a century. However, current screening and treatment of postinjury hypocalcemia are relegated to a secondary consideration in trauma resuscitation. We conclude calcium supplementation should be a primary tier intervention for life-threatening injury.

Surgical Treatment for Empyema Thoracis: Prognostic Role of Preoperative Transthoracic Echocardiography and Serum Calcium

Background: Empyema is a major cause of mortality and hospitalization. Symptoms include difficulty breathing and chest pain. Calcium plays an essential role in the physiology of the cardiovascular system. However, there is little evidence on the role of echocardiography and the serum calcium levels of patients undergoing video-assisted thoracoscopic surgery (VATS) for empyema. This study aimed to investigate the risk factors for postoperative mortality in patients with empyema who required surgery. Methods: This single-institution retrospective study compared the outcomes of VATS for thoracic empyema (in terms of survival and mortality) in 122 patients enrolled between July 2015 and June 2019. Results: This study examined patients with thoracic empyema. The majority of the patients were males (100/122, 81.9%). The in-hospital/30-day mortality rate was 10.6% (13 patients). The calcium levels were 7.82 ± 1.17 mg/dL in the survival group and 6.88 ± 1.88 mg/dL in the mortality group (p = 0.032). In the mortality group, the utilization of echocardiography and serum calcium levels independently contributed to the risk prediction more than clinical variables. Patients in our cohort exhibited elevated pulmonary artery systolic pressure (PASP) and hypocalcemia, which were associated with increased postoperative mortality. Conclusion: Elevated PASP and calcium levels at the low end of the normal range demonstrated significant prognostic value in predicting mortality in patients with thoracic empyema who required surgical intervention. Recognizing this potential is critical in order to obtain better outcomes.

Low Plasma Ionized Calcium Is Associated With Increased Mortality: A Population-based Study of 106 768 Individuals

CONTEXT

Low circulating total calcium or albumin-adjusted calcium has been associated with higher mortality, especially in hospital settings; however, these measures tend to misclassify patients with derangements in calcium homeostasis.

OBJECTIVE

As the association of the biologically active ionized calcium with mortality is poorly elucidated, we tested the hypothesis that low plasma ionized calcium is associated with higher risk of all-cause and cause-specific mortality in the general population.

METHODS

We included 106 768 individuals from the Copenhagen General Population Study. Information on all-cause and cause-specific mortality was from registries and risks were calculated using Cox regression and competing-risks regression by the STATA command stcompet.

RESULTS

During a median follow-up period of 9.2 years, 11 269 individuals died. Each 0.1 mmol/L lower plasma ionized calcium below the median of 1.21 mmol/L was associated with a multivariable adjusted hazard ratio of 1.23 (95% CI, 1.10-1.38) for all-cause mortality. Corresponding hazard ratios for cancer and other mortality were 1.29 (1.06-1.57) and 1.24 (1.01-1.53), respectively. In contrast, for cardiovascular mortality, only high plasma ionized calcium was associated with mortality with a hazard ratio of 1.17 (1.02-1.35) per 0.1 mmol/L higher plasma ionized calcium above the median. We found no interactions between plasma ionized calcium and preexisting cardiovascular or renal disease on all-cause mortality.

CONCLUSION

In the general population, low plasma ionized calcium was associated with increased all-cause, cancer, and other mortality, while high levels were associated with increased cardiovascular mortality.

Advancing in the understanding of coagulopathy during hemorrhagic shock: From the triad to the deadly pentad

The deadly triad concept represented a dogma in the definition of poor outcomes and death associated with major bleeding in trauma. This model of end-stage disease was then rapidly transferred to other major bleeding scenarios. However, and notwithstanding the fact that it represented a severe scenario, the original triad fails to establish a sequence, which would be relevant when defining the objectives during the initial treatment of severe bleeding.  It has been recently suggested that hypoxia and hyperglycemia should be included as isolated, determining factors in this model. Likewise, the model admits only one scenario where all the conditions shall co-exist, knowing that each one of them contributes with a different risk burden. Based on a structured review, we submit a pentad model that includes a natural pattern of events occurring with hypoxemia as the main trigger for the development of hypocalcemia, hyperglycemia, acidosis and hypothermia, as hallmarks of multiple system impairment. This severity model of major bleeding ends with coagulopathy as a result of the failure to resolve the rest of the previous components.

Association of hypocalcemia with in-hospital mortality and complications in patients with acute pulmonary embolism: results from the 2017 Nationwide Inpatient Sample

Background

Acute pulmonary embolism (PE) is a common cause for hospitalization associated with significant mortality and morbidity. Disorders of calcium metabolism are a frequently encountered medical problem. The effect of hypocalcemia is not well defined on the outcomes of patients with PE. We aimed to identify the prognostic value of hypocalcemia in hospitalized PE patients utilizing the 2017 Nationwide Inpatient Sample (NIS).

Methods

In this retrospective study, we selected patients with a primary diagnosis of Acute PE using ICD 10 codes. They were further stratified based on the presence of hypocalcemia. We primarily aimed to compare in-hospital mortality for PE patients with and without hypocalcemia. We performed multivariate logistic regression analysis to adjust for potential confounders. We also used propensity‐matched cohort of patients to compare mortality.

Results

In the 2017 NIS, 187,989 patients had a principal diagnosis of acute PE. Among the above study group, 1565 (0.8%) had an additional diagnosis of hypocalcemia. 12.4% of PE patients with hypocalcemia died in the hospital in comparison to 2.95% without hypocalcemia. On multivariate regression analysis, PE and hypocalcemia patients had 4 times higher odds (aOR-4.03, 95% CI 2.78–5.84, p < 0.001) of in-hospital mortality compared to those with only PE. We observed a similarly high odds of mortality (aOR = 4.4) on 1:1 propensity-matched analysis. The incidence of acute kidney injury (aOR = 2.62, CI 1.95–3.52, p < 0.001), acute respiratory failure (a0R = 1.84, CI 1.42–2.38, p < 0.001), sepsis (aOR = 4.99, CI 3.08–8.11, p < 0.001) and arrhythmias (aOR = 2.63, CI 1.99–3.48, p < 0.001) were also higher for PE patients with hypocalcemia.

Conclusion

PE patients with hypocalcemia have higher in-hospital mortality than those without hypocalcemia. The in-hospital complications were also higher, along with longer length of stay.

Influencing factors of noninvasive positive pressure ventilation in the treatment of respiratory failure: a 10-year study in one single center

Background

The utilization of noninvasive positive pressure ventilation (NPPV) is becoming more and more common, especially in patients with acute or chronic respiratory failure. The purpose of our study is to analyze the factors that influence the efficacy of NPPV in the treatment of respiratory failure caused by a variety of etiology.

Methods

From May 2011 to April 2020, patients treated with NPPV during hospitalization in the First Affiliated Hospital of Soochow University were enrolled. According to the clinical outcome of NPPV treatment and whether converted to invasive mechanical ventilation, patients were divided into the success group and the failure group. The clinical data and the characteristics of NPPV application were compared between the two groups.

Results

A total of 3312 patients were enrolled, including 2025 patients in the success group and 1287 patients in the failure group. Univariate analysis suggested that there were no statistical differences in patients' age, gender, use of analgesia and/or sedation, complicated with barotrauma, inspiratory positive airway pressure and expiratory positive airway pressure between the success and failure groups (P > 0.05). However, there were statistically significant differences in serum albumin levels, Ca²⁺ concentration, blood glucose levels, duration of NPPV treatment and length of hospital stay between the success and failure groups (P < 0.05). Multivariate logistic regression analysis indicated that serum albumin levels and duration of NPPV treatment had statistical significance on the therapeutic effect of NPPV (P < 0.05).

Conclusion

Serum albumin levels and duration of NPPV treatment were independent risk factors for the efficacy of NPPV treatment in respiratory failure.

The Prognostic Value of Calcium in Post-Cardiovascular Surgery Patients in the Intensive Care Unit

Background: Present researches exploring the prognostic value of calcium concentration are undermined by sample size and study design. Our study investigated the association of both total calcium (tCa) and ionized Ca (iCa) to short- and long-term mortality and other outcomes in post-cardiovascular surgery (PCS) patients admitted to intensive care unit (ICU) from two large public data sets.

Methods: The Medical Information Mart for Intensive Care III (MIMIC-III) database and the eICU Collaborative Research Database (eICU) were inspected to identify PCS patients. The primary outcome was 28-day mortality. Multivariate regression was used to elucidate the relationship between calcium concentration and outcomes. The propensity score estimation was performed to validate our findings.

Results: A total of 6122 and 914 patients were included from the MIMIC III and eICU data sets, respectively. The groups with the most patients were the mild hypo-iCa and hypo-tCa groups. The mild hypo-iCa group showed significant association with worse short-term and long-term prognosis, less use of ventilation, longer ICU and hospital stay, and more incidence of 7-day acute kidney injury.

Conclusions: The mild hypo-iCa (0.9–1.15 mmol/L) within the first day of admission to the ICU could serve as an independent prognosis factor for PCS patients.

Characterizing the Patients, Hospitals, and Data Quality of the eICU Collaborative Research Database

OBJECTIVES

The eICU Collaborative Research Database is a publicly available repository of granular data from more than 200,000 ICU admissions. The quantity and variety of its entries hold promise for observational critical care research. We sought to understand better the data available within this resource to guide its future use.

DESIGN

We conducted a descriptive analysis of the eICU Collaborative Research Database, including patient, practitioner, and hospital characteristics. We investigated the completeness of demographic and hospital data, as well as those values required to calculate an Acute Physiology and Chronic Health Evaluation score. We also assessed the rates of ventilation, intubation, and dialysis, and looked for potential errors in the vital sign data.

SETTING

American ICUs that participated in the Philips Healthcare eICU program between 2014 and 2015.

PATIENTS

A total of 139,367 individuals who were admitted to one of the 335 participating ICUs between 2014 and 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Most encounters were from small- and medium-sized hospitals, and managed by nonintensivists. The median ICU length of stay was 1.57 days (interquartile range, 0.82-2.97 d). The median Acute Physiology and Chronic Health Evaluation IV-predicted ICU mortality was 2.2%, with an observed mortality of 5.4%. Rates of ventilation (20-33%), intubation (15-24%), and dialysis (3-5%) varied according to the query method used. Most vital sign readings fell into realistic ranges, with manually curated data less likely to contain implausible results than automatically entered data.

CONCLUSIONS

Data in the eICU Collaborative Research Database are for the most part complete and plausible. Some ambiguity exists in determining which encounters are associated with various interventions, most notably mechanical ventilation. Caution is warranted in extrapolating findings from the eICU Collaborative Research Database to larger ICUs with higher acuity.

Admission Serum Ionized and Total Calcium as New Predictors of Mortality in Patients with Cardiogenic Shock

Background

Although serum calcium has been proven to be a predictor of mortality in a wide range of diseases, its prognostic value in critically ill patients with cardiogenic shock (CS) remains unknown. This retrospective observational study is aimed at investigating the association of admission calcium with mortality among CS patients.

Methods

Critically ill patients diagnosed with CS in the Medical Information Mart for Intensive Care-III (MIMIC-III) database were included in our study. The study endpoints included 30-day, 90-day, and 365-day all-cause mortalities. First, admission serum ionized calcium (iCa) and total calcium (tCa) levels were analyzed as continuous variables using restricted cubic spline Cox regression models to evaluate the possible nonlinear relationship between serum calcium and mortality. Second, patients with CS were assigned to four groups according to the quartiles (Q1-Q4) of serum iCa and tCa levels, respectively. In addition, multivariable Cox regression analyses were used to assess the independent association of the quartiles of iCa and tCa with clinical outcomes.

Results

A total of 921 patients hospitalized with CS were enrolled in this study. A nonlinear relationship between serum calcium levels and 30-day mortality was observed (all P values for nonlinear trend < 0.001). Furthermore, multivariable Cox analysis showed that compared with the reference quartile (Q3: 1.11 ≤ iCa < 1.17 mmol/L), the lowest serum iCa level quartile (Q1: iCa < 1.04 mmol/L) was independently associated with an increased risk of 30-day mortality (Q1 vs. Q3: HR 1.35, 95% CI 1.00-1.83, P = 0.049), 90-day mortality (Q1 vs. Q3: HR 1.36, 95% CI 1.03-1.80, P = 0.030), and 365-day mortality (Q1 vs. Q3: HR 1.28, 95% CI 1.01-1.67, P = 0.046) in patients with CS.

Conclusions

Lower serum iCa levels on admission were potential predictors of an increased risk of mortality in critically ill patients with CS.

Hypocalcemia is associated with severe COVID-19: A systematic review and meta-analysis

BACKGROUND AND AIMS

Hypocalcemia is commonly in critically ill patients and studies have shown that hypocalcemia is prevalent in patients with COVID-19. This meta-analysis aimed to evaluate the prognostic performance of hypocalcemia in patients with coronavirus disease 2019 (COVID-19).

METHODS

We performed a systematic literature search on PubMed, Scopus, and Embase with keywords "SARS-CoV-2″ OR″COVID-19″ OR ″2019-nCoV" AND "hypocalcemia" up until 10 December 2020. The key exposure was hypocalcemia, defined as serum calcium below study-defined cut-off points. The main outcome was poor outcome, which was a composite of mortality and severity. The effect estimate of the main outcome was reported as odds ratio (OR) and its 95% confidence interval (95% CI). We also generate sensitivity, specificity, positive and negative likelihood ratio (PLR & NLR), diagnostic odds ratio (DOR), and area under curve (AUC).

RESULTS

There are 2032 patients from 7 studies included in this systematic review and meta-analysis. The incidence of poor outcome in this study was 26%. Serum calcium was lower in patients with poor outcome (mean difference -0.173 mmol/L [-0.259, -0.087], p < 0.001; I²: 31.3%). Hypocalcemia was associated with poor outcome (OR 3.19 [2.02, 5.06], p < 0.001; I²: 32.86%); with sensitivity of 0.74 [0.53, 0.88], specificity of 0.54 [0.29, 0.77], PLR of 1.6 [1.1, 2.3], NLR of 0.49 [0.35, 0.66], DOR of 3 [2, 5], and AUC of 0.70 [0.66, 0.74]. In this pooled analysis, the post-test probability was 36% in patients with hypocalcemia and 15% in patients without hypocalcemia.

CONCLUSION

Hypocalcemia was associated with poor outcome in COVID-19 patients.

PROSPERO ID

CRD42020225506.

A deep learning backcasting approach to the electrolyte, metabolite, and acid-base parameters that predict risk in ICU patients

BACKGROUND

A powerful risk model allows clinicians, at the bedside, to ensure the early identification of and decision-making for patients showing signs of developing physiological instability during treatment. The aim of this study was to enhance the identification of patients at risk for deterioration through an accurate model using electrolyte, metabolite, and acid-base parameters near the end of patients' intensive care unit (ICU) stays.

METHODS

This retrospective study included 5157 adult patients during the last 72 hours of their ICU stays. The patients from the MIMIC-III database who had serum lactate, pH, bicarbonate, potassium, calcium, glucose, chloride, and sodium values available, along with the times at which those data were recorded, were selected. Survivor data from the last 24 hours before discharge and four sets of nonsurvivor data from 48-72, 24-48, 8-24, and 0-8 hours before death were analyzed. Deep learning (DL), random forest (RF) and generalized linear model (GLM) analyses were applied for model construction and compared in terms of performance according to the area under the receiver operating characteristic curve (AUC). A DL backcasting approach was used to assess predictors of death vs. discharge up to 72 hours in advance.

RESULTS

The DL, RF and GLM models achieved the highest performance for nonsurvivors 0-8 hours before death versus survivors compared with nonsurvivors 8-24, 24-48 and 48-72 hours before death versus survivors. The DL assessment outperformed the RF and GLM assessments and achieved discrimination, with an AUC of 0.982, specificity of 0.947, and sensitivity of 0.935. The DL backcasting approach achieved discrimination with an AUC of 0.898 compared with the DL native model of nonsurvivors from 8-24 hours before death versus survivors with an AUC of 0.894. The DL backcasting approach achieved discrimination with an AUC of 0.871 compared with the DL native model of nonsurvivors from 48-72 hours before death versus survivors with an AUC of 0.846.

CONCLUSIONS

The DL backcasting approach could be used to simultaneously monitor changes in the electrolyte, metabolite, and acid-base parameters of patients who develop physiological instability during ICU treatment and predict the risk of death over a period of hours to days.

Metabolic and Endocrine Challenges

This review aims to provide an overview of metabolic and endocrine challenges in the setting of intensive care medicine. These are a group of heterogeneous clinical conditions with a high degree of overlap, as well as nonspecific signs and symptoms. Several diseases involve multiple organ systems, potentially causing catastrophic dysfunction and death. In the majority of cases, endocrine challenges accompany other organ failures or manifest as a complication of prolonged intensive care unit stay and malnutrition. However, when endocrine disorders present as an isolated syndrome, they are a rare and extreme manifestation. As they are uncommon, these can typically challenge both with diagnosis and management. Acute exacerbations may be elicited by triggers such as infections, trauma, surgery, and hemorrhage. In this complex scenario, early diagnosis and prompt treatment require knowledge of the specific endocrine syndrome. Here, we review diabetic coma, hyponatremia, hypercalcemia, thyroid emergencies, pituitary insufficiency, adrenal crisis, and vitamin D deficiency, highlighting diagnostic tools and tricks, and management pathways through defining common clinical presentations.

Prognostic Value of Ionized Calcium Levels in Neonatal Sepsis

BACKGROUND

Despite recent advances in the treatment of neonatal infection, mortality rates and comorbidities associated with neonatal sepsis remain high. Hypocalcemia has been reported in critically ill patients, especially in as-sociation with sepsis. However, the importance of hypo-calcemia in neonatal sepsis has not been explored in detail.

OBJECTIVES

The purpose of this study was to evaluate the prognostic value of hypocalcemia in neonatal sepsis patients and to identify the risk factors associated with sepsis-related mortality.

METHODS

This retrospective study examined perinatal data from patients in a level IV neonatal in-tensive care unit between January 2010 and June 2016. Univariate analysis was performed to understand the differences in clinical and laboratory characteristics between patients with and without neonatal sepsis. Neonates with sepsis were further stratified as having ionized hypocalcemia (if serum ionized calcium [iCa] <1.0 mmol/L) or not. Uni- and multivariate logistic regression analyses were utilized to evaluate the predictive potential of iCa for identifying sepsis-related mortality.

RESULTS

A total of 472 neonates were enrolled in this study, including 169 neonates diagnosed with culture-proven sepsis and 303 neonates without infection (control group). The comparison of neonates with and without sepsis highlighted significant differences in levels of iCa (0.97 ± 0.26 vs. 1.12 ± 0.25 mmol/L), magnesium (0.75 ± 0.22 vs. 0.89 ± 0.12 mmol/L), and phosphate (2.26 ± 1.08 vs. 1.65 ± 0.85 mmol/L; all p < 0.001). When neonates with sepsis were stratified into 2 subgroups based on serum iCa, neonates with hypocalcemia showed higher rates of organ dysfunction than those with normal iCa, as well as higher rates of cardiovascular system dysfunction (37.35 vs. 17.44%), renal dysfunction (34.94 vs. 30.95%), disseminated intravascular coagulation (26.51 vs. 11.63%), and seizure (16.04 vs. 5.8%; all p < 0.05). Among all neonates who had sepsis, the mortality rate was 13.61%, and this rate was higher among neonates with hypocalcemia than among those with normal iCa (20.48 vs. 6.98%, p < 0.05). Uni- and multivariate analyses showed that acidosis, hypoalbuminemia, hypocalcemia, and hyperphosphatemia were independent prognostic markers of sepsis-related mortality. In receiver-operating characteristic curve analysis, the areas under the curve were 0.70 (95% CI 0.624-0.768; p = 0.0004), 0.74 (95% CI 0.671-0.808; p < 0.0001), 0.73 (95% CI 0.653-0.792; p = 0.0002), and 0.67 (95% CI 0.59-0.737; p = 0.0154) for serum albumin, iCa, phosphate, and acidosis, respectively. Based on these findings, we developed a nomogram to predict sepsis-related mortality.

CONCLUSIONS

Hypocalcemia is common in neonates with sepsis and is significantly associated with organ dysfunction and sepsis-related mortality.

Prevalence and predictive value of hypocalcemia in severe COVID-19 patients

Background

The aim of this study was to investigate the performance and predictive value of hypocalcemia in severe COVID-19 patients.

Methods

We retrospectively investigated the clinical and laboratory characteristics of severe COVID-19 patients. 107 patients were divided into hypocalcemia group and normal serum calcium group. The clinical and laboratory data were compared between two groups. The discriminative power of hypocalcemia regarding poor outcome were evaluated by receiver operating curves (ROC) analyses.

Results

Sixty seven patients (62.6%) had hypocalcemia. In hypocalcemia group, leukocytes, c-reactive protein (CRP), procalcitonin (PCT), Interleukin 6 (IL-6), and D-dimer levels was higher, while lymphocytes and albumin (ALB) levels was lower. No significant difference was identified in gender, age, signs and symptoms, comorbidities and other laboratory indicators. Serum calcium levels were negatively correlated with leukocytes, CRP, PCT, IL-6 and D-dimer, while positively correlated with lymphocytes and ALB. Patients with hypocalcemia more commonly presented poor outcome (47.8% (32/67) vs 25% (10/40), p = 0.02). Median serum calcium levels were significantly lower in the patients with poor outcome (2.01(1.97–2.05) vs 2.10(2.03–2.20), p < 0.001), and it could predict the prognosis with an area under the ROC curve (AUC) of 0.73(95% confidence interval (CI) 0.63–0.83, p < 0.001).

Conclusions

Hypocalcemia commonly occurred in severe COVID-19 patients and it was associated with poor outcome.

The Role of Serum Calcium Level in Intracerebral Hemorrhage Hematoma Expansion: Is There Any?

Spontaneous intracerebral hemorrhage (ICH) is a devastating form of stroke, with a high rate of mortality and morbidity. Even with the best current medical or surgical interventions, outcomes remain poor. The location and initial hematoma volume are strong predictors of mortality. Hematoma expansion (HE) is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for HE have been identified, including baseline ICH volume, anticoagulation, and computed tomography angiography spot signs. Recent studies have shown the correlation of serum calcium (Ca⁺⁺) levels on admission with HE. Low serum Ca⁺⁺ level has been associated with larger hematoma volume at the time of presentation, HE, and worse outcome. Although the causal and mechanistic links between low serum Ca⁺⁺ level and HE are not well understood, several mechanisms have been proposed including coagulopathy, platelet dysfunction, and higher blood pressure (BP) in the context of low serum Ca⁺⁺ level. However, low serum Ca⁺⁺ level might be only a biomarker of the adaptive response due to acute inflammatory response following acute ICH. The purpose of the current review is to discuss the evidence regarding the possible role of low serum Ca⁺⁺ level on HE in acute ICH.

Forgot calcium? Admission ionized-calcium in two civilian randomized controlled trials of prehospital plasma for traumatic hemorrhagic shock

BACKGROUND

Randomized clinical trials (RCTs) support the use of prehospital plasma in traumatic hemorrhagic shock, especially in long transports. The citrate added to plasma binds with calcium, yet most prehospital trauma protocols have no guidelines for calcium replacement. We reviewed the experience of two recent prehospital plasma RCTs regarding admission ionized-calcium (i-Ca) blood levels and its impact on survival. We hypothesized that prehospital plasma is associated with hypocalcemia, which in turn is associated with lower survival.

METHODS

We studied patients enrolled in two institutions participating in prehospital plasma RCTs (control, standard of care; experimental, plasma), with i-Ca collected before calcium supplementation. Adults with traumatic hemorrhagic shock (systolic blood pressure ≤70 mm Hg or 71-90 mm Hg + heart rate ≥108 bpm) were eligible. We use generalized linear mixed models with random intercepts and Cox proportional hazards models with robust standard errors to account for clustered data by institution. Hypocalcemia was defined as i-Ca of 1.0 mmol/L or less.

RESULTS

Of 160 subjects (76% men), 48% received prehospital plasma (median age, 40 years [interquartile range, 28-53 years]) and 71% suffered blunt trauma (median Injury Severity Score [ISS], 22 [interquartile range, 17-34]). Prehospital plasma and control patients were similar regarding age, sex, ISS, blunt mechanism, and brain injury. Prehospital plasma recipients had significantly higher rates of hypocalcemia compared with controls (53% vs. 36%; adjusted relative risk, 1.48; 95% confidence interval [CI], 1.03-2.12; p = 0.03). Severe hypocalcemia was significantly associated with decreased survival (adjusted hazard ratio, 1.07; 95% CI, 1.02-1.13; p = 0.01) and massive transfusion (adjusted relative risk, 2.70; 95% CI, 1.13-6.46; p = 0.03), after adjustment for confounders (randomization group, age, ISS, and shock index).

CONCLUSION

Prehospital plasma in civilian trauma is associated with hypocalcemia, which in turn predicts lower survival and massive transfusion. These data underscore the need for explicit calcium supplementation guidelines in prehospital hemotherapy.

LEVEL OF EVIDENCE

Therapeutic, level II.

Impact of Changes in Serum Calcium Levels on In-Hospital Mortality

Background and objectives: Calcium concentration is strictly regulated at both the cellular and systemic level, and changes in serum calcium levels can alter various physiological functions in various organs. This study aimed to assess the association between changes in calcium levels during hospitalization and mortality. Materials and Methods: We searched our patient database to identify all adult patients admitted to our hospital from January 1st, 2009 to December 31st, 2013. Patients with ≥2 serum calcium measurements during the hospitalization were included. The serum calcium changes during the hospitalization, defined as the absolute difference between the maximum and the minimum calcium levels, were categorized into five groups: 0–0.4, 0.5–0.9, 1.0–1.4, 1.5–1.9, and ≥2.0 mg/dL. Multivariable logistic regression was performed to assess the independent association between calcium changes and in-hospital mortality, using the change in calcium category of 0–0.4 mg/dL as the reference group. Results: Of 9868 patients included in analysis, 540 (5.4%) died during hospitalization. The in-hospital mortality progressively increased with higher calcium changes, from 3.4% in the group of 0–0.4 mg/dL to 14.5% in the group of ≥2.0 mg/dL (p < 0.001). When adjusted for age, sex, race, principal diagnosis, comorbidity, kidney function, acute kidney injury, number of measurements of serum calcium, and hospital length of stay, the serum calcium changes of 1.0–1.4, 1.5–1.9, and ≥2.0 mg/dL were significantly associated with increased in-hospital mortality with odds ratio (OR) of 1.55 (95% confidence interval (CI) 1.15–2.10), 1.90 (95% CI 1.32–2.74), and 3.23 (95% CI 2.39–4.38), respectively. The association remained statistically significant when further adjusted for either the lowest or highest serum calcium. Conclusion: Larger serum calcium changes in hospitalized patients were progressively associated with increased in-hospital mortality.

Epidemiology, clinical features, and management of severe hypercalcemia in critically ill patients

BACKGROUND

Severe hypercalcemia (HCM) is a common reason for admission in intensive-care unit (ICU). This case series aims to describe the clinical and biological features, etiologies, treatments, and outcome associated with severe HCM. This study included all patients with a total calcemia above 12 mg/dL (3 mmol/L) admitted in two ICUs from January 2007 to February 2017.

RESULTS

131 patients with HCM were included. HCM was related to hematologic malignancy in 58 (44.3%), solid tumors in 29 (22.1%), endocrinopathies in 16 (12.2%), and other causes in 28 (21.3%) patients. 108 (82.4%) patients fulfilled acute kidney injury (AKI) criteria. Among them, 25 (19%) patients required renal replacement therapy (RRT). 51 (38.9%) patients presented with neurological symptoms, 73 (55.7%) patients had cardiovascular manifestations, and 50 (38.1%) patients had digestive manifestations. The use of bisphosphonates (HR, 0.42; 95% CI, 0.27-0.67; P < 0.001) was the only treatment significantly associated with a decrease of total calcemia below 12 mg/dL (3 mmol/L) at day 5. ICU and Hospital mortality rates were, respectively, 9.9% and 21.3%. Simplified Acute Physiologic Score (SAPS II) (OR, 1.05; 95% CI 1.01-1.1; P = 0.03) and an underlying solid tumor (OR, 13.83; 95% CI 2.24-141.25; P = 0.01) were two independent factors associated with hospital mortality in multivariate analysis.

CONCLUSIONS

HCM is associated with high mortality rates, mainly due to underlying malignancies. The course of HCM may be complicated by organ failures which are most of the time reversible with early ICU management. Early ICU admission and prompt HCM management are crucial, especially in patients with an underlying solid tumor presenting with neurological symptoms.

Management of Endocrine Emergencies in the ICU

Endocrine emergencies are frequent in critically ill patients and may be the cause of admission or can be secondary to other critical illness. The ability to anticipate endocrine abnormalities such as adrenal excess or , hypothyroidism, can mitigate their duration and severity. Hyperglycemic crisis may trigger hospital and intensive care unit (ICU) admission and may be life threatening. Recognition and safe treatment of severe conditions such as acute adrenal insufficiency, thyroid crisis, and hypoglycemia and hyperglycemic crisis may be lifesaving. Electrolyte abnormalities such as hypercalcemia and hypocalcemia may have underlying endocrine causes, and may be treated differently with recognition of those disorders- electrolyte replacement alone may not be adequate for efficient resolution. Sodium disorders are common in the ICU and are generally related to altered water balance however may be related to pituitary abnormalities in selected patients, and recognition may improve treatment effectiveness and safety.

Is severe hypocalcemia immediately life-threatening?

Objective

Severe hypocalcemia (Ca <1.9 mmol/L) is often considered an emergency because of a potential risk of cardiac arrest or seizures. However, there is little evidence to support this. The aim of our study was to assess whether severe hypocalcemia was associated with immediately life-threatening cardiac arrhythmias or neurological complications.

Methods

A retrospective observational study was carried out over a 2 years period in the Adult Emergency Department (ED) of Nantes University Hospital. All patients who had a protein-corrected calcium concentration measure were eligible for inclusion. Patients with multiple myeloma were excluded. The primary outcome was the number of life-threatening cardiac arrhythmias and/or neurological complications during the stay in the ED.

Results

A total of 41,823 patients had protein-corrected calcium (pcCa) concentrations measured, 155 had severe hypocalcaemia, 22 were excluded because of myeloma leaving 133 for analysis. Median pcCa concentration was 1.73 mmol/L [1.57-1.84]. Seventeen (12.8%) patients presented a life threatening condition, 14 (10.5%) neurological and 3 (2.2%) cardiac during ED stay. However these complications could be explained by the presence of underlying co-morbidities and or electrolyte disturbances other than hypocalcaemia. Overall 24 (18%) patients died in hospital. Vitamin D deficiency, chronic kidney disease and hypoparathyroidism were the most frequently found causes of hypocalcemia.

Conclusion

13% of patients with severe hypocalcaemia presented a life-threatening cardiac or neurological complication on the ED. However a perfectly valid alternative cause could account for these complications. Further research is warranted to define the precise role of hypocalcaemia.

Predictive accuracy of serum total calcium for both critically high and critically low ionized calcium in critical illness

BACKGROUND

The accuracy of total calcium and its corrected value for predicting critically high and critically low ionized calcium in critical illness is controversial. The aim of this study was to investigate whether the concentration of total serum calcium, either corrected for albumin or not, could predict critically high or low values in critical illness.

METHODS

This report describes a retrospective study using the Medical Information Mart for Intensive Care (MIMIC) III database. Test panels that contained serum albumin, total calcium, and ionized calcium (named ATI panels) with order time intervals of less than one hour were extracted. The predictive accuracy of total calcium, either corrected for albumin or not, was assessed using receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 12 118 ATIs with 103 critically low and 92 critically high ionized calcium results were extracted. The areas under ROC curves (AUCs) of corrected and uncorrected total calcium for predicting critically low ionized calcium were 0.69 (95% CI: 0.61-0.76) and 0.70 (95% CI: 0.63-0.78), respectively. For predicting critically high ionized calcium, the AUCs were 0.98 (95% CI: 0.97-1.00) and 0.97 (95% CI: 0.95-1.00), respectively. With positive predictive values (PPVs) of 0.05 and 0.10, the sensitivities (both corrected and uncorrected) were approximately 0.50 for predicting critically low ionized calcium and 0.95 for predicting critically high ionized calcium.

CONCLUSIONS

Total calcium, either corrected for albumin or not, is not a reliable test to predict critically low ionized calcium in critical illness. Total calcium's predictive accuracy for critically high ionized calcium is high.

Association of Initial Serum Total Calcium Concentration with Mortality in Critical Illness

Background

Several studies have suggested that serum ionized calcium (iCa) is associated with mortality in critical illness. However, evidence regarding the predictive significance of serum total calcium (tCa) in critical illness remains scarce. The aim of this study was to assess the association of tCa levels with mortality in critical illness.

Methods

We employed the MIMIC-III v1.3 database. tCa was measured upon ICU admission and its relationship with mortality was determined using smooth curve fitting. The association between admission tCa levels and hospital mortality was determined using logistic regression.

Results

Inclusion criteria were met by 44,886 critically ill patients. A U-shaped pattern was observed between tCa and hospital mortality. Similar trends were observed for hospital mortality when quintiles were used to group patients according to tCa. In multivariate analysis, adjusted for age and sex, the model indicated that admission tCa levels ⩽7.6mg/dl, 7.7-8.1mg/dl, and ⩾9.0mg/dl were associated with an increase in mortality when compared to the reference level (8.6-9.0mg/dl). However, adjusted for more clinical characteristics, tCa was not associated with hospital mortality.

Conclusions

The relationship between tCa and hospital mortality followed a ''U" shaped curve. tCa had certain prognostic value in critically ill patients, but it had no independent association with hospital mortality.

Association Between Disease Severity and Calcium Concentration in Critically Ill Patients Admitted to Intensive Care Unit

Background

Hypocalcemia is very common in critically ill patients admitted to ICU. However, its clinical importance and relation to patient’s outcome during early days of ICU admission is questionable. Based on the mentioned problem, it seems that calcium assessment is highly important in these patients. The present study aimed at evaluating the relationship between different calcium concentrations (total/ionized/corrected) and disease severity in critically ill patients.

Methods

A total of 100 patients admitted to intensive care units of Imam Reza and Shohada hospitals during Feb 2014 and Apr 2016 were enrolled in this prospective trial. Concentrations of total, corrected, and ionized calcium and their relationship with APACHE score and disease severity were noted during the study.

Results

There was a strong and inverse correlation between disease severity and ionized calcium concentration (P < 0.001, r = -0.697). There was a medium and significant inverse correlation between disease severity and total calcium concentration (P < 0.001, r = -0.368). Weak and direct significant correlation was observed between disease severity and corrected calcium concentration (P 0.02, r = 0.232).

Conclusions

A significant correlation was found between total and ionized calcium, but there was not any significant correlation between corrected and ionized calcium. Hypocalcemia is a predictor of disease severity and mortality. We recommend measuring ionized calcium concentration for patients admitted to ICU.

Impact of admission serum calcium levels on mortality in hospitalized patients

OBJECTIVES

To assess the relationship between admission serum calcium levels and in-hospital mortality in all hospitalized patients.

METHODS

All adult hospitalized patients who had admission serum calcium levels available between years 2009 and 2013 were enrolled. Admission serum calcium was categorized based on its distribution into six groups (<7.9, 7.9 to <8.4, 8.4 to <9.0, 9.0 to <9.6, 9.6 to <10.1, and ≥10.1 mg/dL). The odds ratio (OR) of in-hospital mortality by admission serum calcium, using the calcium category of 9.6-10.1 mg/dL as the reference group, was obtained by logistic regression analysis.

RESULTS

18,437 patients were studied. The lowest incidence of in-hospital mortality was associated with admission serum calcium within 9.6 to <10.1 mg/dL. A higher in-hospital mortality rate was observed in patients with serum calcium <9.6 and ≥10.1 mg/dL. Also, 38% and 33% of patients with admission serum calcium <7.9 and ≥10.1 mg/dL were on calcium supplements before admission, respectively. After adjusting for potential confounders, both serum calcium <8.4 and ≥10.1 mg/dL were associated with an increased risk of in-hospital mortality with ORs of 2.86 [95% confidence interval (CI) 1.98-4.17], 1.74 (95% CI 1.21-2.53), and 1.69 (95% CI 1.10-2.59) when serum calcium were within <7.9, 7.9 to <8.4, and ≥10.1 mg/dL, respectively.

CONCLUSION

Hypocalcemia and hypercalcemia on admission were associated with in-hospital mortality. Highest mortality risk is observed in patients with admission hypocalcemia (<7.9 mg/dL). One-third of patients with hypercalcemia on admission were on calcium supplements.

Association of admission serum levels of vitamin D, calcium, Phosphate, magnesium and parathormone with clinical outcomes in neurosurgical ICU patients

To evaluate the association of admission serum levels of 25(OH)D, parathormone and the related electrolytes with severity of illness and clinical outcomes in neurosurgical critically ill patients, serum levels of 25(OH)D, parathormone, calcium, magnesium, and phosphate, along with APACHE II score were measured for 210 patients upon admission. Mean serum 25(OH)D was 21.1 ± 7.4 ng/mL. 25(OH)D deficiency (less than 20 ng/dL) and elevated serum parathormone level were found in 47.6% and 38% of patients respectively. Hypocalcaemia, hypophosphatemia, hypomagnesaemia and hypermagnesaemia were found in 29.5%, %63.8, 41.9% and 27.6% of patients respectively. The APACHE II score was significantly correlated with serum levels of 25(OH)D, parathormone, calcium, and phosphate. Multivariate regression analysis adjusted by other risk factors showed that among all clinical outcomes, admission hypovitaminosis D was associated with longer duration of ICU stay and a high admission of parathormone was associated with in ICU mortality. We concluded that disorders of admission serum levels of 25(OH)D, parathormone, calcium, magnesium, and phosphate are related to the presence of multiple causal factors such as severity of disease and are not independently associated with clinical outcomes. Most often they are normalize spontaneously with resolution of the disease process.

血清钙离子对急性胰腺炎持续性器官功能衰竭的预测价值

目的

探讨血清钙离子(serum calcium Ca²⁺)在急性胰腺炎(acute pancreatitis, AP)持续性器官功能衰竭(persistent organ failure, POF)中的临床意义.

方法

选取2012-01/2016-12温州市龙湾区第一人民医院及温州医科大学附属第二医院进行治疗的AP患者165例, 收集患者在症状发作72 h内的临床资料及实验室数据, 分为AP非持续性器官功能衰竭(non persistent organ failure, NO-POF)127例和POF 38例两组, 多因素Logistic回归分析用于评价血清Ca²⁺的预测能力, 采用工作特征曲线(receiver operator characteristic curve, ROC)分析计算血清Ca²⁺的截断值.

结果

经急性胰腺炎NO-POF 127例和POF 38例临床资料及实验室数据比较, 血清Ca²⁺ POF组明显低于NO-POF组, 差异有统计学意义(P<0.001); 多因素Logistic回归分析, 血清Ca²⁺是急性胰腺炎POF的独立危险因素(OR = 0.30, 95%CI: 0.12-0.76); ROC分析结果显示: 血清Ca²⁺预测急性胰腺炎POF的曲线下面积为0.764(95%CI: 0.27-0.58, P<0.001), 其最佳预测截点1.84 mmol/L, 预测POF的敏感性为75.4%, 特异性为72.5%.

结论

入院患者血清Ca²⁺与急性胰腺炎POF独立相关, 可作为一个潜在的预后因素.

Errors, Omissions, and Outliers in Hourly Vital Signs Measurements in Intensive Care

OBJECTIVE

To empirically examine the prevalence of errors, omissions, and outliers in hourly vital signs recorded in the ICU.

DESIGN

Retrospective analysis of vital signs measurements from a large-scale clinical data warehouse (Multiparameter Intelligent Monitoring in Intensive Care III).

SETTING

Data were collected from the medical, surgical, cardiac, and cardiac surgery ICUs of a tertiary medical center in the United States.

PATIENTS

We analyzed data from approximately 48,000 ICU stays including approximately 28 million vital signs measurements.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We used the vital sign day as our unit of measurement, defined as all the recordings from a single patient for a specific vital sign over a single 24-hour period. Approximately 30-40% of vital sign days included at least one gap of greater than 70 minutes between measurements. Between 3% and 10% of blood pressure measurements included logical inconsistencies. With the exception of pulse oximetry vital sign days, the readings in most vital sign days were normally distributed. We found that 15-38% of vital sign days contained at least one statistical outlier, of which 6-19% occurred simultaneously with outliers in other vital signs.

CONCLUSIONS

We found a significant number of missing, erroneous, and outlying vital signs measurements in a large ICU database. Our results provide empirical evidence of the nonrepresentativeness of hourly vital signs. Additional studies should focus on determining optimal sampling frequencies for recording vital signs in the ICU.

Relationship of on Admission Hypocalcaemia and Illness Severity as Measured by APACHE-II and SOFA Score in Intensive Care Patients'

INTRODUCTION

Hypocalcaemia is very much prevalent in critically ill patients yet very less is known about its association with severity of illness. Acute Physiology and Chronic Health Evaluation (APACHE) and Sequential Organ Failure Assessment (SOFA) are two commonly used and validated scoring tool used to assess the severity of illness in critically ill patients.

AIM

To analyze the relation of on admission hypocalcaemia with severity of illness as measured by APACHE-II and SOFA scores.

MATERIALS AND METHODS

After institute approval, 111 patients admitted during May to June 2016 were evaluated. Age, sex, on admission, ionized calcium (iCa0) levels, first day APACHE-II and SOFA scores were collected. Data were then divided in different classes based on iCa0 levels (i.e., normocalcaemic, mild, moderate and severe hypocalcaemic), APACHE-II and SOFA scores and their relationship was assessed using INSTAT software (GraphPad Software, Inc, La Zolla, CA, USA) with appropriate statistical tests.

RESULTS

Seventy eight (70.27%) patients were having hypocalcaemia on admission (<1.15 mmol/L). The mean APACHE-II score of normocalcaemic patients were significantly (p<0.05) lower as compared to moderate and severe hypocalcaemic patients (15.57±6.85 versus 21.72±6.37 and 15.57±6.85 versus 22.34±7.53, respectively). The mean iCa0 level in patients with APACHE-II > 20 were significantly lower than patients with APACHE-II < 9 (0.88±0.26 versus 1.09±0.24, p <0.05) but the mean iCa0 level in patients with SOFA > 9 were not significantly lower than patients with SOFA < 4 (0.99±0.41 versus 1.04±0.23, p > 0.05). The relative risk of on admission hypocalcaemia across increasing illness severity was also not statistically significant. Both relative risk of mortality and length of ICU stay were higher in on admission moderate hypocalcaemic patients as compared to normocalcaemic but the difference was not statistically significant.

CONCLUSION

On admission, hypocalcaemia has inconsistent correlation with increasing illness severity in adult intensive care patients. iCa0 of 0.81-0.90 mmol/L appears to have maximum deleterious effect with regard to mortality and length of ICU stay.

Serum calcium as an indicator of persistent organ failure in acute pancreatitis

AIM

Decreased level of serum calcium was commonly seen in critical illness. Hypocalcemia was significantly more frequent in patients with severe form of acute pancreatitis (AP), and a negative correlation was observed between endotoxemia and serum calcium in AP. AP patients with persistent organ failure (POF) show an extremely high mortality. The association underlying calcium and POF in AP has not been characterized.

METHODS

We conducted a retrospective cohort study of adult patients who presented within 72hours from symptom onset of AP at our center between January 2014 and May 2015. Demographic parameters on admission, organ failure assessment, laboratory data and in-hospital mortality were compared between patients with and without POF. Uni-and multi-variate logistic regression analyses were utilized to evaluated the predictive ability of serum calcium.

RESULTS

A total of 128 consecutive AP patients, including 29 with POF, were included. Compared to patients without POF, patients with POF showed a significantly lower value of serum calcium on admission (2.11±0.46 vs. 1.55±0.36mmol/L, P<0.001). After multivariate logistic analysis, serum calcium remained an independent risk factor for POF (Hazard ratio 0.21, 95% confident interval: 0.08-0.58; P=0.002). A calcium value of 1.97mmol/L predicted POF with an area under the curve (AUC) of 0.888, a sensitivity with 89.7% and specificity with 74.8%, respectively.

CONCLUSION

Our results indicate that serum calcium on admission is independently associated with POF in AP and may serve as a potential prognostic factor.

Calcium Administration Is Associated with Adverse Outcomes in Critically Ill Patients Receiving Parenteral Nutrition: Results from a Natural Experiment Created by a Calcium Gluconate Shortage

STUDY OBJECTIVE

Parenteral calcium is frequently administered to critically ill patients. However, animal studies demonstrate that calcium administration during critical illness heightens inflammation and leads to shock, organ dysfunction, and mortality. We sought to evaluate the association between calcium administration and adverse outcomes in critically ill patients receiving parenteral nutrition (PN).

DESIGN

Retrospective cohort examined before and during a calcium gluconate shortage. During the shortage, calcium was absent from PN, but calcium supplementation outside of PN was allowed. The shortage resulted in a natural experiment that included a group of patients who did not receive calcium.

SETTING

Intensive care units (ICUs) in three teaching hospitals.

PATIENTS

A total of 259 adults who received PN in the ICU for 48 hours or longer.

MEASUREMENTS AND MAIN RESULTS

Patients were divided into quartiles based on amount of parenteral calcium received; the lowest quartile received no calcium. End points were in-hospital mortality, acute respiratory failure, new-onset shock, and a composite of any one of these end points. For patients not on mechanical ventilation or vasoactive support when PN started, logistic regression revealed that calcium administration was associated with mortality (odds ratio [OR] 2.48, 95% confidence interval [CI] 1.08-5.69), acute respiratory failure (OR 2.43, 95% CI 1.28-4.60), new-onset shock (OR 2.81, 95% CI 1.22-6.44), and the combined end point (OR 2.33, 95% CI 1.31-4.16). The odds of adverse outcomes increased as the calcium dose increased.

CONCLUSION

Calcium administration correlated with adverse outcomes in critically ill patients receiving PN. The data suggest that administration of parenteral calcium to critically ill patients may be harmful.

Perpetual and Virtual Patients for Cardiorespiratory Physiological Studies

As a result of innovations in informatics over the last decades, physiologic models elaborated in the second half of the 20th century could be transformed into specific virtual patients called computational models. These models, developed initially for teaching purposes, are of great potential interest in responding to current concerns about improving patient care and safety. However, even if there are obvious advantages to using computational models in cardiorespiratory management, major concerns persist as to their reliability and their ability to recreate real patient physiologic evolution over time. Once developed, these models require complex validation and configuration phases prior to implementation in daily practice. This article focuses on the development of computational models, and reviews the methodologies to clinically validate the models including specific patient databases (perpetual patients) and the use in clinical practice including very high fidelity simulation.

Admission Serum Calcium Levels Improve the GRACE Risk Score Prediction of Hospital Mortality in Patients With Acute Coronary Syndrome

BACKGROUND

The Global Registry of Acute Coronary Events (GRACE) risk score has been extensively validated to predict risk during hospitalization in patients with acute coronary syndrome (ACS). Recently, serum calcium has been suggested as an independent predictor for in-hospital mortality in patients with ST-segment elevation myocardial infarction; however, the relationship between the 2 has not been evaluated.

HYPOTHESIS

The combination of GRACE risk score and serum calcium could provide better performance in risk prediction.

METHODS

The study enrolled 2229 consecutive patients with ACS. Independent predictors were identified by a multivariate logistic regression model. The incremental prognostic value added by serum calcium to the GRACE score was evaluated by receiver operating characteristic, net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

RESULTS

Patients in the upper quartiles of serum calcium presented with lower in-hospital mortality (odds ratios for 3 upper quartiles vs lowest quartile, respectively: 0.443, 95% confidence interval [CI]: 0.206-0.953; 0.243, 95% CI: 0.090-0.654; and 0.210, 95% CI: 0.082-0.538). Area under the curve increased significantly after adding serum calcium to the GRACE score (0.685 vs 0.746; Z = 2.617, P = 0.009). Furthermore, inclusion of serum calcium in the GRACE score enhanced NRI (0.524; P = 0.009) and IDI (0.011; P = 0.003).

CONCLUSIONS

Lower serum calcium level on admission is a possible indicator of increased risk of in-hospital mortality in ACS patients. Inclusion of serum calcium in the GRACE score may lead to a more accurate prediction of this risk. Large prospective studies are needed to confirm this finding.

Scalable Predictive Analysis in Critically Ill Patients Using a Visual Open Data Analysis Platform

With the accumulation of large amounts of health related data, predictive analytics could stimulate the transformation of reactive medicine towards Predictive, Preventive and Personalized (PPPM) Medicine, ultimately affecting both cost and quality of care. However, high-dimensionality and high-complexity of the data involved, prevents data-driven methods from easy translation into clinically relevant models. Additionally, the application of cutting edge predictive methods and data manipulation require substantial programming skills, limiting its direct exploitation by medical domain experts. This leaves a gap between potential and actual data usage. In this study, the authors address this problem by focusing on open, visual environments, suited to be applied by the medical community. Moreover, we review code free applications of big data technologies. As a showcase, a framework was developed for the meaningful use of data from critical care patients by integrating the MIMIC-II database in a data mining environment (RapidMiner) supporting scalable predictive analytics using visual tools (RapidMiner's Radoop extension). Guided by the CRoss-Industry Standard Process for Data Mining (CRISP-DM), the ETL process (Extract, Transform, Load) was initiated by retrieving data from the MIMIC-II tables of interest. As use case, correlation of platelet count and ICU survival was quantitatively assessed. Using visual tools for ETL on Hadoop and predictive modeling in RapidMiner, we developed robust processes for automatic building, parameter optimization and evaluation of various predictive models, under different feature selection schemes. Because these processes can be easily adopted in other projects, this environment is attractive for scalable predictive analytics in health research.

Platelet-to-Lymphocyte Ratio: A Novel Prognostic Factor for Prediction of 90-day Outcomes in Critically Ill Patients With Diabetic Ketoacidosis

Diabetic ketoacidosis (DKA) is a life-threatening acute complication of diabetes mellitus and the novel systemic inflammation marker platelet-to-lymphocyte ratio (PLR) may be associated with clinical outcome in patients with DKA. This study aimed to investigate the utility of PLR in predicting 90-day clinical outcomes in patients with DKA. Patient data exacted from the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC II) database was analyzed. A cutoff value for PLR of 267.67 was determined using Youden index (P < 0.05) and used to categorize subjects into a high PLR group and a low PLR group. The hazard ratios (HRs) and 95% confidence intervals (CIs) for DKA were calculated across PLR. Clinical outcomes in our study were defined as intensive care unit (ICU) 90-day readmission and all-cause mortality. A total of 278 ICU admissions were enrolled and stratified by cutoff value of PLR. The incidence of readmission and mortality was 17.8% in the high PLR group, significantly higher than 7.4% in the low PLR group. In the multivariable model, after adjusting for known confounding variables including clinical parameters, comorbidities, laboratory parameters, the HRs for DKA were 2.573 (95% CI 1.239-5.345; P = 0.011), 2.648 (95% CI 1.269-5.527; P = 0.009), and 2.650 (95% CI 1.114-6.306; P = 0.028), respectively. The Kaplan-Meier survival curve showed that a high PLR level was associated with a higher risk for 90-day outcomes in patients with DKA. The authors report that higher PLR presents a higher risk for 90-day incidence of readmission and mortality in patients with DKA. It appears to be a novel independent predictor of 90-day outcomes in critically ill DKA patients in ICU units.

Calcium Disorders in the Emergency Department: Independent Risk Factors for Mortality

Background

Calcium disorders are common in both intensive care units and in patients with chronic kidney disease and are associated with increased morbidity and mortality. It is unknown whether calcium abnormalities in unselected emergency department admissions have an impact on in-hospital mortality.

Methods

This cross-sectional analysis included all admissions to the Emergency Department at the Inselspital Bern, Switzerland from 2010 to 2011. For hyper- and hypocalcaemic patients with a Mann-Whitney U-test, the differences between subgroups divided by age, length of hospital stay, creatinine, sodium, chloride, phosphate, potassium and magnesium were compared. Associations between calcium disorders and 28-day in-hospital mortality were assessed using the Cox proportional hazard regression model.

Results

8,270 patients with calcium measurements were included in our study. Overall 264 (3.2%) patients died. 150 patients (6.13%) with hypocalcaemia and 7 patients with hypercalcaemia (6.19%) died, in contrast to 104 normocalcaemic patients (1.82%). In univariate analysis, calcium serum levels were associated with sex, mortality and pre-existing diuretic therapy (all p<0.05). In multivariate Cox regression analysis, hypocalcaemia and hypercalcaemia were independent risk factors for mortality (HR 2.00 and HR 1.88, respectively; both p<0.01).

Conclusion

Both hypocalcaemia and hypercalcaemia are associated with increased 28-day in-hospital mortality in unselected emergency department admissions.

The association between fluid balance and mortality in patients with ARDS was modified by serum potassium levels: a retrospective study

Background and Objective. Acute respiratory distress syndrome (ARDS) is characterized by pulmonary edema and may benefit from conservative fluid management. However, conflicting results exist in the literature. The study aimed to investigate the association between mean fluid balance and mortality outcome in ARDS patients who required invasive mechanical ventilation. Methods. The study was a secondary analysis of a prospectively collected dataset obtained from the NHLBI Biologic Specimen and Data Repository Information Coordinating Center. ARDS patients with invasive mechanical ventilation were eligible. Demographic and laboratory data were extracted from the dataset. Multivariable regression model was built by stepwise selection of covariates. A fractional polynomial approach was used to test the linearity of mean fluid balance in the model. The potential interactions of mean fluid balance with other variables were tested. Main Results. A total of 282 patients were eligible for the analysis, including 61 non-survivors with a mortality rate of 21.6%. After stepwise regression analysis, mean fluid balance remained to be an independent predictor of death (OR: 1.00057; 95% CI [1.00034-1.00080]). The two-term model obtained using fractional polynomial analysis was not superior to the linear model. There was significant interaction between mean fluid balance and serum potassium levels (p = 0.011). While the risk of death increased with increasing mean fluid balance at potassium levels of 1.9, 2.9 , 3.9 and 4.9 mmol/l, the risk decreased at potassium level of 5.9 mmol/l. Conclusion. The present study demonstrates that more positive fluid balance in the first 8 days is significantly associated with increased risk of death. However, the relationship between mean fluid balance and mortality can be modified by serum potassium levels. With hyperkalemia, more positive fluid balance is associated with reduced risk of death.