High Ionized Calcium Concentration Is Associated With Prolonged Length of Stay in the Intensive Care Unit for Postoperative Pediatric Cardiac Patients

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.

A data-driven medical knowledge discovery framework to predict the length of ICU stay for patients undergoing craniotomy based on electronic medical records

Craniotomy is an invasive operation with great trauma and many complications, and patients undergoing craniotomy should enter the ICU for monitoring and treatment. Based on electronic medical records (EMR), the discovery of high-risk multi-biomarkers rather than a single biomarker that may affect the length of ICU stay (LoICUS) can provide better decision-making or intervention suggestions for clinicians in ICU to reduce the high medical expenses of these patients and the medical burden as much as possible. The multi-biomarkers or medical decision rules can be discovered according to some interpretable predictive models, such as tree-based methods. Our study aimed to develop an interpretable framework based on real-world EMRs to predict the LoICUS and discover some high-risk medical rules of patients undergoing craniotomy. The EMR datasets of patients undergoing craniotomy in ICU were separated into preoperative and postoperative features. The paper proposes a framework called Rules-TabNet (RTN) based on the datasets. RTN is a rule-based classification model. High-risk medical rules can be discovered from RTN, and a risk analysis process is implemented to validate the rules discovered by RTN. The performance of the postoperative model was considerably better than that of the preoperative model. The postoperative RTN model had a better performance compared with the baseline model and achieved an accuracy of 0.76 and an AUC of 0.85 for the task. Twenty-four key decision rules that may have impact on the LoICUS of patients undergoing craniotomy are discovered and validated by our framework. The proposed postoperative RTN model in our framework can precisely predict whether the patients undergoing craniotomy are hospitalized for too long (more than 15 days) in the ICU. We also discovered and validated some key medical decision rules from our framework.

The effect of calcium gluconate administration during cardiopulmonary bypass on hemodynamic variables in infants undergoing open-heart surgery

Background

The incidence of complications after heart surgery is a critical factor in disability, deaths, lengthening hospital stays, and increasing treatment costs. The metabolic balance of certain hormones and electrolytes is necessary for proper cardiac function. In children, various biochemical conditions may cause calcium depletion during heart surgery. The purpose of this study was to determine the effect of calcium gluconate administration during cardiopulmonary bypass on hemodynamic variables and clinical outcomes in infants undergoing open-heart surgery. This study was conducted at Rajaie Cardiovascular Medical and Research Center in 2021 using a controlled randomized clinical trial. A total of 60 patients with open-heart surgery weighing up to 10 kg were included in the study. The first group received an intravenous injection of calcium gluconate 20 min after opening the aortic clamp, and the second group was monitored as a control group. Data collection tools included checklists containing demographics, surgical information, and intensive care unit measures.

Results

The Chi-square test or Fisher's exact test showed that the frequency distribution of gender, blood group, Rhesus factor (RH), and clinical diagnosis in the two groups of intervention and control was not statistically significant (p < 0.05). The mean and standard deviation of Ejection Fraction (EF) changes (before and after) were 13.27 ± 9.16 in the intervention group and 8.31 ± 9.80 in the control group (p = 0.065). The results of two-way repeated measures ANOVA showed that mean systolic blood pressure (p = 0.030), mean diastolic blood pressure (p = 0.021), mean heart rate (p = 0.025), mean arterial pressure (p = 0.020), mean pH (p < 0.001), and mean hemoglobin (p = 0.018) in the intervention, and control groups were statistically significant.

Conclusions

In the present study, unlike systolic pressure, mean diastolic blood pressure decreased, and mean arterial pressure increased significantly. As a result, the slope of changes during the study period was different in the intervention and control groups.

Hemodynamic Response to Calcium Chloride Boluses in Single-Ventricle Patients with Parallel Circulation

The purpose of this study is to assess the effect of calcium bolus in response to a hypotensive episode by assessing high-fidelity hemodynamic data obtained from children with single-ventricle physiology with parallel circulation. Single-center, retrospective analysis of hemodynamic data after calcium bolus administrations within the first 2 weeks post-surgery. Time intervals were the baseline (- 60 to - 10 min); the hypotensive episode (- 10 to 0 min); time point zero at the bolus administration; and the response (0 to 60 min). The main responses assessed were the peak increase in mean blood pressure (mBP), duration of the response after the bolus, and markers of oximetric effects. These analyses included 128 boluses in 63 patients. Of the total boluses analyzed, 80% increased the mBP by 5 mmHg or higher with the effect lasting at least 10 min, whereas 10% of the boluses analyzed increased the mBP by 20 mmHg or higher with the effect lasting at least 50 min. The boluses induced a significant increase in arterial oxygen saturation and an upward trend in pulmonary-to-systemic flow ratio, without increasing renal or cerebral oxygen extraction ratios. Calcium chloride boluses are an effective rescue medication for hypotensive episodes in children with parallel circulation. They lead to an improvement in mBP, as well as an increase in pulmonary-to-systemic blood flow ratio. More importantly, these boluses do not compromise systemic oxygen delivery.

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.

Impact of protein-losing enteropathy in children who underwent the Fontan operation

Previous reports have identified risk factors associated with development of post-Fontan protein-losing enteropathy. Less is known about the economic impact and resource utilisation required for post-Fontan protein-losing enteropathy in the current era. We conducted a single-centre retrospective study to assess the impact of post-Fontan protein-losing enteropathy on transplant-free survival. We also described resource utilisation and treatment variations among post-Fontan protein-losing enteropathy patients. Children who received care at our centre between 2009 and 2017 after the Fontan surgery were eligible. Initial admissions for the Fontan operative procedure were excluded. Demographics, hospital admissions, resource utilisation, medications and charges were reviewed. Patients were divided into two groups based on the presence of post-Fontan protein-losing enteropathy. Of the 343 patients screened, 147 met the eligibility criteria. Of these, 28 (19%) developed protein-losing enteropathy. After adjusting for follow-up duration, the protein-losing enteropathy group had higher number of encounters (2.15 ± 2.16 versus 1.47 ± 2.56, p 0.002), hospital length of stay (days) (25 ± 51.3 versus 11.4 ± 41.7, p < 0.0001) and total charges (2018US$) (388,489 ± 759,859 versus 202,725 ± 1,076,625, p < 0.0001). Encounters for patients with protein-losing enteropathy utilised more therapies. Among those with protein-losing enteropathy, use of digoxin was associated with slightly decreased odds for mortality and/or transplant (0.95, confidence interval 0.90-0.99, p 0.021). The 10-year transplant-free survival for patients with/without protein-losing enteropathy was 65.7/97.3% (p 0.002), respectively. Post-Fontan protein-losing enteropathy is associated with reduced 10-year transplant-free survival, higher resource utilisation, charges and medication use compared with the non-protein-losing enteropathy group. Practice variation among post-Fontan protein-losing-enteropathy patients is common. Further larger studies are needed to assess the impact of standardisation on the well-being of children with post-Fontan protein-losing enteropathy.

Outcomes of paediatric cardiac patients after 30 minutes of cardiopulmonary resuscitation prior to extracorporeal support

OBJECTIVES

To characterise the mortality and neurological outcomes of paediatric cardiac patients requiring cardiopulmonary resuscitation for more than 30 minutes prior to extracorporeal membrane oxygenation cannulation and to identify risk factors associated with adverse outcomes in this population.

MATERIALS AND METHODS

Observational retrospective cohort study in paediatric cardiac patients undergoing cardiopulmonary resuscitation for greater than 30 minutes prior to cannulation in a tertiary children's hospital, from July 2000 to July 2013.

RESULTS

Seventy-three paediatric cardiac patients requiring cardiopulmonary resuscitation for more than 30 minutes prior to cannulation were included in the study. Survival to hospital discharge was 43.8%, with 75% of survivors having either normal neurologic function or only mild disability. Multivariable logistic regression analysis demonstrated that increased use of calcium during resuscitation (odds ratio 14.5, p 0.01), cardiopulmonary resuscitation duration >50 minutes (odds ratio 4.12, p 0.03), >6 interruptions of chest compressions during cannulation (odds ratio 6.40, p 0.03), the need for continuous renal replacement therapy (odds ratio 11.1, p 0.001), and abnormal pupillary response during extracorporeal membrane oxygenation (odds ratio 33.9, p 0.006) were independent predictors for hospital mortality.

CONCLUSION

Survival after cardiopulmonary resuscitation for more than 30 minutes prior to extracorporeal membrane oxygenation cannulation in our paediatric cardiac cohort was 43.8%. Factors associated with mortality included calcium use during resuscitation, longer cardiopulmonary resuscitation, increased chest compression pauses during cannulation, the use of continuous renal replacement therapy, and abnormal pupils during extracorporeal membrane oxygenation support. A prospective assessment of these factors in paediatric cardiac patients may be beneficial in improving outcomes.

Serum vitamin D status following pediatric cardiac surgery and association with clinical outcome

Our aim is to determine the prevalence of vitamin D deficiency in children with congenital heart disease (CHD). In addition, we demonstrated the effect of cardiopulmonary bypass (CPB) on vitamin D, parathyroid hormone (PTH), and calcium levels. The association between perioperative vitamin D levels and postoperative clinical outcomes has been explored. A prospective observational study was conducted from February 2018 to June 2019 on 69 children undergoing elective surgery for CHD under CPB. Blood samples were collected preoperatively, immediate postoperatively, and 24 h postoperatively. Vitamin D deficiency was present in 34 (49.3%) patients preoperatively and 63 (91.3%) patients immediately postoperative. We identified 42.03% decline of 25(OH)D immediately postoperative. Changes in ionized calcium (iCa) concentrations were accompanied by reciprocal alterations in PTH concentrations. Lower postoperative 25(OH)D was associated with higher maximum vasoactive inotropic score (VIS) in the first 24 h postoperative (r = - 0.259, p = 0.03).Conclusion: Vitamin D deficiency is common in children with CHD and the majority are vitamin D deficient following cardiac surgery with acute decline of serum 25(OH)D after CPB. Lower postoperative vitamin D levels in children undergoing cardiac surgery are associated with the need for increasing the inotropic support.What is Known:• Vitamin D is a pleiotropic hormone, important for calcium homeostasis.• Vitamin D deficiency might affect the outcome in critically ill patients.What is New:• Cardiopulmonary bypass causes acute decline of vitamin D in children.• Lower postoperative vitamin D is associated with higher inotropic support.