Mitochondrial dysfunction in fatal ventricular arrhythmias

Prevalence and outcomes of hypocalcemia on ED arrival in traumatic patients before blood transfusions: a systematic review and meta-analysis

BACKGROUND

Hypocalcemia represents a critical physiological disturbance in trauma-related hemorrhagic shock patients. Nonetheless, the prevalence and effects of hypocalcemia remain uncertain. This study aims to explore the prevalence of hypocalcemia before blood transfusions and its related mortality in adult patients with major traumatic injuries.

METHOD

We conducted a systematic search through databases, including PubMed, EMBASE, Scopus, and Web of Science, from their inception until June 30, 2024. Patients with major traumatic injuries whose serum calcium was measured upon arrival at the emergency department (ED) were included. We excluded those with prior blood transfusions, pre-clinical studies, review articles, and studies without a control group. Meta-analysis using a random-effect model was performed. Heterogeneity was evaluated using Cochrane Q and I² statistics. The study's risk of bias was assessed using the Joanna Briggs Institute's critical appraisal checklist. Publication bias was assessed using Egger's test and contour funnel plot visualization.

RESULTS

Of the total, 1,984 abstracts were screened, leading to 15 studies in this review and meta-analysis. The overall prevalence of hypocalcemia upon ED arrival was 56% (95% CI 37%-74%), with high heterogeneity (I2 99.8%) observed. Hypocalcemia patients also had higher mortality rates than normocalcemia patients (OR 2.44, 95% CI 1.76-3.40).

CONCLUSION

Hypocalcemia on ED arrival is common among adult trauma patients, who also exhibit a notably high mortality rate within this demographic. We recommend the monitoring of ionized calcium levels in traumatic adult patients. Furthermore, systematically designed studies examining the optimal thresholds, treatment protocols, and outcomes should be prioritized as the focal point of research.

TRIAL REGISTRATION

CRD42024549054 ( http://www.crd.york.ac.uk/PROSPERO ).

Preoperative Risk Prediction Score for and In-Hospital Clinical Outcomes of Reperfusion Ventricular Fibrillation After Release of Aortic Cross-Clamps: A Retrospective Study

Reperfusion ventricular fibrillation (VF) is a common arrhythmia after cardiac surgery. Predictors of reperfusion VF and its relationships with the adverse prognosis are still unclear. This study aimed to identify a risk score model to predict reperfusion VF and its effect on in-hospital outcomes. The authors enrolled 1,024 consecutive patients undergoing cardiac surgery, and a total of 823 patients were included in the study. A novel risk score model was developed following logistic regression analysis of the predictors of reperfusion VF. The receiver operating characteristic curve was used to validate this model, and the effect of VF on prognosis was later identified in multivariate or Kaplan-Meier analyses. Risk factors for reperfusion VF occurrence included weight >55 kg, preoperative left ventricular ejection fraction <50%, prior stroke, hypertension, aortic valve replacement, HTK solution, and the use of ≥3 grafts in coronary artery bypass grafting. A novel risk score model was developed using the abovementioned variables, and points were assigned to each risk factor according to its odds ratio. A high score (>6) predicted greater than 65% of patients with VF occurrence. Reperfusion VF increased the risk of in-hospital cardiovascular death (p = 0.03) and renal replacement therapy postoperatively (p = 0.022). More attention should be given to reperfusion VF due to an adverse postoperative prognosis, and the developed risk score model may predict this risk.

ExActa Mitochondria - more than just batteries for cellular function

Mitochondria are complex small organelles of eukaryotic cells and build the cellular source of energy. Several morphological features of mitochondria such as the double membrane and the circular DNA structure support the thesis that they originated from a prokaryotic eubacterial ancestor that has been taken up by the eukaryotic cell very early during the eukaryotic evolution. Since this "uptake-event" mitochondria were integrated into cellular processes and regulation which was realized by the transfer of mitochondrial genes into the host cell genome. ¹ The mitochondrial genome reduced to for instance 13 encoded protein subunits of the oxidative phosphorylation system in human cells. Mitochondria offer energy for the cell by producing about 95% of cellular ATP.² Nutrients, mainly pyruvate from the glycolysis enter the tricarboxylic acid cycle and undergo iterative oxidations whereas electrons are transferred to the reduction equivalents NADH and FADH₂ . These redox equivalents transport electrons to the electron transport chain located on the inner mitochondrial membrane and protons are pumped into the perimembranal room. The F₁ F₀ -ATP synthase generates ATP driven by protons flowing down an electrochemical gradient during a process named oxidative phosphorylation. As a byproduct reactive oxygen species are generated. Mitochondria are more than simple batteries for the cell, they are furthermore involved in numerous vital cellular processes, among them are calcium homeostasis, cell death, fatty acid oxidation, reactive oxygen species (ROS) signaling, cholesterol synthesis and nucleotide synthesis, topics that are frequently published in Acta Physiologica.

Association between Intra-Arrest Blood Glucose Level and Outcomes of Resuscitation at the Emergency Department: A Retrospective Study

Since current cardiac arrest guidelines do not address the benefit of blood glucose measurement, the ideal ranges and target of blood glucose (BG) levels during cardiac arrest to achieve a better result are warranted. We intended to investigate the associations between intra-arrest BG levels and outcomes of cardiac arrest resuscitation at the emergency department (ED). We conducted a retrospective observational study at a single university hospital. Cardiac arrest patients at the ED between 2017 and 2020 were included. Multivariable logistic regression analysis was performed to examine the associations between intra-arrest BG levels and clinical outcomes. We categorized intra-arrest BG into five groups: <70 mg/dL, 70−99 mg/dL, 100−180 mg/dL, 181−250 mg/dL, and >250 mg/dL. Eight hundred and nineteen patients experienced ED cardiac arrest during the study period. Of all, 385 intra-arrest BG measurements were included in the data analysis. The mean age was 60.4 years. The mean intra-arrest BG level was 171.1 mg/dL, with 64 (16.6%) patients who had intra-arrest BG level below 70 mg/dL and 73 (19.0%) patients who had intra-arrest BG level more than 250 mg/dL. Markedly low (<70 mg/dL) and low (70−99 mg/dL) intra-arrest BG levels were significantly associated with a lower chance of return of spontaneous circulation (ROSC, OR 0.36, 95% CI 0.14−0.99, p = 0.05 and OR 0.33, 95% CI 0.12−0.93, p = 0.04, respectively). For patients who experienced cardiac arrest at the ED, an intra-arrest BG level of less than 100 was inversely correlated with sustained ROSC. Although we could not draw a causal relationship between variables concerning this study design, normalizing intra-arrest BG was shown to result in good clinical outcomes.

Comparing Drugs for Out-of-hospital, Shock-refractory Cardiac Arrest: Systematic Review and Network Meta-analysis of Randomized Controlled Trials

INTRODUCTION

The benefit of medications used in out-of-hospital, shock-refractory cardiac arrest remains controversial. This study aims to compare the treatment outcomes of medications for out-of-hospital, shock-refractory ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT).

METHODS

The inclusion criteria were randomized controlled trials of participants older than eight years old who had atraumatic, out-of-hospital, shock-refractory VF/pVT in which at least one studied group received a medication. We conducted a database search on October 28, 2019, that included PubMed, Scopus, Web of Science, CINAHL Complete, and Cochrane CENTRAL. Citations of relevant meta-analyses were also searched. We performed frequentist network meta-analysis (NMA) to combine the comparisons. The outcomes were analyzed by using odds ratios (OR) and compared to placebo. The primary outcome was survival to hospital discharge. The secondary outcomes included the return of spontaneous circulation (ROSC), survival to hospital admission, and the neurological outcome at discharge. We ranked all outcomes using surface under the cumulative ranking score.

RESULTS

We included 18 studies with 6,582 participants. The NMA of 20 comparisons included 12 medications and placebo. Only norepinephrine showed a significant increase of ROSC (OR = 8.91, 95% confidence interval [CI], 1.88-42.29). Amiodarone significantly improved survival to hospital admission (OR = 1.53, 95% CI, 1.01-2.32). The ROSC and survival-to-hospital admission data were significantly heterogeneous with the I2 of 55.1% and 59.1%, respectively. This NMA satisfied the assumption of transitivity.

CONCLUSION

No medication was associated with improved survival to hospital discharge from out-of-hospital, shock-refractory cardiac arrest. For the secondary outcomes, norepinephrine was associated with improved ROSC and amiodarone was associated with an increased likelihood of survival to hospital admission in the NMA.