Variation in serum ionized calcium on cardiopulmonary resuscitation

2024 RECOVER Guidelines: Monitoring. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR

OBJECTIVE

To systematically review evidence on and devise treatment recommendations for patient monitoring before, during, and following CPR in dogs and cats, and to identify critical knowledge gaps.

DESIGN

Standardized, systematic evaluation of literature pertinent to peri-CPR monitoring following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by Evidence Evaluators, and findings were reconciled by Monitoring Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk:benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4 weeks prior to finalization.

SETTING

Transdisciplinary, international collaboration in university, specialty, and emergency practice.

RESULTS

Thirteen questions pertaining to hemodynamic, respiratory, and metabolic monitoring practices for identification of cardiopulmonary arrest, quality of CPR, and postcardiac arrest care were examined, and 24 treatment recommendations were formulated. Of these, 5 recommendations pertained to aspects of end-tidal CO2 (ETco2) measurement. The recommendations were founded predominantly on very low quality of evidence, with some based on expert opinion.

CONCLUSIONS

The Monitoring Domain authors continue to support initiation of chest compressions without pulse palpation. We recommend multimodal monitoring of patients at risk of cardiopulmonary arrest, at risk of re-arrest, or under general anesthesia. This report highlights the utility of ETco2 monitoring to verify correct intubation, identify return of spontaneous circulation, evaluate quality of CPR, and guide basic life support measures. Treatment recommendations further suggest intra-arrest evaluation of electrolytes (ie, potassium and calcium), as these may inform outcome-relevant interventions.

Intra-arrest blood-based biomarkers for out-of-hospital cardiac arrest: A scoping review

Objective

Blood-based biomarkers play a central role in the diagnosis and treatment of critically ill patients, yet none are routinely measured during the intra-arrest phase of out-of-hospital cardiac arrest (OHCA). Our objective was to describe methodological aspects, sources of evidence, and gaps in research surrounding intra-arrest blood-based biomarkers for OHCA.

Methods

We used scoping review methodology to summarize existing literature. The protocol was designed a priori following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. Inclusion criteria were peer-reviewed scientific studies on OHCA patients with at least one blood draw intra-arrest. We excluded in-hospital cardiac arrest and animal studies. There were no language, date, or study design exclusions. We conducted an electronic literature search using PubMed and Embase and hand-searched secondary literature. Data charting/synthesis were performed in duplicate using standardized data extraction templates.

Results

The search strategy identified 11,834 records, with 118 studies evaluating 105 blood-based biomarkers included. Only eight studies (7%) had complete reporting. The median number of studies per biomarker was 2 (interquartile range 1-4). Most studies were conducted in Asia (63 studies, 53%).  Only 22 studies (19%) had blood samples collected in the prehospital setting, and only six studies (5%) had samples collected by paramedics. Pediatric patients were included in only three studies (3%). Out of eight predefined biomarker categories of use, only two were routinely assessed: prognostic (97/105, 92%) and diagnostic (61/105, 58%).

Conclusions

Despite a large body of literature on intra-arrest blood-based biomarkers for OHCA, gaps in methodology and knowledge are widespread.

Efficacy of emergency department calcium administration in cardiac arrest: A 9-year retrospective evaluation

BACKGROUND

The efficacy of empiric calcium for patients with undifferentiated cardiac arrest has come under increased scrutiny, including a randomized controlled trial that was stopped early due to a trend towards harm with calcium administration. However, small sample sizes and non-significant findings have hindered precise effect estimates. In this analysis we evaluate the association of calcium administration with survival in a large retrospective cohort of patients with cardiac arrest treated in the emergency department (ED).

METHODS

We conducted a retrospective review of medical records from two academic hospitals (one quaternary care center, one county trauma center) in San Francisco between 2011 and 2019. Inclusion criteria were patients aged greater than or equal to 18 years old who received treatment for cardiac arrest during their ED course. Our primary exposure was the administration of calcium while in the ED and the main outcome was survival to hospital admission. The association between calcium and survival to admission was estimated using a multivariable log-binomial regression, and also with two propensity score models.

RESULTS

We examined 781 patients with cardiac arrest treated in San Francisco EDs between 2011 and 2019 and found that calcium administration was associated with decreased survival to hospital admission (RR 0.74; 95% CI 0.66-0.82). These findings remained significant after adjustment for patient age, sex, whether the cardiac arrest was witnessed, and including an interaction term for shockable cardiac rhythms (RR 0.60; 95% CI 0.50-0.72) and non-shockable cardiac rhythms (RR 0.87; 95% CI 0.76-0.99). Risk ratios for the association between calcium and survival to hospital admission were also similar between two propensity score-based models: nearest neighbor propensity matching model (RR 0.79; 95% CI 0.68-0.89) and inverse propensity weighted regression adjustment model (RR 0.75; 95% CI 0.67-0.84).

CONCLUSIONS

Calcium administration as part of ED-directed treatment for cardiac arrest was associated with lower survival to hospital admission. Given the lack of statistically significant outcomes from smaller, more methodologically robust evaluations on this topic, we believe these findings have an important role to serve in confirming previous results and allowing for more precise effect estimates. Our data adds to the growing body evidence against the empiric use of calcium in cardiac arrest.

Calcium during cardiac arrest: A systematic review

Aim

To perform a systematic review of administration of calcium compared to no calcium during cardiac arrest.

Methods

The search included Medline (PubMed), Embase, Cochrane, Web of Science, and CINAHL Plus and was conducted on September 30, 2022. The population included adults and children in any setting with cardiac arrest. The outcomes included return of spontaneous circulation, survival, survival with favourable neurologic outcome to hospital discharge and 30 days or longer, and quality of life outcome. Cochrane Risk of Bias 2 and ROBINS-I were performed to assess risk of bias for controlled and observational studies, respectively.

Results

The systematic review identified 4 studies on 3 randomised controlled trials on 554 adult out-of-hospital cardiac arrest (OHCA) patients, 8 observational studies on 2,731 adult cardiac arrest patients, and 3 observational studies on 17,449 paediatric in-hospital cardiac arrest (IHCA) patients. The randomised controlled and observational studies showed that routine calcium administration during cardiac arrest did not improve the outcome of adult OHCA or IHCA or paediatric IHCA. The risk of bias for the adult trials was low for one recent trial and high for two earlier trials, with randomization as the primary source of bias. The risk of bias for the individual observational studies was assessed to be critical due to confounding. The certainty of evidence was assessed to be moderate for adult OHCA and low for adult and paediatric IHCA. Heterogeneity across studies precluded any meaningful meta-analyses.

Conclusions

This systematic review found no evidence that routine calcium administration improves the outcomes of cardiac arrest in adults or children.PROSPERO Registration: CRD42022349641.

Effect of Intravenous or Intraosseous Calcium vs Saline on Return of Spontaneous Circulation in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial

IMPORTANCE

It is unclear whether administration of calcium has a beneficial effect in patients with cardiac arrest.

OBJECTIVE

To determine whether administration of calcium during out-of-hospital cardiac arrest improves return of spontaneous circulation in adults.

DESIGN, SETTING, AND PARTICIPANTS

This double-blind, placebo-controlled randomized clinical trial included 397 adult patients with out-of-hospital cardiac arrest and was conducted in the Central Denmark Region between January 20, 2020, and April 15, 2021. The last 90-day follow-up was on July 15, 2021.

INTERVENTIONS

The intervention consisted of up to 2 intravenous or intraosseous doses with 5 mmol of calcium chloride (n = 197) or saline (n = 200). The first dose was administered immediately after the first dose of epinephrine.

MAIN OUTCOMES AND MEASURES

The primary outcome was sustained return of spontaneous circulation. The secondary outcomes included survival and a favorable neurological outcome (modified Rankin Scale score of 0-3) at 30 days and 90 days.

RESULTS

Based on a planned interim analysis of 383 patients, the steering committee stopped the trial early due to concerns about harm in the calcium group. Of 397 adult patients randomized, 391 were included in the analyses (193 in the calcium group and 198 in the saline group; mean age, 68 [SD, 14] years; 114 [29%] were female). There was no loss to follow-up. There were 37 patients (19%) in the calcium group who had sustained return of spontaneous circulation compared with 53 patients (27%) in the saline group (risk ratio, 0.72 [95% CI, 0.49 to 1.03]; risk difference, -7.6% [95% CI, -16% to 0.8%]; P = .09). At 30 days, 10 patients (5.2%) in the calcium group and 18 patients (9.1%) in the saline group were alive (risk ratio, 0.57 [95% CI, 0.27 to 1.18]; risk difference, -3.9% [95% CI, -9.4% to 1.3%]; P = .17). A favorable neurological outcome at 30 days was observed in 7 patients (3.6%) in the calcium group and in 15 patients (7.6%) in the saline group (risk ratio, 0.48 [95% CI, 0.20 to 1.12]; risk difference, -4.0% [95% CI, -8.9% to 0.7%]; P = .12). Among the patients with calcium values measured who had return of spontaneous circulation, 26 (74%) in the calcium group and 1 (2%) in the saline group had hypercalcemia.

CONCLUSIONS AND RELEVANCE

Among adults with out-of-hospital cardiac arrest, treatment with intravenous or intraosseous calcium compared with saline did not significantly improve sustained return of spontaneous circulation. These results do not support the administration of calcium during out-of-hospital cardiac arrest in adults.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04153435.

A novel scoring system to predict the outcomes of adult patients with hypoxic-ischemic encephalopathy

BACKGROUND

Adult patients with hypoxic-ischemic encephalopathy (HIE) often incur large costs, but their outcomes are poor. Currently, there is lack of a comprehensive quantitative approach to predict patient prognoses.

METHODS

A total of 73 adult patients with HIE participated in this prospective, observational study. Clinical assessments, laboratory tests, and electrophysiological examinations were conducted within 3 days after HIE occurred. Logistic regression model was used to identify independent factors associated with patient outcomes.

RESULTS

After a 6-month follow-up, 44 (61.1%) patients survived, 28 (38.9%) patients died, and one patient was lost to follow-up. The level of blood calcium and lactate, the presence of electroencephalography reactivity, and Glasgow Coma Scale (GCS) score were significantly associated with the patient's outcome. Based on the regression coefficients from logistic regression analysis, we constructed a scoring system (CEGL; C: calcium, E: EEG reactivity, G: GCS, L: lactate) to predict the possibility of a patient's death. The area under the receiver operating characteristic curve was 0.91 (P < 0.001, 95% CI [0.87-0.95]) with a specificity of 97.7% and a positive predictive value of 97.4%.

CONCLUSION

CEGL score can provide clinicians useful information for assessment of patient prognosis within 6 months after HIE.

Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.

Ionized hypocalcemia during out-of-hospital cardiac arrest and cardiopulmonary resuscitation is not due to binding by lactate

OBJECTIVE

To determine the relationship between ionized calcium concentrations and blood lactate levels during cardiac arrest and cardiopulmonary resuscitation (CPR).

DESIGN

A prospective cohort study.

SETTING

Emergency department (ED) and general intensive care unit in a city hospital (tertiary care center).

PATIENTS AND PARTICIPANTS

32 patients with out-of-hospital cardiac arrest; 14 of the patients had a return of spontaneous circulation (ROSC) and 18 of the patients died.

INTERVENTIONS

Basic and advanced life support.

MEASUREMENTS AND RESULTS

Concentrations of ionized and total calcium, bicarbonate, lactate, and pyruvate and pH were simultaneously determined immediately upon arrival at the ED, and at 30 and 60 min. Upon arrival at the ED, all patients had ionized hypocalcemia (1.09 +/- 0.02 mmol/l). Ionized and total calcium concentrations progressively decreased during and after CPR, but pH and bicarbonate concentrations did not show any significant changes. In patients who had ROSC, a significant, but perhaps not clinically relevant, relationship was observed between the ionized calcium concentrations and pH (r2 = 0.152, p = 0.0117). In the patients who died, there were significant correlations between ionized calcium and pH (r2 = 0.382, p = 0.0001) and bicarbonate concentrations (r2 = 0.298, p = 0.0006). No definite correlations were demonstrated when comparing ionized calcium concentrations with lactate and pyruvate concentrations.

CONCLUSIONS

Ionized hypocalcemia during out-of-hospital cardiac arrest and CPR is not due to binding by both lactate and pyruvate, but may be partly due to complexing by bicarbonate, with some modifications due to variations in pH.

A comparison of serum ionized calcium in arterial and mixed venous blood during CPR

Changes in the actual ionized calcium level (aCa2+) of serum in arterial and mixed venous blood during CPR were investigated in 22 patients with intrinsic cardiopulmonary arrest. Measurements were carried out at an average of 5.4 +/- 0.6 minutes (group 1) and 30 minutes (group 2) after the beginning of CPR, using simultaneously taken blood samples. The aCa2+ of groups 1 and 2 revealed no difference between arterial and mixed venous bloods. As CPR proceeded, the aCa2+ of both bloods diminished, and group 2 had a significantly lower value than did group 1 (arterial blood: 2.36 +/- 0.04 mEq/L vs 2.09 +/- 0.09 mEq/L, P less than .01; mixed venous blood: 2.37 +/- 0.05 mEq/L vs 2.13 +/- 0.06 mEq/L, P less than .001). Conversely, pH values were significantly higher for arterial blood rather than for mixed venous blood, but there was no significant change in pH between groups 1 and 2 (arterial blood, 7.11 +/- 0.05 vs 7.14 +/- 0.04; mixed venous blood, 6.93 +/- 0.04 vs 6.98 +/- 0.03). Furthermore, an analysis of the aCa2+ serum level measurements was carried out in relation to survivors and nonsurvivors and to the presence or absence of a witness at the time of the cardiac arrest. In all groups, there was no difference in aCa2+ between arterial and mixed venous blood. As CPR proceeded, however, the aCa2+ showed a significant decrease in all groups. This decrease was accompanied by a pH increase in arterial blood of patients with a witnessed cardiac arrest and in mixed venous and arterial blood of survivors.