The effect of levosimendan on survival and cardiac performance in an ischemic cardiac arrest model - A blinded randomized placebo-controlled study in swine

Re-evaluating intra-cardiac arrest adjunctive medications and routes of drug administration

PURPOSE OF REVIEW

This narrative review summarizes the evidence for the most commonly used intra-cardiac arrest adjunctive medications and routes of administration and discusses promising new therapies from preclinical animal models.

RECENT FINDINGS

Large trials on the administration of calcium as well as the combination of vasopressin and glucocorticoids during cardiac arrest have been published. Calcium administration during cardiopulmonary resuscitation does not improve outcomes and might cause harm. Vasopressin and glucocorticoid administration during cardiopulmonary resuscitation improve the chance of return of spontaneous circulation but has uncertain effects on survival. We identified a total of seven ongoing clinical trials investigating the potential role of bicarbonate, of vasopressin and glucocorticoids, and of intravenous versus intraosseous vascular access. Several medications such as levosimendan and inhaled nitric oxide show promise in preclinical studies, and clinical trials are either planned or actively recruiting.

SUMMARY

Large trials on intra-cardiac arrest administration of calcium and vasopressin with glucocorticoids have been performed. Several trials are ongoing that will provide valuable insights into the potential benefit of other intra-cardiac arrest medications such as bicarbonate as well as the potential benefit of intravenous or intraosseous vascular access.

Current animal models of extracorporeal cardiopulmonary resuscitation: A scoping review

Aim

Animal models of Extracorporeal Cardiopulmonary Resuscitation (ECPR) focusing on neurological outcomes are required to further the development of this potentially life-saving technology. The aim of this review is to summarize current animal models of ECPR.

Methods

A comprehensive database search of PubMed, EMBASE, and Web of Science was undertaken. Full-text publications describing animal models of ECPR between January 1, 2000, and June 30, 2022, were identified and included in the review. Data describing the conduct of the animal models of ECPR, measured variables, and outcomes were extracted according to pre-defined definitions.

Results

The search strategy yielded 805 unique reports of which 37 studies were included in the final analysis. Most studies (95%) described using a pig model of ECPR with the remainder (5%) describing a rat model. The most common method for induction of cardiac arrest was a fatal ventricular arrhythmia through electrical stimulation (70%). 10 studies reported neurological assessment of animals using physical examination, serum biomarkers, or electrophysiological findings, however, only two studies described a multimodal assessment. No studies reported the use of brain imaging as part of the neurological assessment. Return of spontaneous circulation was the most reported primary outcome, and no studies described the neurological status of the animal as the primary outcome.

Conclusion

Current animal models of ECPR do not describe clinically relevant neurological outcomes after cardiac arrest. Further work is needed to develop models that more accurately mimic clinical scenarios and can test innovations that can be translated to the application of ECPR in clinical medicine.

The Use of Levosimendan after Out-of-Hospital Cardiac Arrest and Its Association with Outcome-An Observational Study

Background: Levosimendan improves resuscitation rates and cardiac performance in animal cardiac arrest models. The aim of this study was to describe the use of levosimendan in out-of-hospital cardiac arrest (OHCA) patients and its association with outcome. Methods: A retrospective observational study of OHCA patients admitted to six intensive care units in Stockholm, Sweden, between 2010 and 2016. Patients treated with levosimendan within 24 h from admission were compared with those not treated with levosimendan. Propensity score matching and multivariable logistic regression analysis were used to assess the association between levosimendan treatment and 30-day mortality Results: Levosimendan treatment was initiated in 94/940 (10%) patients within 24 h. The proportion of men (81%, vs. 67%, p = 0.007), initial shockable rhythm (66% vs. 37%, p < 0.001), acute myocardial infarction, AMI (47% vs. 24%, p < 0.001) and need for vasoactive support (98% vs. 61%, p < 0.001) were higher among patients treated with levosimendan. After adjustment for age, sex, bystander cardiopulmonary resuscitation, witnessed status, initial rhythm and AMI, the odds ratio (OR) for 30-day mortality in the levosimendan group compared to the no-levosimendan group was 0.94 (95% Confidence interval [CI], 0.56−1.57, p = 0.82). Similar results were seen when using a propensity score analysis comparing patients with circulatory shock. Conclusions: In this observational study of OHCA patients, levosimendan was used in a limited patient group, most often in those with initial shockable rhythms, acute myocardial infarction and with a high need for vasopressors. In this limited patient cohort, levosimendan treatment was not associated with 30-day mortality. However, a better matching of patient factors and indications for use is required to derive conclusions on associations with outcome.

Cardiac Arrest in Pigs With 48 hours of Post-Resuscitation Care Induced by 2 Methods of Myocardial Infarction: A Methodological Description

Background

Systematic reviews have disclosed a lack of clinically relevant cardiac arrest animal models. The aim of this study was to develop a cardiac arrest model in pigs encompassing relevant cardiac arrest characteristics and clinically relevant post‐resuscitation care.

Methods and Results

We used 2 methods of myocardial infarction in conjunction with cardiac arrest. One group (n=7) had a continuous coronary occlusion, while another group (n=11) underwent balloon‐deflation during arrest and resuscitation with re‐inflation after return of spontaneous circulation. A sham group was included (n=6). All groups underwent 48 hours of intensive care including 24 hours of targeted temperature management. Pigs underwent invasive hemodynamic monitoring. Left ventricular function was assessed by pressure‐volume measurements. The proportion of pigs with return of spontaneous circulation was 43% in the continuous infarction group and 64% in the deflation‐reinflation group. In the continuous infarction group 29% survived the entire protocol while 55% survived in the deflation‐reinflation group. Both cardiac arrest groups needed vasopressor and inotropic support and pressure‐volume measurements showed cardiac dysfunction. During rewarming, systemic vascular resistance decreased in both cardiac arrest groups. Median [25%;75%] troponin‐I 48 hours after return of spontaneous circulation, was 88 973 ng/L [53 124;99 740] in the continuous infarction group, 19 661 ng/L [10 871;23 209] in the deflation‐reinflation group, and 1973 ng/L [1117;1995] in the sham group.

Conclusions

This article describes a cardiac arrest pig model with myocardial infarction, targeted temperature management, and clinically relevant post‐cardiac arrest care. We demonstrate 2 methods of inducing myocardial ischemia with cardiac arrest resulting in post‐cardiac arrest organ injury including cardiac dysfunction and cerebral injury.

A cohort study investigating the occurrence of differences in care provided to men and women in an intensive care unit

It has been reported that there are differences in the care given within the intensive care unit (ICU) between men and women. The aim of this study is to investigate if any differences still exist between men and women regarding the level of intensive care provided, using prespecified intensive care items. This is a retrospective cohort study of 9017 ICU patients admitted to a university hospital between 2006 and 2016. Differences in use of mechanical ventilation, invasive monitoring, vasoactive treatment, inotropic treatment, echocardiography, renal replacement therapy and central venous catheters based on the sex of the patient were analysed using univariate and multivariable logistic regressions. Subgroup analyses were performed on patients diagnosed with sepsis, cardiac arrest and respiratory disease. Approximately one third of the patients were women. Overall, men received more mechanical ventilation, more dialysis and more vasoactive treatment. Among patients admitted with a respiratory disease, men were more likely to receive mechanical ventilation. Furthermore, men were more likely to receive levosimendan if admitted with cardiac arrest. We conclude that differences in the level of intensive care provided to men and women still exist.