Long term outcomes of participants in the PARAMEDIC2 randomised trial of adrenaline in out-of-hospital cardiac arrest

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

OBJECTIVE

To systematically review the evidence and devise clinical recommendations on advanced life support (ALS) in dogs and cats and to identify critical knowledge gaps.

DESIGN

Standardized, systematic evaluation of literature pertinent to ALS following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by Evidence Evaluators, and findings were reconciled by ALS 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

Seventeen questions pertaining to vascular access, vasopressors in shockable and nonshockable rhythms, anticholinergics, defibrillation, antiarrhythmics, and adjunct drug therapy as well as open-chest CPR were reviewed. Of the 33 treatment recommendations formulated, 6 recommendations addressed the management of patients with nonshockable arrest rhythms, 10 addressed shockable rhythms, and 6 provided guidance on open-chest CPR. We recommend against high-dose epinephrine even after prolonged CPR and suggest that atropine, when indicated, is used only once. In animals with a shockable rhythm in which initial defibrillation was unsuccessful, we recommend doubling the defibrillator dose once and suggest vasopressin (or epinephrine if vasopressin is not available), esmolol, lidocaine in dogs, and/or amiodarone in cats.

CONCLUSIONS

These updated RECOVER ALS guidelines clarify the approach to refractory shockable rhythms and prolonged CPR. Very low quality of evidence due to absence of clinical data in dogs and cats continues to compromise the certainty with which recommendations can be made.

Early pharmacological interventions for prevention of post-traumatic stress disorder (PTSD) in individuals experiencing acute traumatic stress symptoms

BACKGROUND

Acute traumatic stress symptoms may develop in people who have been exposed to a traumatic event. Although they are usually self-limiting in time, some people develop post-traumatic stress disorder (PTSD), a severe and debilitating condition. Pharmacological interventions have been proposed for acute symptoms to act as an indicated prevention measure for PTSD development. As many individuals will spontaneously remit, these interventions should balance efficacy and tolerability.

OBJECTIVES

To assess the efficacy and acceptability of early pharmacological interventions for prevention of PTSD in adults experiencing acute traumatic stress symptoms.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trial Register (CCMDCTR), CENTRAL, MEDLINE, Embase and two other databases. We checked the reference lists of all included studies and relevant systematic reviews. The search was last updated on 23 January 2023.

SELECTION CRITERIA

We included randomised controlled trials on adults exposed to any kind of traumatic event and presenting acute traumatic stress symptoms, without restriction on their severity. We considered comparisons of any medication with placebo, or with another medication. We excluded trials that investigated medications as an augmentation to psychotherapy.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Using a random-effects model, we analysed dichotomous data as risk ratios (RR) and calculated the number needed to treat for an additional beneficial/harmful outcome (NNTB/NNTH). We analysed continuous data as mean differences (MD) or standardised mean differences (SMD). Our primary outcomes were PTSD severity and dropouts due to adverse events. Secondary outcomes included PTSD rate, functional disability and quality of life.

MAIN RESULTS

We included eight studies that considered four interventions (escitalopram, hydrocortisone, intranasal oxytocin, temazepam) and involved a total of 779 participants. The largest trial contributed 353 participants and the next largest, 120 and 118 participants respectively. The trials enrolled participants admitted to trauma centres or emergency departments. The risk of bias in the included studies was generally low except for attrition rate, which we rated as high-risk. We could meta-analyse data for two comparisons: escitalopram versus placebo (but limited to secondary outcomes) and hydrocortisone versus placebo. One study compared escitalopram to placebo at our primary time point of three months after the traumatic event. There was inconclusive evidence of any difference in terms of PTSD severity (mean difference (MD) on the Clinician-Administered PTSD Scale (CAPS, score range 0 to 136) -11.35, 95% confidence interval (CI) -24.56 to 1.86; 1 study, 23 participants; very low-certainty evidence), dropouts due to adverse events (no participant left the study early due to adverse events; 1 study, 31 participants; very low-certainty evidence) and PTSD rates (RR 0.59, 95% CI 0.03 to 13.08; NNTB 37, 95% CI NNTB 15 to NNTH 1; 1 study, 23 participants; very low-certainty evidence). The study did not assess functional disability or quality of life. Three studies compared hydrocortisone to placebo at our primary time point of three months after the traumatic event. We found inconclusive evidence on whether hydrocortisone was more effective in reducing the severity of PTSD symptoms compared to placebo (MD on CAPS -7.53, 95% CI -25.20 to 10.13; I2 = 85%; 3 studies, 136 participants; very low-certainty evidence) and whether it reduced the risk of developing PTSD (RR 0.47, 95% CI 0.09 to 2.38; NNTB 14, 95% CI NNTB 8 to NNTH 5; I2 = 36%; 3 studies, 136 participants; very low-certainty evidence). Evidence on the risk of dropping out due to adverse events is inconclusive (RR 3.19, 95% CI 0.13 to 75.43; 2 studies, 182 participants; low-certainty evidence) and it is unclear whether hydrocortisone might improve quality of life (MD on the SF-36 (score range 0 to 136, higher is better) 19.70, 95% CI -1.10 to 40.50; 1 study, 43 participants; very low-certainty evidence). No study assessed functional disability.

AUTHORS' CONCLUSIONS

This review provides uncertain evidence regarding the use of escitalopram, hydrocortisone, intranasal oxytocin and temazepam for people with acute stress symptoms. It is therefore unclear whether these pharmacological interventions exert a positive or negative effect in this population. It is important to note that acute traumatic stress symptoms are often limited in time, and that the lack of data prevents the careful assessment of expected benefits against side effects that is therefore required. To yield stronger conclusions regarding both positive and negative outcomes, larger sample sizes are required. A common operational framework of criteria for inclusion and baseline assessment might help in better understanding who, if anyone, benefits from an intervention. As symptom severity alone does not provide the full picture of the impact of exposure to trauma, assessment of quality of life and functional impairment would provide a more comprehensive picture of the effects of the interventions. The assessment and reporting of side effects may facilitate a more comprehensive understanding of tolerability.

The Pharmacologic Management of Cardiac Arrest

The effectiveness of pharmacologic management of cardiac arrest patients is widely debated; however, several studies published in the past 5 years have begun to clarify some of these issues. This article covers the current state of evidence for the effectiveness of the vasopressor epinephrine and the combination of vasopressin-steroids-epinephrine and antiarrhythmic medications amiodarone and lidocaine and reviews the role of other medications such as calcium, sodium bicarbonate, magnesium, and atropine in cardiac arrest care. We additionally review the role of β-blockers for refractory pulseless ventricular tachycardia/ventricular fibrillation and thrombolytics in undifferentiated cardiac arrest and suspected fatal pulmonary embolism.

The Pharmacologic Management of Cardiac Arrest

The effectiveness of pharmacologic management of cardiac arrest patients is widely debated; however, several studies published in the past 5 years have begun to clarify some of these issues. This article covers the current state of evidence for the effectiveness of the vasopressor epinephrine and the combination of vasopressin-steroids-epinephrine and antiarrhythmic medications amiodarone and lidocaine and reviews the role of other medications such as calcium, sodium bicarbonate, magnesium, and atropine in cardiac arrest care. We additionally review the role of β-blockers for refractory pulseless ventricular tachycardia/ventricular fibrillation and thrombolytics in undifferentiated cardiac arrest and suspected fatal pulmonary embolism.

Determination of Exogenous Adrenaline Levels in Patients Undergoing Cardiopulmonary Resuscitation

Core-shell quantum dot ZnS/CdSe screen-printed electrodes were used to electrochemically measure human blood plasma levels of exogenous adrenaline administered to cardiac arrest patients. The electrochemical behavior of adrenaline on the modified electrode surface was investigated using differential pulse voltammetry (DPV), cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). Under optimal conditions, the linear working ranges of the modified electrode were 0.001-3 μM (DPV) and 0.001-300 μM (EIS). The best limit of detection for this concentration range was 2.79 × 10^-8 μM (DPV). The modified electrodes showed good reproducibility, stability, and sensitivity and successfully detected adrenaline levels.

Determinants of health-related quality of life after out-of-hospital cardiac arrest (OHCA): A systematic review

OBJECTIVE

With a growing number of out-of-hospital cardiac arrest (OHCA) survivors globally, the focus of OHCA management has now broadened to survivorship. An outcome central to survivorship is health-related quality of life (HRQoL). This systematic review aimed to synthesise evidence related to the determinants of HRQoL of OHCA survivors.

METHODS

We systematically searched MEDLINE, Embase, and Scopus from inception to 15 August 2022 to identify studies investigating the association of at least one determinant and HRQoL in adult OHCA survivors. All articles were independently reviewed by two investigators. We abstracted data pertaining to determinants and classified them using a well-established HRQoL theoretical framework - the Wilson and Cleary (revised) model.

RESULTS

31 articles assessing a total of 35 determinants were included. Determinants were classified into the five domains in the HRQoL model. 26 studies assessed determinants related to individual characteristics (n=3), 12 studied biological function (n=7), nine studied symptoms (n=3), 16 studied functioning (n=5), and 35 studied characteristics of the environment (n=17). In studies that included multivariable analyses, most reported that individual characteristics (older age, female sex), symptoms (anxiety, depression), and functioning (impaired neurocognitive function) were significantly associated with poorer HRQoL.

CONCLUSIONS

Individual characteristics, symptoms, and functioning played significant roles in explaining the variability in HRQoL. Significant non-modifiable determinants such as age and sex could be used to identify populations at risk of poorer HRQoL, while significant modifiable determinants such as psychological health and neurocognitive functioning could serve as targets for post-discharge screening and rehabilitation plans. PROSPERO registration number: CRD42022359303.

Improving vasopressor use in cardiac arrest

The Chain of Survival highlights the effectiveness of early recognition of cardiac arrest and call for help, early cardiopulmonary resuscitation and early defibrillation. Most patients, however, remain in cardiac arrest despite these interventions. Drug treatments, particularly the use of vasopressors, have been included in resuscitation algorithms since their inception. This narrative review describes the current evidence base for vasopressors and reports that adrenaline (1 mg) is highly effective at achieving return of spontaneous circulation (number needed to treat 4) but is less effective on long-term outcomes (survival to 30 days, number needed to treat 111) with uncertain effects on survival with a favourable neurological outcome. Randomised trials evaluating vasopressin, either as an alternative to or in addition to adrenaline, and high-dose adrenaline have failed to find evidence of improved long-term outcomes. There is a need for future trials to evaluate the interaction between steroids and vasopressin. Evidence for other vasopressors (e.g. noradrenaline, phenylephedrine) is insufficient to support or refute their use. The use of intravenous calcium chloride as a routine intervention in out of hospital cardiac arrest is not associated with benefit and may cause harm. The optimal route for vascular access between peripheral intravenous versus intraosseous routes is currently the subject of two large randomised trials. Intracardiac, endobronchial, and intramuscular routes are not recommended. Central venous administration should be limited to patients where an existing central venous catheter is in situ and patent.

Does time heal fatigue, psychological, cognitive and disability problems in people who experience an out-of-hospital cardiac arrest? Results from the DANCAS survey study

AIMS

Out-of-hospital cardiac arrest (OHCA) survivors may suffer short-term fatigue, psychological, cognitive and disability problems, but we lack information on the proportion of survivors with these problems in the long-term. Hence, we investigated these problems in survivors 1-5 years post-OHCA and whether the results are different at different time points post-OHCA.

METHODS

All adults who survived an OHCA in Denmark from 2016 to 2019 were identified using the Danish Cardiac Arrest Registry and invited to participate in a survey between October 2020 and March 2021. The survey included the Modified Fatigue Impact Scale, Hospital Anxiety and Depression Scale, "Two simple questions" (everyday activities and mental recovery), and the 12-item World Health Organisation Disability Assessment Schedule 2.0. To investigate results at different time points, survivors were divided into four time-groups (12-24, 25-36, 37-48 and 49-56 months post-OHCA). Differences between time-groups were determined using the Kruskall-Wallis test for the mean scores and Chi-square test for the proportion of survivors with symptoms.

RESULTS

Total eligible survey population was 2116, of which 1258 survivors (60 %) responded. Overall, 29 % of survivors reported fatigue, 20 % anxiety, 15 % depression, and 27 % disability. When survivors were sub-divided by time since OHCA, no significant difference was found on either means scores or proportion between time groups (p = 0.28 to 0.88).

CONCLUSION

Up to a third of survivors report fatigue, anxiety, depression, reduced mental function and disability 1-5 years after OHCA. This proportion is the same regardless of how much time has passed supporting early screening and tailored post-OHCA interventions to help survivors adapt to their new situation.

Drug routes in out-of-hospital cardiac arrest: A summary of current evidence

Recent evidence showing the clinical effectiveness of drug therapy in cardiac arrest has led to renewed interest in the optimal route for drug administration in adult out-of-hospital cardiac arrest. Current resuscitation guidelines support use of the intravenous route for intra-arrest drug delivery, with the intraosseous route reserved for patients in whom intravenous access cannot be established. We sought to evaluate current evidence on drug route for administration of cardiac arrest drugs, with a specific focus on the intravenous and intraosseous route. We identified relevant animal, manikin, and human studies through targeted searches of MEDLINE in June 2022. Across pre-hospital systems, there is wide variation in use of the intraosseous route. Early administration of cardiac arrest drugs is associated with improved patient outcomes. Challenges in obtaining intravenous access mean that the intraosseous access may facilitate earlier drug administration. However, time from administration to the central circulation is unclear with pharmacokinetic data limited mainly to animal studies. Observational studies comparing the effect of intravenous and intraosseous drug administration on patient outcomes are challenging to interpret because of resuscitation time bias and other confounders. To date, no randomised controlled trial has directly compared the effect on patient outcomes of intraosseous compared with intravenous drug administration in cardiac arrest. The International Liaison Committee on Resuscitation has described the urgent need for randomised controlled trials comparing the intravenous and intraosseous route in adult out-of-hospital cardiac arrest. Ongoing clinical trials will directly address this knowledge gap.

Effect of Calcium vs. Placebo on Long-Term Outcomes in Patients with Out-of-hospital Cardiac Arrest A Randomized Clinical Trial

OBJECTIVE

The Calcium for Out-of-hospital Cardiac Arrest (COCA) trial was a randomized, placebo-controlled, double-blind trial of calcium for out-of-hospital cardiac arrest. The primary and secondary outcomes have been reported previously. This article describes the long-term outcomes of the trial.

METHODS

Patients aged ≥ 18 years were included if they had a non-traumatic out-of-hospital cardiac arrest during which they received adrenaline. The trial drug consisted of calcium chloride (5 mmol) or saline placebo given after the first dose of adrenaline and again after the second dose of adrenaline for a maximum of two doses. This article presents pre-specified analyses of 6-month and 1-year outcomes for survival, survival with a favorable neurological outcome (modified Rankin Scale of 3 or less), and health-related quality of life.

RESULTS

A total of 391 patients were analyzed. At 1 year, 9 patients (4.7%) were alive in the calcium group while 18 (9.1%) were alive in the placebo group (risk ratio 0.51; 95% confidence interval 0.24, 1.09). At 1 year, 7 patients (3.6%) were alive with a favorable neurological outcome in the calcium group while 17 (8.6%) were alive with a favorable neurological outcome in the placebo group (risk ratio 0.42; 95% confidence interval 0.18, 0.97). Outcomes for health-related quality of life likewise suggested harm of calcium but results were imprecise with wide confidence intervals.

CONCLUSIONS

Effect estimates remained constant over time suggesting harm of calcium but with wide confidence intervals. The results do not support calcium administration during out-of-hospital cardiac arrest. Trial registration ClinicalTrials.gov-number, NCT04153435.

Effect of Vasopressin and Methylprednisolone vs. Placebo on Long-Term Outcomes in Patients with In-Hospital Cardiac Arrest A Randomized Clinical Trial

OBJECTIVE

The primary results from the Vasopressin and Methylprednisolone for In-Hospital Cardiac Arrest (VAM-IHCA) trial have previously been reported. The objective of the current manuscript is to report long-term outcomes.

METHODS

The VAM-IHCA trial was a multicenter, randomized, double-blind, placebo-controlled trial conducted at ten hospitals in Denmark. Adult patients (age ≥ 18 years) were eligible for the trial if they had an in-hospital cardiac arrest and received at least one dose of epinephrine during resuscitation. The trial drugs consisted of 40 mg methylprednisolone (Solu-Medrol®, Pfizer) and 20 IU of vasopressin (Empressin®, Amomed Pharma GmbH) given as soon as possible after the first dose of epinephrine. This manuscript report outcomes at 6 months and 1 year including survival, survival with favorable neurological outcome, and health-related quality of life.

RESULTS

501 patients were included in the analysis. At 1 year, 15 patients (6.3%) in the intervention group and 22 patients (8.3%) in the placebo group were alive corresponding to a risk ratio of 0.76 (95% CI, 0.41-1.41). A favorable neurologic outcome at 1 year, based on the Cerebral Performance Category score, was observed in 14 patients (5.9%) in the intervention group and 20 patients (7.6%) in the placebo group (risk ratio, 0.78 [95% CI, 0.41-1.49]. No differences existed between groups for favorable neurological outcome and health-related quality of life at either 6 months or 1 year.

CONCLUSIONS

Administration of vasopressin and methylprednisolone, compared with placebo, in patients with in-hospital cardiac arrest did not improve long-term outcomes in this trial.

Effect of adrenaline dose on neurological outcome in out-of-hospital cardiac arrest: a nationwide propensity score analysis

BACKGROUND

Adrenaline is recommended during cardio-pulmonary resuscitation. The optimal dose remains debated, and the effect of lower than recommended dose is unknown.

OBJECTIVE

To compare the outcome of patients treated with the recommended, lower or higher cumulative doses of adrenaline.

DESIGN, SETTINGS, PARTICIPANTS

Patients were included from the French National Cardiac Arrest Registry and were grouped based on the received dose of adrenaline: recommended, higher and lower dose.

OUTCOME MEASURES AND ANALYSIS

The primary endpoint was good neurologic outcome at 30 days post-OHCA, defined by a cerebral performance category (CPC) of less than 3. Secondary endpoints included return of spontaneous circulation and survival to hospital discharge. A multiple propensity score adjustment approach was performed.

MAIN RESULTS

27 309 patients included from July 1st 2011 to January 1st 2019 were analysed, mean age was 68 (57-78) years and 11.2% had ventricular fibrillation. 588 (2.2%) patients survived with a good CPC score. After adjustment, patients in the high dose group had a significant lower rate of good neurologic outcome (OR, 0.6; 95% CI, 0.5-0.7). There was no significant difference for the primary endpoint in the lower dose group (OR, 0.8; 95% CI, 0.7-1.1). There was a lower rate of survival to hospital discharge in the high-dose group vs. standard group (OR, 0.5; 95% CI, 0.5-0.6).

CONCLUSION

The use of lower doses of adrenaline was not associated with a significant difference on survival good neurologic outcomes at D30. But a higher dose of adrenaline was associated with a lower rate of survival with good neurological outcomes and poorer survival at D30.

Brain injury after cardiac arrest: pathophysiology, treatment, and prognosis

Post-cardiac arrest brain injury (PCABI) is caused by initial ischaemia and subsequent reperfusion of the brain following resuscitation. In those who are admitted to intensive care unit after cardiac arrest, PCABI manifests as coma, and is the main cause of mortality and long-term disability. This review describes the mechanisms of PCABI, its treatment options, its outcomes, and the suggested strategies for outcome prediction.

Brain injury after cardiac arrest

As more people are surviving cardiac arrest, focus needs to shift towards improving neurological outcomes and quality of life in survivors. Brain injury after resuscitation, a common sequela following cardiac arrest, ranges in severity from mild impairment to devastating brain injury and brainstem death. Effective strategies to minimise brain injury after resuscitation include early intervention with cardiopulmonary resuscitation and defibrillation, restoration of normal physiology, and targeted temperature management. It is important to identify people who might have a poor outcome, to enable informed choices about continuation or withdrawal of life-sustaining treatments. Multimodal prediction guidelines seek to avoid premature withdrawal in those who might survive with a good neurological outcome, or prolonging treatment that might result in survival with severe disability. Approximately one in three admitted to intensive care will survive, many of whom will need intensive, tailored rehabilitation after discharge to have the best outcomes.

Stress hormones kinetics in ventricular fibrillation cardiac arrest and resuscitation: Translational and therapeutic implications

BACKGROUND

Knowing the kinetics of endogenous stress hormones during cardiac arrest and cardiopulmonary resuscitation (CRP) will help to optimize personalized physiology-guided treatment. The aim of this study was to examine the dynamic changes in stress hormones in a swine model of ventricular fibrillation (VF) cardiac arrest.

METHODS

Ventricular fibrillation was induced in 10 healthy Landrace/Large White piglets, which were subsequently left untreated for 8 min. All animals were resuscitated according to the 2015 European Resuscitation Council guidelines. The concentration of adrenalin, noradrenalin, and cortisol was measured at baseline and at the 4th and 8th minute of VF-cardiac arrest, as well as at 30-min, 60-min, 24 h and 48 h post-ROSC.

RESULTS

By the end of the 4th min of VF, the animals of the ROSC group exhibited significantly higher adrenaline levels compared to those of the no-ROSC group (7264 pg/ml vs. 1648 pg/ml, p = 0.03). Noradrenaline was higher in the ROSC group at the 4th min of VF (3021 pg/ml vs. 1626 pg/ml, p = 0.02). Cortisol levels in the ROSC group were significantly lower by the end of the 8th min of VF [16.25 ng/ml vs. 92.82 ng/ml, p = 0.03]. With a cut-off point of 5970 pg/ml, adrenaline at the 4th min of VF exhibited 100% sensitivity and 80% specificity for predicting ROSC.

CONCLUSION

Higher endogenous adrenaline and lower endogenous cortisol levels were associated with ROSC.