Intraosseous versus intravenous administration of adrenaline in patients with out-of-hospital cardiac arrest: a secondary analysis of the PARAMEDIC2 placebo-controlled trial

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.

Intraosseous and Intravenous Epinephrine Administration Routes in Out-of-Hospital Cardiac Arrest: Survival and Neurologic Outcomes

BACKGROUND

The rate of survival after out-of-hospital cardiac arrest varies depending on the timeliness and effectiveness of prehospital interventions. This study was conducted to compare out-of-hospital cardiac arrest outcomes between intravenous and intraosseous routes and between upper and lower extremity routes for drug administration.

METHODS AND RESULTS

We retrospectively analyzed data (collected using the Utstein template) from 1220 patients who had experienced out-of-hospital cardiac arrest in Taiwan's Taoyuan City between January 2021 and August 2023. The patients were stratified into intravenous and intraosseous groups by treatment approach and upper and lower extremity access groups by access site. The study outcomes were survival to discharge, favorable neurologic outcomes (Cerebral Performance Category score 1 or 2), and survival for >2 hours. The study groups were statistically compared before and after propensity score matching. Significant pre-propensity score matching differences were observed between intravenous and intraosseous groups, and the aforementioned study outcomes were better in the intravenous group than in the intraosseous group. However, the between-group differences became nonsignificant after propensity score matching. Furthermore, lower extremity access and delayed epinephrine administration were associated with worse outcomes. Survival rates fell below 12.6% when time to treatment exceeded 15 minutes, particularly in the cases of intraosseous access and lower extremity access.

CONCLUSIONS

This study highlights the benefits of early intervention and upper extremity access for drug administration in patients with out-of-hospital cardiac arrest. Intraosseous access may serve as a viable alternative to intravenous access. Timely administration of essential drugs during resuscitation can improve clinical outcomes and thus has implications for emergency medical service training.

Intraosseous or Intravenous Vascular Access for Out-of-Hospital Cardiac Arrest

BACKGROUND

Out-of-hospital cardiac arrest is a leading cause of death worldwide. Establishing vascular access is critical for administering guideline-recommended drugs during cardiopulmonary resuscitation. Both the intraosseous route and the intravenous route are used routinely, but their comparative effectiveness remains unclear.

METHODS

We conducted a randomized clinical trial to compare the effectiveness of initial attempts at intraosseous or intravenous vascular access in adults who had nontraumatic out-of-hospital cardiac arrest. The primary outcome was a sustained return of spontaneous circulation. Key secondary outcomes were survival at 30 days and survival at 30 days with a favorable neurologic outcome, defined by a score of 0 to 3 on the modified Rankin scale (scores range from 0 to 6, with higher scores indicating greater disability).

RESULTS

Among 1506 patients who underwent randomization, 1479 were included in the primary analysis (731 in the intraosseous-access group and 748 in the intravenous-access group). The successful establishment of vascular access within two attempts occurred in 669 patients (92%) assigned to the intraosseous-access group and in 595 patients (80%) assigned to the intravenous-access group. Sustained return of spontaneous circulation occurred in 221 patients (30%) in the intraosseous-access group and in 214 patients (29%) in the intravenous-access group (risk ratio, 1.06; 95% confidence interval [CI], 0.90 to 1.24; P = 0.49). At 30 days, 85 patients (12%) in the intraosseous-access group and 75 patients (10%) in the intravenous-access group were alive (risk ratio, 1.16; 95% CI, 0.87 to 1.56); a favorable neurologic outcome at 30 days occurred in 67 patients (9%) and 59 patients (8%), respectively (risk ratio, 1.16; 95% CI, 0.83 to 1.62). Prespecified adverse events were uncommon.

CONCLUSIONS

There was no significant difference in sustained return of spontaneous circulation between initial intraosseous and intravenous vascular access in adults who had out-of-hospital cardiac arrest. (Funded by the Novo Nordisk Foundation and others; IVIO EU Clinical Trials Register number, 2022-500744-38-00; ClinicalTrials.gov number, NCT05205031.).

The Route to ROSC: Evaluating the Impact of Route and Timing of Epinephrine Administration in Out-of-Hospital Cardiac Arrest Outcomes

OBJECTIVES

Previous investigations comparing intraosseous (IO) and intravenous (IV) epinephrine delivery in out-of-hospital cardiac arrest (OHCA) suggest that epinephrine is oftentimes more expeditiously administered via the IO route, but this temporal benefit doesn't always translate to clinical benefit. However, very few studies adequately controlled for indication and resuscitation time biases, making the influence of first epinephrine route on OHCA outcomes unclear. To determine the association between first epinephrine route and return of spontaneous circulation (ROSC) while controlling for resuscitation time bias and other potential confounders.

METHODS

We conducted a retrospective analysis using the 2020 ESO Data Collaborative dataset. Adult patients with a witnessed, non-traumatic OHCA prior to EMS arrival were included. Logistic regression was used to determine the association between medication route and ROSC. Linear regression was then used to calculate the probability of ROSC for each route across all call receipt-to-drug delivery intervals. Using these linear equations, the call receipt-to-drug delivery intervals were calculated that would yield equivalent probabilities of ROSC between the IV and IO routes.

RESULTS

Data were available for 10,350 patients, of which 27.4% presented with a shockable rhythm, 29.7% received bystander CPR, and 39.6% experienced ROSC. After controlling for confounders, IO epinephrine was associated with decreased likelihood of ROSC (OR = 0.77, p < 0.001). The linear regression models provided differing slope coefficients for ROSC between each route, with the IV route associated with a higher likelihood of ROSC for any given call receipt-to-drug-delivery interval. From these equations, the additional time allowed to establish an IV and administer epinephrine intravenously beyond the time required for IO delivery, yet with an equivalent predicted probability of ROSC via the IO route, was calculated. This additional time interval for intravenous administration declined linearly from 9 min at a call receipt-to-intraosseous epinephrine interval of 4 min to no additional time at a call receipt-to-intraosseous epinephrine interval of 29 min.

CONCLUSIONS

This retrospective analysis of a national EMS database revealed that IO epinephrine was negatively associated with ROSC. Additionally, there appears to be a finite time window during which intravenous epinephrine remains superior to the intraosseous route even if there are brief initial delays in IV drug delivery.

The association of intravenous vs. humeral-intraosseous vascular access with patient outcomes in adult out-of-hospital cardiac arrests

AIM

While intravenous (IV) vascular access for out-of-hospital cardiac arrest (OHCA) resuscitation is standard, humeral-intraosseous (IO) access is commonly used, despite few supporting data. We investigated the association between IV vs. humeral-IO and outcomes.

METHODS

We utilized BC Cardiac Arrest Registry data, including adult OHCA where the first-attempted intra-arrest vascular access route performed by advanced life support (ALS)-trained paramedics was IV or humeral-IO. We fit a propensity-score adjusted model with inverse probability treatment weighting to estimate the association between IV vs. humeral-IO routes and favorable neurological outcomes (CPC 1-2) and survival at hospital discharge. We repeated models within subgroups defined by initial cardiac rhythm.

RESULTS

We included 2,112 cases; the first-attempted route was IV (n = 1,575) or humeral-IO (n = 537). Time intervals from ALS-paramedic on-scene arrival to vascular access (6.6 vs. 6.9 min) and epinephrine administration (9.0 vs. 9.3 min) were similar between IV and IO groups, respectively. Among IV and humeral-IO groups, 98 (6.2%) and 20 (3.7%) had favorable neurological outcomes. Compared to humeral-IO, an IV-first approach was associated with improved hospital-discharge favorable neurological outcomes (AOR 1.7; 95% CI 1.1-2.7) and survival (AOR 1.5; 95% CI 1.0-2.3). Among shockable rhythm cases, an IV-first approach was associated with improved favorable neurological outcomes (AOR 4.2; 95% CI 2.1-8.2), but not among non-shockable rhythm cases (AOR 0.73; 95% CI 0.39-1.4).

CONCLUSION

An IV-first approach, compared to humeral-IO, for intra-arrest resuscitation was associated with an improved odds of favorable neurological outcomes and survival to hospital discharge. This association was seen among an initial shockable rhythm, but not non-shockable rhythm, subgroups.

Intraosseous versus intravenous vascular access in upper extremity among adults with out-of-hospital cardiac arrest: cluster randomised clinical trial (VICTOR trial)

OBJECTIVE

To compare the effectiveness of intraosseous versus intravenous vascular access in the treatment of adult patients with out-of-hospital cardiac arrest.

DESIGN

Cluster randomised controlled trial.

SETTING

The VICTOR (Venous Injection Compared To intraOsseous injection during resuscitation of patients with out-of-hospital cardiac arrest) trial involved emergency medical service agencies with all four advanced life support ambulance teams in Taipei City, Taiwan. The enrolment period spanned 6 July 2020 to 30 June 2023 and was temporarily suspended between 20 May 2021 and 31 July 2021 owing to the covid-19 pandemic.

PARTICIPANTS

Adult (age 20-80 years) patients with non-traumatic out-of-hospital cardiac arrest.

INTERVENTIONS

Biweekly randomised clusters of four participating advanced life support ambulance teams were assigned to insert either intravenous or intraosseous access.

MAIN OUTCOME MEASURES

The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation, sustained return of spontaneous circulation (≥2 hours), and survival with favourable neurological outcomes (cerebral performance category score ≤2) at hospital discharge.

RESULTS

Among 1771 enrolled patients, 1732 (741 in the intraosseous group and 991 in the intravenous group) were included in the primary analysis (median age 65.0 years; 1234 (71.2%) men). In the intraosseous group, 79 (10.7%) patients were discharged alive, compared with 102 (10.3%) patients in the intravenous group (odds ratio 1.04, 95% confidence interval 0.76 to 1.42; P=0.81). The odds ratio of intraosseous versus intravenous access was 1.23 (0.89 to 1.69; P=0.21) for pre-hospital return of spontaneous circulation, 0.92 (0.75 to 1.13; P=0.44) for sustained return of spontaneous circulation, and 1.17 (0.82 to 1.66; P=0.39) for survival with favourable neurological outcomes.

CONCLUSIONS

Among adults with non-traumatic out-of-hospital cardiac arrest, initial attempts to establish vascular access through the intraosseous route did not result in different outcomes compared with intravenous access in terms of the proportion of patients surviving to hospital discharge, pre-hospital return of spontaneous circulation, sustained return of spontaneous circulation, and favourable neurological outcomes.

TRIAL REGISTRATION

NCT04135547ClinicalTrials.gov NCT04135547.

Impact of intravenous accessibility and prehospital epinephrine use on survival outcomes of adult nontraumatic out-of-hospital cardiac arrest patients

BACKGROUND

This study compared out-of-hospital cardiac arrest (OHCA) patient outcomes based on intravenous (IV) access and prehospital epinephrine use.

METHODS

A retrospective study in Ulsan, South Korea, from January 2017 to December 2022, analyzed adult nontraumatic OHCA cases. Patients were grouped: Group 1 (no IV attempts), Group 2 (failed IV access), Group 3 (successful IV access without epinephrine), and Group 4 (successful IV access with epinephrine), with comparisons using logistic regression analysis.

RESULTS

Among 2,656 patients, Group 4 had significantly lower survival to hospital discharge (adjusted OR 0.520, 95% CI 0.346-0.782, p = 0.002) and favorable neurological outcomes (adjusted OR 0.292, 95% CI 0.140-0.611, p = 0.001) than Group 1. Groups 2 and 3 showed insignificant survival to hospital discharge (adjusted OR 0.814, 95% CI 0.566-1.171, p = 0.268) and (adjusted OR 1.069, 95% CI 0.810-1.412, p = 0.636) and favorable neurological outcomes (adjusted OR 0.585, 95% CI 0.299-1.144, p = 0.117) and (adjusted OR 1.075, 95% CI 0.689-1.677, p = 0.751). In the shockable rhythm group, Group 3 had better survival to hospital discharge (adjusted OR 1.700, 95% CI 1.044-2.770, p = 0.033).

CONCLUSIONS

Successful IV access with epinephrine showed worse outcomes in both rhythm groups than no IV attempts. Outcomes for failed IV and successful IV access without epinephrine were inconclusive. Importantly, successful IV access without epinephrine showed favorable survival to hospital discharge in the shockable rhythm group, warranting further research into IV access for fluid resuscitation in shockable rhythm OHCA patients.

Endotracheal epinephrine at standard versus high dose for resuscitation of asystolic newborn lambs

INTRODUCTION

Endotracheal (ET) epinephrine administration is an option during neonatal resuscitation, if the preferred intravenous (IV) route is unavailable.

OBJECTIVES

We assessed whether endotracheal epinephrine achieved return of spontaneous circulation (ROSC), and maintained physiological stability after ROSC, at standard and higher dose, in severely asphyxiated newborn lambs.

METHODS

Near-term fetal lambs were asphyxiated until asystole. Resuscitation was commenced with ventilation and chest compressions. Lambs were randomly allocated to: IV Saline placebo (5 ml/kg), IV Epinephrine (20 micrograms/kg), Standard-dose ET Epinephrine (100 micrograms/kg), and High-dose ET Epinephrine (1 mg/kg). After three allocated treatment doses, rescue IV Epinephrine was administered if ROSC had not occurred. Lambs achieving ROSC were monitored for 60 minutes. Brain histology was assessed for microbleeds.

RESULTS

ROSC in response to allocated treatment (without rescue IV Epinephrine) occurred in 1/6 Saline, 9/9 IV Epinephrine, 0/9 Standard-dose ET Epinephrine, and 7/9 High-dose ET Epinephrine lambs respectively. Blood pressure during CPR increased after treatment with IV Epinephrine and High-dose ET Epinephrine, but not Saline or Standard-dose ET Epinephrine. After ROSC, both ET Epinephrine groups had lower pH, higher lactate, and higher blood pressure than the IV Epinephrine group. Cortex microbleeds were more frequent in High-dose ET Epinephrine lambs (8/8 lambs examined, versus 3/8 in IV Epinephrine lambs).

CONCLUSIONS

The currently recommended dose of ET Epinephrine was ineffective in achieving ROSC. Without convincing clinical or preclinical evidence of efficacy, use of ET Epinephrine at this dose may not be appropriate. High-dose ET Epinephrine requires further evaluation before clinical translation.

The association of tibial vs. humeral intraosseous vascular access with patient outcomes in adult out-of-hospital cardiac arrests

AIM

Humeral and tibial intraosseous (IO) vascular access can deliver resuscitative medications for out-of-hospital cardiac arrest (OHCA), however the optimal site is unclear. We examined the association between IO tibia vs. humerus as the first-attempted vascular access site with OHCA outcomes.

METHODS

We used prospectively-collected data from the British Columbia Cardiac Arrest registry, including adult OHCAs treated with IO humerus or IO tibia as the first-attempted intra-arrest vascular access. We fit logistic regression models on the full study cohort and a propensity-matched cohort, to estimate the association between IO site and both favorable neurological outcomes (Cerebral Performance Category 1-2) and survival at hospital discharge.

RESULTS

We included 1041 (43%) and 1404 (57%) OHCAs for whom IO humerus and tibia, respectively, were the first-attempted intra-arrest vascular access. Among humerus and tibia cases, 1010 (97%) and 1369 (98%) had first-attempt success, and the median paramedic arrival-to-successful access interval was 6.7 minutes (IQR 4.4-9.4) and 6.1 minutes (IQR 4.1-8.9), respectively. In the propensity-matched cohort (n = 2052), 31 (3.0%) and 44 (4.3%) cases had favourable neurological outcomes in the IO humerus and IO tibia groups, respectively; compared to IO humerus, we did not detect an association between IO tibia with favorable neurological outcomes (OR 1.44; 95% CI 0.90-2.29) or survival to hospital discharge (OR 1.29; 95% CI 0.83-2.01). Results using the full cohort were similar.

CONCLUSIONS

We did not detect an association between the first-attempted intra-arrest IO site (tibia vs. humerus) and clinical outcomes. Clinical trials are warranted to test differences between vascular access strategies.

Trend of Outcome Metrics in Recent Out-of-Hospital-Cardiac-Arrest Research: A Narrative Review of Clinical Trials

Cardiopulmonary resuscitation (CPR) research traditionally focuses on survival. In 2018, the International Liaison Committee on Resuscitation (ILCOR) proposed more patient-centered outcomes. Our narrative review assessed clinical trials after 2018 to identify the trends of outcome metrics in the field OHCA research. We performed a search of the PubMed database from 1 January 2019 to 22 September 2023. Prospective clinical trials involving adult humans were eligible. Studies that did not report any patient-related outcomes or were not available in full-text or English language were excluded. The articles were assessed for demographic information and primary and secondary outcomes. We included 89 studies for analysis. For the primary outcome, 31 (35%) studies assessed neurocognitive functions, and 27 (30%) used survival. For secondary outcomes, neurocognitive function was present in 20 (22%) studies, and survival was present in 10 (11%) studies. Twenty-six (29%) studies used both survival and neurocognitive function. Since the publication of the COSCA guidelines in 2018, there has been an increased focus on neurologic outcomes. Although survival outcomes are used frequently, we observed a trend toward fewer studies with ROSC as a primary outcome. There were no quality-of-life assessments, suggesting a need for more studies with patient-centered outcomes that can inform the guidelines for cardiac-arrest management.

Trends in use of intraosseous and intravenous access in out-of-hospital cardiac arrest across English ambulance services: A registry-based, cohort study

INTRODUCTION

The optimum route for drug administration in cardiac arrest is unclear. Recent data suggest that use of the intraosseous route may be increasing. This study aimed to explore changes over time in use of the intraosseous and intravenous drug routes in out-of-hospital cardiac arrest in England.

METHODS

We extracted data from the UK Out-of-Hospital Cardiac Arrest Outcomes registry. We included adult out-of-hospital cardiac arrest patients between 2015-2020 who were treated by an English Emergency Medical Service that submitted vascular access route data to the registry. The primary outcome was any use of the intraosseous route during cardiac arrest. We used logistic regression models to describe the association between time (calendar month) and intraosseous use.

RESULTS

We identified 75,343 adults in cardiac arrest treated by seven Emergency Medical Service systems between January 2015 and December 2020. The median age was 72 years, 64% were male and 23% presented in a shockable rhythm. Over the study period, the percentage of patients receiving intraosseous access increased from 22.8% in 2015 to 42.5% in 2020. For each study-month, the odds of receiving any intraosseous access increased by 1.019 (95% confidence interval 1.019 to 1.020, p < 0.001). This observed effect was consistent across sensitivity analyses. We observed a corresponding decrease in use of intravenous access.

CONCLUSION

In England, the use of intraosseous access in out-of-hospital cardiac arrest has progressively increased over time. There is an urgent need for randomised controlled trials to evaluate the clinical effectiveness of the different vascular access routes in cardiac arrest.

The Lancet Commission to reduce the global burden of sudden cardiac death: a call for multidisciplinary action

Despite major advancements in cardiovascular medicine, sudden cardiac death (SCD) continues to be an enormous medical and societal challenge, claiming millions of lives every year. Efforts to prevent SCD are hampered by imperfect risk prediction and inadequate solutions to specifically address arrhythmogenesis. Although resuscitation strategies have witnessed substantial evolution, there is a need to strengthen the organisation of community interventions and emergency medical systems across varied locations and health-care structures. With all the technological and medical advances of the 21st century, the fact that survival from sudden cardiac arrest (SCA) remains lower than 10% in most parts of the world is unacceptable. Recognising this urgent need, the Lancet Commission on SCD was constituted, bringing together 30 international experts in varied disciplines. Consistent progress in tackling SCD will require a completely revamped approach to SCD prevention, with wide-sweeping policy changes that will empower the development of both governmental and community-based programmes to maximise survival from SCA, and to comprehensively attend to survivors and decedents' families after the event. International collaborative efforts that maximally leverage and connect the expertise of various research organisations will need to be prioritised to properly address identified gaps. The Commission places substantial emphasis on the need to develop a multidisciplinary strategy that encompasses all aspects of SCD prevention and treatment. The Commission provides a critical assessment of the current scientific efforts in the field, and puts forth key recommendations to challenge, activate, and intensify efforts by both the scientific and global community with new directions, research, and innovation to reduce the burden of SCD worldwide.

A Machine Learning Prediction Model for Non-cardiogenic Out-of-hospital Cardiac Arrest with Initial Non-shockable Rhythm

Objectives

The purpose of this study was to develop and validate a machine learning prediction model for the prognosis of non-cardiogenic out-of-hospital cardiac arrest (OHCA) with an initial non-shockable rhythm.

Design

Data were obtained from a nationwide OHCA registry in Japan. Overall, 222,056 patients with OHCA and an initial non-shockable rhythm were identified from the registry in 2016 and 2017. Patients aged <18 years and OHCA caused by cardiogenic origin, cancer, and external factors were excluded. Finally, 58,854 participants were included.

Methods

Patients were classified into the training dataset (n=29,304, data from 2016) and the test dataset (n=29,550, data from 2017). The training dataset was used to train and develop the machine learning model, and the test dataset was used for internal validation. We selected XGBoost as the machine learning classifier. The primary outcome was the poor prognosis defined as cerebral performance category of 3-5 at 1 month. Eleven prehospital variables were selected as outcome predictors.

Results

In validation, the machine learning model predicted the primary outcome with an accuracy of 90.8% [95% confidence interval (CI): 90.5-91.2], a sensitivity of 91.4% [CI: 90.7-91.4], a specificity of 74.1% [CI: 69.2-78.6], and an area under the receiver operating characteristic value of 0.89 [0.87-0.92]. The important features for model development were the prehospital return of spontaneous circulation, prehospital adrenaline administration, and initial electrical rhythm.

Conclusions

We developed a favorable machine learning model to predict the prognosis of non-cardiogenic OHCA with an initial non-shockable rhythm in the early stage of resuscitation.

Impact of the route of adrenaline administration in patients suffering from out-of-hospital cardiac arrest on 30-day survival with good neurological outcome (ETIVIO study)

BACKGROUND

Over the past decades, international guidelines for cardiopulmonary resuscitation (CPR) have changed the recommendation for alternative routes for drug administration. Until now, evidence for the substantial superiority of one route with respect to treatment outcome after CPR has been lacking. The present study compares the effects of intravenous (IV), intraosseous (IO) and endotracheal (ET) adrenaline application during CPR in out-of-hospital cardiac arrest (OHCA) on clinical outcomes within the database of the German Resuscitation Registry (GRR).

METHODS

This registry analysis was based on the GRR cohort of 212,228 OHCA patients between 1989 and 2020. Inclusion criteria were: OHCA, application of adrenaline, and out-of-hospital CPR. Excluded from the study were patients younger than 18 years, those who had trauma or bleeding as suspected causes of cardiac arrest, and incomplete data sets. The clinical endpoint was hospital discharge with good neurological outcome [cerebral performance category (CPC) 1/2]. Four routes of adrenaline administration were compared: IV, IO, IO + IV, ET + IV. Group comparisons were done using matched-pair analysis and binary logistic regression.

RESULTS

In matched-pair group comparisons of the primary clinical outcome hospital discharge with CPC 1/2, the IV group (n = 2416) showed better results compared to IO (n = 1208), [odds ratio (OR): 2.43, 95% confidence interval (CI): 1.54-3.84, p < 0.01] and when comparing IV (n = 8706) to IO + IV (n = 4353), [OR: 1.33, 95% CI: 1.12-1.59, p < 0.01]. In contrast, no significant difference was found between IV (n = 532) and ET + IV (n = 266), [OR: 1.26, 95% CI: 0.55-2.90, p = 0.59]. Concurrently, binary logistic regression yielded a highly significant effect of vascular access type (χ² = 67.744(3), p < 0.001) on hospital discharge with CPC1/2, with negative effects for IO (regression coefficient (r.c.) = - 0.766, p = 0.001) and IO + IV (r.c. = - 0.201, p = 0,028) and no significant effect for ET + IV (r.c. = 0.117, p = 0.770) compared to IV.

CONCLUSIONS

The GRR data, collected over a period of 31 years, seem to emphasize the relevance of an IV access during out-of-hospital CPR, in the event that adrenaline had to be administered. IO administration of adrenaline might be less effective. ET application, though removed in 2010 from international guidelines, could gain importance as an alternative route again.

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.

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.

Impact of intraosseous versus intravenous resuscitation during in-hospital cardiac arrest: A retrospective study

AIM

To compare outcomes between Intraosseous (IO) and peripheral intravenous (PIV) injection during in-hospital cardiac arrest (IHCA) and examine its utility in individuals with obesity.

METHODS

We performed a retrospective cohort analysis of adult, atraumatic IHCA at a single tertiary care center. Subjects were classified as either IO or PIV resuscitation. The primary outcome of interest was survival to hospital discharge. The secondary outcomes of interest were survival with favourable neurologic status, rates-of-ROSC (ROR) and time-to-ROSC (TTR). Subgroup analysis among patients with BMI ≥ 30 kg/m² was performed.

RESULTS

Complete data were available for 1852 subjects, 1039 of whom met eligibility criteria. A total of 832 were resuscitated via PIV route and 207 via IO route. Use of IO compared to PIV was associated with lower overall survival to hospital discharge (20.8% vs 28.4% p = 0.03), lower rates of survival with favourable neurologic status (18.4% vs 25.2% p = 0.04), lower ROR (72.2% vs 80.7%) and longer TTR (12:38 min vs 9:01 min). After multivariate adjustment there was no significant differences between IO and PIV in rates of survival to discharge (OR 0.71, 95% CI 0.47-1.06, p = 0.09) or rates of survival with favourable neurologic status (OR 0.74, 95% CI 0.49-1.13, p = 0.16). The ROR and TTR remained significantly worse in the IO group. Subgroup analysis of patients with BMI ≥ 30 kg/m² identified no benefit or harm with use of IO compared to PIV.

CONCLUSION

Intraosseous medication delivery is associated with inferior rates-of-ROSC and longer times-to-ROSC compared to PIV, but no differences in overall survival to hospital discharge or survival with favourable neurologic status during IHCA.

[Adult advanced life support]

These European Resuscitation Council Advanced Life Support guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the prevention of and ALS treatments for both in-hospital cardiac arrest and out-of-hospital cardiac arrest.

European Resuscitation Council Guidelines 2021: Adult advanced life support

These European Resuscitation Council Advanced Life Support guidelines, are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the prevention of and ALS treatments for both in-hospital cardiac arrest and out-of-hospital cardiac arrest.

Validation of intraosseous delivery of valproic acid in a swine model of polytrauma

Background

Intraosseous (IO) drug delivery may be necessary in emergency situations when intravenous access is unattainable. Valproic acid (VPA) is a histone deacetylase inhibitor that has previously been shown to improve survival in preclinical models of lethal polytrauma. In this study, we sought to compare serum levels of intravenously and IO-delivered VPA, and to analyze the effect of IO-delivered VPA.

Methods

Swine were subjected to 40% blood volume hemorrhage, brain injury, femur fracture, rectus crush injury and liver laceration. After 1 hour of shock, animals were randomized (n=3/group) to receive normal saline resuscitation (control), normal saline+intravenous VPA 150 mg/kg (intravenous group) or normal saline +IO VPA 150 mg/kg (IO group). Serum levels of VPA were assessed between groups, and proteomics analyses were performed on IO and control groups on heart, lung and liver samples.

Results

Intravenous and IO serum VPA levels were similar at 1, 3, 5 and 7 hours after starting the infusion (p>0.05). IO-delivered VPA induced significant proteomics changes in the heart, lung and liver, which were most pronounced in the lung. Biologic processes affected included inflammation, metabolism and transcriptional & translational machinery. The control group had 0% survival, and the intravenous and IO group both had 100% survival to the end of the experiment (p<0.05).

Discussion

IO-delivered VPA is noninferior to intravenous administration and is a viable option in emergent situations when intravenous access is unattainable.

Level of evidence

Not applicable (animal study).

Intraosseous versus intravenous vascular access during cardiopulmonary resuscitation for out-of-hospital cardiac arrest: a systematic review and meta-analysis of observational studies

INTRODUCTION

This study is aimed to investigate the association of intraosseous (IO) versus intravenous (IV) route during cardiopulmonary resuscitation (CPR) with outcomes after out-of-hospital cardiac arrest (OHCA).

METHODS

We systematically searched PubMed, Embase, Cochrane Library and Web of Science from the database inception through April 2020. Our search strings included designed keywords for two concepts, i.e. vascular access and cardiac arrest. There were no limitations implemented in the search strategy. We selected studies comparing IO versus IV access in neurological or survival outcomes after OHCA. Favourable neurological outcome at hospital discharge was pre-specified as the primary outcome. We pooled the effect estimates in random-effects models and quantified the heterogeneity by the I² statistics. Time to intervention, defined as time interval from call for emergency medical services to establishing vascular access or administering medications, was hypothesized to be a potential outcome moderator and examined in subgroup analysis with meta-regression.

RESULTS

Nine retrospective observational studies involving 111,746 adult OHCA patients were included. Most studies were rated as high quality according to Newcastle-Ottawa Scale. The pooled results demonstrated no significant association between types of vascular access and the primary outcome (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.27-1.33; I², 95%). In subgroup analysis, time to intervention was noted to be positively associated with the pooled OR of achieving the primary outcome (OR: 3.95, 95% CI, 1.42-11.02, p: 0.02). That is, when the studies not accounting for the variable of "time to intervention" in the statistical analysis were pooled together, the meta-analytic results between IO access and favourable outcomes would be biased toward inverse association. No obvious publication bias was detected by the funnel plot.

CONCLUSIONS

The meta-analysis revealed no significant association between types of vascular access and neurological outcomes at hospital discharge among OHCA patients. Time to intervention was identified to be an important outcome moderator in this meta-analysis of observation studies. These results call for the need for future clinical trials to investigate the unbiased effect of IO use on OHCA CPR.

Intraosseous or Peripheral IV Access in Pediatric Cardiac Arrest? Results From the French National Cardiac Arrest Registry

OBJECTIVES

Despite the evolving recommendations that favor the use of intraosseous access in pediatric resuscitation, the impact of vascular access type on survival in young children has not been demonstrated. The aim of this study was to assess the impact of the intravascular injection route on the return on spontaneous circulation, survival to hospital admission (0 day), and 30 days or survival to hospital discharge, by comparing survival rates in young children having intraosseous and peripheral IV access. The second aim was to compare the rates of favorable neurologic outcome after 30 days or survival to hospital discharge.

DESIGN

This was a multicenter retrospective comparative study between July 2011 and October 2018.

SETTING

Based on the French cardiac arrest registry data.

PATIENTS

All prepubescent (males < 12 yr old, females < 10 yr old) victims of an out-of-hospital cardiac arrest.

INTERVENTIONS

Patients with adrenaline administration by intraosseous versus peripheral venous technique were compared, using propensity score matching.

MEASUREMENTS AND MAIN RESULTS

The analysis included 603 prepubescent patients, 351 (58%) in the intraosseous group and 252 (42%) in the peripheral IV group. Intraosseous group patients were younger, lighter, with more medical cause for arrest. The intraosseous group had lower survival rates at 30 days or hospital discharge (n = 6; 1.7%) than the peripheral IV group (n = 12; 4.8%) (p = 0.030). After matching, 101 pairs of patients were created. No difference was observed on return of spontaneous circulation or 0-day survival rates (odds ratio = 1.000 [95% CI, 0.518-1.930]; odds ratio = 0.946 [95% CI, 0.492-1.817], respectively) and on 30 days or hospital discharge survival (n = 3 in both groups) (odds ratio = 1.000 [95% CI, 0.197-5.076]). Meaningful statistical evaluation of neurologic status among survivors was precluded by inadequate numbers.

CONCLUSIONS

The type of injection route (intraosseous or peripheral venous access) does not appear to have an impact on survival of out-of-hospital cardiac arrest in a prepubescent population, but limitations of propensity matching limit a definitive conclusion.

The effect of airway management on CPR quality in the PARAMEDIC2 randomised controlled trial

INTRODUCTION

Good quality basic life support (BLS) is associated with improved outcome from cardiac arrest. Chest compression fraction (CCF) is a BLS quality indicator, which may be influenced by the type of airway used. We aimed to assess CCF according to the airway strategy in the PARAMEDIC2 study: no advanced airway, supraglottic airway (SGA), tracheal intubation, or a combination of the two. Our hypothesis was that tracheal intubation was associated with a decrease in the CCF compared with alternative airway management strategies.

METHODS

PARAMEDIC2 was a multicentre double-blinded placebo-controlled trial of adrenaline vs placebo in out-of-hospital cardiac arrest. Data showing compression rate and ratio from patients recruited by London Ambulance Service (LAS) as part of this study was collated and analysed according to the advanced airway used during the resuscitation attempt.

RESULTS

CPR process data were available from 286/ 2058 (13.9%) of the total patients recruited by LAS. The mean compression rate for the first 5 min of data recording was the same in all groups (P = 0.272) and ranged from 104.2 (95% CI of mean: 100.5, 107.8) min^-1 to 108.0 (95% CI of mean: 105.1, 108.3) min^-1. The mean compression fraction was also similar across all groups (P = 0.159) and ranged between 74.7% and 78.4%. There was no difference in the compression rates and fractions across the airway management groups, regardless of the duration of CPR.

CONCLUSION

There was no significant difference in the compression fraction associated with the airway management strategy.

Systematic review and meta-analysis appraising efficacy and safety of adrenaline for adult cardiopulmonary resuscitation

BACKGROUND

There is a beneficial effect of adrenaline during adult cardiopulmonary resuscitation (CPR) from cardiac arrest but there is also uncertainty about its safety and effectiveness. The aim of this study was to evaluate the use of adrenaline versus non-adrenaline CPR.

METHODS

PubMed, ScienceDirect, Embase, CENTRAL (Cochrane Central Register of Controlled Trials) and Google Scholar databases were searched from their inception up to 1st July 2020. Two reviewers independently assessed eligibility and risk of bias, with conflicts resolved by a third reviewer. Risk ratio (RR) or mean difference of groups were calculated using fixed or random-effect models.

RESULTS

Nineteen trials were identified. The use of adrenaline during CPR was associated with a significantly higher percentage of return of spontaneous circulation (ROSC) compared to non-adrenaline treatment (20.9% vs. 5.9%; RR = 1.87; 95% confidence interval [CI] 1.37-2.55; p < 0.001). The use of adrenaline in CPR was associated with ROSC at 19.4% and for non-adrenaline treatment - 4.3% (RR = 3.23; 95% CI 1.89-5.53; p < 0.001). Survival to discharge (or 30-day survival) when using adrenaline was 6.8% compared to non-adrenaline treatment (5.5%; RR = 0.99; 95% CI 0.76-1.30; p = 0.97). However, the use of adrenaline was associated with a worse neurological outcome (1.6% vs. 2.2%; RR = 0.57; 95% CI 0.42-0.78; p < 0.001).

CONCLUSIONS

This review suggests that resuscitation with adrenaline is associated with the ROSC and survival to hospital discharge, but no higher effectiveness was observed at discharge with favorable neurological outcome. The analysis showed higher effectiveness of ROSC and survival to hospital discharge in non-shockable rhythms. But more multicenter randomized controlled trials are needed in the future.

Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations for advanced life support includes updates on multiple advanced life support topics addressed with 3 different types of reviews. Topics were prioritized on the basis of both recent interest within the resuscitation community and the amount of new evidence available since any previous review. Systematic reviews addressed higher-priority topics, and included double-sequential defibrillation, intravenous versus intraosseous route for drug administration during cardiac arrest, point-of-care echocardiography for intra-arrest prognostication, cardiac arrest caused by pulmonary embolism, postresuscitation oxygenation and ventilation, prophylactic antibiotics after resuscitation, postresuscitation seizure prophylaxis and treatment, and neuroprognostication. New or updated treatment recommendations on these topics are presented. Scoping reviews were conducted for anticipatory charging and monitoring of physiological parameters during cardiopulmonary resuscitation. Topics for which systematic reviews and new Consensuses on Science With Treatment Recommendations were completed since 2015 are also summarized here. All remaining topics reviewed were addressed with evidence updates to identify any new evidence and to help determine which topics should be the highest priority for systematic reviews in the next 1 to 2 years.

Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations for advanced life support includes updates on multiple advanced life support topics addressed with 3 different types of reviews. Topics were prioritized on the basis of both recent interest within the resuscitation community and the amount of new evidence available since any previous review. Systematic reviews addressed higher-priority topics, and included double-sequential defibrillation, intravenous versus intraosseous route for drug administration during cardiac arrest, point-of-care echocardiography for intra-arrest prognostication, cardiac arrest caused by pulmonary embolism, postresuscitation oxygenation and ventilation, prophylactic antibiotics after resuscitation, postresuscitation seizure prophylaxis and treatment, and neuroprognostication. New or updated treatment recommendations on these topics are presented. Scoping reviews were conducted for anticipatory charging and monitoring of physiological parameters during cardiopulmonary resuscitation. Topics for which systematic reviews and new Consensuses on Science With Treatment Recommendations were completed since 2015 are also summarized here. All remaining topics reviewed were addressed with evidence updates to identify any new evidence and to help determine which topics should be the highest priority for systematic reviews in the next 1 to 2 years.