Administration of epinephrine has been associated with worse neurological outcomes for survivors of out-of-hospital cardiac arrest. The publication of the 2018 PARAMEDIC-2 trial, a randomized and double-blind study of epinephrine in out-of-hospital cardiac arrest, provides the strongest evidence to date that epinephrine increases return of spontaneous circulation (ROSC) but not neurologically intact survival. This study aims to determine if Emergency Medical Services (EMS) cardiac arrest protocols have changed since the publication of PARAMEDIC-2.

States in the US utilizing mandatory or model state-wide EMS protocols, including Washington DC, were included in this study. The nontraumatic cardiac arrest protocol as of January 1, 2018 was compared to the protocol in effect on January 1, 2021 to determine if there was a change in the administration of epinephrine. Protocols were downloaded from the relevant state EMS website. If a protocol could not be obtained, the state medical director was contacted.

A 2021 state-wide protocol was found for 32/51 (62.7%) states. Data from 2018 were available for 21/51 (41.2%) states. Of the 11 states without data from 2018, all follow Advanced Cardiac Life Support (ACLS) guidelines in the 2021 protocol. Five (15.6%) of the states with a state-wide protocol made a change in the cardiac arrest protocols. Maximum cumulative epinephrine dose was limited to 4mg in Maryland and 3mg in Vermont. Rhode Island changed epinephrine in shockable rhythms to be administered after three cycles of cardiopulmonary resuscitation (CPR) and an anti-arrhythmic. Rhode Island also added an epinephrine infusion as an option. No states removed epinephrine administration from their cardiac arrest protocol. Simple statistical analysis was performed with Microsoft Excel.

Several states have adjusted cardiac arrest protocols since 2018. The most frequent change was limiting the maximum cumulative dosage of epinephrine. One state changed timing of epinephrine dosing depending on the rhythm and also provided an option of an epinephrine infusion in place of bolus dosing. While the sample size is small, these changes may reflect the future direction of prehospital cardiac arrest protocols. Significant limitations apply, including the exclusion of local and regional protocols which are more capable of quickly adjusting to new research. Additionally, this study is only focused on EMS in the United States.

Anaphylactic reactions can lead to a life-threatening situation. In the event of anaphylaxis, rapid and targeted emergency treatment is indicated.

The study sought to determine the emergency therapy administered for anaphylaxis in children and adults. Focus was placed on therapy with adrenaline. In addition, the study aimed to investigate demographic data, triggers, and hospitalization rates of the different severities of anaphylaxis.

A retrospective analysis of anaphylactic reactions was conducted using data from prehospital emergency missions performed by the Air Rescue Dresden/Germany from 2008 through 2015 using the standardized application protocol EPRO-5.0 (MIND 3) anonymized. Data from 152 adults and 29 children were evaluated, focusing especially on the acute treatment as well as demographic information, triggers, and symptoms of anaphylactic reactions.

In total, 152 adults (73 female, 79 male) from 18 to 87 years (mean 50.5 years) and 29 children (9 female, 20 male) from 1 to 16 years (mean 7.5 years) with anaphylactic reactions were analyzed. The most common trigger for severe anaphylactic reactions (Grade II-IV; classification modified according to Ring and Messmer) was food in children (33%) and insect venom in adults (59%). The data show that 19% of adults with Grade II-IV anaphylactic reactions (classification modified according to Ring and Messmer) received adrenaline. Regarding children, the appliance of adrenaline was only administered in seven percent of the cases of Grade II-IV anaphylactic reactions. Adults with Grade II or higher anaphylactic reactions were hospitalized in 92%. Three percent refused hospitalization and five percent were not transferred to hospital. One-hundred percent of the children with Grade II-IV anaphylaxis were hospitalized.

Analysis of data from the Air Rescue Dresden/Germany shows that despite existing recommendations, only 19% of adults with severe anaphylaxis received adrenaline. Among children, only in seven percent was a treatment with adrenaline performed.

On the other hand, all patients survived the acute emergency treatment without apparent adverse outcomes. Thus, further studies are needed to determine the proper use of adrenaline in anaphylactic reactions.

Anaphylaxis is a severe allergic reaction that can be life-threatening. The literature indicates that the incidence of anaphylaxis is increasing and that there are deficiencies in both recognition and management. We aimed to examine the magnitude of these gaps in Canadian pediatric emergency medicine (PEM).

We conducted a self-administered survey of the Pediatric Emergency Research Canada (PERC) physician database. The survey tool was developed through a literature review to identify recurring themes of gaps in anaphylaxis diagnosis and management. The final tool contained four scenarios; three scenarios featured each of the National Institute of Allergy and Infectious Diseases (NIAID) anaphylaxis criteria, separately, and a fourth case of non-anaphylactic allergy. Multiple-choice questions associated with each scenario addressed diagnosis, management, and disposition. Additional questions focused on epinephrine prescribing, observation durations, and respondent demographics.

Of the 214 members invited to participate in the survey, 152 (71%) responded. Anaphylaxis was accurately recognized 93%, 82%, and 99% of the time for the NIAID criteria one through three, respectively. When anaphylaxis was recognized, epinephrine was prescribed for each case 96%, 95%, and 72% of the time, respectively. Of all respondents, 115 (76%) accurately diagnosed all three cases of anaphylaxis and 82 (54%) treated anaphylaxis with epinephrine each time it was indicated.

Most respondents recognized cases of anaphylaxis; however, a substantial number demonstrated gaps in management that may adversely impact this vulnerable population. The recognition of anaphylaxis without urticaria or pulmonary findings and treatment of anaphylaxis with epinephrine, where indicated, were the main gaps identified.

The utility and efficacy of bolus dose vasopressors in hemodynamically unstable patients is well-established in the fields of general anesthesia and obstetrics. However, in the prehospital setting, minimal evidence for bolus dose vasopressor use exists and is primarily limited to critical care transport use. Hypotensive episodes, whether traumatic, peri-intubation-related, or septic, increase patient mortality. The purpose of this study is to assess the efficacy and adverse events associated with prehospital bolus dose epinephrine use in non-cardiac arrest, hypotensive patients treated by a single, high-volume, ground-based Emergency Medical Services (EMS) agency.

This is a retrospective, observational study of all non-cardiac arrest EMS patients treated for hypotension using bolus dose epinephrine from September 12, 2018 through September 12, 2019. Inclusion criteria for treatment with bolus dose epinephrine required a systolic blood pressure (SBP) measurement <90mmHg. A dose of 20mcg every two minutes, as needed, was allowed per protocol. The primary data source was the EMS electronic medical record.

Forty-two patients were treated under the protocol with a median (IQR) initial SBP immediately prior to treatment of 78mmHg (65-86) and a median (IQR) initial mean arterial pressure (MAP) of 58mmHg (50-66). The post-bolus SBP and MAP increased to 93mmHg (75-111) and 69mmHg (59-83), respectively. The two most common patient presentations requiring protocol use were altered mental status (55%) and respiratory failure (31%). Over one-half of the patients treated required both advanced airway management (62%) and multiple bolus doses of vasopressor support (55%). A single episode of transient severe hypertension (SBP>180mmHg) occurred, but there were no episodes of unstable tachyarrhythmia or cardiac arrest while en route or upon arrival to the receiving hospitals.

These preliminary data suggest that the administration of bolus dose epinephrine may be effective at rapidly augmenting hypotension in the prehospital setting with a minimal incidence of adverse events. Paramedic use of bolus dose epinephrine successfully increased SBP and MAP without clinically significant side effects. Prospective studies with larger sample sizes are needed to further investigate the effects of prehospital bolus dose epinephrine on patient morbidity and mortality.

Epinephrine has been recommended for out-of-hospital cardiac arrest (OHCA) resuscitation for nearly one century, but its efficacy and safety remain unclear in the literature. The primary aim of this review was to determine whether epinephrine increases the return of spontaneous circulation in OHCA patients.

A systematic review and meta-analysis were conducted using the following databases: MEDLINE, EMBASE, and CENTRAL, from their inception until October 2018. All the randomized controlled trials (RCTs) were included. Observational studies, case reports, case series, and non-systematic reviews were excluded.

Two trials including 8,548 patients were eligible for inclusion in the data synthesis. In patients who received epinephrine during OHCA, the incidence of return of spontaneous circulation was increased, with an odds ratio (95%CI) of 4.25 (3.79-4.75), P <.001, high-quality of evidence. The number of patients transported to hospital was increased in patients who had prehospital epinephrine, with an odds ratio (95%CI) of 2.31 (2.11-2.53), P <.001, high-quality of evidence. The prehospital use of epinephrine was associated with an increased survival to hospital discharge, the odds ratio (95%CI) being 1.43 (1.10-1.87), P = .008, moderate-quality of evidence. No significant effect was noted on the favorable neurologic state of patient at hospital discharge, with an odds ratio (95%CI) of 1.21 (0.90-1.64), P = .21, moderate-quality of evidence.

This meta-analysis suggests that the prehospital use of epinephrine increases return of spontaneous circulation, transport of patients to hospital, and survival to hospital discharge for OHCA. However, no significant effects on favorable neurologic function at hospital discharge were demonstrated. The general quality of evidence ranged from moderate to high.

Vasopressors are associated with return of spontaneous circulation (ROSC), but no long-term benefit has been demonstrated in randomized trials. However, these trials did not control for the timing of vasopressor administration which may influence outcomes. Consequently, the objective of this study was to develop a model describing the likelihood of favorable neurological outcome (cerebral performance category [CPC] 1 or 2) as a function of the public safety answering point call receipt (PSAP)-to-pressor-interval (PPI) in prolonged out-of-hospital cardiac arrest.

The likelihood of favorable neurological outcome declines with increasing PPI.

This investigation was a retrospective study of cardiac arrest using linked data from the Cardiac Arrest Registry to Enhance Survival (CARES) database (Centers for Disease Control and Prevention [Atlanta, Georgia USA]; American Heart Association [Dallas, Texas USA]; and Emory University Department of Emergency Medicine [Atlanta, Georgia USA]) and the North Carolina (USA) Prehospital Medical Information System. Adult patients suffering a bystander-witnessed, non-traumatic cardiac arrest between January 2012 and June 2014 were included. Logistic regression was used to calculate the adjusted odds ratio (OR) of neurological outcome as a function of PPI, while controlling for patient age, gender, and race; endotracheal intubation (ETI); shockable rhythm; layperson cardiopulmonary resuscitation (CPR); and field hypothermia.

Of the 2,100 patients meeting inclusion criteria, 913 (43.5%) experienced ROSC, 618 (29.4%) survived to hospital admission, 187 (8.9%) survived to hospital discharge, and 155 (7.4%) were discharged with favorable neurological outcomes (CPC 1 or 2). Favorable neurological outcome was less likely with increasing PPI (OR=0.90; P<.01) and increasing age (OR=0.97; P<.01). Compared to patients with non-shockable rhythms, patients with shockable rhythms were more likely to have favorable neurological outcomes (OR=7.61; P<.01) as were patients receiving field hypothermia (OR=2.13; P<.01). Patient gender, non-Caucasian race, layperson CPR, and ETI were not independent predictors of favorable neurological outcome.

In this evaluation, time to vasopressor administration was significantly associated with favorable neurological outcome. Among adult, witnessed, non-traumatic arrests, the odds of hospital discharge with CPC 1 or 2 declined by 10% for every one-minute delay between PSAP call-receipt and vasopressor administration. These retrospective observations support the notion of a time-dependent function of vasopressor effectiveness on favorable neurological outcome. Large, prospective studies are needed to verify this relationship.

HubbleMW, TysonC. Impact of Early Vasopressor Administration on Neurological Outcomes after Prolonged Out-of-Hospital Cardiac Arrest. Prehosp Disaster Med. 2017; 32(3):297–304.

Survival from pulseless cardiac arrest typically is dismal. Some suggest that adding vasopressin to epinephrine as a cardiovascular stimulant can improve outcomes.

This study compares survival outcomes using epinephrine verses vasopressin and epinephrine in persons with pulseless cardiac arrest.

This is a retrospective, cohort evaluation of two resuscitative protocols (P1-epinephrine or P2-vasopressin with epinephrine) in a tiered response, community emergency medical service (EMS) with an approximately 100,000 catchment area. Cases are defined as 18 years or older determined to be in pulseless cardiac arrest. Outcomes were survival to emergency department arrival, to 24 hours, and to hospital discharge. Data were entered into Microsoft Office Excel® and processed using Analyze-it® for continuous and categorical data and Epi-Info® for odds ratios with confidence intervals.

There were 204 cases (60.3% males and 39.7% females) who met the inclusion criteria. Thirteen cases received electrical therapy only, and were dropped from analysis, leaving 191 (93.6%) who were included in the study; P1 to 85 (44.5%) and P2 to 106 (55.5%). Younger age was associated with improved survival to discharge home in both protocols, p = 0.003 (95% CI = 0.004–0.010). No difference in survival was noted at the levels of emergency department arrival OR 1.42 (95% CI = 0.73, 2.76) p = 0.26; 24 hour survival OR 0.54 (95% CI = 0.22–1.30) p = 0.133, or discharge home OR = 1.81 (95% CI = 0.49–6.88) p = 0.319.

This study in a community EMS did not demonstrate improved survival with the addition of vasopressin to epinephrine for pulseless cardiac arrest.

The arterial switch operation is the corrective operation for transposition of the great arteries, defined as the combination of concordant atrioventricular and discordant ventriculo–arterial connections, but there have been concerns about silent subendocardial ischaemia on exercise and coronary artery growth. The arterial switch divides the majority of the sympathetic nerves entering the heart; we have studied the effects of coronary flow and sensitivity to catecholamine stimulation in an animal model.

A total of 10 piglets were operated on cardiopulmonary bypass with section and resuturing of aortic trunk, pulmonary artery and both coronary arteries, with 13 sham-operated controls. After 5–7 weeks of recovery, seven simulated switch survivors and 13 controls were studied.

Basal heart rate was significantly higher in switch piglets: in vivo mean (standard deviation) 112 (12) versus sham 100 (10) beats per minute, (p = 0.042); in vitro (Langendorff preparation): 89 (9) versus sham 73 (8) beats per minute (p = 0.0056). In vivo maximal heart rate in response to epinephrine was increased in switch piglets, 209 (13) versus 190 (17) beats per minute (p = 0.044). In vitro dose–response curves to norepinephrine were shifted leftward and upwards (p = 0.0014), with an 80% increase in heart rate induced by 0.095 (0.053) norepinephrine micromole per litre perfusate in switch hearts versus 0.180 (0.035) norepinephrine micromole per litre (p = 0.023). Increase in coronary flow on norepinephrine stimulation and maximal coronary flow were significantly reduced in switch hearts: 0.3 (0.2) versus 0.8 (0.4) millilitre per gram heart weight (p = 0.045) and 2.5 (0.4) versus 3.1 (0.4) millilitre per gram heart (p = 0.030), respectively.

A combination of increased intrinsic heart rate, increased sensitivity to chronotropic actions of norepinephrine, and a decreased maximal coronary flow creates potential for a mismatch between perfusion and energy demands.