The Resuscitative and Pharmacokinetic Effects of Humeral Intraosseous Vasopressin in a Swine Model of Ventricular Fibrillation

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.

Intravenous vs. intraosseous vascular access during out-of-hospital cardiac arrest - protocol for a randomised clinical trial

Objective

During cardiac arrest, current guidelines recommend attempting intravenous access first and to consider intraosseous access if intravenous access is unsuccessful or impossible. However, these recommendations are only based on very low-certainty evidence. Therefore, the "Intravenous vs Intraosseous Vascular Access During Out-of-Hospital Cardiac Arrest" (IVIO) trial aims to determine whether there is a difference in patient outcomes depending on the type of vascular access attempted during out-of-hospital cardiac arrest. This current article describes the clinical IVIO trial.

Methods

The IVIO trial is an investigator-initiated, randomised trial of intravenous vs. intraosseous vascular access during adult non-traumatic out-of-hospital cardiac arrest in Denmark. The intervention will consist of minimum two attempts (if unsuccessful on the first attempt) to successfully establish intravenous or intraosseous vascular access during cardiac arrest. The intraosseous group will be further randomised to the humeral or tibial site. The primary outcome is sustained return of spontaneous circulation and key secondary outcomes include survival and survival with a favourable neurological outcome at 30 days. A total of 1,470 patients will be included.

Results

The trial started in March 2022 and the last patient is anticipated to be included in the spring of 2024. The primary results will be reported after 90-day follow-up and are anticipated in mid-2024.

Conclusion

The current article describes the design of the Danish IVIO trial. The findings of this trial will help inform future guidelines for selecting the optimal vascular access route during out-of-hospital cardiac arrest.

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.

Effects of adrenaline and vasopressin on cerebral microcirculation at baseline and during global brain ischemia and reperfusion in rabbits

BACKGROUND

During cardiopulmonary resuscitation, the brain becomes ischemic. Adrenaline and vasopressin have been recommended for use during cardiopulmonary resuscitation. We aimed to investigate the direct effects of adrenaline and vasopressin on the cerebral microvasculature at baseline and during ischemia and reperfusion in rabbits.

METHODS

The closed cranial window method was used to visualize the cerebral microcirculation and changes in the pial arteriole diameter in rabbits. Adrenaline and vasopressin were administered topically on the brain tissue. First, the effects of adrenaline and vasopressin on pial arterioles were evaluated in 7 rabbits that were given 4 different concentrations of adrenaline, and another 7 rabbits that received 4 different concentrations of vasopressin. Second, the effects of adrenaline and vasopressin were determined during the global brain ischemia and reperfusion, which was induced by clamping the brachiocephalic, left common carotid, and left subclavian arteries for 15 min. An additional 21 rabbits were randomly assigned to receive artificial cerebrospinal fluid (aCSF) (n = 7), adrenaline 10^-5 mol/L (n = 7), or vasopressin 10^-7 mol/L (n = 7). Each drug was continuously infused from 5 min after the initiation of ischemia until 120 min after reperfusion. The pial arteriole diameters were recorded before and during ischemia, and after reperfusion.

RESULTS

At baseline, adrenaline and vasopressin did not affect the cerebral pial arterioles. During ischemia, vasopressin, but not aCSF and adrenaline constricted the pial vessels. Late in the reperfusion phase, pial diameter became reduced in the vasopressin and aCSF groups whereas pial diameter was higher in the animals treated with adrenaline.

CONCLUSIONS

Adrenaline and vasopressin did not affect pial arterioles at baseline. During reperfusion, adrenaline may counteract the cerebral vasoconstriction.

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.

Effects of humeral intraosseous epinephrine in a pediatric hypovolemic cardiac arrest porcine model

Background

Aims of the study were to determine the effects of humerus intraosseous (HIO) versus intravenous (IV) administration of epinephrine in a hypovolemic, pediatric pig model. We compared concentration maximum (Cmax), time to maximum concentration (Tmax), mean concentration (MC) over time and return of spontaneous circulation (ROSC).

Methods

Pediatric pig were randomly assigned to each group (HIO (n=7); IV (n=7); cardiopulmonary resuscitation (CPR)+defibrillation (defib) (n=7) and CPR-only group (n=5)). The pig were anesthetized; 35% of the blood volume was exsanguinated. pigs were in arrest for 2 min, and then CPR was performed for 2 min. Epinephrine 0.01 mg/kg was administered 4 min postarrest by either route. Samples were collected over 5 min. After sample collection, epinephrine was administered every 4 min or until ROSC. The Cmax and MC were analyzed using high-performance liquid chromatography. Defibrillation began at 3 min postarrest and administered every 2 min or until ROSC or endpoint at 20 min after initiation of CPR.

Results

Analysis indicated that the Cmax was significantly higher in the IV versus HIO group (p=0.001). Tmax was shorter in the IV group but was not significantly different (p=0.789). The MC was significantly greater in the IV versus HIO groups at 90 and 120 s (p<0.05). The IV versus HIO had a significantly higher MC (p=0.001). χ² indicated the IV group (5 out of 7) had significantly higher rate of ROSC than the HIO group (1 out of 7) (p=0.031). One subject in the CPR+defib and no subjects in the CPR-only groups achieved ROSC.

Discussion

Based on the results of our study, the IV route is more effective than the HIO route.

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

PURPOSE

To compare the effectiveness of the intravenous (IV) and intraosseous (IO) routes for drug administration in adults with a cardiac arrest enrolled in the Pre-Hospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug Administration in Cardiac Arrest (PARAMEDIC2) randomised, controlled trial.

METHODS

Patients were recruited from five National Health Service Ambulance Services in England and Wales from December 2014 through October 2017. Patients with an out-of-hospital cardiac arrest who were unresponsive to initial resuscitation attempts were randomly assigned to 1 mg adrenaline or matching placebo. Intravascular access was established as soon as possible, and IO access was considered if IV access was not possible after two attempts.

RESULTS

Among patients with out-of-hospital cardiac arrest, 3631 received adrenaline and 3686 received placebo. Amongst these, 1116 (30.1%) and 1121 (30.4%) received the study drug via the IO route. The odds ratios were similar in the IV and IO groups for return of spontaneous circulation (ROSC) at hospital handover [adjusted odds ratio (aOR) 4.07 (95% CI 3.42-4.85) and (aOR 3.98 (95% CI 2.86-5.53), P value for interaction 0.90]; survival to 30 days [aOR 1.67 (1.18-2.35) versus 0.9 (0.4-2.05), P = 0.18]; and favourable neurological outcome [aOR 1.39 (0.93-2.06) versus 0.62 (0.23-1.67), P = 0.14].

CONCLUSION

There was no significant difference in treatment effect (adrenaline versus placebo) on ROSC at hospital handover between drugs administered by the intraosseous route or by the intravenous route. We could not detect any difference in the treatment effect between the IV and IO routes on the longer term outcomes of 30-day survival or favourable neurological outcome at discharge (ISRCTN73485024).

Intravenous versus intraosseous adrenaline administration in out-of-hospital cardiac arrest: A retrospective cohort study

BACKGROUND

Adrenaline is an important component in the resuscitation of individuals experiencing out-of-hospital cardiac arrest (OHCA). The 2018 Advanced Cardiac Life Support (ACLS) algorithm gives the option of either intravenous (IV) or intraosseous (IO) routes for adrenaline administration during cardiac arrest. However, the optimal route during prehospital resuscitation remains controversial. This study aims to investigate whether IV and IO routes lead to different outcomes in OHCA patients who received prehospital adrenaline.

METHODS

This retrospective analysis included adult patients with OHCA of presumed cardiac origin who had Emergency Medical Services (EMS) CPR, received adrenaline, and were enrolled in the Resuscitation Outcomes Consortium (ROC) Cardiac Epistry version 3 database between 2011 and 2015. We divided the study population into IV and IO groups based on the administration route. Logistic regression analysis was performed to evaluate the association between adrenaline delivery routes and prehospital return of spontaneous circulation (ROSC), survival to hospital discharge, and favorable neurological outcome.

RESULTS

Of the 35,733 patients included, 27,758 (77.7%) had adrenaline administered via IV access and 7975 (22.3%) via IO access. With the IO group as a reference in the logistic regression model, the adjusted odds ratios of the IV group for prehospital ROSC, survival and favorable neurological outcome were 1.367 (95%CI, 1.276-1.464), 1.468 (95%CI, 1.264-1.705) and 1.849 (95%CI, 1.526-2.240), respectively. Similar results were found in the propensity score matched population and subgroup analysis.

CONCLUSION

Compared with the IO approach, the IV approach appears to be the optimal route for adrenaline administration in advanced life support for OHCA during prehospital resuscitation.

Survival After Intravenous Versus Intraosseous Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Shock-Refractory Cardiac Arrest

BACKGROUND

Antiarrhythmic drugs have not proven to significantly improve overall survival after out-of-hospital cardiac arrest from shock-refractory ventricular fibrillation/pulseless ventricular tachycardia. How this might be influenced by the route of drug administration is not known.

METHODS

In this prespecified analysis of a randomized, placebo-controlled clinical trial, we compared the differences in survival to hospital discharge in adults with shock-refractory ventricular fibrillation/pulseless ventricular tachycardia out-of-hospital cardiac arrest who were randomly assigned by emergency medical services personnel to an antiarrhythmic drug versus placebo in the ALPS trial (Resuscitation Outcomes Consortium Amiodarone, Lidocaine or Placebo Study), when stratified by the intravenous versus intraosseous route of administration.

RESULTS

Of 3019 randomly assigned patients with a known vascular access site, 2358 received ALPS drugs intravenously and 661 patients by the intraosseous route. Intraosseous and intravenous groups differed in sex, time-to-emergency medical services arrival, and some cardiopulmonary resuscitation characteristics, but were similar in others, including time-to-intravenous/intrasosseous drug receipt. Overall hospital discharge survival was 23%. In comparison with placebo, discharge survival was significantly higher in recipients of intravenous amiodarone (adjusted risk ratio, 1.26 [95% CI, 1.06-1.50]; adjusted absolute survival difference, 5.5% [95% CI, 1.5-9.5]) and intravenous lidocaine (adjusted risk ratio, 1.21 [95% CI, 1.02-1.45]; adjusted absolute survival difference, 4.7% [95% CI, 0.7-8.8]); but not in recipients of intraosseous amiodarone (adjusted risk ratio, 0.94 [95% CI, 0.66-1.32]) or intraosseous lidocaine (adjusted risk ratio, 1.03 [95% CI, 0.74-1.44]). Survival to hospital admission also increased significantly when drugs were given intravenously but not intraosseously, and favored improved neurological outcome at discharge. There were no outcome differences between intravenous and intraosseous placebo, indicating that the access route itself did not demarcate patients with poor prognosis. The study was underpowered to assess intravenous/intraosseous drug interactions, which were not statistically significant.

CONCLUSIONS

We found no significant effect modification by drug administration route for amiodarone or lidocaine in comparison with placebo during out-of-hospital cardiac arrest. However, point estimates for the effects of both drugs in comparison with placebo were significantly greater for the intravenous than for the intraosseous route across virtually all outcomes and beneficial only for the intravenous route. Given that the study was underpowered to statistically assess interactions, these findings signal the potential importance of the drug administration route during resuscitation that merits further investigation.

Evidence for vasopressors during cardiopulmonary resuscitation in newborn infants

An estimated 0.1% of term infants and up to 15% of preterm infants (2-3 million worldwide) need extensive resuscitation, defined as chest compression and 100% oxygen with or without epinephrine in the delivery room. Despite these interventions, infants receiving extensive resuscitation in the DR have a high incidence of mortality and neurologic morbidity. Successful resuscitation from neonatal cardiac arrest requires the delivery of high-quality chest compression using the most effective vasopressor with the optimal dose, timing, and route of administration during CPR. Current neonatal resuscitation guidelines recommend administration of epinephrine once CPR has started at a dose of 0.01-0.03 mg/kg preferably given intravenously, with repeated doses every 3-5 min until return of spontaneous circulation. This review examines the current evidence for epinephrine and alternative vasopressors during neonatal cardiopulmonary resuscitation.

[Supraglottic airway devices and intraosseous access in the treatment of patients after out-of-hospital cardiac arrest : Do we use the wrong tool too often?]

INTRODUCTION

Only a little is known about the frequency of use of supraglottic airway devices (SADs) and intraosseous (IO) access in patients who have had out-of-hospital cardiac arrest (OHCA).

MATERIALS AND METHODS

We analyzed data from all patients who had had OHCA admitted to our hospital between 1 January 2008 and 31 December 2017.

RESULTS

A total of 135 (33.8%) patients who had had OHCA were admitted with a SAD, 223 (55.8%) with an endotracheal tube, 3 (0.8%) with mask ventilation, and 32 (8.0%) breathed spontaneously on admission to hospital. Three hundred and twenty-eight patients (82.0%) were admitted with a peripheral intravenous line, one (0.3%) with a central venous catheter, one (0.3%) with a port catheter, and 32 (8.0%) with IO access.

CONCLUSIONS

Irrespective of an increasing number of studies that raise the question whether the airway management of patients who have had OHCA using an SGA might be inferior to that with endotracheal tubes, approximately one third of all patients who have had OHCA were admitted with an SAD in this study. On the other hand, IO access is significantly less frequently used, despite fewer critical study results overall.

The Resuscitative and Pharmacokinetic Effects of Humeral Intraosseous Vasopressin in a Swine Model of Ventricular Fibrillation

Introduction The American Heart Association (AHA; Dallas, Texas USA) and European Resuscitation Council (Niel, Belgium) cardiac arrest (CA) guidelines recommend the intraosseous (IO) route when intravenous (IV) access cannot be obtained. Vasopressin has been used as an alternative to epinephrine to treat ventricular fibrillation (VF). Hypothesis/Problem Limited data exist on the pharmacokinetics and resuscitative effects of vasopressin administered by the humeral IO (HIO) route for treatment of VF. The purpose of this study was to evaluate the effects of HIO and IV vasopressin, on the occurrence, odds, and time of return of spontaneous circulation (ROSC) and pharmacokinetic measures in a swine model of VF.

METHODS

Twenty-seven Yorkshire-cross swine (60 to 80 kg) were assigned randomly to three groups: HIO (n=9), IV (n=9), and a control group (n=9). Ventricular fibrillation was induced and untreated for two minutes. Chest compressions began at two minutes post-arrest and vasopressin (40 U) administered at four minutes post-arrest. Serial blood specimens were collected for four minutes, then the swine were resuscitated until ROSC or 29 post-arrest minutes elapsed.

RESULTS

Fisher's Exact test determined ROSC was significantly higher in the HIO 5/7 (71.5%) and IV 8/11 (72.7%) groups compared to the control 0/9 (0.0%; P=.001). Odds ratios of ROSC indicated no significant difference between the treatment groups (P=.68) but significant differences between the HIO and control, and the IV and control groups (P=.03 and .01, respectively). Analysis of Variance (ANOVA) indicated the mean time to ROSC for HIO and IV was 621.20 seconds (SD=204.21 seconds) and 554.50 seconds (SD=213.96 seconds), respectively, with no significant difference between the groups (U=11; P=.22). Multivariate Analysis of Variance (MANOVA) revealed the maximum plasma concentration (Cmax) and time to maximum concentration (Tmax) of vasopressin in the HIO and IV groups was 71753.9 pg/mL (SD=26744.58 pg/mL) and 61853.7 pg/mL (SD=22745.04 pg/mL); 111.42 seconds (SD=51.3 seconds) and 114.55 seconds (SD=55.02 seconds), respectively. Repeated measures ANOVA indicated no significant difference in plasma vasopressin concentrations between the treatment groups over four minutes (P=.48).

CONCLUSIONS

The HIO route delivered vasopressin effectively in a swine model of VF. Occurrence, time, and odds of ROSC, as well as pharmacokinetic measurements of HIO vasopressin, were comparable to IV. Burgert JM , Johnson AD , Garcia-Blanco J , Fulton LV , Loughren MJ . The resuscitative and pharmacokinetic effects of humeral intraosseous vasopressin in a swine model of ventricular fibrillation. Prehosp Disaster Med. 2017;32(3):305-310.