Comparison of epinephrine with vasopressin on bone marrow blood flow in an animal model of hypovolemic shock and subsequent cardiac arrest

The association of intraosseous vascular access and survival among pediatric patients with out-of-hospital cardiac arrest

INTRODUCTION

In pediatric out-of-hospital cardiac arrest (OHCA) the effect of intraosseous (IO) or intravenous (IV) access on outcomes is unclear.

METHODS

We analyzed prospectively collected data of non-traumatic OHCA in the Resuscitation Outcomes Consortium registry from 2011 to 2015. We included EMS-treated patients ≤17 years of age, classified patients based on vascular access routes, and calculated success rates of IO and IV attempts. After excluding patients with obvious non-cardiac etiologies and those with unsuccessful vascular access or multiple routes, we fit a logistic regression model to evaluate the association of IO vascular access (reference IV access) with the primary outcome of survival, using multiple imputation to address missing data. We analyzed a subgroup of patients at least 2 years of age.

RESULTS

There were 1549 non-traumatic OHCA: 895 (57.8%) patients had an IO line attempted with 822 (91.8%) successful; 488 (31.5%) had an IV line attempted with 345 (70.7%) successful (difference 21%, 95% CI 17 to 26%). Of the 761 patients included in our logistic regression, 601 received IO (30 [5.2%] survived) and 160 received IV (40 [25%] survived) vascular access. Intraosseous access was associated with a decreased probability of survival (adjusted OR 0.46; 95% CI 0.21-0.98). Patients at least 2 years of age showed a similar association (adjusted OR 0.36; CI 0.15-0.86).

CONCLUSIONS

Intraosseous access was associated with decreased survival among pediatric non-traumatic OHCA. These results are exploratory and support the need for further study to evaluate the effect of intravascular access method on outcomes.

Prehospital Tibial Intraosseous Drug Administration is Associated with Reduced Survival Following Out of Hospital Cardiac Arrest: A study for the CARES Surveillance Group

BACKGROUND

Recent reports have questioned the efficacy of intraosseous (IO) drug administration for out-of-hospital cardiac arrest (OHCA) resuscitation. Our aim was to determine whether prehospital administration of resuscitative medications via the IO route was associated with lower rates of return of spontaneous circulation (ROSC) and survival to hospital discharge than peripheral intravenous (IV) infusion in the setting of OHCA.

METHODS

We obtained data on all OHCA patients receiving prehospital IV or IO drug administration from the three most populous counties in Michigan over three years. Data was from the Michigan Cardiac Arrest Registry to Enhance Survival (CARES) database. The association between route of drug administration and outcomes was tested using a matched propensity score analysis.

RESULTS

From a total of 10,626 OHCA patients, 6869 received parenteral drugs during their prehospital resuscitation (37.8% by IO) and were included in analysis. Unadjusted outcomes were lower in patients with IO vs. IV access: 18.3% vs. 23.8% for ROSC (p < 0.001), 3.2% vs. 7.6% for survival to hospital discharge (p < 0.001), and 2.0% vs. 5.8% for favorable neurological function (p < 0.001). After adjustment, IO route remained associated with lower odds of sustained ROSC (OR 0.72, 95% CI 0.63-0.81, p < 0.001), hospital survival (OR 0.48, 95% CI 0.37-0.62, p < 0.001), and favorable neurological outcomes (OR 0.42, 95% CI 0.30-0.57, p < 0.001).

CONCLUSION

In this cohort of OHCA patients, the use of prehospital IO drug administration was associated with unfavorable clinical outcomes.

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.

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.

The effect of hemorrhagic shock and intraosseous adrenaline injection on the delivery of a subsequently administered drug - an experimental study

Background

Intraosseous (IO) access is a recommended method when venous access cannot be rapidly established in an emergency. Experimental data suggest that major hemorrhage and catecholamine administration both reduce bone marrow blood flow. We studied the uptake of gentamicin as a tracer substance administered IO following adrenaline administration in hemorrhagic shock and in cardiac arrest.

Methods

Twenty anesthetized pigs underwent hemorrhage corresponding to 50% of the blood volume. They then received injections of either; adrenaline IO (n = 5), saline IO n = 5), adrenaline IO during cardiac arrest and cardiopulmonary resuscitation (CPR, n = 5), or intravenous adrenaline. The injections were followed by an injection of gentamicin by the same route. Doses and volumes were equivalent among the groups. In all animals, mixed venous antibiotic concentrations were analyzed at 5, 15 and 30 min after administration.

Results

Mean (SD) plasma gentamicin concentrations (mg x L^− 1) at 5 min were 26.4 (2.3) in the group with previous IO adrenaline administration, 26.6 (4.5) in the IO saline group, 31. 2 (12) in the IO adrenaline + CPR group and 23 (4.5) in the IV group. Concentrations in the CPR group were significantly higher than the others.

Conclusions

No impairment of drug uptake with IO administration after recent IO adrenaline exposure was demonstrable in this shock model.

Sternal Route More Effective than Tibial Route for Intraosseous Amiodarone Administration in a Swine Model of Ventricular Fibrillation

OBJECTIVE

The pharmacokinetics of IO administered lipid soluble amiodarone during ventricular fibrillation (VF) with ongoing CPR are unknown. This study measured mean plasma concentration over 5 minutes, maximum plasma concentration (Cmax), and time to maximum concentration (Tmax) of amiodarone administered by the sternal IO (SIO), tibial IO (TIO), and IV routes in a swine model of VF with ongoing CPR.

METHODS

Twenty-one Yorkshire-cross swine were randomly assigned to three groups: SIO, TIO, and IV. Ventricular fibrillation was induced under general anesthesia. After 4 minutes in VF, 300 mg amiodarone was administered as indicated by group assignment. Serial blood specimens collected at 30, 60, 90, 120, 150, 180, 240, and 300 seconds were analyzed using high performance liquid chromatography with tandem mass spectrometry.

RESULTS

The mean plasma concentration of IV amiodarone over 5 minutes was significantly higher than the TIO group at 60 seconds (P = 0.02) and 90 seconds (P = 0.017) post-injection. No significant differences in Cmax between the groups were found (P <0.05). The Tmax of amiodarone was significantly shorter in the SIO (99 secs) and IV (86 secs) groups compared to the TIO group (215 secs); P = 0.002 and P = 0.002, respectively.

CONCLUSIONS

The SIO and IV routes of amiodarone administration were comparable. The TIO group took nearly three times longer to reach Tmax than the SIO and IV groups, likely indicating depot of lipid-soluble amiodarone in adipose-rich tibial yellow bone marrow. The SIO route was more effective than the TIO route for amiodarone delivery in a swine model of VF with ongoing CPR. Further investigations are necessary to determine if the kinetic differences found between the SIO and TIO routes in this study affect survival of VF in humans.

Intraosseous compared to intravenous drug resuscitation in out-of-hospital cardiac arrest

AIMS

Although the intraosseous (IO) route is increasingly used for vascular access in out-of-hospital cardiac arrest (OHCA), little is known about its comparative effectiveness relative to intravenous (IV) access. We evaluated clinical outcomes following OHCA comparing drug administration via IO versus IV routes.

METHODS

This retrospective cohort study evaluated Emergency Medical Services (EMS)-treated adults with atraumatic OHCA in a large metropolitan EMS system between 9/1/2012-12/31/2014. Access was classified as IO or IV based on the route of first EMS drug administration. Study endpoints were survival to hospital discharge, return of spontaneous circulation (ROSC) and survival to hospital admission.

RESULTS

Among 2164 adults with OHCA, 1800 met eligibility criteria, 1525 of whom were treated via IV and 275 principally via tibial-IO routes. Compared to IV, IO-treated patients were younger, more often women, had unwitnessed OHCA, a non-cardiac aetiology, and presented with non-shockable rhythms. IO versus IV-treated patients were less likely to survive to hospital discharge (14.9% vs 22.8%, p=0.003), achieve ROSC (43.6% vs 55.5%, p<0.001) or be hospitalized (38.5% vs 50.0% p<0.001). In multivariable adjusted analyses, IO treatment was not associated with survival to discharge (odds ratio (OR) (95% confidence interval) 0.81 (0.55, 1.21), p=0.31), but was associated with a lower likelihood of ROSC (OR=0.67 (0.50, 0.88), p=0.004) and survival to hospitalization (OR=0.68 (0.51, 0.91), p=0.009).

CONCLUSION

Though not independently associated with survival to discharge, principally tibial IO versus IV treatment was associated with a lower likelihood of ROSC and hospitalization. How routes of vascular access influence clinical outcomes after OHCA merits additional study.

Blueprint for Implementing New Processes in Acute Care: Rescuing Adult Patients With Intraosseous Access

The intraosseous (IO) access initiative at an urban university adult level 1 trauma center began from the need for a more expeditious vascular access route to rescue patients in extremis. The goal of this project was a multidisciplinary approach to problem solving to increase access of IO catheters to rescue patients in all care areas. The initiative became a collaborative effort between nursing, physicians, and pharmacy to embark on an acute care endeavor to standardize IO access. This is a descriptive analysis of processes to effectively develop collaborative strategies to navigate hospital systems and successfully implement multilayered initiatives. Administration should empower nurse to advance their practice to include IO for patient rescue. Intraosseous access may expedite resuscitative efforts in patients in extremis who lack venous access or where additional venous access is required for life-saving therapies. Limiting IO dwell time may facilitate timely definitive venous access. Continued education and training by offering IO skill laboratory refreshers and annual e-learning didactic is optimal for maintaining proficiency and knowledge. More research opportunities exist to determine medication safety and efficacy in adult patients in the acute care setting.

Use of intra-osseous access in adults: a systematic review

Background

Indications for intra-osseous (IO) infusion are increasing in adults requiring administration of fluids and medications during initial resuscitation. However, this route is rarely used nowadays due to a lack of knowlegde and training. We reviewed the current evidence for its use in adults requiring resuscitative procedures, the contraindications of the technique, and modalities for catheter implementation and skill acquisition.

Methods

A PubMed search for all articles published up to December 2015 was performed by using the terms “Intra-osseous” AND “Adult”. Additional articles were included by using the “related citations” feature of PubMed or checking references of selected articles. Editorials, comments and case reports were excluded. Abstracts of all the articles that the search yielded were independently screened for eligibility by two authors and included in the analysis after mutual consensus. In total, 84 full-text articles were reviewed and 49 of these were useful for answering the following question “when, how, and for which population should an IO infusion be used in adults” were selected to prepare independent drafts. Once this step had been completed, all authors met, reviewed the drafts together, resolved disagreements by consensus with all the authors, and decided on the final version.

Results

IO infusion should be implemented in all critical situations when peripheral venous access is not easily obtainable. Contraindications are few and complications are uncommon, most of the time bound to prolonged use. The IO infusion allows for blood sampling and administration of virtually all types of fluids and medications including vasopressors, with a bioavailability close to the intravenous route. Unfortunately, IO infusion remains underused in adults even though learning the technique is rapid and easy.

Conclusions

Indications for IO infusion use in adults requiring urgent parenteral access and having difficult intravenous access are increasing. Physicians working in emergency departments or intensive care units should learn the procedures for catheter insertion and maintenance, the contraindications of the technique, and the possibilities this access offers.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1277-6) contains supplementary material, which is available to authorized users.

Intraosseous vascular access: A review

Intraosseous cannulation is an increasingly common means of achieving vascular access for the administration of fluids and medications during the emergent resuscitation of both paediatric and adult patients. Improved tools and techniques for intraosseous vascular access have recently been developed, enabling the healthcare provider to choose from a wide range of devices and insertion sites. Despite its increasing popularity within the adult population, and decades of use in the paediatric population, questions remain regarding the safety and efficacy of intraosseous infusion. Although various potential complications of intraosseous cannulation have been theorized, few serious complications have been reported. This article aims to provide a review of the current literature on intraosseous vascular access, including discussion on the various intraosseous devices currently available in the market, the advantages and disadvantages of intraosseous access compared to conventional vascular access methods, complications of intraosseous cannulation and current recommendations on the use of this approach.

Vasopressin for hemorrhagic shock management: revisiting the potential value in civilian and combat casualty care

The evolution of trauma care is driven by a synergistic relationship between civilian and military medical systems. Although the characteristics of civilian injuries differ from those encountered on the battlefield, the pathophysiologic process of dying is the same and dominated by exsanguination and central nervous trauma. As such, therapies that interfere with the physiologic ability to compensate hemorrhage may play a key role to buy time until hemostatic surgery can be initiated. From a variety of remedies with the potential to prolong the compensation phase or to reverse the decompensation phase of shock, arginine vasopressin (AVP) is one of the most promising and best-evaluated drugs. Animal studies and various case report series provide some evidence that AVP may improve blood pressure even when conventional therapies fail, thus preventing hypovolemic cardiac arrest and enabling resuscitation from fatal hemorrhage. On the basis of this civilian experience, it seems reasonable to consider AVP for hypotensive resuscitation in the austere, resource-constrained battlefield environment. However, the significance of AVP as a rescue medication for life-threatening hemorrhage has yet to be proven.

A treatment protocol including vasopressin and hydroxyethyl starch solution is associated with increased rate of return of spontaneous circulation in blunt trauma patients with pulseless electrical activity

BACKGROUND

Survival after cardiopulmonary resuscitation (CPR) using standard vasopressor therapy is disappointing. Vasopressin is a potent vasopressor that could become a useful therapeutic alternative in the treatment of cardiac arrest.

AIMS

The aim of this prehospital prospective cohort study was to assess the influence of treatment with vasopressin and hydroxyethyl starch solution (HHS) on outcome in resuscitated blunt trauma patients with pulseless electrical activity (PEA) cardiac arrest.

METHODS

Two treatment groups of resuscitated trauma patients in cardiac arrest were compared: in the epinephrine group patients received epinephrine 1 mg IV every 3 min only; in the vasopressin group patients first received hypertonic HHS and arginine vasopressin 40 units IV only or followed by epinephrine 1 mg every 3 min until cessation of CPR. Medical trauma care was provided according to advanced trauma life support (ATLS) guidelines.

RESULTS

The study included 31 patients and there were no significant demographic or clinical differences between the treatment groups. Significantly more circulatory restorations [11/13 (85%) vs 3/18 (17%); P < 0.01] and better 24-h survival rates [8/13 (62%) vs 2/18 (11%); P = 0.001] were observed in the vasopressin group. Average mean arterial pressure (100.4 +/- 11.4 mmHg vs 80.3 +/- 12.4 mmHg) and final end-tidal partial pressure of carbon dioxide (PETCO(2)) at admission (4.5 +/- 0.9 kPa vs 2.8 +/- 0.4 kPa) were also higher in the vasopressin group.

CONCLUSION

Our results suggest that victims of severe blunt trauma with PEA should be initially treated with vasopressin in combination with HHS volume resuscitation followed by standard resuscitation therapy and other procedures when appropriate. Vasopressin might be potentially lifesaving in blunt trauma cardiac arrest compared to standard treatment with epinephrine.

[Intraosseous puncture in preclinical emergency medicine. Ten years experience in air rescue service]

INTRODUCTION

The intraosseous puncture (IO) is a fast and safe alternative to the puncture of peripheral veins in emergency situations in children < or =6 years of age. The purpose of this paper is to summarize 10 years of experience on the prehospital use of the IO method by the Helicopter Emergency Medical Service (HEMS) "Christoph 22", Ulm.

MATERIALS AND METHODS

This was a retrospective study from 1 January 1996 to 31 December 2005.

RESULTS

Out of a total of 9,549 missions, the proportion of children was 11.1%. In 27 children (4.2% of the children < or =6 years of age) an IO puncture was performed. Patients of the IO group were younger (1.0 vs. 3.7 years of age; p<0.001) and showed a higher degree of injury severity (NACA 6 vs. 4; p<0.001) compared to the total children group. In all children of the IO group (100%), the intraosseous puncture was the method of first choice to obtain access to the vascular system by the HEMS team. In 96.4% of these cases (26/27), the first IO puncture attempt was successful - in one child, a second puncture attempt was necessary. A standardized puncture technique was performed using the proximal tibia. The time required for successful placement of the IO infusion line was 60 s or less in all cases. In 37% of the cases (10/27) the IO infusion line was used for induction of general anaesthesia; dosage and onset of administered drugs were described as being equivalent to a peripheral infusion line. In all cases, the IO needle was replaced in-hospital within 2 h by a central or peripheral iv line. No complications were observed.

CONCLUSIONS

The IO infusion technique is a simple, fast and safe alternative method for emergency access to the vascular system in children < or =6 years of age in the prehospital setting.

Intraosseous drug administration in children and adults during cardiopulmonary resuscitation

OBJECTIVE

To review and assess the available literature on the use of intraosseous (IO) drug administration during cardiopulmonary resuscitation, addressing the benefits and risks of using this method of drug delivery in children and adults.

DATA SOURCES

The MEDLINE (1950-July 2007) database was searched for pertinent abstracts, using the key term intraosseous infusions. Additional references were obtained from the bibliographies of the articles reviewed. Manufacturer Web sites were used to obtain information about IO insertion devices.

STUDY SELECTION AND DATA EXTRACTION

All available English-language clinical trials, retrospective studies, and review articles describing IO drug administration were reviewed. Studies conducted in animal models to evaluate the effectiveness and safety of IO drug administration were also included.

DATA SYNTHESIS

IO access uses the highly vascularized bone marrow to deliver fluids and medications during cardiopulmonary resuscitation. This route, developed in the 1940s, has been revived in the past decade as a means of achieving rapid vascular access when intravenous access cannot be obtained. The primary advantage of IO access is the high success rate (approximately 80%). Most trained providers can place an IO line within 1-2 minutes. A number of small-scale studies and retrospective reviews have established the usefulness of this route for the delivery of many commonly used resuscitation drugs. In addition, animal models have demonstrated rapid drug delivery to the systemic circulation. While all resuscitation drugs can be given by the IO route, administration of ceftriaxone, chloramphenicol, phenytoin, tobramycin, and vancomycin may result in lower peak serum concentrations. The most common adverse effect seen with IO use, extravasation, has been reported in 12% of patients. Compartment syndrome, osteomyelitis, and tibial fracture are rare, but have also been reported.

CONCLUSIONS

IO administration is a safe and effective method for delivering drugs during cardiopulmonary resuscitation. It should be considered whenever intravenous access cannot be rapidly obtained.

Impact of Vasopressin on Hemodynamic and Metabolic Function in the Decompensatory Phase of Hemorrhagic Shock

OBJECTIVES

To explore how the potent vasoconstrictive features of vasopressin impact the rate of cardiovascular collapse and metabolic derangements associated with prolonged hemorrhagic shock.

DESIGN

A prospective randomized trial.

SETTING

University hospital-based animal laboratory.

PARTICIPANTS

Sixteen swine.

INTERVENTIONS

Swine were bled in an isobaric fashion to achieve a linear decrease in the mean arterial blood pressure to 40 mmHg. The mean arterial blood pressure was then maintained at 40 mmHg until the onset of cardiovascular decompensation, defined as the need to reinfuse shed blood to maintain the blood pressure at 40 mmHg. Once at the onset of cardiovascular decompensation, animals were randomly assigned to 2 resuscitation groups: the crystalloid group received lactated Ringer's solution and the vasopressin group received lactated Ringer's solution and arginine vasopressin. Resuscitation consisted of infusing lactated Ringer's solution with and without vasopressin (0.05 U/kg/min) to maintain a blood pressure of 70 mmHg for 60 minutes.

MEASUREMENTS AND MAIN RESULTS

The rate of crystalloid infusion was compared between groups using an unpaired 2-tailed t test. Metabolic and hemodynamic parameters between groups over time were compared with a repeated measures analysis of variance. Vasopressin decreased the rate of crystalloid infusion during resuscitation by 50%. During resuscitation, the cardiac index in the crystalloid group was restored to near baseline levels and was decreased to near half of baseline levels in the vasopressin group. Animals in the vasopressin group developed a lactic acidemia, but animals in the crystalloid group revealed no change from baseline in the arterial pH and a slight decrease in the plasma lactate.

CONCLUSIONS

Administration of vasopressin used as an adjunct to maintain blood pressure in the decompensatory phase of hemorrhagic shock slows cardiovascular collapse, but has an adverse effect on metabolic and hemodynamic function. Further investigation is warranted to clarify the role of vasopressin in the delayed management of severe hemorrhagic shock.

Invasive Techniken in der Notfallmedizin

There can be few more daunting challenges for the emergency physician than an infant or small child in shock or cardiac arrest. At the best of times, the combination of small veins and abundant subcutaneous tissue makes vascular access difficult or impossible, even in experienced hands. For these situations, the intraosseous vascular access is an easy, rapid and safe alternative. The intraosseous route is recommended for children < or =6 years of age, where conventional vascular access cannot be timely established. The preferred sites are the medial aspect of the proximal end of the tibia, just below the tibial tuberosity. Access should be obtained with a commercially available intraosseous needle. All emergency drugs and infusion fluids for intravenous usage can safely be infused via the intraosseous route (except hypertonic solutions) and it is not necessary to adjust drug dosage compared to the intravenous route. To avoid complications caused by the intraosseous needle, such as osteomyelitis, it should be replaced within 2 h by a conventional vascular access.

Is vasopressin superior to adrenaline or placebo in the management of cardiac arrest? A meta-analysis

Vasopressin is currently recommended in the management of patients with cardiac arrest, but its efficacy is still incompletely established. We systematically reviewed randomized trials comparing vasopressin to control treatment in the management of cardiac arrest in humans and animals. Two human and 33 animal studies were retrieved. At pooled analysis vasopressin appeared equivalent to adrenaline (epinephrine) in the management of human cardiac arrest (N=240), with, respectively 63 (78/124) vs 59% (68/116) ROSC (P=0.43), and 16 (20/124) vs 14% (16/116) survival to hospital discharge (P=0.52). In animal trials (N=669) vasopressin appeared instead significantly superior to both placebo (ROSC, respectively 93 [98/105] vs 19% [14/72], P<0.001) or adrenaline (ROSC, respectively 84 [225/268] vs 52% [117/224], P<0.001). In conclusion, vasopressin is superior to both placebo or adrenaline in animal models of cardiopulmonary resuscitation. Evidence in humans is still limited and confidence intervals estimates too wide to reliably confirm or disprove results obtained in experimental animal settings.

Science Review: Vasopressin and the cardiovascular system part 2 - clinical physiology

Vasopressin is emerging as a rational therapy for vasodilatory shock states. In part 1 of the review we discussed the structure and function of the various vasopressin receptors. In part 2 we discuss vascular smooth muscle contraction pathways with an emphasis on the effects of vasopressin on ATP-sensitive K+ channels, nitric oxide pathways, and interaction with adrenergic agents. We explore the complex and contradictory studies of vasopressin on cardiac inotropy and coronary vascular tone. Finally, we summarize the clinical studies of vasopressin in shock states, which to date have been relatively small and have focused on physiologic outcomes. Because of potential adverse effects of vasopressin, clinical use of vasopressin in vasodilatory shock should await a randomized controlled trial of the effect of vasopressin's effect on outcomes such as organ failure and mortality.

Intraosseous infusion

Establishing vascular access is vital in the resuscitation of critically-ill children and adults. Intraosseous infusion (IOI) is a viable route for providing vascular access when traditional intravenous methods cannot be accomplished. IOI is relatively easy to perform and is a standard recommended intervention for the resuscitation of both adults and children. The authors review the history, anatomy, technique, and clinical application of IOI. They also highlight the use of IOI in the prehospital setting.