Emergency Medicine Australasia (2015) 27, 312–316

doi: 10.1111/1742-6723.12405


Adrenaline in cardiac arrest: Prefilled syringes are faster Claire HELM1 and Mark GILLETT2 1 Emergency Department, Nepean Hospital, Sydney, New South Wales, Australia, and 2Emergency Department, Royal North Shore Hospital, Sydney, New South Wales, Australia

Abstract Objective: Standard ampoules and prefilled syringes of adrenaline are widely available in Australasian EDs for use in cardiac arrest. We hypothesise that prefilled syringes can be administered more rapidly and accurately when compared with the two available standard ampoules. Methods: This is a triple arm superiority study comparing the time to i.v. administration and accuracy of dosing of three currently available preparations of adrenaline. Results: In their standard packaging, prefilled syringes were on average more than 12 s faster to administer than the 1 mL 1:1000 ampoules and more than 16 s faster than the 10 mL 1:10 000 ampoules (P < 0.01 in both comparisons). With packaging removed, the time to administration was equal for the 1 mL (1:1000) ampoule and the prefilled syringe. Accuracy of dosing was excellent with both the 10 mL (1:10 000) ampoules and prefilled syringes. The 1 mL (1:1000) ampoules delivered a small number of markedly inaccurate doses, but these did not reach statistical significance. Conclusions: The speed of administration of adrenaline utilising a Minijet (CSL Limited, Parkville, Victoria, Australia) is faster than using adrenaline in glass ampoules presented in their plastic packaging. Removing the plastic packaging from the 1 mL (1 mg) ampoule might result in more rapid administration similar to the Minijet. Re-

suscitation personnel requiring rapid access to adrenaline should consider storing it as either Minijets or ampoules devoid of packaging. These results might be extrapolatable to other clinical scenarios, including pre-hospital and anaesthesia, where other drugs are required for rapid use. Key words: adrenaline, ampoule, dose accuracy, Minijet, time to administer.

Introduction I.v. adrenaline is administered for cardiac arrest in both hospital and prehospital environments as part of current ACLS protocols.1 Rapid administration and accurate dosing of the recommended drugs are standard aims in these settings.1 Often, resuscitation teams have a limited number of members, for example, pre-hospital Paramedic team, solo anaesthetist or ED staff. This necessitates team member(s) taking on multiple roles simultaneously. With limited operators, drugs are often not given at the recommended intervals because of the competing priorities of continuous chest compressions, rhythm analysis, defibrillation,2,3 gaining i.v. access and airway management. Extended intervals between boluses of arrest drugs might increase morbidity and mortality, because of both delay in any possible positive effect of pharmacotherapy and interruptions to other interventions.1 Larsen et al. demonstrated a reduction in survival of 2.3%

Correspondence: Dr Mark Gillett, Emergency Department, Royal North Shore Hospital, Reserve Road, St Leonards, NSW 2065, Australia. Email: [email protected] Claire Helm, MBBS, FACEM, Emergency Physician; Mark Gillett, MBBS, FACEM, Emergency Physician. Accepted 26 March 2015

Key findings • Packaged prefilled adrenaline syringes (“Minijets”) are faster to administer i.v. than equivalent dose packaged adrenaline ampoules. • High concentration/low volume adrenaline ampoules (1:1000) are possibly more prone to volume error with i.v. administration than low concentration/high volume (1:10 000) dose equivalent preparations. • Prefilled adrenaline syringes enjoy high staff satisfaction compared with adrenaline ampoules.

per minute in delay to ACLS in out-of-hospital cardiac arrest due to VF, independent of time to CPR or defibrillation.4 The most recent recommendations in 2010 by the International Liaison Committee on Resuscitation (ILCOR)1 placed less emphasis on pharmacotherapy in cardiac arrest, reflecting the lack of high-quality evidence supporting any particular drug intervention at this time (or indeed since).1–17 However, ILCOR’s recommendations for the use of i.v. adrenaline in cardiac arrest were essentially unchanged, and thus it remains in most cardiac arrest algorithms. Prognosis after cardiac arrest is poor. Improvements in all aspects of the chain of survival, encompassing early activation of the emergency medical system, early BLS, early defibrillation and early ACLS, could potentially achieve 20–30% survival rates.18 Speed and accuracy of administration of cardiac arrest drugs might strengthen a vital link in the chain, while minimising interruptions to other, better-proven interventions.

© 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine



Anaesthetists in Canada, New Zealand and the UK have been surveyed regarding their attitudes to drawing up ‘emergency drugs’ (e.g. suxamethonium, metaraminol, atropine) in a time-critical case.19 Drug errors (syringe swap, mislabelling of a syringe or misreading of the label) were common, occasionally with fatal results.19–21 Thirty-seven per cent of New Zealand anaesthetists had perceived a delay in drawing up these drugs in an emergency situation.20 Only one study, by Simons et al., has specifically measured the time taken to draw up a drug.22 The present study was a comparison of time taken and accuracy of dose for three groups (doctor, nurse and parent) to draw up adrenaline from ampoules to treat anaphylaxis by i.m. injection in a paediatric population. Two steps were required: calculating drug volume based on weight, followed by administration. Parents performed slowest and least accurately. A recommendation from the present study was to develop premeasured doses of adrenaline suitable for infants for lay person use. In Australia, adrenaline is available in a number of 1 mg formulations, including 1 mL (1:1000) and 10 mL (1:10 000) ampoules, as well as prefilled 10 mL syringes (‘Minijets’). There are no published studies comparing the speed or accuracy of administration of these formulations in this setting. The hypothesis for the present study was that prefilled 1 mg adrenaline syringes reduced the time to administration of drug compared with standard adrenaline 1 mg ampoules (both 1:1000 and 1:10 000 types) when all three were presented in their standard packaging. Secondary aims of the project were to assess the comparative dosing accuracy of the three delivery systems, ascertain if removing ampoules from their plastic wrapping improved speed of administration and assess staff experience and opinion on using each of these systems.

Methods A literature search was undertaken (utilising Medline, Cochrane Library and ACP Journal Club databases) for


Demographic variables

Years postgraduate clinical experience 0–1 1–2 2–4 5–7 8–10 >10 Total (n = 36)

studies of drug administration in emergency or cardiac arrest situations. Approval for the present study was granted by Northern Sydney Health Human Research Ethics Committee. Participants were formally consented volunteer ED clinical staff of variable experience, reflecting the range of staff who might expect to be involved in cardiac arrest scenarios. They ranged from new graduate nurses and resident doctors to Nurse Educators and Emergency Staff Specialists (Table 1). All were familiar with both drug administration systems, but not all had used them clinically. Drugs used were out-of-date stock donated by the hospital pharmacy. No funding was sought or received from any external source. Adrenaline formulations come as a standard 1 mg dose in varying concentrations. The prefilled syringes were all CSL ‘Minijet’TM adrenaline in a 10 mL (1:10 000) syringe. These were all in the original (‘untampered’) boxes. The ampoules were all clear glass Astra Zeneca (North Ryde, NSW, Australia) either 1 mL (1:1000) or 10 mL (1:10 000) preparations in their original plastic outer packaging (unless otherwise stated) as this is how they are stored in many EDs. A mock clinical area was configured within the ED with a mannequin, simulated injection port, drug trolley and sharps bin. A common injection port (SAFSITE RV1000NCTM, Braun Medical Inc., Bella Vista, NSW, Australia) was connected to tubing interrupted along its length by two threeway taps, each of which was connected to a vertically oriented pipette (either 1 mL or 10 mL), to enable volume to be measured (Fig. 1). By adjustment of the three-way taps, a pipette


Registered nurse

0 0 1 3 1 2 7

0 3 5 8 3 10 29

was brought into series within the circuit and volume within it measured by calibrated markings. The tubing was clear to allow inspection for bubbles/air locks that could falsely alter volume measurements. This tubing was primed with normal saline before each trial, and each pipette was zeroed by the lead author for standardisation. Time was measured by two independently operated stopwatches (DSE Digital LCD Stopwatch, Sydney, NSW, Australia) to accuracy of 0.01 s, and the times averaged. As the study was designed to focus on the injection process, we eliminated potential confounders, such as dose calculation, finding equipment and donning gloves. There was no possible blinding of subjects or timekeepers within the present study design. The three systems were tested in random order using non-algorithmic manual randomisation. Depending on which preparation was being tested, participants either: (i) removed the ampoules from their plastic wrapping, broke the ampoule neck and drew up the adrenaline into a syringe before injection; or (ii) assembled the prefilled syringe and injected directly into the port. A fourth subset of testing was done with the 1 mL ampoules ‘bare’ (removed from plastic packaging) to determine the time saved by presentation in this fashion. This fourth subset of tests was performed after the other three limbs of the trial. Volume was also measured to ascertain whether accuracy was lost from any of the systems with rapid injection. Volumes were measured to 0.01 mL for 1 mL ampoule and to

© 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine



ampoule (40.0 s, SD 10.6, 95% CI 36.4–43.6). The fourth group (n = 21), which was included in the study to assess the time difference by presenting the 1 mL ampoule bare of its plastic package, showed a mean time for injection of 23.8 s (SD 12.3, 95% CI 21.3–26.3). The time taken to inject from the ‘bare’ 1 mL ampoule was significantly faster than either of the ampoules in their packaging, but there was no significant difference compared with the Minijet preparation.

Accuracy of dose

Figure 1.

Volume measuring apparatus

0.1 mL for 10 mL ampoule/prefilled syringe (accuracy of ±1%). Variations in volume were nominally divided into three groups, that is, accurate (>80% predicted volume), moderately inaccurate (50–80%) or markedly inaccurate (

Adrenaline in cardiac arrest: Prefilled syringes are faster.

Standard ampoules and prefilled syringes of adrenaline are widely available in Australasian EDs for use in cardiac arrest. We hypothesise that prefill...
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