As ED staff we all know that in an emergency we have our trusty guidelines to turn to. This helps with cognitive off-load in stressful situations, but are these guidelines always up to date with the evidence?
This post aims to look at some of the most current research, and make you question the guidelines we use. We are not advocating suddenly throwing these guidelines out of the window, just asking you to read the case study and see what you think. You can use our new reflection form to write about it afterwards and include it in your portfolio!
It has been well documented that outcomes in out of hospital cardiac arrest (OOHCA) are poor[1]. In the UK the guidelines used in-hospital come from the UK resuscitation council, who in turn adapt theirs from those of the European Resuscitation Council. These are updated every five years.
In recent years up to date research has become much more freely available with the emergence of Free Open Access Medical Education (FOAMed) across the Internet and social media. This, led by sites such as Life in the Fast Lane and St Emlyn’s to name but a few, has meant that the latest evidence is available at just a few clicks of a keyboard[2]. However, many caution that this will result in clinicians changing their practice without fully appreciating the evidence behind it[3]. Indeed I have had senior paramedics approach me, concerned that their colleagues have deviated from established guidelines based on the publication of a recent journal article.
A 68-year-old male was brought into the department by ambulance in cardiac arrest. The gentleman had been found collapsed in a shopping centre by a passer by who had called 999 and commenced Cardiopulmonary Resuscitation (CPR). The collapse had been un-witnessed so nobody was sure of exactly how long he had been unconscious. On crew arrival 4 minutes later the patient had been found to be in Ventricular Fibrillation, which accounts for approximately 20% of both in hospital and out of hospital cardiac arrests (UK resus council 2015).
On arrival to ED, approximately 20 minutes from the initial call, the patient had an i-gel insitu as the crew had found him difficult to intubate, and care of this was taken over by an ED ST3. He had a cannula in his anticubital fossa. He had had 3 doses of adrenaline, one dose of amiodarone and three attempts at defibrillation. Between these attempts at defibrillation the gentleman had changed to a non-shockable rhythm and then back again which meant the recently qualified paramedic had become confused around how much adrenaline should have been given and admits that this was a stressful scenario as the patients wife arrived during the resuscitation attempt.
On arrival to the ED the patient was found to be in a non-shockable rhythm of PEA. On moving the patient we suspected the cannula had been displaced and so intraosseous access was established and a further dose of adrenaline given at the earliest opportunity. We continued the resuscitation attempt and addressed any possible reversible causes but the patient deteriorated to asystole and point of care focused ultrasound showed very little spontaneous cardiac activity.
I spoke with the patient’s wife, explained the current situation and discussed the patients’ medical history, which included extensive cardiac problems, a long smoking history and both hypertension and hypercholesterolemia. Given that the patient now had a ‘down-time’ approaching one-hour I explained the poor prognosis and his wife agreed that stopping CPR was the next step.
Following the termination of resuscitation I gathered the team for a debrief. There were a few concerns they had.
The first concern was whether or not the failure to intubate the patient would have had a detrimental effect on his outcome.
The UK Resus Council (2015) states that tracheal intubation has generally been considered the optimal method of managing the airway during cardiac arrest. Jarvis et al[4]however, found that it often takes multiple attempts to achieve advanced airway management. This is corroborated by Buis et al [5]who observe that it takes over 50 successful intubations to achieve a 90% success rate. Buis also goes on to caution that two or more failed intubation attempts increase the risk of death or other complications. The ALS guideline does clarify that an attempt at intubation should not interrupt compressions for more than 5 seconds.
Newell et al[6]state that one of the most common arguments against endotracheal tube intubation is the amount of time taken to perform, thus resulting in a pause in compressions. Indeed, It was found by Wang et al[7]that a quarter of cases they studied had a pause in compressions of over three minutes whilst attempting to intubate. This begs the question, is achieving satisfactory endotracheal intubation necessary for a good outcome in out-of-hospital cardiac arrest, and what is the alternative?
Sulzgruber et al[8]observe that whilst the guidelines mention the use of a supraglottic airway device as an alternative to endotracheal intubation, they also noted that evidence for their use remains scarce and inconclusive. This year however a ground breaking UK based pre-hospital trial was published, which specifically looked at the use of supraglottic airway device as the initial strategy. The AIRWAYS-2 trial attempted to determine whether or not the supraglottic airway device was superior to endotracheal intubation[9]. To do this the authors randomised the paramedics, rather than the patients, to an arm of the trial, whilst giving them the opportunity to override this if their clinical decision-making dictated. It measured the functional outcome at 30 days or hospital discharge by calculating a Modified Rankin Score. The trial did not find any superiority in the use of supraglottic airway.
Also this year this result was echoed by another large randomised controlled trial; the PART trial in the US. This paper observed that laryngeal tube was superior in 72 hour survival, but not in the long term[10]. Interestingly both of these papers discussed the possibility of a ‘skill-fade’ given the complexity of intubation as a problem which would impact on the clinicians ability to perform a tracheal intubation on the first attempt.
As a clinician who does not intubate patients, and therefore supraglottic airway is the top of my ‘airway ladder’, this research will not directly impact my personal practice. It does however beg the question for others in my team as to whether endotracheal intubation should be the gold standard.
Liebig[11]comments that performing endotracheal intubation takes time and multiple staff members to perform the necessary safety checks, and wonders if supraglottic airway should be used first. Indeed, this is observed in the PART trial, which found that endotracheal intubation took an average of 2.7 minutes longer than laryngeal tube insertion. This observation is directly compounded by the primary author of the AIRWAYS-2 trial who states “In OHCA, there is high quality randomized evidence that suggests that if you place a supraglottic airway device, the outcomes for your patient will be at least as good, if not possibly better than had you attempted to place an ET instead”.
Based on this evidence, when debriefing my paramedic colleague following our failed resuscitation attempt, I could reassure her that having an iGel in place as opposed to an endotracheal tube would not have had a detrimental effect on the patients outcome. In fact she could be further reassured that having resorted to an iGel rather than continue to make further attempts at tracheal intubation and neglect other aspects of cardiac arrest management was the correct choice to make.
The next concern that the crew had was whether or not skipping at least one dose of adrenaline during the resuscitation attempt would have had a negative effect on the patients outcome.
It has already been reported by the UK resus council, in the 2015 guidelines, that there is little evidence for the use of drugs in cardiac arrest, and the evidence that does exist is inconclusive. Improved short-term survival rates were shown by Olasveengen et al[12]but the guideline observes that, at the time of their publication, there was no randomised-controlled trial to show that the use of adrenaline in cardiac arrest improves long-term outcomes. Reazie[13]echoes this, noting that despite its widespread use in guidelines there is little evidence for the use of adrenaline.
The Paramedic-2 trial was a further large UK based pre-hospital trial. This double-blind randomised trial sought to find if there was any improved outcome in the use of adrenaline in out of hospital cardiac arrest as opposed to a placebo[14]. This paper used a primary outcome of survival at 30 days, with multiple secondary outcomes. Morgenstern[15]comments that the big caveat that will drive most opposing views on this trial is the presence of two different but important outcomes: survival, and survival with good neurologic function.
One of the biggest take home messages for myself from this trail was the incredibly low survival rate. Given that patients who achieved ROSC prior to trial-trained paramedic arrival weren’t included in the study, the survival at 30 days total from the adrenaline arm of the trial was only 3.2% and 2.4% in the placebo arm. However, when looked at in an entirely black and white view, the paper shows that those patients who received adrenaline had a better survival rate at 30 days than those who did not. When looking at this evidence alone, I could tell my paramedic colleague that having not given the adrenaline would have had a direct negative outcome on that patient’s prognosis.
However, very few things in Emergency and pre-hospital medicine are black and white, and this paper is no exception. The team at The Resus Room[16]counter with the comment that the trade off for this increased survival is the significant number of survivors with a poor neurological outcome. Indeed, the trial found, as a secondary outcome, that those who did survive to 30 days from the adrenaline are had a poor neurological outcome. There was no evidence of a significant difference in the proportion of patients who survived until hospital discharge with a favourable neurological outcome. At the time of hospital discharge, however, those in the adrenaline arm had a worse neurological outcome than those in the placebo arm. As with the AIRWAYS-2 trial this was measured using a Modified Rankin scale, and categorised a score of 4 or 5 as a severe neurological impairment. Therefore, those patients given adrenaline are more likely to survive, but have poor neurological outcome. In my opinion this then becomes a question of personal ethics rather than clinical guidelines. Morgenstern argues that that any intervention that increases survival, but doesn’t increase survival with good neurologic outcomes, is clearly harmful and goes on to state that this combination means that patients “saved” are left with poor functional outcomes and a quality of life that might not be appreciated. However, is it up to us as clinicians to decide whether the patient should be treated based on whether they would want to survive at whatever outcome possible? Is this a discussion we should be having with families? I certainly feel it adds an argument to having early discussions around your wishes with your family. Walker[17]agrees that this paper certainly leaves some moral questions. This is expanded on by Wood[18]who theorises the results should prompt some soul-searching among policy makers around the globe in terms of which outcomes are most valued.
The trial authors did in fact seek to answer this question prior to starting the trial. They spoke to over three hundred people, and found that over 95% of them prioritised surviving without brain damage over survival alone.
Once again this paper will not affect my immediate practice, and as with AIRWAYS-2 this evidence needs to be considered before the next revision of the Advanced Life Support Guidelines.
With all this in mind, I can reassure my paramedic colleague that the difference in survival is less than 1% in adrenaline vs. placebo, therefore missing a dose during the resuscitation attempt is unlikely to have had a huge impact on the patient’s outcome.
A further discussion we had during the debrief was whether having designated cardiac arrest centres would have had an impact on the outcome. In our area we are the adult major trauma centre, but we do not have a local network for cardiac arrest centres. In the case of ST-elevation patients can be taken directly to the nearest cardiac centre for PPCI, but not in non ST-elevation cardiac arrest.
Soreide and Busch[19]argue that having regional Cardiac Arrest Centres is a must for improving outcomes. The ARREST pilot[20]looked at whether regionalisation to Cardiac Arrest Centres can improve the discrepancy between inter-centre outcomes in out-of-hospital cardiac arrest. Carley[21]notes however that the results of this pilot study are confusing, and a lot more work into the design needs to be done before a large multi centre randomised controlled study can take place.
To conclude the debrief I could reassure my pre-hospital colleagues that, whilst they did deviate from the accepted Advanced Life Support Guidelines in places, current evidence shows that this would not have had a detrimental effect on the outcome of this patients.
My further take home messages from all of this research are that the basic interventions in cardiac arrest of good quality chest compressions and early defibrillation remain those that give the best outcomes.
Hope this helps!
Liz xx
RCN Emergency Care Competencies: CD1 2.1.3, CD2 2.1.2, CD2 2.1.3
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