Evidence-based Research for Paramedic Decision Making

Formative Assignment.

Working as a paramedic encompasses attending a variety of jobs. These include attending out-of-hospital cardiac arrest (OHCA). During 2017-2018 The London Ambulance Service (LAS) were called to 10,654 OHCA and resuscitation was attempted in 4,389 of these cases (shown in Appendix 1). This assignment will discuss how to conduct thorough search of research surrounding this subject. It will describe the way to access evidence-based research which will support and enhance future decision making and practice for a paramedic.

In line with the current JRCALC 2016 guidelines (Brown. et el 2016), adrenaline is used as part of advanced life support when attending an adult in OHCA resulting from all causes and heart rhythms. This treatment has been used for decades and was implemented form research done over 40 years ago. Callaway (2012) details the historic use and also the research behind the first implementation of the guideline. Research has shown that the use of adrenaline in OHCA can increase the return of spontaneous circulation (ROSC). Fothergill (2019) was influential in the current research into the relationship between ROSC and subsequent survival to discharge outcomes.

In order to investigate this in more depth and critically analyse the research, Beitz (2006) recommends formulating a question to assist with a more focused search for material. This is achieved by using the format of patient/problem, intervention, comparison and outcome (PICO). The PICO question does not have to include all 4 elements. This essay’s PICO question does not include a comparison component to it.

A search was carried out using the PICO question “In adult patients who suffer out of hospital cardiac arrest, does adrenaline improve survival to discharge rates?” (see Appendix 2).

A search was conducted using the Cochrane and Elsevier search engines.

The first search produced many, sometimes irrelevant pieces of literature. In order to manage the amount of appropriate information a more advanced search was then performed. This was conducted by making a list of all the key words and descriptors, referencing a dictionary and thesaurus for relevant terms and phrases, all of these optimised the search.

To assist further in filtering the literature, there are different search techniques that can be used. For example, “Boolean logic” allows the person searching to link specific terms and exclude words which are not relevant to the search (Open University 2014). Using the words AND, OR and NOT help to refine the search results as required. “Proximity” searching allows examination of words in the same sentence in order to locate more specific information. Using the word SAME, NEAR or W (within) (number following) can also help to refine a search based on proximities to preferred words and phrases. For example, using the W with a number, ‘W5’, will search for the same words used within a parameter of 5 words in the same sentence string.

“Truncation” can also be used, this is performed with the prefix or suffix of the * symbol (Open University, 2014). For example, a * as a suffix would denote a need for search results which should include both singular or plural representations of a word. During the search * was added to the word patient* and adult* to encompass any research which had the words patients or adults.

A “wildcard” as described in Open University article (2014) is the process of searching for a word which may be spelt differently in variations of the British language. This is done by using the * or ? symbol to search for alternative spellings of a word.

The terms which were used at each stage of this research were: adult; out of hospital; cardiac arrest; adrenaline and survival to discharge rate. Parameters were set for publication dates between 2009-2019. This made a provision for relevant and up to date search results.

Language filters were used to make sure all publications were written in English. Full details of the search and additional terms which were used are detailed in Appendix 2. The search was conducted using the CINAHL database, Rotterbury (2014) was a piece of literature among the search results and was an extremely in depth and informative publication. Subsequently, conducting an additional search using Elsevier, Fothergill et al (2019) gave a more concise argument and additional background knowledge around the use of adrenaline in OHCA and the impact on survival to discharge rates.

When searching for evidence it is important to critically analyse the results. Using the Hierarchy of evidence, we can also determine the authenticity of the literature. This is explained in Murad et al (2016) which states that there is a huge importance in the relationship between good evidenced based research when using it to develop future practice.

This Hierarchy of evidence can be explained in the pyramid of evidence in table 1. This approach emphasises the order of importance and reliability at each stage of the pyramid.

Table 1: The pyramid of evidence Murad et al (2016)

Randomised control trails (RCTs) are often used to determine if a treatment, intervention or medication would be beneficial for a certain demographic of patient (Kendall 2003).

Figure 1 Kendall (2003)

RCTs do have their limitations and this is evident in Kendall (2003) and describes the ethical constraints and also medical bias that can surround a trial. Not giving a patient a specific treatment in a trial could cause mortality and this must be addressed when an RCT is being planned and implemented. Figure 1 shows how a randomised trail can be done using a new treatment compared to a control treatment. However, this can also be done using a placebo.

Set at the top of the pyramid is the systematic review and this is considered to be the highest level of evidence. The systematic review is the most reliable way of evaluating evidence, RCT’s, reviewing published and unpublished studies to give a more balanced and impartial summary. These are rigorously performed and give a more robust outcome of comparison (Crombie,1996).

Systematic reviews also have their limitations. Crombie (2009) addresses these limitations in his description of systematic reviews and explains that even when conducted robustly these will only give you the best possible estimate of clinical effectiveness.

Ultimately, all health care interventions will only become best practice guidelines after the most up-to-date scientific evidence has been reviewed and all RCT’s have been though the process of a systematic review (De Bruin 2013).

It is abundantly evident that a concise PICO question and performing a thorough search are vital when any medical professional is faced with making an informed clinical decision on a patient’s treatment and / or understanding the rationale behind clinical guidelines.

References:

Beitz JM. (2006). ‘Writing the researchable question’. Ostomy school of Nursing. 33(2). pp.122–4.

• Brown, S.N, Kumar, D., Millins, M., Mark, J. (2016). UK ambulance services clinical practice guidelines. 4^th edn. Bridgewater: Class Professional.
• Callaway, C, W. (2012). ‘Questioning the use of epinephrine to treat cardiac arrest’. JAMA. 11 (3). pp. 1198-1200.
• Crombie, I.K. (1996). Pocket Guide to Critical Appraisal. 1st edn. London: BMJ Publishing Group.
• Crombie, I.K. (2009). What is systematic review. Evidence-based medicine, 2nd edn. Pp 1-8.
• De Brun, C. (2013). ‘Finding evidence a key step in the information production process’. The information Standard. 2 (11), pp. 1-18.
• Fothergill, R.T, Emmerson, A.C, Iyer, R, Lazarus, J, Whitbread, M, Nolan, J.P, Deakin, C.D, Perkins, G.D. (2019) ‘Repeated adrenaline doses and survival from an out of hospital cardiac arrest’. Resuscitation. 138 (1) pp. 316-321
• Kendall JM. (2013). ‘Designing a research project: Randomised Controlled trials and their principles’, Emergency Medical Journal. 20(2), pp.164-168.
• Maurad, M.H., Noor, A, Mousaz, A, Fares, A. (2016. ‘New evidence pyramid’. Evid Based Med, vol 21, 4 (8). pp. 125-127.
• Open University (2014). Advanced serch techniques. Available at: http://www.open.ac.uk/libraryservices/documents/advanced-search-techniques.pdf
  [Accessed 23 May 2019].
• Rottenberg, E.M. (2014). ‘Could the survival and outcome benefit of adrenaline also be dependent upon the presence of gasping upon arrival of emergency rescuers?’. American Journal of emergency medicine, 32(9), pp. 1074-1076.

Appendix 1