Table 2 A narrative summary, themes, and context, for the top ten topic categories in the sample (n = 239; N.B., two articles could not be mapped to the top 10 topic categories and are not included in this table)

Operations: How paramedicine functions within itself, and within a larger health system.

264

42

1. System Impact and Costs (n = 14)

2. Resource Utilization (n = 12)

3. Triage in Dispatch (n = 7)

4. Disaster Management (n = 4)

Literature in this category tended to ask questions about how paramedicine fits with other health services, including how these resources can be best used. Articles discussing “positions” (i.e., ideas about how paramedicine should operate, what roles paramedics could act in) tended to be editorial or commentary, whereas those that included clinical outcomes were more empirically focused. Additionally, approximately half of the literature came from journals specific to paramedicine, though the majority was published in trade journals. Of note, ‘Resource utilization’ literature increased in 2011/2012, with 2011 particularly focused on ambulance diversion. In 2007, and preceding the increased interest in utilization, there were articles under ‘triage in dispatch’, which studied the dispatcher’s role in ensuring appropriate use of paramedicine.

For this category, 37 of the 42 articles could be retrieved and analyzed.

Of the 14 articles in the System Impact and Costs theme, 13 focused on paramedicine system planning, and described a diverse range of topics that included equipment and supplies, training, funding, staffing, alternative roles for paramedics, performance measurement, interoperability, urban and remote usage, and the optimal implementation of evidence-based guidelines [28,29,30,31,32,33,34,35,36,37,38,39,40]. One article focused on the impact to a single hospital from receiving air ambulance patients [41].

Of the 12 articles in the Resource Utilization theme, six articles explored system planning, which included diverse topics such as physician staffing of helicopters, planning prehospital critical care, describing specific examples of system reform, use of the system by diabetic patients, and community care in a First Nations community [42,43,44,45,46,47]. Three articles focused on emergency call management, including better understanding why people activate paramedicine systems, and management of frequent users [48,49,50]. Finally, one article described a program reducing hospital transportation [51], and two the use of the paramedicine system by pediatric patients [52, 53].

Of the seven articles in the Triage in Dispatch theme, five articles focused on ground ambulance dispatch, and included specific groups such as stroke and myocardial infarction and Alpha level patients, scoring the potential for a life-threatening condition, and dispatch adherence and patient outcome [54,55,56,57,58]. For air ambulance, the focus was on cancelling and triaging helicopter paramedicine calls [59, 60].

Of the four articles in the Disaster Management theme, three of the articles focused on system planning in specific types of disasters – blast injuries, hurricanes, and shootings [61,62,63]. One focused on laws and negligence in shootings [64].

Resuscitation: Discussion of prehospital assessment, treatment, and outcomes associated with out-of-hospital cardiac arrest and resuscitation.

229

29

1. Clinical Protocol (n = 9)

2. CPR (n = 7)

3. Survival (n = 7)

4. Recognition of Cardiac Arrest (n = 2)

Literature in this category asked questions focused on improving outcomes related to out of hospital cardiac arrest (OHCA). Early literature appears to have less focused questions, and studies were developed out of general concern for poor OHCA outcomes. Literature around 2011/2012 turned toward testing specific interventions/hypotheses. The majority of work was clinical/quantitative, however some qualitative work focused on behavior related to recognizing and acting on OHCA, for both paramedicine and bystanders. Most of the literature in this category came from academic journals related to emergency medicine, rather than academic or trade journals specific to paramedicine.

For this category 25 of the 29 articles could be retrieved and analyzed.

Of the nine articles in the Clinical Protocol theme, there were two articles on non-invasive near-infrared spectroscopy (NIRS) [65, 66], two on therapeutic hypothermia [67, 68], and two on termination of resuscitation [69, 70]. There was one article respectively on double sequential external defibrillation [71], extracorporeal CPR [72], and CPR induced consciousness [73].

Of the seven articles in the CPR theme, there were two studies on bystander CPR [74, 75], and two on telephone CPR [76, 77]. There was one article respectively on CPR training technology [78], CPR during transport [79], and high-performance CPR by paramedics [80].

Of the seven articles in the Survival theme, there was a diverse range of topics with one article respectively on best practice [81], paramedic compared to physician [82], paramedic compared to bystander [83], echocardiography informed prediction [84], a national registry [85], hospital predictors [86], and research challenges [87].

Of the two articles in the recognition of cardiac arrest theme, both explore the recognition of cardiac arrest by Emergency Medical Dispatchers [88, 89].

Airway Management: Prehospital techniques and training for equipment and protocols for securing and managing the airway.

205

29

1. Intubation (n = 22)

2. Ventilation and Oxygenation (n = 4)

3. Airway (n = 3)

Articles in this category overwhelmingly focused on intubation. Many studies attached a question of safety and appropriateness to scientific investigation. The ability and necessity of paramedics to perform intubation in the field was often in question, and in studies that used clinical evaluations, paramedics were often compared to other providers such as physicians. Nearly half of literature was found in the journal Prehospital Emergency Care, and most of the methods were evaluation or review based. Specific topics in this category varied over time and did not appear to follow any trends, except video laryngoscopy, which began in 2011.

For this category all 29 of the articles could be retrieved and analyzed.

Of the 22 articles in the Intubation theme, 12 focused on the procedure, with three primarily focused on drug assisted intubation [90,91,92], and two on trauma [93, 94]. The remaining seven procedure articles addressed myriad topics including intubation compared to other airway techniques, continuing competence, high-fidelity simulation, delayed sequence intubation, data, and a national committee review [95,96,97,98,99,100,101]. Of the seven articles on equipment, five focused on video laryngoscopy [102,103,104,105,106], and the remainder compared bougie use to no bougie use, and cuffed to uncuffed tubes [107, 108]. Of the three articles focusing on the provider and setting, paramedics were compared with other prehospital or hospital-based providers, one study focused on different specialties of physicians working prehospital [109,110,111].

Of the four articles in the Ventilation and Oxygenation theme, varied areas of focus included critical ventilation events, foreign body obstruction, non-invasive ventilation, and oxygenation guidelines [112,113,114,115].

Of the three articles in the Airway theme, articles addressed advanced or basic airway in out-of-hospital cardiac arrest, pediatric King-LT and data [116,117,118].

Pharmacology: Indication for and administration of medications for both primary and advanced care paramedics.

180

19

1. Safety, Efficacy and Effectiveness (n = 13)

2. Level of Paramedic Practice (n = 4)

In this category, the literature largely focused on the safety of medications used for sedation and pain control, and asked questions about which level of providers should administer them. Questions were most often investigated using non-experimental evaluations, and reviews, and most often appeared in academic journals. Some conversations around medication changed over time, for example naloxone was first tentatively discussed in 2013, and by 2019 it was seen as common practice for paramedics. Other conversations stayed consistent, for example early studies on ketamine focused on safety and effectiveness in prehospital care, and these questions appear to persist to present day. A number of studies looked at the level of training a paramedic needed to administer medications, asking if there was potential for those at an entry level to safely expand scope of practice. Overall, articles appear to identify a need for reliable, safe, and effective ways to use prehospital pharmacology.

For this category 17 of the 19 articles could be retrieved and analyzed.

Of the 13 articles in the Safety theme, four articles addressed analgesia (two ketamine and two fentanyl) [119,120,121,122], and three opioid overdose (naloxone) [123,124,125]. Further articles addressed bleeding (tranexamic acid) [126], bronchospasm (oral prednisolone) [127], arrhythmia (lidocaine) [128], seizure (midazolam) [129], acute agitation (ziprasidone) [130], and heart failure (furosemide) [131].

Of the four articles in the Levels of Paramedic Practice theme, three articles addressed analgesia (2 ketamine and 1 fentanyl) [132,133,134], and one article hypoglycemia (oral glucose) [135].

Trauma Care: Assessment and treatment of traumatic injuries, as well as triage and trauma system efficiency.

155

27

1. Trauma Systems and Care (n = 13)

2. Hemorrhage (n = 8)

3. Immobilization (n = 6)

Literature in this category asked questions about core practices in trauma such as hemorrhage and immobilization (spinal, and other fractures) and prediction tools in an effort to improve outcomes. The majority of studies in this category were clinical and quantitative, and specific to practices seen as vital for paramedicine. Some practices, particularly those around hemorrhage, came from foundations in military medicine, which is compared to civilian paramedicine. Research related to interventions remained consistent over time, evaluating traditional interventions like spine boards, as well as innovative ones such as hemostatic dressings. The literature sources were fairly evenly split between emergency medicine journals and those specific to paramedicine, as well as between academic and trade journals.

For this category all 27 articles could be retrieved.

Of the 13 articles in the trauma systems and care theme, four articles were on the management of different trauma populations, including burn victims requiring escharotomy [136], pediatric diaphragmatic injuries [137], pregnant patients [138], and minor head injuries [139]. Four articles were on triage [140,141,142,143], four were on trauma system assessment or design [144,145,146,147], and one was on prehospital levels of care [148].

Of the eight articles in the Hemorrhage theme, four articles focused on hemostatic dressings [149,150,151,152], and one each on tourniquets [153], IV infusion strategies [154], blood transfusion [155], and triage [156].

Of the six articles in the Immobilization theme, four focused on spinal immobilization [157,158,159,160], one on pelvis [161] and one on neck of femur fractures [162].

Clinical Skills: Foundational skills in paramedic practice, relating to the clinical assessment and care of patients.

149

30

1. Clinical Acumen (n = 11)

2. Specific Interventions (n = 11)

3. Decision Making Theory (n = 3)

4. Skill Description (n = 2)

Literature in this category commonly sought to understand paramedic decision making and clinical acumen. Up until around 2013, the focus was on thought processes around diagnosis and decision to use particular types of interventions. In more recent years, researchers have tried to identify the specific decision-making styles of paramedics in a more philosophical way. Most of the studies were qualitative in nature, with some quantitative analysis of specific interventions. Approximately half of the articles in this category were found in paramedic specific journals, however the vast majority were published in academic journals.

For this category 27 out of 30 articles could be retrieved.

Of the 11 articles in the Clinical Acumen theme, three articles compared paramedic diagnosis to that of physicians [163,164,165], two articles described pediatric anaphylaxis [166, 167], and one each described anaphylaxis [168], pediatric resuscitation [169], sepsis [170], extracorporeal membrane oxygenation (ECMO) [171], reducing harm [172], and paramedic clinical skills [173].

Of the 11 articles in the Specific Interventions theme, three were on intraosseous access, fluid, or pressure monitoring [174,175,176], two were focused on intravenous access or fluid [177, 178], and one each on blood transfusion [179], spinal immobilization [180], oxygen [181], continuous positive airway pressure (CPAP) [182], tourniquets [183], and ultrasound [184].

Of the three articles in the Decision Making Theory theme, two were focused on decision making styles [185, 186], and one on decision making models [187].

Of the two articles in the Skill Description theme, one described paramedic interventions [188], and the other treating obese patients [189].

Education/Simulation: Paramedic training, skills development, and continuing competence.

134

28

1. Skill Based Training and Continuing Competence (n = 13)

2. Formative Education (n = 8)

Literature in this category asked broad questions about the most effective ways to educate paramedics, as well as maintain competence. Early literature tended toward training for traditional paramedicine scenarios such as mass casualty and provision of CPR, as well as general professional development. Later literature (2014 and onward) began to describe innovative training reflective of evolving paramedic role, as well as advancements in technique such as simulation. Nearly a quarter of the literature found in trade journals was in this category, and much of it was editorial, or based on survey data.

For this category 21 out of 28 articles could be retrieved and analyzed.

Of the 13 articles in the Skill Based Training and Continuing Competence Theme, three focused on simulation [190,191,192], two on continuing education [193, 194], two on disaster training [195, 196], two on paramedic performance feedback [197, 198], and one each on research literacy [199], prescribing [200], stress inoculation [201], and training officers [202].

Of the eight articles in the Formative Education theme, three focused on education considerations [203,204,205], and one each on such diverse topics as assessment of practitioners [206], human factors [207], virtual reality [208], and community paramedic and critical care paramedic training [209, 210].

Practitioner Health and Wellness: Physical and psychological health and well-being of paramedics.

112

25

1. Fatigue (n = 10)

2. Psychological Wellness (n = 7)

3. Operational Safety (n = 6)

Literature in this category asked questions about both the physical and mental health of paramedics. Most of the research questions were framed in a way that put prevention of physical and psychological injury as the focus; very few focused on how practitioner injury could impact patient care. There has been a clear shift and expansion of what is meant by occupational safety. Prior to 2012, literature around practitioner health and wellness was dedicated to operational safety issues such as ambulance egress and driving. Starting in 2012, the literature has had an increased focus on discussion of fatigue, and psychological wellness of paramedics. The majority of this work was qualitative, with some editorial and commentary pieces. There were also a number of systematic reviews on the topic of fatigue, all appearing in 2018. Psychological wellness tended to appear in trade journals, where fatigue tended to appear in academic journals.

For this category 23 out of 25 articles could be retrieved and analyzed.

Of the 10 articles in the Fatigue theme, there was a diverse set of topics with one article each on air ambulance crew fatigue [211], biomathematical models [212], caffeine [213], data collection instruments [214], fatigue training [215], inter-shift recovery [216], napping [217], shift pattern [218], task load [219], and sleep and safety [220].

Of the seven articles in the psychological wellness theme, three were focused on critical incidents [221,222,223], and one each on inclusivity (LGBTQ2) [224], mental health matters [225], rural paramedicine [226], and the “national EMS memorial” [227].

Of the six articles in the Operational Safety theme, there were two articles on paramedic fitness [228, 229], and one each on ambulance stretchers [230], lift injuries [231], scene safety [232], and firefighting [233].

Transport/ Destination: Effective and appropriate use of air and ground resources, and transfer of care to hospitals and other health centers.

100

16

1. Appropriate Transport (n = 7)

2. Offload and Diversion (n = 5)

3. Interfacility Transfer (n = 3)

Literature in this category generally asked questions about the most effective way to use paramedic resources, by looking at external influencing factors. Articles on this topic did not appear in any significant number until 2011; there were some noticeable trends. Earlier articles tended to study the use of air transport. In recent years there has been increased discussion of offload delay, from both a measurement perspective, and examining perception as reported by paramedics. The question of what constitutes a legitimate cause for ambulance transport, and what is the most effective way to transport, appears to be enduring. This category was more often seen in academic journals, particularly around the sub-theme ‘appropriate transport,’ and much of the study was based on evaluation.

For this category 15 out of 16 articles could be retrieved and analyzed.

Of the seven articles in the Appropriate Transport theme, three articles focused on alternative transport, with one exploring transport to a community health centre [234], one on low-risk syncope patients [235], and one on non-urgent transports [236]. Two studies focused on transport mode, with one focused on air versus ground [237], and one on ambulance versus private car [238]. One study described an air ambulance system [239] and one was a position statement on air ambulance marketing [240].

Of the five articles in the Offload and Diversion theme, three focused on ambulance diversion [241,242,243,244], and two on offload delay [243, 245].

Of the three articles in the Interfacility Transfer theme, one focused on air versus ground transport criteria [246], one described a botulism outbreak in a regional hospital [247], and one assessed the interfacility transport process [248].

Myocardial Infarction (MI): Prehospital factors impacting outcomes of MI.

99

18

1. Assessment and Treatment (n = 16)

2. Transport (n = 2)

Literature in this category asked questions about the paramedic role in achieving the best outcomes for MI. Study of the topic has remained fairly consistent over time, with shift in focus every few years. Literature in 2006/2007 saw a concentrated discussion on the effectiveness of thrombolysis, whereas in 2010 and 2011 there seemed to be a “back to basics” type focus looking at interventions such as ECG and transport. From 2013 on, most literature has looked at the importance of catheter lab activations. MI literature tended to be published in academic journals, and was evenly split between journals specific to paramedicine, and those in emergency medicine; the majority of studies were empirical.

For this category all 18 articles could be retrieved and analyzed.

Of the 16 articles in the Assessment and Treatment theme, four were generally focused on prehospital ECG and ST elevation MI identification and thrombolysis [249,250,251,252]. Three were focused on adverse events, with one each on acute coronary syndrome in the air medical environment [253], dextrocardia [254], and basic life support paramedic nitroglycerin use [255]. Three articles focused on patient outcomes, with one describing patients with acute chest pain [256], one percutaneous coronary intervention versus thrombolytic therapy [257], and one early versus late bleeding [258]. Three articles described paramedicine-initiated catheter lab activation [259,260,261]. One study focused on non-ST elevation MI [262], another on alternative lead placement [263], and another on the identification by paramedics of a rare presentation of an acute coronary syndrome [264].

Of the two articles in the Transport theme, one focused on transport time [265] and the other on ambulance diversion [266] as related to MI treatment.