Conflict of Interest Declaration
The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. The following Task Force members and other authors were recused from the discussion as they declared a conflict of interest: none applicable.
The following Task Force members and other authors declared an intellectual conflict of interest and this was acknowledged and managed by the Task Force Chairs and Conflict of Interest committees: none applicable.
CoSTR Citation
Boulton AJ, Edwards R, Gadie A, Clayton D, Smyth MA, Brown T, Yeung J on behalf of the International Liaison Committee on Resuscitation EIT Life Support Task Force.
Methodological Preamble and Link to Published Systematic Review
The continuous evidence evaluation process for the production of Consensus on Science with Treatment Recommendations (CoSTR) started with this new PICOST and was registered on PROSPERO (CRD42023478216). Evidence for adult and paediatric literature was sought and considered by the EIT Task Force. The search strategy was developed in collaboration with Samantha Johnson, Information specialist at University of Warwick. A systematic review process was followed, including independent multiple author screening, data extraction, and risk of bias assessment using ROBINS-I for non-randomised studies of interventions. Synthesis was informed by the Cochrane Handbook for Systematic Reviews of Interventions and included study characteristic tabulation and subsequent meta-analysis. Studies at serious risk of bias were excluded from meta-analysis. Only adjusted analyses were included in meta-analysis, using the analysis judged to minimise the risk of confounding in accordance with Cochrane recommendations. Certainty of evidence assessments followed the GRADE approach and GRADE tables for evidence profile and evidence to decision were developed. These tables and assessments were used to formulate the Treatment Recommendations.
Systematic Review
Webmaster to insert the Systematic Review citation and link to Pubmed using this format when it is available if published
PICOST
Population: Adults and children in the out-of-hospital setting with cardiac arrest and attempted resuscitation. Traumatic cardiac arrest was excluded.
Intervention: Attendance of a prehospital critical care team. Prehospital critical care was defined as any provider with clinical competencies beyond that of standard paramedics using ALS algorithms and dedicated dispatch to critically ill patients.
Comparison: Advanced life support (ALS) by any other prehospital healthcare provider.
Outcomes: Clinical outcomes of survival (critical), favourable neurological outcome (critical), and return of spontaneous circulation (ROSC) (critical), resource and cost implications (important).
Study Design: Randomised controlled trials (RCTs) and non-randomised studies (non-randomised controlled trials, interrupted time series, controlled before-and-after studies, cohort studies) are eligible for inclusion. Unpublished studies (e.g., conference abstracts, trial protocols) are excluded. All relevant publications in any language are included as long as there is an English abstract
Timeframe: From inception to 20th April 2024.
PROSPERO Registration: CRD42023478216
Consensus on Science
There was a total of 6,444 search results, and after duplicates were removed 4,524 records remained. Full texts were obtained for 52 articles of interest following title and abstract screening. Fifteen articles met eligibility criteria and were included.[1–15] The associated PRISMA diagram is attached (Fig. 1).
No randomised studies were identified. All identified studies were non-randomised studies of interventions. A total of 1,188,287 patients were included. One study included only children.[15]
The majority of studies reported that prehospital critical care teams included physicians (n=14).[1–9,11–15] Where professional background was reported, these physicians were specialists in emergency medicine,[2–4,6,11,13,15] anaesthesia,[3,9,13] or critical/intensive care medicine.[2,3,6,11,13] Four studies reported prehospital critical care teams that included specially trained critical care paramedics.[1,10,12,13] These studies were from the United Kingdom (n=3) [1,12,13] and Australia (n=1) [10] only. One study reported prehospital critical care teams including solely critical care paramedics.[10]
Survival to hospital admission/return of spontaneous circulation
For the critical outcome of “survival to hospital admission/ROSC” in non-traumatic OHCA we identified low certainty evidence (downgraded for risk of bias) from eight non-randomised studies enrolling 639,760 patients.[1–4,6,9,11,13] The estimate of effect indicated improved outcome associated with prehospital critical care teams (OR 1.95, 95% CI 1.35-2.82) (Fig. 2).
For the critical outcome of “survival to hospital admission/ROSC” in paediatric OHCA we have identified very low certainty evidence (downgraded for risk of bias and imprecision) from one non-randomised study enrolling 1,187 patients.[15] The estimate of effect indicated improved outcome associated with prehospital critical care teams (OR 1.48, 95% CI 1.08-2.04) (Fig. 2).
Survival to hospital discharge
For the critical outcome of “survival to hospital discharge” in non-traumatic OHCA we identified low certainty evidence (downgraded for risk of bias) from seven non-randomised studies enrolling 12,171 patients. [1–4,9,12,13] The estimate of effect indicated improved outcome associated with prehospital critical care teams (OR 1.34, 95% CI 1.10-1.63) (Fig. 3).
We did not identify any evidence in paediatric OHCA to address the critical outcome of “survival to hospital discharge”
Survival at 30 days
For the critical outcome of “survival at 30 days” in non-traumatic OHCA we identified low certainty evidence (downgraded for risk of bias) from seven non-randomised studies enrolling 704,880 patients.[5–8,10,11,14] The estimate of effect indicated improved outcome associated with prehospital critical care teams (OR 1.56, 95% CI 1.38-1.75) (Fig. 3).
For the critical outcome of “survival at 30 days” in paediatric OHCA we identified very low certainty evidence (downgraded for risk of bias and imprecision) from one non-randomised study enrolling 1,187 patients.[15] The estimate of effect indicated improved outcome associated with prehospital critical care teams (OR 1.49, 95% CI 0.97-2.88) (Fig. 4).
Favourable neurological outcome at hospital discharge
For the critical outcome of “favourable neurological outcome at hospital discharge” in non-traumatic OHCA we identified very low certainty evidence (downgraded for risk of bias and imprecision) from one non-randomised study enrolling 973 patients, showing no significant difference (OR 1.35, 95% CI 0.71-2.60).[9]
We did not identify any evidence in paediatric OHCA to address the critical outcome of “favourable neurological outcome at hospital discharge”
Favourable neurological outcome at 30 days
For the critical outcome of “favourable neurological outcome at 30 days” in non-traumatic OHCA we identified low certainty evidence (downgraded for risk of bias) from six non-randomised studies enrolling 689,738 patients. [5–8,11,14] The estimate of effect indicated improved outcome associated with prehospital critical care teams (OR 1.48, 95% CI 1.19-1.84) (Fig. 5).
For the critical outcome of “favourable neurological outcome at 30 days” in paediatric OHCA we identified very low certainty evidence (downgraded for risk of bias and imprecision) from one non-randomised study enrolling 1,187 patients.[15] The estimate of effect indicated improved outcome associated with prehospital critical care teams (OR 1.98, 95% CI 1.08-3.66) (Fig. 5).
Treatment Recommendations
We recommend adults with non-traumatic out-of-hospital cardiac arrest have prehospital critical care teams attend within EMS systems with sufficient resource infrastructure (weak recommendation, low certainty of evidence).
We suggest children with out-of-hospital cardiac arrest have prehospital critical care teams attend within EMS systems with sufficient resource infrastructure (weak recommendation, very low certainty of evidence).
Justification and Evidence to Decision Framework Highlights
- This PICOST was prioritised by the ILCOR EIT taskforce to assess possible improvements in outcomes for out-of-hospital cardiac arrest patients as that is a priority for many healthcare systems. Prehospital critical care was considered as enhanced clinical competencies beyond advanced life support with dedicated EMS teams dispatched to critically ill patients. This was compared to standard advanced life support.
- Studies were included from multiple EMS systems across the world, with seven from Japan, three from the UK, and one each from Australia, Iceland, Norway, Poland, and the USA.
- Meta-analysis found moderate desirable effects for adult non-traumatic OHCA patients in all critical outcomes (survival, favourable neurological outcome, survival to hospital admission/ROSC) with low certainty of evidence from 14 studies reporting 1,187,100 patients. The ILCOR taskforce has made a recommendation alongside low certainty of evidence for adults with non-traumatic OHCA in light of consistent moderate desirable effects across clinical outcomes in a large number of reported patients and studies from a variety of different health care systems.
- There were moderate desirable effects based on very low certainty of evidence for paediatric OHCA patients from one study reporting 1,187 patients. As there was only one study a limited number of patients, the ILCOR task issued a suggestion favouring prehospital critical care teams for paediatric OHCA patients.
- The associated resource costs, cost-effectiveness, impact on health equity, and feasibility of implementation were not reported by the included studies. These costs are likely to be healthcare system specific. This systematic review demonstrates that many settings have already implemented prehospital critical care teams and they are treating many OHCA patients in contemporary clinical practice. Expanding prehospital critical care services and implementing these services in other healthcare systems is likely to incur resource, training, and EMS infrastructure costs, and hence may not be universally available. Implementing prehospital critical care teams is likely to be setting specific.
Knowledge Gaps
- The evidence on children with out-of-hospital cardiac arrest is based on only one study. More evidence is required to understand if the individualised and enhanced care provided by prehospital critical care teams confers clinical benefit.
- Which patient groups would benefit most from prehospital critical care teams in order to optimise emergency medical service systems and target care delivery.
- The optimal composition of prehospital critical care teams, their professional background, and training requirements are unknown. This may be EMS system specific.
- The enhanced interventions prehospital critical care teams are delivering and what interventions are resulting in the observed desirable effects.
- Cost-effectiveness of prehospital critical care teams and implementation costs. This may be EMS system specific.
- There is no data from RCTs investigating prehospital critical care teams for OHCA.
Note to Webmaster: CoSTR posting should be linked to ETD summary table
Attachment: Et D Prehospital critical care for OHCA 080724, Figure 1 PRISMA diagram, Figure 2 ROSC, Figure 5 Neuro 30, Figure 4 Survival 30, Figure 3 Survival dc, GRADE Pro 300624
References
[1] Barnard EBG, Bach DD, Nicholls TL, Wilson AW, Ercole A. Prehospital determinants of successful resuscitation after traumatic and non-traumatic out-of-hospital cardiac arrest. Emergency Medicine Journal (EMJ) 2019;36:333–9.
[2] Bjornsson HM, Bjornsdottir GG, Olafsdottir H, Mogensen BA, Mogensen B, Thorgeirsson G. Effect of replacing ambulance physicians with paramedics on outcome of resuscitation for prehospital cardiac arrest. European Journal of Emergency Medicine 2021;28:227–32.
[3] Bujak K, Nadolny K, Trzeciak P, Gałązkowski R, Ładny JR, Gąsior M. Does the presence of physician-staffed emergency medical services improve the prognosis in out-of-hospital cardiac arrest? A propensity score matching analysis. Polish Heart Journal / Kardiologia Polska 2022;80:685–92.
[4] Dickinson ET, Schneider RM, Verdile VP. The impact of prehospital physicians on out-of-hospital nonasystolic cardiac arrest... presented at the ACEP Research Forum, Cincinnati, Ohio, February 1996. Prehospital Emergency Care 1997;1:132–5.
[5] Goto Y, Maeda T, Nakatsu-Goto Y. Neurological outcomes in patients transported to hospital without a prehospital return of spontaneous circulation after cardiac arrest. Crit Care 2013;17:R274.
[6] Goto Y, Funada A, Goto Y. Impact of prehospital physician-led cardiopulmonary resuscitation on neurologically intact survival after out-of-hospital cardiac arrest: A nationwide population-based observational study. Resuscitation 2019;136:38–46.
[7] Hatakeyama T, Kiguchi T, Sera T, Nachi S, Ochiai K, Kitamura T, et al. Physician’s presence in pre-hospital setting improves one-month favorable neurological survival after out-of-hospital cardiac arrest: A propensity score matching analysis of the JAAM-OHCA Registry. Resuscitation 2021;167:38–46.
[8] Nakajima S, Matsuyama T, Watanabe M, Komukai S, Kandori K, Okada A, et al. Prehospital Physician Presence for Patients With out-of-Hospital Cardiac Arrest Undergoing Extracorporeal Cardiopulmonary Resuscitation: A Multicenter, Retrospective, Nationwide Observational Study in Japan (The JAAM-OHCA registry). Curr Probl Cardiol 2023;48:101600.
[9] Olasveengen TM, Lund-Kordahl I, Steen PA, Sunde K. Out-of hospital advanced life support with or without a physician: Effects on quality of CPR and outcome. Resuscitation 2009;80:1248–52.
[10] Pemberton K, Franklin RC, Bosley E, Watt K. Pre-hospital predictors of long-term survival from out-of-hospital cardiac arrest. Australas Emerg Care 2023;26:184–92.
[11] Sato N, Matsuyama T, Akazawa K, Nakazawa K, Hirose Y. Benefits of adding a physician-staffed ambulance to bystander-witnessed out-of-hospital cardiac arrest: A community-based, observational study in Niigata, Japan. BMJ Open 2019;9:e032967.
[12] von Vopelius-Feldt J, Coulter A, Benger J. The impact of a pre-hospital critical care team on survival from out-of-hospital cardiac arrest. Resuscitation 2015;96:290–5.
[13] von Vopelius-Feldt J, Morris RW, Benger J. The effect of prehospital critical care on survival following out-of-hospital cardiac arrest: A prospective observational study. Resuscitation 2020;146:178–87.
[14] Yasunaga H, Horiguchi H, Tanabe S, Akahane M, Ogawa T, Koike S, et al. Collaborative effects of bystander-initiated cardiopulmonary resuscitation and prehospital advanced cardiac life support by physicians on survival of out-of-hospital cardiac arrest: a nationwide population-based observational study. Crit Care 2010;14:R199.
[15] Obara T, Yumoto T, Nojima T, Hongo T, Tsukahara K, Matsumoto N, et al. Association of Prehospital Physician Presence During Pediatric Out-of-Hospital Cardiac Arrest With Neurologic Outcomes. Pediatr Crit Care Med 2023;24:e244–52. https://doi.org/10.1097/PCC.00....