Influence of EMS-physician presence on survival after out-of-hospital cardiopulmonary resuscitation: systematic review and meta-analysis

Conclusions: The results of this meta-analysis show that CPR guided by EMS physicians is associated with improved rates of ROSC, hospital admission, and hospital discharge compared with CPR guided by paramedics in OOHCA patients

********Before citing those conclusions consider that this Metanalisys has several and important limitations: 

1. No RCT exists (and probably never will) about this topic so just prospective and retrospective study were included
2. Despite the big numbers(126,000 patients) 90% of patients included comes from two big study from Japan and no sensitivity analyses excluding these two studies was conducted.
3. No RCT means selection bias. One example: EMS-physician-staffed ambulances have the capacity of declare futile the initiation of CPR which may have influenced the denominator of “potential cardiac arrests” in sense of more favourable outcomes in EMS physician staffed ambulances. 
4. Geographic distribution of EMS systems is highly variable and is often influenced by many historical factors that all may have confounded the results of this meta-analysis.

********Despite the significant limitations this systematic review provides the only available evidence for the effectiveness of a paramedic versus EMS-physician-based emergency response system for prehospital cardiac arrest. 

What could EMS physicians provide beyond what paramedics already contribute? 

1. It has been demonstrated that because of the limited number of invasive procedures performed by EMS crews (like airway management, tracheal intubation, etc.) in out-of-hospital patients, it is very difficult to obtain or maintain life-saving skills and physician presence increases invasive procedures and drugs delivery. 
2. Physician presence during CPR has been reported to increase compliance with guidelines, resulting in less hands-off time during CPR.

References

Influence of EMS-physician presence on survival after out-of-hospital cardiopulmonary resuscitation: systematic review and meta-analysis

By Mario Rugna