“…The included studies were classified into eight levels of evidence by study design and methodology following a modification of the system described by the American Heart Association and International Liaison Committee on Resusci- Abouleish [42], Auden [43], Carenzi [44], Cortez [45], Ellis [46], Hansen [47], Hinton [48], Johr [49], Lesmes [50], Lonnqvist [51], Lopez-Gil [11], Markakis [52], Mecklem [53], Oliva [54], Park [55], Puebla [56], Shank [57], Theroux [58], Trevisanuto [59],…”