There are new statements about doing two minutes of CPR after each shock and in some cases providing two minutes of CPR before shock for unwitnessed out-of-hospital VF.
It is now recommended a compression-to-ventilation ratio of 30:2 be used for single rescuers treating victims of all ages and 2 - rescuer CPR for adults. Healthcare providers should use a 15:2 ratio for 2 rescuer CPR for infants and children." Class IIa. (p. IV-25).
"...recommend that all rescuers minimize interruptions of chest compressions for checking the pulse, analyzing rhythm, or performing other activities. Class IIa. (p. IV-25).
During 2 rescuer CPR with an advanced airway, rescuers provide continuous compressions (100 compressions/minute) and the rescuer giving the rescue breaths does so at a rate of 8 - 10 breaths/minute. Class IIa.(p. IV-22)
"Effective" chest compressions are essential for providing blood flow during CPR (Class I). The rule is: "push hard and push fast." Rescuers must provide compressions of an adequate rate (100/minute) and depth (1.5-2 inches) and allow complete chest recoil with minimal interruptions. Also, the compression/relaxation ratio of each compression should be 50:50. Class IIb. (p. IV-24)
Fatigue is a major factor in compression quality. When 2 or more rescuers are performing CPR, it is reasonable to switch the compressor every 2 minutes. Class IIb. (p. IV-25)