• Resuscitation
• Accident & Emergency
• Clinical Procedures
• Evidence Based Medicine

The report by Martin et al1 describing the accuracy of resuscitation interventions by Advanced Paediatric Life Support instructors raises some interesting questions, not least for the writers of resuscitation guidelines.

The most obvious question is: Does it really matter that external chest compressions (ECCs) during cardiopulmonary resuscitation (CPR) are performed slightly too fast, not deep enough or in the wrong ratio? From the perspective of the guideline writer, the answer is complex. For example, there is very good evidence that CPR performed by bystanders improves survival in infants and children, but there is no direct evidence in humans that strict compliance with the international recommendations on ECC rate, depth, duty cycle (the ratio between compression and relaxation) and relaxation force will achieve improved patient outcomes during resuscitation.2 Indeed, it would be impossible to design an ethical study to prove this. There is, however, evidence from laboratory animal studies, and some human observations, that inform best methods of optimising pressure and flow during ECC and it is a reasonable assumption that better perfusion should create the potential for improved outcomes.3 Hence, the guideline writer has the difficult task of translating such research evidence into a number or, as in this case,1 a small range of numbers for the interventions during ECC. If a resuscitation provider performs ECC outside these ranges, there will be no sudden failure of blood flow—it is likely the ratio of blood flow to, say, …