Bystander initiated actions in out-of-hospital cardiopulmonary resuscitation: results from the Amsterdam Resuscitation Study (ARRESUST).

The objective of this study was to analyze the functioning of the first two links of the chain of survival: 'access' and 'basic cardiopulmonary resuscitation (CPR)'. In a prospective study, all bystander witnessed circulatory arrests resuscitated by emergency medical service (EMS) personnel, were recorded consecutively. Univariate differences in survival were calculated for various witnesses, the performance of basic CPR, the quality of CPR, the performers of CPR and the delays. A logistic regression model for survival was developed from all potential predictors of these first two links. From the 922 included patients, 93 survived to hospital discharge. In 21% of the cases, the witness did not immediately call 112, but first called others, resulting in a longer delay and a lower survival. Family members were frequent witnesses of the arrest (44%), but seldom started basic CPR (11%). Survival, when basic CPR performers were untrained and had no previous experience, was similar to that when no basic CPR was performed (6%). Not performing basic CPR, delay in basic CPR, the interval between basic CPR and EMS arrival, and being both untrained and inexperienced in basic CPR were independent predictors for survival. Basic CPR performed by persons trained a long time ago did not appear to have a negative influence on outcome, nor did basic CPR limited to chest compressions alone. The mere reporting that basic CPR has been performed does not describe adequately the actual value of basic CPR. The interval from collapse to initiation of basic CPR, and the training and experience of the performer must be taken into account. Policy makers for basic CPR training should focus on partners of the patients, who are most likely witness of an arrest.