Understanding the statistics in cardiac arrest survival

Sudden cardiac arrest gives rise to haemodynamic collapse, and in most cases—results in patient death. Those who are already in, or are quickly transferred to a hospital equipped with sophisticated devices, machines, and highly trained professionals, are treated using every conceivable means possible, and thus have a chance of returning to their daily routine without any neurological consequences. On the other end of the spectrum, however, there is the patient who drops dead without any witnesses in which case, mortality is 100%.

The most frequent scenario though, is the case that falls between these two extremes, in which some sort of cardiac resuscitation can be performed, either in an outpatient space or within the inpatient arena.

Most of the data we have concerns outpatients; there are 30-year-old studies from New York describing those who had suffered, and subsequently survived, cardiac arrest for a period of 1 year (Lombardi et al, 1994; Westfal et al, 1996). The studies documented a mortality rate of 90% in one year with 5% of the survivors experiencing significant neurologic sequelae. Unfortunately, over the past three decades, these statistics have not changed much.