The moment someone’s heart stops, they’re legally dead. Whether they stay dead or can be quickly revived, depends largely on the immediate medical care and medications they receive. Prior research has shown the most common medication used in cardiac arrest, Epinephrine, is helpful in restarting the heart but it’s uncertain if it’s equally helpful in allowing patients to live in anything other than a persistent vegetative state. While keeping people alive is paramount to doctors, nurses, and first responders, Epinephrine has recently been questioned if there’s no benefit to its’ use in preventing patients who are brain dead.
Epinephrine as a medication in cardiac arrest is so deeply ingrained in medical practice that to establish a prospective randomized trial for hospitalized patients is nearly impossible. This is despite the fact that of the few studies that exist examining out of hospital cardiac arrest patients or in limited retrospective studies, no statistical difference has been found in regards to facilitating improved neurologic function in arresting patients. To date, limited and contradictory research has examined Epinephrine’s use in hospitalized patients suffering cardiac arrest.
Looking at the EICU database, a research co-operative of over 200,000patients in dozens of intensive care units across the county, 2,000 patients were identified to have experienced in hospital cardiac arrest. While 1,200 of those patients received Epinephrine, 800 did not, and of the original 2,000, 600 in total survived or which 300 were discharged neurologically in-tact. If these patients received Epinephrine, the overwhelming majority received only one dose. Within these patients, information regarding age, race, admission diagnosis, length of stay in hospital, and other medical and demographic information can be obtained.
In evaluating the use of Epinephrine, outcome measures can be studied in two ways, death and neurologic status for those that did not die. Starting with a principal component analysis, the overwhelming variable of importance in both measures was simply whether a patient received any amount of Epinephrine. As mentioned, the overwhelming number of patients who received Epinephrine (roughly 1,200) received only one dose.
Starting with PCA analysis, the most prominent feature in determining if patients lived or died was whether they received any amount or epinephrine. This was true as well for whether patient survived ICU stays neurologically in tact. In fact, of all features examined, surprisingly age, admitting diagnosis, ethnicity, were all insignificance in determining or modeling these outcomes. By this dataset, the only real thing that mattered was whether patients received epinephrine. When these factors are taken into consideration, logistic regressions yield the best but still poor results. While Rsquare values are low, there are still statistically significant odds ratios which can be used to produce a number needed to treat, both suggesting that only approximately 3 patient need to receive epinephrine to both survive their ICU stay and to do so neurologically in tact. While this is encouraging in justifying the current standard of care practices, what is really suggests is the need for a prospective randomized control trial in the future to further discern which dose of epinephrine, if any, may be helpful in these patients.
By: Jim Saunders MD