Can red blood cell distribution width predict outcome after cardiac arrest?

In critically ill patients, high red blood cell distribution width (RDW) values have been associated with increased hospital mortality, but there are no data on the impact of RDW on outcomes of patients resuscitated from cardiac arrest (CA). The aim of this study was to investigate the relationship between RDW and long-term neurologic outcome in CA survivors.

We performed a retrospective analysis of an institutional database including all unconscious adult patients admitted to the intensive care unit (ICU) after non-traumatic CA between January 2007 and January 2015. Patients who survived <24 hours were excluded. The RDW (normal values 10.9-13.4%) was obtained daily from the day of admission to day 3. Patients with a cerebral performance category (CPC) score of 3-5 at 3 months were considered to have an unfavourable neurological outcome.

Three hundred and ninety patients were included. The ICU mortality rate was 56% (N.=220) and 64% of patients (N.=251) had an unfavorable 3-month neurological outcome. The median RDW on the day of admission was 14% (13.0-15.2%) and remained stable over the observation period. Two hundred and forty-five patients (63%) had a high RDW (>13.4%) on admission. In multivariable logistic regression analysis, older age, absence of bystander cardiopulmonary resuscitation (CPR), a non-cardiac etiology of the arrest, a non-shockable initial rhythm, high adrenaline dose during CPR and high admission RDW levels were independently associated with an unfavorable outcome at 3 months.

High RDW values are associated with poor neurological outcome among CA survivors.