Background: Prognostication after an out-of-hospital cardiac arrest (OHCA) remains a challenge. The peripheral-derived perfusion index (PI) is a simple and non-invasive way to assess perfusion. We sought to assess whether the PI was able to discriminate the prognosis of patients resuscitated from an OHCA.
Methods: All the reports generated by the manual monitor/defibrillator (Corpuls 3 by GS Elektromedizinische Geräte G. Stemple GmbH, Germany) used for all the OHCAs who achieved ROSC treated by our Emergency Medical Service from January 2015 to December 2018 were reviewed. The mean PI value of each minute after ROSC was automatically provided by the device and the mean value of 30 min of monitoring (MPI30) was calculated. Pre-hospital data were collected according to the Utstein 2014 recommendations.
Results: Among 1,909 resuscitation attempts, ROSC was achieved in 346 and it was possible to calculate an MPI30 in 164. MPI30 was higher in the patients who survived at 30 days [1.6 (95% CI 1.2-2.1) vs 1 (95% CI 0.8-1.3), p = 0.0017]. At the multivariable Cox regression model, after correction for shockable rhythm, witnessed status, bystander CPR, age, and blood pressure, MPI30 was found to be an independent predictor of both 30-day mortality [RR 0.83 (95% CI 0.69-0.99), p = 0.036] and 30-day mortality or poor neurologic outcome [RR 0.85 (95% CI 0.72-0.99), p = 0.04]. Overall 30-day survival with good neurologic outcome was significantly different in the three tertiles [T1: 0.1-0.8; T2: 0.9-1.8 and T3: 1.82-7.8, log-rank p = 0.007].
Conclusion: The post-ROSC peripheral perfusion index was found to be an independent predictor of 30-day mortality or poor neurologic outcome. It could help prognostication in OHCA patients.
Keywords: Out-of-hospital cardiac arrest; Perfusion index; Prognostication.