Ischaemia-modified albumin predicts the outcome of cardiopulmonary resuscitation: An experimental study

Abstract

Introduction: Ischaemia-modified albumin (IMA) has recently been shown to be an early and sensitive marker of ischaemia. It is generally accepted that cardiac arrest causes the most severe form of global ischaemia. The aim of the present study was to identify whether IMA is an independent predictor of return of spontaneous circulation (ROSC) in a swine model of cardiac arrest.

Methods: Ventricular fibrillation (VF) was induced in 30 piglets, which were left untreated for 8 min before attempting resuscitation with precordial compression, mechanical ventilation and electrical defibrillation. Electrical defibrillation was attempted after 10 min of VF. Blood samples for IMA determination were drawn at baseline, after 8 min of VF and before delivery of each shock. A binary logistic regression model was implemented for the prediction of animals achieving ROSC from data available before the first defibrillation attempt. Backward stepwise selection was used to extract the final model. Inclusion and exclusion significance levels were 0.1 and 0.05, respectively. Receiver operating characteristic curves were used to determine the diagnostic accuracy, sensitivity and specificity of the parameters and to obtain the appropriate cut-off points.

Results: IMA exhibited 100% sensitivity and 93.8% specificity in defining the subgroup of animals that will achieve ROSC. This high-accuracy prediction had a very early onset (from eighth VF minute) and remained at the same level until the end of the experiment. When combining IMA and coronary perfusion pressure (CPP) measurements from the first CPR cycle in the form of the simple ratio IMA/CPP, a cut-off point of 7 could provide 100% sensitivity and specificity in distinguishing the animals that will achieve ROSC in the upcoming defibrillation attempts.

Conclusions: Until today, CPP has been found to be the only key determinant of successful resuscitation. Our study suggests that IMA can be a predictive index of ROSC even before the initiation of CPR.