The NACA score as a predictor of ventricular cardiac arrhythmias - A retrospective six-year study

Abstract

Background: Helicopter Emergency Medical Service (HEMS) conducts the evaluation of a patient's condition using NACA score before transporting the patient to hospital. The conditions inside the rescue helicopter limit or even make it impossible to conduct some medical procedures. An appropriate classification of the patient may lead to a lower possibility of occurrence of adverse events during the flight. The aim of the research was to evaluate the correlation of NACA score with the cardiac arrhythmia that may be life threatening.

Methods: A retrospective observational study included a group of 47,131 patients, who were transported by HEMS services between 2012 and 2017. The research was conducted using the analysis of variance ANOVA running a post hoc test. In order to calculate the correlation of variables, Kruskal-Wallis and r-Pearson tests were carried out, interpreting the results according to J. Gilville's scale. The significance level was set at α = 0,05.

Results: The average number of points using NACA score for the studied group was 4,06 (SD ± 1,38). Twelve heart rhythms were selected while evaluating correlations using NACA score. There was a significant relation between the ECG variable and NACA score (p = 0,003). There was a very strong correlation between NACA score and the following: VF/pVT (r-Pearson = 0,856; p = 0,006), PEA (r-Pearson = 0,810; p = 0,015) and Asystole (r-Pearson = 0,728; p = 0,026).

Conclusions: NACA score allows to predict the risk of occurrence of ventricular arrhythmia of the myocardium as well as cardiac arrest. The possibility of occurrence of a life-threatening rhythm is significantly higher in patients classified as NACA IV or higher.

Keywords: Arrhythmia; Cardiovascular risk factors; Emergency medicine; Transport - emergency.