Predictive value of heart rate variability in critically ill patients in ICU

Abstract

The human body presents itself as a model system with nonlinear behavior, ie, presents varying patterns that do not follow the logic of the classical mechanistic approach. This dynamic, nonlinear, can be measured by a variety of approaches, the most widespread and reliable, at present, has the heart rate variability (HRV). It is known for hours that morbid states alter the balance of the autonomic nervous system resulting in a significant decrease in HRV. This is due to a chronic increase in sympathetic activity and a considerable decrease of the parasympathetic component. The HRV indices are obtained by analyzing the intervals between normal R waves (RR interval) being captured and recorded by various devices, the Polar ® frequency meter (S810i models or RS800) is shown by analyzing the variable cost and practicality, the most accessible.The Intensive Care Units are undoubtedly places where these states are exacerbated morbidity. The high maintenance costs, the chronicity of patients coupled with high mortality rates, and the existence of a model of death institutionalized, taking terminally ill patients to the ICU, generate the construction of indices and protocols aimed at helping practices performed in that environment; APACHE and UNICAMP II are the most used by the medical community. The analysis of HRV in patients admitted to the Intensive Care, therefore, aims to build Parameters that, combined with existing, are effective and can add verisimilitude to the protocols. His nonlinear parameter becomes essential complementarity of the current rates, it does not fail for an hour to reach this bias. (AU)