Identificação de medicamentos e fatores de risco para prolongamento de intervalo QT em pacientes de unidade de terapia intensiva de um hospital de ensino.

Abstract

The heart muscle is considered a pump that promotes successive contractions that produces the heartbeat through transmission of action potentials. When the heart impulses pass through the heart propagates an electric current, in which a small part is transmitted to the body, may be recorded through the electrocardiogram (ECG), which generates electrical voltages, P, Q, R, S, and T waves. The measurement between the beginning of the QRS complex until the end of the T wave is known as the QT interval (iQT) and corresponding to the duration of the electrical activity of the ventricle. The iQT is of clinical importance because it causes several complications when prolonged, as Torsade de pointes (TdP) what is a rare ventricular arrhythmia identified on the ECG, and in more severe cases can cause sudden death. Medicinal products used alone or in combination may increase the risk of prolonging iQT and/or causing TdP and may be considered an undesirable effect. In the field of clinical pharmacy, it is considered the importance of clinical pharmacist on accompaniment of pharmacotherapy on critical users, in order to ensure its effectiveness and safety, through pharmaceutical interventions. Considering the importance of these changes in critical patients, the overall objective of this project is to identify the medications and risk factors for QT interval prolongation on patients in the intensive care unit of the teaching hospitaital. The study consisted of a descriptive study, with a cross - sectional design and a quantitative approach. Data collection was performed in a period of 30 days, based on the analysis of the prescriptions and medical records of the users (whose defined inclusion criteria were: being over 18 years and with a minimum stay of 48 hours) hospitalized in the ICU of a hospital in the municipality of João Pessoa-PB. The research involved a review of the literature on ICU medications that may interfere with iQT, in addition to monitoring for possible ECG changes in susceptible users undergoing treatment, following interaction analysis using Micromedex® software. A total of 21 users were entered into the study; of these, more than half (n = 14) used medications that could provoke iQT prolongation, with female users (n = 9) prevailing, which already corroborates as a risk factor. Considering the age group over 65 years, also a risk factor, 11 of the users were then elderly, female (n = 8) and male (n = 3). Several drug interactions with potential risks (n = 7) were identified, as well as the association of other risk factors. Of the users involved in the research, considering inclusion criteria, and post-ECG analysis, none developed IQT prolongation. Therefore it is concluded that medicinal products when used alone or in combination, may cause in an extended QT interval, in the presence or not of certain factors considered at risk, that despite the identification of both (drugs and other factors), was not observed in the users of the study.