Drug-Induced QTc-Interval Prolongation in the Intensive Care Unit: Incidence and Predictors

Abstract

There is a paucity of information regarding QTc prolongation in critically ill patients. A prospective observational study was conducted to assess the incidence and predictors of QTc prolongation associated with medications in intensive care unit (ICU) patients. Consecutive adult patients prescribed prespecified QTc-prolonging medications were assessed for development of the combined incidence of QTc >500 ms at anytime and QTc increase >60 ms above baseline. Over 3 months, 200 consecutive patients (63 ± 18 years; 52% female; 73% Caucasian; baseline QTc 447.3 ± 51.5 ms) were evaluated. The primary end point occurred in 48% of the patients (QTc >500 ms 40%, QTc increase >60 ms 29%). The majority of patients experienced a QTc >470 or 450 ms (60.5%). Mean increase in QTc at 48 hours was 20 ± 35 ms. Upon multivariate analysis, length of stay [odds ratio 1.30, 95% confidence interval (1.15, 1.47)] and baseline QTc [1.01 (1.01, 1.02)] were associated with an increased risk for the primary end point, while beta-blockers [0.41 (0.20, 0.81)] were associated with a risk reduction. In conclusion, increased risk of proarrhythmia, as assessed by QTc prolongation, occurs in the majority of ICU patients when prescribed medications with electrophysiologic properties. Increased vigilance is warranted. The possible protective effect of beta-blockers requires confirmation.

Provider Response to QTc Prolongation on Standard 12‐Lead EKG: Do We Notice or Do We Care?

“…Thus, it is most likely that the QTc was overlooked or ignored. This maybe particularly dangerous during admissions for acute illnesses and particularly in intensive care settings where there are frequent transitions of care and rapidly changing clinical conditions . Our findings are particularly resonant with those of Tisdale et al .…”

“…Our report corroborates previous studies that medications known to prolong QTc are commonly administered in combination. This is particularly true among inpatients in the acute inpatient setting . Inpatients not infrequently received two or more medications known to prolong QTc.…”

“…This is particularly true among inpatients in the acute inpatient setting. 9 Inpatients not infrequently received two or more medications known to prolong QTc. In our review, these patients were frequently admitted to units with cardiac monitoring capability reflecting their degree of illness.…”

QTc prolongation during erythromycin used as prokinetic agent in ICU patients

“…Other studies in ICU populations found prolongation of QTc above 500 ms in 13%–40% of patients, partially caused by medication 7 11 12. Prolongation of QTc in ICU is associated with longer lengths of hospitalisation and increased mortality 13.…”

Drug-Induced Cardiovascular Adverse Events in the Intensive Care Unit

“…21,22 Corrected QT (QTc) prolongation is defined as a QTc interval more than 440 milliseconds in men and 460 milliseconds in women, with the risk of arrhythmias increasing when values are 500 milliseconds or more. 21,22 Corrected QT (QTc) prolongation is defined as a QTc interval more than 440 milliseconds in men and 460 milliseconds in women, with the risk of arrhythmias increasing when values are 500 milliseconds or more.…”