THE EFFECTS OF SEDATIVE AGENTS USED IN INTENSIVE CARE UNIT ON QT INTERVAL

Abstract

Objective: The aim of this research is the effects of sedative drugs which are used on intensive care unit (ICU) patients on QT interval. Method: 90 patients who were hospitalized at ICU due to respiratory insufficiency and connected to mechanic ventilator were included. After the respiratory and cardiac monitorizations were enabled on patient with respiratory insufficiency in ICU, 12 derivations ECG's were recorded, systolic blood pressure (SBP), diastolic blood pressure(DBP), mean arterial blood pressure(MABP), heart rate(HR) and peripheric oxygen saturation (SpO2) values were recorded simultaneously. These values were used as base. At 1st and 12th hours of sedation (midazolam, propofol or dexmedetomidin), 12 derivations ECG's were recorded and again, SBP, DBP, MBP, HR and SpO2 values were recorded. ECG's were recorded at the speed of 25mm/s and at the height of 1 mV. Among the derivations in ECG recordings, the longest QT interval was measured by 2 anesthesiologists who don't know the groups and by measuring the RR interval on the same derivation, QTc (corrected QT) interval was measured with Bazzet formula. (QTc=QT intervali / √ RR interval) .Measured QT and QTc values were recorded. Results: When HR's at 12th hour were evaluated, HR at dexmedetomidin group was lower than both midazolam and propofol groups' HR and this was statistically significant (p<0,05). When MABP's at 12th hour were evaluated, MABP in propofol group was lower than dexmedetomidin group and this was statistically significant (p<0,05). When SpO2 values at 12th hour were evaluated, SpO2 values in midazolam group was significantly lower than the other 2 groups' SpO2 values. (p<0,05). For QT interval; dexmedetomidin prolonged the interval more than the other 2 agents both at 1st and 12th hours and this was statistically significant (p<0,05). There was statistically significant difference in QT intervals between propofol and midazolam groups at 12th hours (p<0,05). When QTc intervals were evaluated; only QTc values at 12th hour were different between different sedative agents and the QTc values in these groups belong to these different sedative agents were different each other and this was statistically different (p<0,05). Dexmedetomidin prolonged QTc mostly however propofol shows favorable efficacy by shortening the QTc interval. Conclusions: In our opinion, propofol is a good alternative sedative agent for dexmedetomidin and midazolam in patients with long QT interval because it shortens the QT interval however dexmedetomidin and midazolam can cause cardiac arrhythmia by prolonging QT interval. When making drug choice for sedation in ICU, patient's clinical situation, hemodynamic parameters and cardiac monitorization must be considered. (English) [ABSTRACT FROM AUTHOR]