Effects of Dexmedetomidine on Changes in Heart Rate Variability and Hemodynamics During Tracheal Intubation.
Sympathetic hyperactivation during tracheal intubation prolongs the QT interval and increases the risk of arrhythmias. We investigated if dexmedetomidine pretreatment affected autonomic nervous system balance and QT intervals during intubation. Sixty-six patients were randomized to receive 1.0 μg/kg fentanyl (group F, n = 22), 0.5 μg/kg dexmedetomidine (group D0.5, n = 22), or 1.0 μg/kg dexmedetomidine (group D1.0, n = 22) before induction. Autonomic nervous system balance was assessed by the ratio of low-frequency/high-frequency (LF/HF) power for heart rate variability at baseline (T0), before intubation (T1), and after intubation (T2). QT intervals were corrected by the Bazett's formula (QTc) and compared at baseline, before intubation, and 1, 2, and 3 minutes after intubation. The LF/HF ratio was higher after intubation compared with that at T0 in group F (P < 0.001). There were no significant changes in groups D0.5 and D1.0. The LF/HF ratio was significantly higher in group F compared with those in groups D0.5 and D1.0 after intubation (7.9 vs. 2.1 and 2.5; P < 0.001). The heart rate was increased for 3 minutes after intubation in group F, whereas only for 1 minute after intubation in groups D0.5 and D1.0, compared with that at baseline. More patients in group F had QTc greater than 440 ms compared with that in group D0.5 or D1.0 (8 vs. 1 and 2; P = 0.005) at 1 minute after intubation. In contrast to 1.0 μg/kg fentanyl, pretreatment with 0.5 or 1.0 μg/kg dexmedetomidine suppressed sympathetic hyperactivity and attenuated QTc prolongation during intubation.
Departments of 1Anesthesiology and Pain Medicine and 2Cardiology, Yonsei University College of Medicine, Seoul, Republic of Korea; and 3Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
Jin Sun
JS
Cho
Shin Hyung
SH
Kim
Seokyung
S
Shin
Hui-Nam
HN
Pak
Shi Joon
SJ
Yang
Young Jun
YJ
Oh
D058647:Adrenergic alpha-2 Receptor Agonists / Q000494:pharmacology*; D000328:Adult; D020927:Dexmedetomidine / Q000494:pharmacology*; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D013564:Sympathetic Nervous System / Q000502:physiology
D058647:Adrenergic alpha-2 Receptor Agonists; D020927:Dexmedetomidine