Effect of dexmedetomidine on heart rates variability during induction of anesthesia in patients with hypertension

Objective To investigate effect of dexmedetomidine sedation anesthesia on perioperative hemodynamics and heart rate variability in patients with hypertension. Methods 50 cases with selective laparoscopic cholecystectomy were randomly divided into Group A（ dexmedetomidine sedation）and Group B （saline control） ,25 cases each group. Low-frequency （ LFnu ）, high-frequency （ HFnu ）, LF/HF, LFnu （ LF/TP × 100% ）, HFnu （ HF/TP × 100% ）and total-power（TP） were recorded at the time points of baseline （T0） ,immediately after administration（ T1 ）, immediately after anesthesia induction（ T2）, 1 min after anesthesia induction（ 33 ）, 5 rain after anesthesia induction （T4）and 10 min after anesthesia induction（T5 ）. NIBP and HR were recorded at the points of T0- T5. Results Compared with TO or Group A, there was an increase in SBP and HR at T2 - T4 （ P 〈 0.05 ） in Group B. Heart rate variability changes showed that Lfnu [ （66.3 ± 7.8 ）, （64.5 ± 6.0）, （65.3 ± 6.5 ） ], LF/HF [ （ 1.9 ± 0.7 ）, （ 1.7 ± 0.5 ）, （ 1.7 ± 0. 8 ） ], TP [ （2 283 ± 472）, （2 197 ± 310）, （2 108 ± 256） ] decreased significantly at T2-T4 （ tLFnu = 5.16,4.15,4.40, tLF/HF = 4.55,4.24,3.49, tTP = 3.27,1.71,0.96, P 〈 0.05 ） in Group A, while there was no significant change in Group A. Conclusion Dexmedetomidine sedation may have less influence on hemodynamics and automomic nerve,which be an useful analgesic adjuvanct for the patients undergoing selective laparoscopic cholecysteetom. Key words: Heart Rate, dexmedetomidine, hypertension;  Laparoscopy