The correlation of heart rate between natural sleep and dexmedetomidine sedation

• Published in: Korean journal of anesthesiology Vol. 72; no. 2; pp. 164 - 168
• Main Authors: Kang, Donghee, Lim, Changwoo, Shim, Dong-Jin, Kim, Huiyoung, Kim, Ji-Wook, Chung, Hyung-Joo, Shin, Yusom, Kim, Joo-Duck, Ryu, Sie Jeong
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society of Anesthesiologists 01.04.2019
• Subjects: Adult; Anesthesia, Spinal - adverse effects; Anesthesia, Spinal - methods; Bradycardia - chemically induced; Bradycardia - diagnosis; Bradycardia - physiopathology; Clinical; Consciousness Monitors; dexmedetomidine; Dexmedetomidine - administration & dosage; Dexmedetomidine - adverse effects; Elective Surgical Procedures - methods; Female; heart rate; Heart Rate - drug effects; Heart Rate - physiology; Humans; Hypnotics and Sedatives - administration & dosage; Hypnotics and Sedatives - adverse effects; Male; Middle Aged; sedatives; sleep; Sleep - drug effects; Sleep - physiology; spinal anesthesia; Heart rate; Sedatives; Sleep; Dexmedetomidine; Spinal anesthesia
• DOI: 10.4097/kja.d.18.00208
• ISSN: 2005-6419

Sedation by dexmedetomidine, like natural sleep, often causes bradycardia. We explored the nature of heart rate (HR) changes as they occur during natural sleep versus those occurring during dexmedetomidine sedation. The present study included 30 patients who were scheduled to undergo elective surgery with spinal anesthesia. To assess HR and sedation, a pulse oximeter and bispectral index (BIS) monitor were attached to the patient in the ward and the operating room. After measuring HR and BIS at baseline, as the patients slept and once their BIS was below 70, HR and BIS were measured at 5-minute intervals during sleep. Baseline HR and BIS were also recorded before spinal anesthesia measured at 5-minute intervals after dexmedetomidine injection. During natural sleep, HR changes ranged from 2 to 19 beats/min (13.4 ± 4.4 beats/min), while in dexmedetomidine sedation, HR ranged from 9 to 40 beats/min (25.4 ± 8.5 beats/min). Decrease in HR was significantly correlated between natural sleep and dexmedetomidine sedation (R2 = 0.41, P < 0.001). The lowest HR was reached in 66 min during natural sleep (59 beats/min) and in 13 min with dexmedetomidine sedation (55 beats/min). The time to reach minimum HR was significantly different (P < 0.001), but there was no difference in the lowest HR obtained (P = 0.09). There was a correlation between the change in HR during natural sleep and dexmedetomidine sedation. The bradycardia that occurs when using dexmedetomidine may be a normal physiologic change, that can be monitored rather than corrected.