Postoperative Delirium after Dexmedetomidine versus Propofol Sedation in Healthy Older Adults Undergoing Orthopedic Lower Limb Surgery with Spinal Anesthesia: A Randomized Controlled Trial
In healthy adult patients undergoing elective lower limb surgery with spinal anesthesia, sedation with dexmedetomidine will result in a lower rate of post-op delirium than propofol
Methods
RCT
Single center in South Korea
748 subjects
Randomized into dexmedetomidine and propfol sedation groups
Inclusion criteria
Age > 65
ASA I or II
Elective lower limb orthopedic surgery with spinal anesthesia and sedation
Exclusion criteria
Refusal of intraoperative sedation
Visual, cognitive, language or speech impairments
Neuropsychiatric diseaseÂ
Blinding
Subjects and evaluators for delirium blinded
Intraop anesthesiologist was not blinded to the study drug
Clinical protocol
No premedications
Spinal with 0.5% hyperbaric bupivicaine and 10-20 micrograms of fentanyl
Sedation
Titrated to mild-moderate level of sedation
Propfol delivered as a TCI
Dexmedetomidine titrated manually
Standardized protocol for hypotenstion and bradycardia
Delirium assessment
Subjects assessed for 3 post-op days using the confusion assessment method
Results
Delirium present in 24 (6.6%) of patients in propofol group vs. 11 (3.3%) in the dexmedetomidine group
Hemodynamics
Intraop
MAP slightly higher and HR slightly lower in the dexmedetomidine group
PACU
MAP and HR slightly lower in the dexmedetomidine group
Dexmedetomidine group required more vasopressor support
Strengths
Randomized controlled trial
Large # of subjects
Subjects and assessors blinded
No premedications given
Weaknesses
Not completely blinded
Industry sponsored
Didn't assess medications given in PACU
Only ASA I/II subjects
Questionable clinical significance of some results
Level of sedation titrated subjectively
Infusions titrated differently
Delirium subtype not recorded
Excluded patient with neuropsychiatric conditions
No data on other anti-delirum methods used
Key Point: The use of dexmedetomidine for sedation resulted in post-op delirium in fewer than one-half of subjects as compared to propofol.