Veterans Special Report

Clinical Trial – Effects of Dexmedetomidine Premedication on Geriatric Patients With Chronic Renal Failure Undergoing Hip Surgery

by | Apr 17, 2013 | Chronic Renal Failure, Clinical Trials, HBOT Research

Geriatric patients (age ≥ 65 years) undergo surgery for hip fractures that develops due to
osteoporosis and falls. Dialysis-dependent chronic kidney disease is associated with an
increased risk of cardiovascular comorbidity. Elective or urgent surgical operations may be
required for geriatric patients with end stage renal disease. These patients have severe
comorbidities, fluid, electrolyte disturbances and drug metabolism abnormalities during the
perioperative period. For this reasons a careful anesthesia plan should be planned and
performed. Spinal anesthesia can be used for hip fracture surgery at geriatric patients with
chronic renal failure. Anterograde femoral intramedullary nailing can be performed in supine
position with a fracture table. Intraoperative sedation might be necessary for patients under
regional anesthesia on traction table. Dexmedetomidine is an alpha 2 receptor agonist that is
being used as an agent for its sedative and adjuvant analgesic effects.

The aim of this study is to evaluate the effects of dexmedetomidine premedication on
geriatric patients with end stage renal disease, who will be undergoing a surgical operation
for hip fracture under spinal anesthesia with hyperbaric bupivacaine and BIS (Bispectral
Index) guided sedation with intraoperative propofol infusion.

Clinical Trial – Effective Dose of Dexmedetomidine for Sedation in Patients Undergoing TURP/TURB Under Spinal Anesthesia With or Without Fentanyl by Age Groups: Randomized Comparative Study

by | Jul 31, 2012 | Benign Prostate Hyperplasia, Clinical Trials, HBOT Research

Recently many studies reported that intraoperative dexmedetomidine administration undergoing
spinal anesthesia give a satisfactory sedation in elderly patients and cause less respiratory
depressions compared other sedatives(e.g. benzodiazepine) But the optimal dose of
dexmedetomidine for sedative effect in elderly patients undergoing spinal anesthesia was not
got general consensus.

The investigators hypothesized that the dose requirements would be lower than in elderly
patients than young patients. Furthermore, intrathecal small dose opioids enhance the
analgesia provided by bupivacaine due to synergistic effects and it would reduce the dose of
dexmedetomidine.

The purpose of this study was to determine the dose of dexmedetomidine to provide
satisfactory sedation undergoing spinal anesthesia with or without additive small dose
intrathecal opioids.

Elderly patients(65~85 years old) undergoing TURP or TURB were enrolled in this
single-blinded study. Forty patients were randomly assigned to receive intrathecal hyperbaric
bupivacaine 6mg coadministered with 20mcg fentanyl or placebo normal saline 0.4cc. After the
induction (bilateral T10 sensory level to pinprick within 5 mins of intrathecal drug
administration), continuous intravenous dexmedetomidine was started in dose of 0.8, 0.6, 0.5,
0.4, 0.3, or 0.2mcg. Successful sedation was defined as OASS score 3 or 4 within 20 minutes
of dexmedetomidine infusion. The dose of dexmedetomidine was selected for each patient
according to an up and down method. Intraoperative arterial pressure, heart rate, and
bispectral index was compared. Postoperative pain score, the time for the regression of
sensory and motor was recorded for further analysis.