RT Journal Article
SR Electronic
T1 Free Lidocaine Concentrations During Continuous Epidural Anesthesia in Geriatric Patients
JF Regional Anesthesia & Pain Medicine
JO Reg Anesth Pain Med
FD BMJ Publishing Group Ltd
SP 215
OP 220
DO 10.1053/rapm.2003.50131
VO 28
IS 3
A1 Taeko Fukuda
A1 Yoshihiro Kakiuchi
A1 Masayuki Miyabe
A1 Shinichi Kihara
A1 Yukinao Kohda
A1 Hidenori Toyooka
YR 2003
UL http://rapm.bmj.com/content/28/3/215.abstract
AB Background and Objectives To evaluate the effects of aging on lidocaine pharmacokinetics, the plasma concentrations of total and free lidocaine and its metabolites were measured during continuous thoracic epidural anesthesia in middle-aged (age 41 ± 9 years, n = 7) and elderly (age 72 ± 2 years, n = 7) male patients.Methods After establishment of general anesthesia, 7 mL 1.5% lidocaine with epinephrine 1:200,000 was injected into the epidural space and subsequently infused at a rate of 5 mL/h for 5 hours. Plasma concentrations of total and free lidocaine, monoethylglycinexylidide (MEGX), and glycinexylidide (GX) were measured at 10, 15, 20, 30, 45, 60, 90, 120, 150, 180, 240, and 300 minutes after initial lidocaine injection using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection.Results The elderly group showed a stronger upward trend in the corrected free lidocaine concentrations and lower corrected total MEGX concentrations than the middle-aged group.Conclusions Lidocaine metabolite activity in the elderly male patients was lower than that in the middle-aged male patients. Free lidocaine concentration is prone to increase in elderly patients. Caution must be exercised during continuous thoracic epidural anesthesia combined with general anesthesia in geriatric patients.