Effect of lumbar flexion on the extent of epidural blockade.
OBJECTIVE
This study examined the effect of lumbar flexion on the extent of the epidural block during lumbar epidural anesthesia.


METHODS
The epidural catheter was introduced at the L3-4 interspace with the patient in the lateral decubitus position with the surgical side down. After administering a test drug (3 mL of 2% lidocaine and 15 mug of epinephrine), the patients were randomly allocated to 1 of 2 groups: Group F (n = 16, lumbar spine flexed) and Group N (n = 17, lumbar spine in the neutral position). In both groups, 2% lidocaine (16 mL) mixed with sodium bicarbonate (2 mL) was administered through the epidural catheter while the patient maintained the lateral decubitus position with the lumbar spine either flexed or in the neutral position. All the patients maintained their respective positions for 5 minutes and were subsequently turned to the supine position. The pinprick block level and the degree of motor blockade were assessed every 10 minutes for 60 minutes after administering the local anesthetics. A 2-dermatomal difference in uppermost block between groups was determined to be clinically significant.


RESULTS
The median difference between groups in the uppermost pinprick block level was only 1.5 dermatomes and it did not satisfy our criteria for clinical significance. There were no significant differences between the 2 groups in the lowermost pinprick block level and the degree of motor block.


CONCLUSIONS
Lumbar flexion has no clinically relevant effect on sensory spread during epidural anesthesia.
Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Korea.
Jin-Tae
JT
Kim
Jong-Hwan
JH
Lee
Seung-Zhoo
SZ
Yoon
Young-Jin
YJ
Lim
Jae-Hyon
JH
Bahk
Chong-Sung
CS
Kim
Yunseok
Y
Jeon
D000328:Adult; D000767:Anesthesia, Epidural; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001182:Arthroscopy; D001794:Blood Pressure / Q000187:drug effects; D004562:Electrocardiography / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007717:Knee / Q000601:surgery; D008297:Male; D020393:Manipulation, Spinal; D009407:Nerve Block; D010092:Oximetry; D010147:Pain Measurement / Q000187:drug effects
D000779:Anesthetics, Local