Direction of catheter insertion and incidence of paresthesias and failure rate in continuous epidural anesthesia: a comparison of cephalad and caudad catheter insertion.
OBJECTIVE
Paresthesias and unblocked segments during continuous epidural anesthesia--sometimes leading to higher doses of local anesthetics--can increase the risk of this technique. A cephalad insertion of the epidural catheter might decrease the incidence of these problems, but this has not been evaluated before in a controlled study.


METHODS
In a prospective, double-blind, randomized study, we compared the incidence of paresthesias during catheter insertion and the failure rate of continuous epidural anesthesia in two groups of obstetric patients. In group 1 (n = 52), the Tuohy needle bevel was directed cephalad during catheter insertion. In group 2 (n = 53), it was directed caudad. The catheter was introduced 4-5 cm into the epidural space, and bupivacaine 25 mg plus fentanyl 50 micrograms were administered through it.


RESULTS
Twenty percent of the patients in group 1 had paresthesias versus 40% in group 2 (p = 0.0249; 95% confidence interval of the difference 1-40%); intensity of paresthesias was greater in group 2. Pain relief was complete in 75% and 80% of the patients in groups 1 and 2, respectively (NS); three patients in group 1 and one in group 2 had unblocked segments (NS).


CONCLUSIONS
Our results support the contention that the catheter should be directed cephalad during insertion for continuous epidural anesthesia.
Departamento de Anestesiología, Hospital Clínico, Universidad Católica de Chile, Santiago.
H R
HR
Muñoz
J A
JA
Dagnino
M
M
Allende
G J
GJ
Bugedo
J M
JM
Montes
O G
OG
Cherres
D000328:Adult; D000767:Anesthesia, Epidural; D000773:Anesthesia, Obstetrical; D002404:Catheterization / Q000379:methods*; D002408:Catheters, Indwelling; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D015994:Incidence; D007743:Labor, Obstetric; D010292:Paresthesia / Q000453:epidemiology / Q000209:etiology*; D011247:Pregnancy; D011446:Prospective Studies