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.
Muñoz
H R
HR
Departamento de Anestesiología, Hospital Clínico, Universidad Católica de Chile, Santiago.
Dagnino
J A
JA
Allende
M
M
Bugedo
G J
GJ
Montes
J M
JM
Cherres
O G
OG
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