[Effect of the local anesthetic on visceral pain in cesarean sections done under intradural anesthesia].
OBJECTIVE
To evaluate the influence of local anesthetic on the incidence and severity of visceral pain during cesarean section performed under subarachnoid anesthesia.


METHODS
This was a randomized double blind study of 90 parturients undergoing scheduled or emergency cesareans. The women were distributed among three groups according to local anesthetic used: 2% isobaric mepivacaine in group 1, 0.5% hyperbaric bupivacaine in group 2, and 0.5% isobaric bupivacaine with adrenalin in group 3. The total anesthetic dose was selected based on height, and pain was defined as silent and dull, or a sensation of pressure that was poorly defined, diffuse or referred to another area and accompanied or not by nausea and/or vomiting. Pain was assessed on a visual analog scale at various moments during surgery. Other variables recorded were metameric level of blockade, hemodynamic function and presence of nausea and/or vomiting.


RESULTS
One patient in each group was excluded. The incidences of visceral pain and 95% confidence intervals were as follows: 38% (23-56%) in group 1 and 10% (3.5-25%) in groups 2 and 3 (p = 0.002). The metameric level of blockade differed significantly among the groups. The highest level (T1-5) was reached in group 1 but level was the most consistent (T3-5) in group 2. Systolic arterial pressures in all groups were significantly lower than baseline levels 5 min after puncture and the decrease was greatest in group 3. The highest incidence (p = 0.01) of nausea and/or vomiting occurred in the isobaric bupivacaine group.


CONCLUSIONS
Use of hyperbaric bupivacaine offers advantages over the other techniques, as it assures more consistent attainment of metameric level, an incidence of visceral pain that is lower than that of isobaric mepivacaine, and fewer hemodynamic repercussions than isobaric bupivacaine with vasoconstrictor.
Echevarría
M
M
Servicio de Anestesiología y Reanimación, Hospital Universitario Virgen de Valme, Sevilla.
Caba
F
F
Bernal
L
L
Pallarés
J A
JA
Rodríguez
R
R
D000328:Adult; D000773:Anesthesia, Obstetrical; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000494:pharmacology; D002045:Bupivacaine / Q000008:administration & dosage / Q000494:pharmacology; D002585:Cesarean Section; D004311:Double-Blind Method; D004837:Epinephrine / Q000008:administration & dosage / Q000494:pharmacology; D005260:Female; D006801:Humans; D008619:Mepivacaine / Q000008:administration & dosage / Q000494:pharmacology; D009325:Nausea / Q000209:etiology / Q000517:prevention & control; D010146:Pain / Q000517:prevention & control*; D010147:Pain Measurement; D011247:Pregnancy; D011312:Pressure; D013346:Subarachnoid Space; D016896:Treatment Outcome; D014781:Viscera / Q000294:innervation; D017833:Visceral Afferents / Q000187:drug effects*; D014839:Vomiting / Q000209:etiology / Q000517:prevention & control
D000779:Anesthetics, Local; D008619:Mepivacaine; D002045:Bupivacaine; D004837:Epinephrine