What determines the analgesic effect of paracervical block?
BACKGROUND
The objective of the study was to evaluate the analgesic effect of paracervical block (PCB) in labor pain relief and to discover the determinants associated with good analgesia.


METHODS
In a prospective trial, 341 women received PCB for pain relief in the first stage of labor, with 10 ml of 0.25% levobupivacaine or racemic bupivacaine. All these pregnancies were uncomplicated and the progress of labor was normal. The analgesic effect of PCB was measured by using a visual analog scale (VAS). The factors associated with good pain relief (>50% decrease in the VAS score within 30 min) were analyzed statistically by Student's t-test or the Mann-Whitney test (continuous variables), Fisher's exact test (categorial variables) and after univariate analysis by logistic regression analysis. For pairwise comparisons, Wilcoxon's signed ranks test was used.


RESULTS
Good pain relief was achieved in 47.2% of the cases. 12.3% of the parturients needed subsequent epidural or spinal analgesia. In logistic regression analysis, primiparity, a high pain score before PCB, and PCB given by a specialized obstetrician were found to affect the level of pain relief 30 min after PCB.


CONCLUSIONS
The best pain relief after PCB was achieved among primiparas. Good pain relief was connected with a high pain score before PCB and an experienced obstetrician.
Palomäki
Outi
O
Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland. outi.palomaki@pshp.fi
Huhtala
Heini
H
Kirkinen
Pertti
P
D000293:Adolescent; D000328:Adult; D000773:Anesthesia, Obstetrical; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D002045:Bupivacaine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use*; D015148:Cardiotocography; D005260:Female; D006801:Humans; D048949:Labor Pain; D007747:Labor Stage, First; D000077554:Levobupivacaine; D010147:Pain Measurement; D011247:Pregnancy; D011446:Prospective Studies; D013237:Stereoisomerism; D016896:Treatment Outcome
D000779:Anesthetics, Local; D000077554:Levobupivacaine; D002045:Bupivacaine