A comparison of patient-controlled analgesia fentanyl and alfentanil for labour analgesia.
OBJECTIVE
To determine the analgesic efficacy of equipotent doses of PCA (patient-controlled analgesia) fentanyl and PCA alfentanil for labour pain.


METHODS
Twenty three, ASA I - II parturients between 32-42 wk gestational age in whom epidural analgesia was contraindicated were randomized to receive PCA fentanyl (Group F)or alfentanil (Group A). Plain numbered vials contained 21 ml fentanyl 50 microg x ml(-1) or alfentanil 500 microg x ml(-1). A one millilitre loading dose was administered. The PCA solution was prepared by diluting 10 ml study drug with 40 ml saline and the PCA pump was programmed to deliver a dose of 2 ml, delay of five minutes and a basal rate of 2 ml x hr(-1). Maternal measurements obtained were hourly drug dose, total dose, Visual Analog Pain Score (VAPS) q 30 min, sedation score q 1 hr and side effects. Neonates were assessed by 1,5, and 10-min Apgar scores, umbilical venous and arterial blood gases and neurobehavioural scores at four and 24 hr.


RESULTS
Mean VAPS from 7 - 10 cm cervical dilatation were higher in Group A than in Group F (85.7+/-13.9 vs. 64.6+/-12.1; P<0.01) There were no inter-group differences in VAPS from 1-3 cm, or from 4-6 cm dilatation, in maternal sedation scores or side effects, or in neonatal outcomes.


CONCLUSIONS
In the doses prescribed in this study, PCA fentanyl was found to provide more effective analgesia in late first stage labour than PCA alfentanil.
Morley-Forster
P K
PK
Department of Anaesthesia, St. Joseph's Health Centre, University of Western Ontario, Canada. pmorleyf@julian.uwo.ca
Reid
D W
DW
Vandeberghe
H
H
D000328:Adult; D015760:Alfentanil / Q000009:adverse effects / Q000627:therapeutic use*; D016362:Analgesia, Obstetrical; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D005260:Female; D005283:Fentanyl / Q000009:adverse effects / Q000627:therapeutic use*; D005333:Fetus / Q000187:drug effects; D006801:Humans; D011247:Pregnancy; D012119:Respiration / Q000187:drug effects
D000701:Analgesics, Opioid; D015760:Alfentanil; D005283:Fentanyl