Premium
Lack of analgesic effect of systemically administered morphine or pethidine on labour pain
Author(s) -
Olofsson Ch.,
Ekblom A.,
EkmanOrdeberg G.,
Hjelm A.,
Irestedt L.
Publication year - 1996
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.1996.tb09545.x
Subject(s) - pethidine , medicine , sedation , anesthesia , morphine , analgesic , visual analogue scale , sedative
Objective To evaluate the true analgesic effect of morphine and pethidine on labour pain. Design The analgesic and sedative effects of intravenous morphine or pethidine and their effect on anxiety were compared in a prospective, double‐blind, randomised dose‐response study. Setting A Stockholm teaching hospital obstetric unit. Participants Ten healthy nulliparous parturients in active labour were included in each group. Results Even after repeated doses (up to 0.15 mgkg body weight morphine and up to 15 mag body weight pethidine) the findings were uniform, with very high pain scores maintained in each group as assessed with visual analogue scale. The parturients were all significantly sedated and several fell asleep but were awakened by pain during contractions. Conclusion It is concluded that labour pain is not sensitive to systemically administered morphine or pethidine. These drugs only cause heavy sedation. It therefore seems unethical and medically incorrect to meet parturients' requests for pain relief by giving them sedation. Considering the well documented negative effects on newborn infants we also believe systemic pethidine should be avoided in labour.