Oxytocin at caesarean section – are we giving too much?
Article first published online: 10 DEC 2009
© 2009 The Authors Journal compilation © RCOG 2009 BJOG An International Journal of Obstetrics and Gynaecology
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 117, Issue 1, page 119, January 2010
How to Cite
Jonsson, M. (2010), Oxytocin at caesarean section – are we giving too much?. BJOG: An International Journal of Obstetrics & Gynaecology, 117: 119. doi: 10.1111/j.1471-0528.2009.02430.x
- Issue published online: 10 DEC 2009
- Article first published online: 10 DEC 2009
- Accepted 29 September 2009.
I thank Muhammad Ajmal1 for the valuable comments about the dose of oxytocin required and methods of administration at caesarean delivery.
Practice regarding doses and administration of oxytocin at caesarean section varies widely. In the literature, examples of a quick, single intravenous bolus of 5–10 iu oxytocin given over a few seconds can be found, as well as an infusion with diluted oxytocin given over a few hours. Others use a bolus plus a continuing infusion of oxytocin.
The risks of oxytocin, especially given by rapid injection, have been highlighted, and a slow, intravenous bolus dose of 5 iu of oxytocin following delivery of the infant at caesarean section is currently recommended by the National Institute for Clinical Excellence (NICE) in the UK.2 A more detailed definition of ‘slow’ is, however, not given in this guideline. It has been shown that when oxytocin is given at a slower rate, greater haemodynamic stability will result.3 Thomas et al.3 administered oxytocin either as an intravenous bolus of 5 iu diluted to 5 ml with normal saline, given as quickly as possible (1 s), or as 5 iu diluted to 15 ml with normal saline, given over 5 minutes using an infusion pump. The slower injection of oxytocin effectively minimised the cardiovascular side effects (hypotension and tachycardia) of a bolus without compromising the therapeutic benefits.
It is important for the reader to notice that the regimen in the studies where lower doses of oxytocin showed effectiveness was not that of a single intravenous bolus of oxytocin, but of a bolus followed by an oxytocin infusion.4 An additional oxytocin infusion at caesarean section may reduce blood loss, and while awaiting results of ongoing studies, giving too much oxytocin too quickly should be avoided.5
- 2National Collaborating Centre for Women’s and Children’s Health. Caesarean Section. Clinical Guideline. April 2004 National Collaborating Centre for Women’s and Children’s Health. London: RCOG Press, 2004.