This article contains posts and extracts from the UK Midwives and Consumers email list, a discussion group for people interested in midwifery in the UK. Open to midwives, students, mothers, and anyone interested in improving maternity services in UK. Posts in these archives express the views of the individual authors, and not those of the Association of Radical Midwives. Unless otherwise stated, the comments are personal experiences rather than evidence-based research.

Cannulas in Labour

I am a student midwife and in the hospital in which I am training the use of a grey cannula is standard written in stone practice for all women. I would like to know if anything different is used in other hospitals or alternatively if there is any research that supports the use of such a large bore cannula. It is my belief from that it is not necessary to use these they are painful and restrict the mobility of the woman. I have also seen smaller cannula used in my practice as a haematology nurse effectively for patients with life threatening bleeding problems


I do not have specific research in this area, but witnessed that in a haematological crisis, blood related products do not transfuse fast enough through a smaller bore.

To add a thought, do you use a local analgesia (sc lignocaine or topical product such as Emla) to numb before an insertion of a grey needle? And what about siting that does not restrict movement ie., in the back of the hand, which incidently impedes the flow by position of the hand?


At the hospital I train at we also use the grey cannula. I was told it was because it was the largest size and therefore the quickest way to get blood/fluids into a woman if need be. But do you mean that ALL women get one put in? Regardless of their perceived risk? My hopital could not really be called progressive but most women don’t have these things unless they are deemed to be high risk.


I do hope I have misunderstood – are you saying that ALL women have a cannula inserted? If so, I think this should be debated at a very high level, and soon!


I questioned the ‘routine’ use of such cannula at my own hospital, and was told that it was decided by the aneasthetic consultant as the potential for extensive blood loss in childbirth is real. But my clinical manager (midwife) agreed that for ‘low risk’ women, for example, having epidurals for pain relief it would probably not be a problem.

Test the system – I have since on occasion, used smaller cannula.


This sounds like the American way of birth. Let’s just anticipate every disaster and inflict as many contraptions onto the body of a laboring woman as possible. In America, there is the continuous fetal heart and contraction monitor, preferably internal, a continuous BP cuff that is run by a machine, an IVI as she is allowed nil by mouth. She may also have a pulse/O2 monitor attached to her as well. Did you know that these machines are all monitored by a nurse at the nurse’s station and she can monitor multiple women in labor this way. How efficient, wouldn’t you say? Don’t we all strive for efficiency in labor care? And of course she will need to LIE DOWN so all the machines can run efficiently, so guess what? She will soon be asking for another device to be attached to her, called an epidural cannula.

Which may be a good thing as she will probably have between 10-15 internal exams in the course of her labor. (No, I am not kidding or even exaggerating.) No doctor can ever believe what a mere obstetric nurse thought she felt and no senior doctor can believe what a more junior doctor thought they felt, and hey, it was at least 15 minutes ago that she was examined, so let’s all do it again.

And then for second stage, she gets to put her legs in stirrups and push up hill, but it’s REALLY necessary for the doctor to have a good view and not have to bend over when she/he comes rushing back just as the head is crowning.

So as bad as things may look to you in the UK, please keep in mind that you aren’t in America, where it really is a whole lot worse.


I work at a university hospital in Sweden. We have all the high risk patients from our region. We do not use cannula as a standard procedure for women giving birth. I, and most of my colleauges, would use it if we have a high risk patient. A women with a previous ceasarian and an epidural anesthesia is high risk – but she would have the cannula any way, wouldn´t she? Also a women with severe preeclampsia or with a serious IUGR would be a candidate. In short any woman where you think there might be a great risk of an emergency cesarian. But just to feel safe – who is the most important person who should feel safe and able? If you get into trouble, getting a cannula in place is the minor problem unless you are all by yourself.

As for the size of the cannula – in Sweden we are taught that a good flow is the main concern you should have. A thin cannula in a good vein will give you the best flow. We as a standard use the pink ones, that is 1,00 I think. I have never found that to be a problem. With a patient in shock you will allways try to get two or more cannulas anyway.

How often do you give blood or blood products? With all the new forms of hepatitis we almost never give blood at the labour ward. We check the womans Hb and that should be very low before the woman wants blood or the doctor wishes to ordinate it.At an operation, with a blood loss around 2500 – 3000 ml of course, but how often does that happen? What we seem to forget is that there also is a risk with the cannula “for safety” and that is that many women get a thromboflebitis from them.

Summing up – as a student you will do a lot of stuff that you know is not right, but just standard procedure at that hospital. You can always ask what support they have for their practice in an innocent way, but better safe than sorry – abide your time. With good information about the things that concern you, you can allways try to improve for your patients later on. Good luck!


AH updated 27 March 2000


Submit a Comment

Your email address will not be published. Required fields are marked *

Pin It on Pinterest

Share This