Investigating anaesthesia for c-sections in obese mothers

Fiona Denison, Julia Critchley, Naz Lone, Arlene Wise

C-sections for obese mothers can be more complicated and take longer than expected. This can make it difficult to predict what type of anaesthetic should be used – particularly in emergencies. Our researchers are gathering data to help doctors pick the best type of anaesthesia to keep both mother and baby safe.

Start: 2019

End: 2022

Why do we need this research?

During a caesarean section, the mother needs anaesthesia to avoid pain. There are lots of different ways that anaesthesia can be given. These include general anaesthesia, where she is fully unconscious, or a regional anaesthetic such as an epidural or spinal injection, where only one part of the body is numbed.

Using general anaesthesia during a caesarean section can be risky for both mother and baby, so anaesthetists would prefer to not use it. However, for obese women, caesarean sections can be more complicated and take longer than expected. This can mean that women might end up having a general anaesthetic if their spinal or epidural anaesthetic wears off. Also, in emergencies, general anaesthesia may be the only option, as it tends to act quicker.

Right now, we don’t know for certain what the best type of anaesthetic is for obese mothers having a caesarean section. This can potentially mean that mothers receive anaesthetic that isn’t appropriate for them, which could cause problems for them and their baby.

What’s happening in this project?

In this study, researchers funded by Tommy’s have gathered data on thousands of caesarean section surgeries taking place in and around Edinburgh between 2011 and 2015. For each one, the team have collected data on the age and obesity of the mother, how long the surgery took, what kind of anaesthetic was used, and whether it was an emergency operation or not.

So far, the team have confirmed that for women who are obese (particularly if they are very obese), the time taken to give anaesthesia and for surgery increases significantly, compared to women with a normal weight. They have also found that in emergency caesarean sections, giving a ‘top-up’ epidural anaesthetic during surgery is almost as fast as a general anaesthetic. This is important, as it suggests that mothers could opt for the safer epidural anaesthetic instead of a general anaesthetic.  

The team are now analysing the data to reveal any further findings which could be useful for anaesthetists. 

What difference will this project make?

The findings from this project will help healthcare teams make better decisions about what kind of anaesthesia is best for each mother having a caesarean section. This will help to reduce the risks of surgery for both mother and baby, particularly in emergency situations.

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