I do surgeries on rats using isofluorane as anesthetic.
This is a gas that the rats breathe in, but because of poor ventilation, the
person doing the surgery in our lab also occasionally smells the isofluorane
(it has a very distinct smell). When I found out I was pregnant I wasn’t sure
if I should still be using isofluorane, so I asked google. Google told me:
“Pregnancy Category CIsoflurane has been shown to have a possible anesthetic-related fetotoxic effect in mice when given in doses 6 times the human dose. There are no adequate and well-controlled studies in pregnant women. Isoflurane should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.”
“Pregnant mice exposed to light doses of isoflurane were found to have an increased frequency of cleft palate, skeletal variations and fetal growth retardation (Mazze et al., 1985). At doses similar to those used in humans, other investigators have not observed teratogenic effects among the offspring of pregnant rats or rabbits treated repeatedly with isoflurane (Kennedy et al., 1977; Mazze et al., 1986). There are no epidemiological studies reporting congenital anomalies in children born to women exposed to isoflurane during pregnancy. Therefore, its risk in human pregnancy remains undetermined.”
Still, from this information
I found it very hard to make an informed decision. So I decided not to use
isofluorane but instead use injectable anesthesia for my surgeries. The
surgeries that I do are also performed under ketamine/xylazine anesthesia, so I
think that should be fine.
However, this whole search
for a risk assessment made me realize how hard it is do determine exactly how
dangerous something is for you. This is especially important when you’re
pregnant (or breastfeeding), but also just for your own health. A friend of
mine who also uses isofluorane had her PI tell her when she was pregnant that
it was okay for her to use this. I don’t know where the PI found this
information, or that ze just really wanted this post-doc to continue her work.
If you ask me, it would be
great if there was someone you could ask how dangerous the things are that you
encounter on a daily basis in the lab; someone who could tell you what to
change when you are pregnant. For radioactivity this is very well documented, but in the lab
you encounter so many things for which it is hard to determine the risk using
google and common sense. Does this information exist somewhere that I just don’t
know about? If not, this should be a thing!
When I was pregnant with Kiddo, I contacted EH&S to find out if there was anything I shouldn't be doing. You're in the US (for now), right? Your institution should have an EH&S department you can ask. And if they don't know something, I'm sure they can point you to the right direction. :)
ReplyDeleteThanks! That's what DrugMonkey said on twitter too and it made me feel kind of dumb that I never considered that. Didn't realize EH&S does more than making you take tests about whether to smoke next to your oxygen tank...
ReplyDeleteOops! I didn't see that. At the time, I didn't realize that EH&S did anything other than tie up our autoclave on Wednesday mornings, but my PI told me to contact them. They turned out to be (surprisingly) helpful.
DeleteWhere I work the isoflourane is not allowed for preggers. It's not completely elucidated how much levels etc so they just say no. EH&S are the ones to contact. also, ethydium bromide (if you use that) isn't great when pregnant either, and as you state radioactivity. There are some more aromatic chemicals that makes it more important to be in the hood when pipetting them etc (chloroform, phenol among other things).
ReplyDeleteI also recommend EH&S. When I moved to my new office (while pregnant), I wasn't sure if I should be concerned about a piece of equipment in the lab next to my office. I contacted our version of EH&S, and they were really helpful.
ReplyDeleteMaybe EH&S is useful to some extent, but in all truth the effects of most chemicals on developing fetuses is pretty much unknown and unstudied. When I was pregnant I tried to find info on the various pesticides that I was working (indirectly) with. Impossible to come to any conclusion, except to minimize exposure. Right now I work in a museum and you can smell the old toxic chemicals that were used for pest control; even though these chemicals are no longer actively used, they're still detectable. Hazardous? Hazardous for pregnancy? No one really knows. The lack of knowledge is pretty staggering.
ReplyDeleteYes that's true too! And also the fact that really early in your pregnancy is probably the most critical period for exposure to exogenous substances, but also the period where you don't necessarily want to share your pregnancy with everyone.
DeleteI switched labs in my 24th week to one where I need to do rodent surgeries/expts with isoflurane. I also found it hard to find out any decent information, and my OB/GYN was not particularly helpful. I only have to do the expts intermittantly, the lab is pretty well ventilated and I was well into my second trimester, so I have carried on doing them... fingers crossed the baby comes out okay in 5 weeks time :-/
ReplyDeleteOn a practical note about K/X: do you have any tips on how to maintain a level plane of anesthesia for a decent length of time?
From my googling, I think you're good if you're in your second trimester and with good ventilation.
DeleteWith K/X I'm not sure that you can as well as with isofluorane. Luckily my surgeries are only ~30 min so that should be fine, but for anything longer I think you almost have to use gas. (but I'm not an expert on this).
Thanks! And congrats on the pregnancy btw :-)
DeleteI've used isofluorane this whole time while preg, but always in the fume hood. I have been slightly worried that I could be exposed to it simply by getting it from residual amounts on or in the anesthetized mouse body (which I take out of the fume hood to the surgery bench), but I never smell it. (and I definitely know what it smells like.)
ReplyDeleteWhen I found out I was pregnant, i looked up anything i was using (MSDS) for the label 'teratogen' or 'reproductive harm'
It seems like following good basic lab safety procedures should keep you safe in pregnancy. My baby is due in 10 weeks, so I'm certainly hoping this is true.
As a libarian, this reminded me of LactMed, which looks at substances and lactation..not the same as substances and pregnancy, and I can't think of a database that does that. The closest is probably the Hazardous Substances Data Bank of TOXNET, which you probably already know about.
ReplyDeleteTheir info on this substance is at http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~xSvpCA:1
You can look up pretty much anything and see if there's any data on pregnancy risk. Again, you probably knew this, but...medical librarian, gotta plug my resources. :)
Congratulations and I hope things go well!
Thanks! I actually wasn't aware of this resource!
DeleteJeebus, this stuff isn't rocket science:
ReplyDeleteIF IT SMELLS, DO IT IN THE FUME HOOD !
Lab doesn't have a fume hood? Find another lab and/or sue the f*** out of the university.