Explosive effects

Cesarean section is meant to spare the breech neonate from the trauma of a stuck head but the breech baby's last and most important part to emerge is still prone to entrapment by the uterus.
Glyceryl trinitrate seems to be the drug of choice of most authors, including this one. Don't bother asking an OB for the dose size though.

The use of GTN dose in this situation does not have a strong evidence base. Prophylactic use in RCTs of routine cephalic elective cesarean sections does not seem to benefit, but published retrospectives trumpet the success of GTN in easing out trapped fetuses and placentas. 200ug seems to be the dose that reliably relaxes the uterus without a high incidence of maternal hypotension. So prophylaxis is probably unnecessary but it is prudent to have it ready to hand in cases of breech, multiples and retained placenta.

The other issue is how to actualy administer this potent drug. It comes in a 50 mg ampoule. Some centres have a published guideline on how to dilute and administer; one guideline advises dilution into a 1000ml bag. Steps of dilution take time, and often when seconds seem extremely precious, so I just draw 0.2 ml neat in a 1 ml syringe and give it directly into the running IV infusion. Give it 45 seconds to work, and give further 100 ug boluses every further 30 seconds until the recalcitrant item has been delivered. Fortunately its rapid offset does not seem to increase the risk of atony.

Oh, and watch out for it on your fingers: it can be another cause of anaesthetist's headache.