[The effect of nitroglycerin 200 microg on uterine relaxation during cesarean delivery].

BACKGROUND

Rapid and transient uterine relaxation is sometimes required for fetal distress or difficult delivery due to uterine hyperactivity during cesarean section. For its rapid onset and short duration, intravenous nitroglycerin (NTG) is commonly used for this purpose. But its suitable dose is unclear.

METHODS

We evaluated the effect of NTG 200 microg on uterine relaxation in 14 parturients who required rapid uterine relaxation during cesarean delivery from October 2010 to March 2011. We assessed the softness of the uterus, maternal hemodynamic changes after NTG administration, blood loss, uterine contraction after delivery, and Apgar scores.

RESULTS

Obstetricians graded the uterus as "moderately soft" in 9, and "very soft" in 5 patients, respectively. Uterine contraction after delivery was good with intravenous oxytocin or dinoprost. Blood loss was acceptable. Six patients exhibited moderate but transient hypotension, and in two of which blood pressure was immediately restored with phenylephrine 100 microg. Four patients complained of nausea and 1 patient complained of headache, but all of which were transient. Median Apgar scores at 1 and 5 minutes were 8.0 and 8.5, respectively.

CONCLUSIONS

This study indicated that an intravenous administration of NTG 200 microg was effective for rapid uterine relaxation during cesarean delivery.