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Local anesthetic agents are commonly used for obstetric anesthesia and analgesia. We determined the effects of bupivacaine, ropivacaine and mepivacaine on the contractility of isolated pregnant rat uterine muscle strips. Uterine specimens were obtained from 18- to 21-day pregnant Wistar rats (n = 28). Myometrial strips were obtained from the uterine horns after removing the fetuses and non-uterine tissue, incubated in organ baths and contractions stimulated with oxytocin. When contractions became regular, strips were exposed to increasing concentrations of the study drugs. Mepivacaine (n = 8), ropivacaine (n = 10) and bupivacaine (n = 10) were used at cumulative doses from 10(-8) to 10(-4) mol/L. Two of the local anesthetics, bupivacaine most, ropivacaine least, caused a dose-dependent inhibition of uterine contractility. In contrast, mepivacaine significantly increased uterine contractility. Bupivacaine, ropivacaine and mepivacaine were found to have no effect on frequency of uterine contractions. These results demonstrate that bupivacaine and ropivacaine may inhibit myometrium contractility.

A case is reported of acute intracranial subdural haematoma following accidental dural puncture during epidural anaesthesia. A 36-year-old primigravida with a gestation of 37 weeks and 3 days underwent caesarean section for which epidural anaesthesia was initially planned. An 18-gauge Tuohy needle was inserted into the L3-4 interspace but accidental dural puncture occurred. The needle was removed and general anaesthesia was initiated for surgery. On the second day post partum, the patient described a headache in both occipital area and neck that was relieved by lying down. On the seventh post-partum day she suffered tonic-clonic convulsions and underwent computerised tomography (CT). Despite different analgesic treatments and a normal CT, the patient suffered severe headaches in the following days. Magnetic resonance imaging revealed a 4-mm subdural hematoma in the right frontal area. The persisting headache decreased on day 12 and disappeared on day 14. The patient was discharged from hospital on day 15. The presence of post dural puncture headache complicated by atypical neurological deterioration following epidural anaesthesia should prompt the anaesthetist to consider the existence of intracranial complications and to seek immediate clinical and radiological diagnosis.