Sedation prior to electrical cardioversion
Most drugs used for analgesia and sedation are capable of getting into
the umbilical venous blood and fetal circulation. Thus, the potential
adverse effects of an agent on the fetus must be considered when
selecting a medication. For analgesia, any opioid is acceptable since
they are not considered to be human teratogens. Sedation is required to
tolerate electrical cardioversion. Midazolam is theoretically superior
to lorazepam based on the observation of teratogenic effects in animal
studies. However, the clinical importance of these findings is unclear.
Propofol crosses the placenta and may be associated with neonatal
respiratory depression. Data on the clinical use of propofol in pregnant
critically ill patients is limited to case reports, so its use should be
limited until more prospective data is available. The limited available
human data suggest that ketamine may be used in low doses throughout
pregnancy, but other agents may be preferable.