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.