Boxed Warning (Boxed Warning)
The text describes a warning not to use a 0.75% concentration of bupivacaine hydrochloride for obstetrical anesthesia due to reports of cardiac arrest and death among obstetrical patients. The use of this concentration has resulted in resuscitation difficulties even in cases where adequate preparation and management were taken. The cardiac arrests have occurred after systemic toxicity resulting from unintentional intravascular injection. The 0.75% concentration should only be used for surgical procedures that require a high degree of muscle relaxation and prolonged effect.*