Is there a need for chloroprocaine 3% and bupivacaine 0.75%?

Bupivacaine and chloroprocaine have proven to be valuable local anesthetics for a variety of surgical and obstetrical situations. Bupivacaine is particularly useful as a long acting agent which provides excellent sensory analgesia particularly during labor with minimal blockade of motor fibers. The 0.75% solution is useful for epidural surgical anesthesia since it does result in a decrease in onset time and a more marked motor blockade. In recent years, this agent has been reported to cause rapid cardiovascular collapse in some patients. Cardiotoxicity associated with bupivacaine is related not to the concentration employed but to the total dosage administered as a rapid intravenous injection. The careful administration of this agents to avoid an accidental intravenous injection should not preclude the use of 0.75% bupivacaine for epidural anesthesia in surgical patients. This concentration is not recommended in obstetrical cases. Chloroprocaine is valuable as a rapid onset, short duration local anesthetic with a low potential for systemic toxicity. The 3% solution is particularly useful for providing a rapid onset of action. In recent years, localized neural irritation has occurred in some patients in whom large amounts of this agent were administered epidurally or intrathecally. The local neural toxicity of chloroprocaine solutions is referably to the low pH and the inclusion of sodium bisulfite in these particular solutions. The toxicity of chloroprocaine solutions is related to total dosage rather than the concentration of solution employed. Careful administration of chloroprocaine epidurally in order to avoid accidental subarachnoid injection should preclude the possibility of local neural toxicity.