Three per cent 2-chloroprocaine for caesarean section: appraisal of a standardized dose technique

We evaluated 2-chloroprocaine, three per cent, in 44 women having epidural anaesthesia for Caesarean section. All subjects received a minimum dose of 25 ml (750 mg) in increments designed to allow early recognition of accidental subarachnoid or intravascular injection. Further increments were given as needed to achieve a T5 sensory level or higher. We recorded pulse and blood pressure at two-minute intervals and used a simple pain scale to assess analgesia. Ninety-three per cent of subjects had acceptable analgesia. Seventeen mothers required more than 25 ml to attain a T5 level; subjects having a BMI (body mass index) equal to or greater than 35, or over 35 years of age, demonstrated more cephalad spread. Hypotension (MAP 80 per cent of control or less) occurred in 24, mothers (54 per cent), often transiently, but an infused fluid volume exceeding 30 ml X kg-1 at delivery significantly reduced post-delivery hypotension. Nausea and vomiting accompanied the hypotension in 12 mothers. No neonatal depression occurred. We conclude the incremental administration of chloroprocaine, as described, permits safe administration of the drug, with excellent analgesia in most parturients.