Comparison of two different doses of lignocaine used in paracervical block during oocyte collection in an IVF programme

We have recently demonstrated the efficacy of paracervical block (PCB) used in conjunction with conscious sedation during egg collection. The dosage of lignocaine used in various studies ranges from 50 mg to 200 mg, There are, however, no studies evaluating the efficacy of different doses of local anaesthetic agents used in PCB, In this prospective, double-blind and placebo-controlled study, 150 women undergoing egg collection in their first IVF cycle were randomized to receive 200 mg and 150 mg lignocaine in PCB, No differences were seen in the demographic data, the ovarian responses, the duration of egg collection and the number of follicles punctured. The fertilization, implantation and pregnancy rates were similar when either 150 mg or 200 mg lignocaine was employed. The median pain levels during vaginal punctures were 14.0 (2.5th-97.5th centiles: 0-75.4) and 14.0 (2.5th-97.5th centiles: 0-86.5) in patients receiving 200 mg and 150 mg lignocaine respectively, whereas the corresponding median abdominal pain levels were 14.0 (2.5th-97.5th centiles: 0-85.6) and 14.0 (2.5th-97.5th centiles: 0-99.1), These pain levels during egg collection were not significantly different between the two groups. The use of 200 mg lignocaine in PCB is not justified, even in the absence of toxic effects.