Spinal anaesthesia with lidocaine 2% for Caesarean section

Spinal anaesthesia with 2, 2.5 or 3 ml of glucose-free lidocaine 2% was studied in 50 patients undergoing Caesarean section. Onset time, cephalad spread of analgesia, quality of analgesia, muscle relaxation, the cardiovascular effects and duration of analgesia and motor block were assessed. Reliable anaesthesia was provided with 2.5 and 3 ml while 2 ml of 2% lidocaine was insufficient. Onset time varied between 5.5 to 6 min and maximum cephalad spread was achieved in 10-15 min. The mean maximum extent of sensory analgesia was higher after 2.5 ml (T4.1) and 3 ml (T3.6) than after 2 ml (T7) (P < 0.001). Complete motor block was achieved in all the patients. The mean duration of sensory block was 123 +/- 6.23 min (2 ml) to 126 +/- 7.53 min (2.5 and 3 ml). The mean duration of motor block in 2.5 and 3 ml groups was higher (P < 0.001) than in the 2 ml group and was correlated with the dose of lidocaine (P < 0.05). Hypotension (SBP < 100 mmHg) was noted in 10% (n = 5) of patients in whom the cephalad spread of analgesia was also higher. All the neonates had an apgar score of 7 or more at 1 min. These results suggest that 2.5 to 3 ml of 2% lidocaine provides satisfactory anaesthesia for Caesarean section.