The incidence of transient neurologic syndrome in obstetric and non-obstetric patients with spinal 0.5% hyperbaric bupivacaine and 5 % hyperbaric lignocaine - A randomized double blind control study

Background: Lignocaine has been used for spinal anesthesia since 1948 for many decades without any serious complications. In subjects who were recovering from lignocaine spinal anaesthesia, Transient Neurologic Symptoms (TNS) have been reported. In pregnant women, small doses of spinal anaesthesia are known to produce higher levels of spinal anaesthesia compared to non-pregnant women. The aetiology of TNS is still poorly understood and the incidence of TNS has been reported to be low in pregnancy. Materials and methods: We conducted a randomised controlled clinical trial on 200 subjects who were admitted to Dhanalakshmi Srinivasan Medical College and Hospital. 100 obstetric subjects were randomised to receive either 1.1 ml of 5% lignocaine (Group 1 – OL, n=50) or 2 ml of 0.5% bupivacaine (Group 2 – OB, n=50). 100 non obstetric subjects were randomised to receive either 2 ml of 5% lignocaine (Group 3 – NL, n=50) or 3 ml of 0.5% bupivacaine (Group 4 – NB, n=50). Incidence of Transient Neurological Symptoms was our primary outcome variable. Results: Out of 50 people with OL none had TNS. The proportion of subjects developing TNS was 2%, 4% and 4% respectively in OB, NL and NB groups. None of the factors such as degree of motor blockade, age, weight, occurrence of hypotension, lowest SBP, lowest DBP, lowest heart rate had a significant association with occurrence of TNS. Conclusions: The incidence of TNS in OL group was 0. The occurrence of transient neurologic symptoms with intrathecal lidocaine among obstetric patients in the supine surgical position appears to be infrequent and also without any serious complications.