Some immediate serious complications of obstetric epidural analgesia and anaesthesia: a prospective study of 145,550 epidurals

Background: Inadvertent intravascular, intrathecal or subdural injection in obstetric regional analgesia are potentially life-threatening, so following a catastrophic complication it was decided to collect data regionally. Method: Obstetric anaesthetists from 14, later 12 maternity units in the South West Thames Region collected and pooled data on obstetric anaesthetic interventions and complications from 1987 to 2003. Results: During the 17-year period, 145 550 epidurals (26.3%) were administered to 553 905 mothers. The incidence of intravascular injection was 1 in 5000 epidurals (0.02% [95%CI 0.014-0.029%]), of intrathecal injection 1 in 2900 epidurals (0.035% [95%CI 0.027-0.046%]), of subdural injection 1in 4200 epidurals (0.024% [95%CI 0.017-0.033%]) and of high or total spinal block I in 16 200 epidurals (0.006% [95%CI 0.003-0.012%]). The incidence of serious complications did not change during the course of the study, nor was there any difference in the incidence of serious complications in obstetric units of different sizes or in obstetric units with different rates of epidural analgesia. Conclusion: The incidence of intravascular, intrathecal and subdural injection and of high or total spinal block was similar to that found in previous prospective studies in obstetric and non-obstetric patients. The incidence of these complications has not changed and is not related to the number of deliveries or the epidural rate in obstetric units. (C) 2004 Elsevier Ltd. All rights reserved.