Failure of subarachnoid block in caesarean section.

Subarachnoid block is the most convenient and safe anaesthesia during caesarean section. But there are incidences where subarachnoid block does not work and other methods of anaesthesia have to be employed. This study was done in 2039 female patients who underwent caesarean Section at Paropakar Maternity and Women's Hospital, Thapathali, Kathmandu Nepal from 1st October 2005 to end of September 2006 to find the rate of failure of subarachnoid block in Caesarean Section and look for the causes of failure. Patients of age 17 years to 43 years (mean age 25.40 years) and ASA I and II were included in the study. Spinal needle (Sprotte) of 26 Gauze with Quincke's bevel was used. Solution injected was 2.20 ml of 0.5% hyperbaric Bupivacaine. Of the total 2039 patients who received subarachnoid block with the above mentioned methods, 6.0% (n=123) needed further anesthetic agents. Conversion to general anesthesia was needed in 87 (4.3%) patients. Rest 1.8% (n=36) could be operated with further administration of intravenous agents (Ketamine, Diazepam and/or Pentazocine) only.