Incidence of failed subarachnoid block in patients undergoing caesarean section

Abstract

Background: The narrowest, and perhaps most specific, definition of a failed spinal blockade was developed by Praxedes and Filho (2010). Neuraxialanaesthesia is the commonest, safest, and most logical choice of anaesthesia for caesarean section. Prevention of injection of wrong drug is of utmost importance. Apart from failure, wrong drug injection can cause maternal mortality (e.g., tranexamic acid.). Such errors are unpardonable and must be avoided by double checking of drugs before injection, use of prefilled syringes, and use of luer-lock connection. Objectives: To determine the incidence of failed subarachnoid block in patients undergoing caesarean section and to identify the contributory factors to the failure. Methods: The study was conducted on 1000parturientsundergoing caesarean section under single-shot spinal anaesthesia. Study women underwent either elective or emergency caesarean section with ASA II-III. 25 or 26 G Quincke type short beveled spinal needle was used. After confirmation of free-clear flow cerebrospinal fluid was confirmed the volume 0.5% hyperbaric bupivacaine decided by one attending anesthetist was injected slowly into intrathecal space. Results: Majority of patients were below 35 years (86; 86%).32% had previous caesearean section and 68% patients belong either to primigravidae or had no surgical intervention in previous deliveries. Out of 1000 patients, 4% parturients had a history of failed spinal anaesthesia. The incidence of failed spinal was 19%, highest in L3-L4 interspace, followed by 1% in L4-L5 interspace. Among the anaesthetists, the incidence of failed spinal anaesthesia was observed higher when junior resident performed the lumbar puncture as compared to certified anaesthetists. Conclusion: Greater prevention efforts by anaesthesia professional to avoid spinal anaesthesia failure will most likely lead to an improvement in failure rates. A decrease in failure rates can greatly improve the safety, care, and outcomes for the parturient and fetus.