Failed Spinal Anesthesia: Incidence and Associated Factors

Introduction Spinal anesthesia, a commonly used technique for lower abdominal, pelvic, and lower extremity surgeries, involves injecting a local anesthetic into the subarachnoid space to temporarily block sensory, motor, and sympathetic nerves. Despite its high success rate, the failure of spinal anesthesia, which can lead to adverse patient outcomes, remains a concern. The failure rate varies widely, from 1% to 17%, influenced by factors such as technical challenges, patient anatomy, and practitioner experience. This study aims to determine the incidence and causes of spinal anesthesia failure in a university hospital setting. Methodology This cross-sectional, prospective observational study was conducted at Dr. D.Y. Patil Medical College and Research Centre, Pimpri, Pune. Data were collected from patients aged ≥18 years who underwent spinal anesthesia over one year. The study recorded various parameters, including patient demographics, surgical details, and anesthetic techniques. Failed spinal anesthesia was categorized into total failure (no block achieved) and partial failure (need for additional analgesia). Statistical analysis was performed to identify the incidence and contributing factors to spinal anesthesia failure. Results Out of 3933 patients receiving spinal anesthesia, 72 experienced failure, resulting in an incidence rate of 1.83%. The majority of failures were total (87.5%), with partial failures accounting for 12.5%. Among the cases of failed spinal anesthesia, failures were most common in obstetric surgeries (37.5%), followed by orthopedic (25%), general (22.22%), and urologic (15.28%) surgeries. The highest failure rate according to surgery type in all patients receiving spinal anesthesia was seen in orthopedic surgery (3.46%) followed by urologic surgery (2.17%). Elective surgeries had a lower failure rate (1.39%) compared to emergency surgeries (3.87%). Quincke-type needles were predominantly used, and spinal anesthesia was most often administered at the L3-L4 intervertebral space in the sitting position. Notably, first-year residents had the highest failure rate (43.06%), while more experienced practitioners had lower failure rates. Conclusion The incidence of spinal anesthesia failure in our study was 1.83%, with total failures being more common than partial failures. Factors such as surgical type, emergency status, and practitioner experience can impact the failure rate. The higher failure rate among less experienced practitioners underscores the need for improved training and expertise. Regular monitoring and refinement of spinal anesthesia techniques are essential to enhance patient safety and optimize anesthetic care.