FACTORS OF FAILED SPINAL ANESTHESIA IN DIFFERENT SURGICAL PROCEDURES AT TERTIARY CARE HOSPITALS DISTRICT PESHAWAR, PAKISTAN

Background: Spinal anesthesia is a widely preferred technique for surgeries involving the lower extremities and abdomen due to its rapid onset, predictable blockade, and reduced systemic complications. Despite its efficacy, failures still occur, leading to intraoperative discomfort, delayed procedures, or conversion to general anesthesia. Understanding the underlying demographic and procedural factors influencing spinal anesthesia outcomes is essential to enhance safety and effectiveness in clinical practice. Objective: To identify patient-specific and procedural factors associated with the success and failure of spinal anesthesia in surgical patients. Methods: A cross-sectional analytical study was conducted on 175 patients undergoing various elective and emergency surgeries under spinal anesthesia. Data on patient demographics, BMI, clinical history, surgery type and urgency, needle type, number of puncture attempts, local anesthetic type and dose, and intraoperative pain were collected. Logistic regression was used to identify significant predictors of spinal anesthesia failure, with statistical significance set at p<0.05. Results: Spinal anesthesia failed in 15 out of 175 patients (8.57%). Significant predictors included underweight status (OR 4.76, p=0.049), obesity (OR 3.21, p=0.074), back pain history (OR 6.31, p=0.003), and previous spine surgery (OR 9.14, p=0.001). Procedural risk factors were Quincke needle use (OR 3.82, p=0.027), multiple puncture attempts—especially more than three (OR 10.53, p=0.002), use of Lidocaine (OR 10.5, p=0.001) or Ropivacaine (OR 8.4, p=0.018) instead of Bupivacaine, and low anesthetic dose (OR 0.69 per mg, p=0.041). Pain during incision (OR 6.72, p=0.002) and emergency surgery (OR 5.11, p=0.007) were also significantly associated with failure. Conclusion: Spinal anesthesia outcomes are influenced by a combination of patient-related conditions and technical decisions. Recognizing these factors can help tailor anesthesia strategies, reduce failure rates, and enhance procedural safety.