Peripheral nerve blocks for above knee amputation in high-risk patients

Abstract

Background and Aims: Above knee amputation (AKA) is associated with considerable mortality and morbidity. There is paucity of data describing the use of peripheral nerve blocks (PNB) as the sole anesthetic technique in high-risk patients undergoing AKA. Our objectives were to evaluate the use of PNB as sole anesthetic technique in the above-mentioned population and its clinical outcomes. Material and Methods: This was a retrospective descriptive study conducted in a tertiary hospital. For this study, patients with American Society of Anesthesiologist [ASA] IV physical status underwent AKA using PNB between January 2010 and December 2016, were identified. The primary outcome measured was the success of the operation. The secondary outcomes were block details, intraoperative hemodynamics, usage of sedation and analgesia, patients' comorbidities, mortality rates at 30 days and one year. Results: Out of fifty-seven patients, the median age (interquartile range) was 74 (57 – 81) years and 60% were males. The results show 91% successfully underwent surgery with PNB (95% CI 81% to 96%). 95% required intraoperative sedation and analgesia. 67% received combined femoral, obturator and sciatic nerve blocks, in which nine cases had an additional lateral femoral cutaneous nerve block. Interestingly, 33% only received combined femoral and sciatic nerve blocks, and they required higher sedation analgesia (p = 0.013). The 30-day and one-year mortality were 12.3% & 47.4%. Majority had stable hemodynamics during the surgery. Conclusion: This study shows that PNB is a viable option for reliable anesthesia for AKA in high-risk patients. Combined FOS nerve block would reduce the dose for sedation–analgesia during the operation.

Keywords

• Above knee amputation
• high-risk patients
• peripheral nerve blocks
• regional anesthesia
• survival