Ojective To investigate the hemodynamic changes in the lower after sciatic nerve block (SNB), and to explore its clinical efficacy in predicting successful SNB. Methods Patients who underwent elective lower extremity orthopedic surgery were selected, including 27 males and 40 females, aged 20-60 years, BMI 20-27 kg/m2, ASA physical status Ⅰ or Ⅱ. All of the patients underwent ultrasonic guidance SNB, and the blood flow values of the anterior tibial artery region and posterior tibial artery region were recorded 1 minute before SNB and 5, 10, 20, 30, 40, and 45 minutes after SNB on the blocked side, including peak systolic velocity (PSV), end-diastolic velocity (EDV), time-mean velocity (TAmean), and time-maximal mean velocity (TAmax). Patients with a Hollmen score ≥ 2 were defined as successful SNB block 45 minutes after block. The patients were divided into SNB success group (group S, Hollmen score ≥ 2 points) and SNB failure group (group F, Hollmen score < 2 points). Receiver operating characteristic (ROC) curves of percent increase in regional hemodynamic parameters 10 minutes after SNB completion were constructed to predict the effect of SNB. Results Fifty-nine patients (88.1%) were successfully blocked in this study. The ROC curve of the rate of change of regional hemodynamic parameters 10 minutes after SNB was constructed. The AUC of PSV in the anterior tibial artery region was 0.893 (95% CI 0.780-1.000), the cutoff value was 19.22%, the sensitivity was 86.7%, and the specificity was 90.0%. The AUC of EDV was 0.748 (95% CI 0.615-0.880), the cutoff value was 48.65%, the sensitivity was 75.0%, and the specificity was 72.7%. The AUC of TAmean was 0.827 (95% CI 0.728-0.925), the cutoff value was 72.88%, the sensitivity was 68.3%, and the specificity was 100%. The AUC of TAmax was 0.850 (95% CI 0.763-0.937), the cutoff value was 82.12%, the sensitivity was 70.5%, and the specificity was 100%. The AUC of PSV in the posterior tibial artery region was 0.880 (95% CI 0.790-0.970), the cutoff value was 35.9%, the sensitivity was 68.3%, and the specificity was 100%. The AUC of EDV was 0.786 (95% CI 0.659-0.913), the cutoff value was 49.8%, the sensitivity was 81.7%, and the specificity was 70.0%. The AUC of TAmean was 0.804 (95% CI 0.701-0.908), the cutoff value was 53.3%, the sensitivity was 68.3%, and the specificity was 90.9%. The AUC of TAmax was 0.852 (95% CI 0.758-0.947), the cutoff value was 45.9%, the sensitivity was 76.7%, and the specificity was 90.0%. Conclusion Regional hemodynamic parameters can be used as good indicators for clinicians to early predict the effect of SNB. |