Please confirm that an ethics committee approval has been applied for or granted: Yes: I’m uploading the Ethics Committee Approval as a PDF file with this abstract submission

Background and Aims Self-reported pain levels, such as the Visual Analogue Scale (VAS), allow patients to report pain. If we want to measure the pain in patients who may have impaired consciousness or dementia, we may have difficulty with subjective measurements. This study is aimed to compare the objective measure of Analgesia Nociception Index (ANI) and self-reported VAS, for diagnosing pain in individuals with femoral neck fracture before and after Fascia iliaca blockade (FICB).

Methods Prospective, observative study was carried out in Hospital of Traumatology and Orthopedics, Riga, Latvia. Patients with isolated femoral neck fracture, underwent Suprainguinal fascia iliaca block (FICB), done by anesthesiologist, using Ropivacaine 0.375% - 30.0 ml and ultrasonography. ANI and VAS were measured before and after the procedure (10, 20, 30 minutes), alongside with vital signs.

Results 22 patients were enrolled in the study. ANIm mean value before FICB was 60.05 [44-97], after 10 minutes 73.95 [58-98], after 20 minutes 83.68 [60-98], after 30 minutes 89.77 [78-98]. VAS mean value before FICB 6.09 [3-8], after 10 minutes 3.86 [1-8], after 20 minutes 2.41 [1-8], after 30 minutes 2.09 [1-6]. There was no significant correlation between ANI and VAS before, during or after FICB. Significant correlation was found between VAS and arterial pressure (r=0.466; p=0.002). ANI measures correlated weak with respiratory rates (r=0.487; p=0.022) and heartbeat rates (r=0.548; p=0.008) after FICB.

Conclusions There was no significant correlation between VAS and ANI despite significant changes in both. But judging by results on their own and observations during study itself, VAS subjectivity was major problem.