What does this research mean for the field?

Monitoring injection pressure during ultrasound-guided popliteal sciatic nerve blocks reduces the risk of intraneural injection and associated neurologic injury in diabetic patients undergoing below-knee amputation. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

The study aims to assess whether monitoring injection pressure can prevent intraneural injections during nerve blocks in diabetic patients undergoing amputation.

March 2, 2026Open Access

The Effect Opening Injection Pressure Monitoring Device for Detects Needle Nerve Contact During Ultrasound Guided Popliteal Approach in Diabetic Patients for Below Knee Amputation

Key Points

The study aims to assess whether monitoring injection pressure can prevent intraneural injections during nerve blocks in diabetic patients undergoing amputation.
Randomized assignment of 50 ASA class III-IV patients to receive sciatic nerve blocks or femoral nerve blocks.
Use of ultrasound guidance and a pressure monitoring device during local anesthetic (LA) injection.
Assessment of sensory and motor block durations, along with monitoring of vital signs throughout the procedure.
44% of patients had needle nerve contact during the procedure.
38% required low pressure (<15 psi) for effective injections, while 18% had intrafascular injections.
Most patients reported significant pain reduction within 30 minutes post-injection, achieving complete pain relief.

Abstract

Background: Ultrasound-guided popliteal sciatic nerve blocks and femoral are useful adjuncts for below knee amputation limb also provide excellent analgesia for all major foot and ankle procedures. Using of the injection pressure monitoring device enhances the accuracy of the local anesthetic deposition in popliteal sciatic nerve blocks. Our hypothesis is that an intraneural injection is associated with higher pressures and an increase in the risk of neurologic injury as compared with perineural injection. Aim of the study: The injection pressure monitoring enhances accuracy of local anesthetic deposition in addition to the use of ultrasound during popliteal sciatic nerve blocks and to Prevention of an intraneural injection of a local anesthetic during peripheral nerve block is considered important to avoid neurologic injury. Methods: Fifty patients ASA class IIIIV, age (30₈0) years of either sex scheduled for elective surgery unilateral below knee amputation were randomly assigned to receive either sciatic nerve block using a popliteal approach In a lateral position received amount of LA (20 ml of bupivacaine (0. 375%) with monitoring of the bupivacaine injection pressure by a disposable pressure manometer and the continuous ultrasound view monitoring pressure level and additional ultrasound guided femoral nerve block by 12 ml of bupivacaine (0. 375%) to ensure sensory block of the medial side of the leg. Time to complete sensory and motor block, time taken to perform the block, block-related complications, block duration were recorded and intraoperatively PR, noninvasive mean BP, RR, ECG, SpO2 was monitored. Results: Regarding to the pressure of the injections monitoring, we noticed that in this study, the highest proportion of study patients recorded needle nerve contact (44%), needed low pressure 15psi may indicate an intraneural needle placement and lead to severe fascicular injury and persistent neurologic deficits. If these results are applicable to clinical practice, avoiding excessive injection pressure during nerve block administration may help to reduce the risk of neurologic injury. The injection pressure monitoring enhances the accuracy of local anesthetic deposition in addition to the use of ultrasound.

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