Real-Time Ultrasound/MRI Fusion for Suprasacral Parallel Shift Approach to Lumbosacral Plexus Blockade and Analysis of Injectate Spread: An Exploratory Randomized Controlled Trial

Circum-Psoas Block versus Supra-Inguinal Fascia Iliaca Block for Postoperative Analgesia in Patients Undergoing Total Hip Arthroplasty: A Randomized Clinical Trial

Purpose

Total hip arthroplasty (THA) is often associated with moderate to severe pain. The present study compared the efficacy of circum-psoas block (CPB) with supra-inguinal fascia iliaca block (SIFIB) for postoperative analgesia in patients undergoing THA.

Patients and Methods

In this randomized trial, sixty-four patients undergoing THA were allocated randomly to the CPB group or SIFIB group with 40 mL of 0.3% ropivacaine. The primary outcome was dynamic pain score at 6 h postoperatively. Secondary outcomes included dynamic pain scores at 12, 24 and 48 h; static pain scores; sensory and motor block; opioid consumption; time to first opioid request; length of hospital stay; patient satisfaction; and adverse events.

Results

CPB patients showed significantly lower dynamic pain scores at 6 (3.11 ± 0.66 vs 4.47 ± 0.74, respectively; P = 0.000), 12 (2.52 ± 0.73 vs 3.53 ± 0.85, respectively; P = 0.000) and 24 h (2.30 ± 0.57 vs 2.87 ± 0.71, respectively; P = 0.001) after surgery, as well as lower static pain scores at 6 and 12h (P = 0.001 and P = 0.033 respectively) than SIFIB patients. Lower opioid consumption was observed in the CPB group at 24 and 48 h (P = 0.000, both) than in the SIFIB group. Patients in the CPB group reported improved quadriceps strength at 6 and 12 h (P = 0.000, both), as well as better muscle strength of hip flexion at 6, 12 and 24 h (P = 0.000, P = 0.000 and P = 0.025 respectively). Compared with SIFIB, CPB was associated with increased sensory block coverage at 6, 12 and 24 h (P = 0.000, P = 0.000, and P =0.022, respectively).

Conclusion

CPB has a greater potential to alleviate postoperative pain and improve recovery in THA patients than SIFIB.

Depth of cervical plexus block and phrenic nerve blockade: a randomized trial

Background and objectives

Cervical plexus blocks are commonly used to facilitate carotid endarterectomy (CEA) in the awake patient. These blocks can be divided into superficial, intermediate, and deep blocks by their relation to the fasciae of the neck. We hypothesized that the depth of block would have a significant impact on phrenic nerve blockade and consequently hemi-diaphragmatic motion.

Methods

We enrolled 45 patients in an observer blinded randomized controlled trial, scheduled for elective, awake CEA. Patients received either deep, intermediate, or superficial cervical plexus blocks, using 20 mL of 0.5% ropivacaine mixed with an MRI contrast agent. Before and after placement of the block, transabdominal ultrasound measurements of diaphragmatic movement were performed. Patients underwent MRI of the neck to evaluate spread of the injectate, as well as lung function measurements. The primary outcome was ipsilateral difference of hemi-diaphragmatic motion during forced inspiration between study groups.

Results

Postoperatively, forced inspiration movement of the ipsilateral diaphragm (4.34±1.06, 3.86±1.24, 2.04±1.20 (mean in cm±SD for superficial, intermediate and deep, respectively)) was statistically different between block groups (p<0.001). Differences were also seen during normal inspiration. Lung function, oxygen saturation, complication rates, and patient satisfaction did not differ. MRI studies indicated pronounced permeation across the superficial fascia, but nevertheless easily distinguishable spread of injectate within the targeted compartments.

Conclusions

We studied the characteristics and side effects of cervical plexus blocks by depth of injection. Diaphragmatic dysfunction was most pronounced in the deep cervical plexus block group.

Trial registration number

EudraCT 2017-001300-30.

Evaluation of Sensory Loss Obtained by Circum-Psoas Blocks in Patients Undergoing Total Hip Replacement: A Descriptive Pilot Study

Purpose

Methods

Results

Conclusion

Clinical Trial Registration

Development of Guidance Techniques for Regional Anesthesia: Past, Present and Future

Regional anesthesia has been widely used in clinical practice. Over the past 30 years, various guidance techniques have been developed for regional anesthesia ranging from paresthesia progressing to neurostimulation and currently ultrasound guidance. Especially, the use of point-of-care ultrasound greatly enhances the success rate of regional anesthesia. However, the poor imaging quality of ultrasound in patients with obesity, fat infiltration, etc., limits the use of ultrasound. The combined use of ultrasound with neurostimulator, electromyography, pressure monitoring, etc. is advocated in order to facilitate regional anesthesia in this cohort of patients. The accumulated evidence has shown that the ultrasound combined with other techniques (UCOT) can help to solve the difficulties of puncture location caused by obesity, anatomical variation, and other factors when using ultrasound guidance alone. In recent years, with the development of medical image fusion and medical image artificial intelligence identification technology, guidance techniques for regional anesthesia have advanced considerably. To understand the advantages and disadvantages of the various guidance techniques for regional anesthesia developed in recent years and to guide their rational clinical application, this paper reviews these techniques, describing the progression from the early use of paresthesia to the latest UCOT, as well as the latest research on UCOT, and the prospects for the development of new guidance techniques for regional anesthesia.

Anatomical considerations for obturator nerve block with fascia iliaca compartment block

This report reviews the topographical and functional anatomy relevant for assessing whether or not the obturator nerve (ON) can be anesthetized using a fascia iliaca compartment (FIC) block. The ON does not cross the FIC. This means that the ON would only be blocked by an FIC block if the injectate spreads to the ON outside of the FIC. Such a phenomena would require the creation of one or more artificial passageways to the ON in the retro-psoas compartment or the retroperitoneal compartment by disrupting the normal anatomical integrity of the FI. Due to this requirement for an artificial pathway, an FIC block probably does not block the ON.

Real-time ultrasound-computed tomography image fusion for transforaminal lumbar approach: a lumbosacral spine phantoms study

PURPOSE

Ultrasound (US) is increasingly used for transforaminal approaches. We evaluated whether fusing computed tomography (CT) images with dynamic US could be based on bony and surface landmarks in two phantom models.

METHODS

Recordings were performed in a gelatin-based sonographic phantom and in a computerized imaging reference system training phantom. Three anesthesiologists performed 10 US and CT image fusions via three different techniques: (1) using locations of the fifth lumbar vertebra (L5) spinous process and the two posterior superior iliac spines in both images, (2) using the two lateral edges of the laminae rather than posterior superior iliac spines, and (3) using skin landmarks. Techniques were compared using values of precision (High quality of fusion: VP inferior to 10). Three punctures targeting the L4-L5 right foramina were made, and needle positions were checked using X-ray.

RESULTS

Sixty fusions were performed in the gelatin phantom and 90 in the training phantom. VPs values of the 150 fusions were inferior to 5. Technique 2 was superior to one [operator 1: VP: 1.12 ± 0.54 vs. 2.38 ± 1.49; operator 2: 0.6 ± 0.39 vs. 3.66 ± 1.22; operator 3: 0.89 ± 0.31 vs. 1.23 ± 0.63 (p < 0.001)] with the gelatin phantom. There were no differences with the second phantom. X-ray examinations confirmed L4-L5 needle positioning.

CONCLUSION

Bony and surface landmarks allowed for accurate fusion of CT and US images of the lumbar spine. These techniques, performed on phantoms, allowed for precise localization and puncturing of lumbar neural foramina.

Peripheral nerve catheters: A critical review of the efficacy

Continuous peripheral nerve blocks are commonly used for postoperative analgesia after surgery. However, catheter failure may occur due to either primary (incorrect insertion) or secondary reasons (displacement, obstruction, disconnection). Catheter failure results in unanticipated pain, need for opioid use, and risk of readmission or delay in hospital discharge. This review aimed to assess definition and frequency of catheter failure, and discuss the alternatives to prolong duration of single-shot nerve blocks. A literature search was performed on peripheral catheters reporting failure as the main outcome measure. Thirty-three studies met the selection criteria, comprising 2711 catheters. Literature review suggests that peripheral nerve catheters have clinically significant failure rate when the assessment is performed using an objective (imaging) method. Subjective methods of assessment (without imaging) may underestimate the incidence of catheter failure.