Femoral artery block (FAB) attenuates thigh tourniquet-induced hypertension: a prospective randomized, double-blind, placebo-controlled trial

Incidence of acute compartment syndrome with routine use of regional anesthesia for patients with long bone fractures: a large single-center retrospective review from a level I trauma tertiary academic institution

INTRODUCTION

Traditionally, using peripheral nerve blocks (PNBs) in patients with long bone fractures has been limited due to concerns that it may interfere with the timely diagnosis of acute compartment syndrome (ACS). However, our large academic institution and level I trauma center have been using regional anesthesia routinely for pain management of patients with long bone fractures for more than a decade, with strict adherence to a comprehensive management protocol. The aim of this retrospective review is to present our experience with this practice.

METHODS

Following Institutional Review Board approval, we performed a retrospective chart review of patients with long bone fractures and ACS over a 10-year period (2008-2018).

RESULTS

26 537 patients were included in the review. Approximately 20% of these patients required surgery, and 91.5% of surgically treated patients received regional anesthesia. The incidence of ACS in our cohort was 0.1% or 1.017 per 1000 patients with long bone fractures.

CONCLUSION

Current recommendations on using PNBs in patients at risk for ACS have been mainly based on expert opinion and dated case reports. Due to the nature of the condition, prospective data are lacking. Our large observational dataset evaluated the risk of missing or delaying ACS diagnosis when PNBs were offered for trauma patients and demonstrated a relatively low incidence of ACS despite the routine use of PNBs under strictly protocolized conditions when patients were managed by a dedicated multidisciplinary care team.

Ultrasound-guided caudal quadratus lumborum block combined with the greater ischiatic notch plane block as motor-protective analgesia for the pelvic limb in dogs

OBJECTIVE

To develop an ultrasound-guided caudal quadratus lumborum block (C-QLB) technique in canine cadavers and to compare sensory and motor blockade resulting from the combination of ultrasound-guided greater ischiatic notch (GIN) plane and C-QLB approaches (GIN-CQLB group) versus a lumbosacral plexus (LSP group) approach [combination of lateral pre-iliac (LPI) and parasacral (PS) techniques] in dogs.

STUDY DESIGN

Descriptive anatomical study and prospective randomized, blinded, experimental crossover trial.

ANIMALS

A total of six canine cadavers and six adult Beagle dogs.

METHODS

Phase I: following ultrasound-guided C-QLB injections of 0.3 mL kg-1 of dye, using the interfascial plane located lateral to the quadratus lumborum muscle at the level of the sixth lumbar vertebra (L6) as injection point, the spread of injectate and nerve staining was evaluated using gross anatomical dissection.

PHASE II

sensory and motor blockade achieved with the GIN-CQLB or LSP blocks in Beagle dogs were evaluated and compared. The assigned technique was performed with 2% lidocaine: 0.2 mL kg-1 for the GIN and PS approaches and 0.3 mL kg-1 for the C-QLB and LPI approaches.

RESULTS

Dissection revealed distribution of dye around the lumbar hypaxial musculature, extending into the paravertebral spaces, with staining of 3 (2-4) [median (interquartile range)] spinal nerves, spanning L3 to L6. The median motor blockade in the GIN-CQLB and LSP groups was 7 (7-8) versus 16 (10-16) (p = 0.026), whereas the median sensory blockade was 5 (4-5) versus 3 (3-3) (p = 0.025), respectively.

CONCLUSION AND CLINICAL SIGNIFICANCE

The GIN-CQLB approach desensitized the thigh dermatomes effectively. Compared with the LSP approaches, GIN-CQLB exhibits a motor-protective effect by preserving tonic muscle function.

Lower Extremity Peripheral Nerve Blocks for Patients at Risk for Acute Compartment Syndrome

A delayed acute compartment syndrome (ACS) diagnosis often results in devastating complications; however, the sensitivity of the classic signs and symptoms is very low. All analgesic modalities have been implicated in delaying the diagnosis, but there is very little evidence linking peripheral nerve blocks (PNBs) with delays in diagnosis. In fact, there is evidence that PNBs may facilitate an early diagnosis; this may be in part due to differences in how ischemic and inflammatory pain is transmitted through unique nociceptive pathways. Collaboration is required to optimize care for patients at risk for ACS.

Pro-Con Debate: Peripheral Nerve Blockade Should Be Provided Routinely in Extremity Trauma, Including in Patients At Risk for Acute Compartment Syndrome

In this Pro-Con commentary article, we discuss the controversial debate of whether to provide peripheral nerve blockade (PNB) to patients at risk of acute extremity compartment syndrome (ACS). Traditionally, most practitioners adopt the conservative approach and withhold regional anesthetics for fear of masking an ACS (Con). Recent case reports and new scientific theory, however, demonstrate that modified PNB can be safe and advantageous in these patients (Pro). This article elucidates the arguments based on a better understanding of relevant pathophysiology, neural pathways, personnel and institutional limitations, and PNB adaptations in these patients.

Combined femoral artery block and femoral nerve block reduces thigh tourniquet-induced hypertension

STUDY OBJECTIVE

Tourniquet hypertension (TH) is thought to be caused by sympathetically mediated C-fibers in the femoral epicardium following prolonged intraoperative inflation of the tourniquet, and we hypothesized that blocking the femoral artery at the same time as a conventional femoral nerve block would reduce the incidence of TH.

DESIGN

A prospective, double-blind, randomized, controlled trial.

SETTING

Operating room and hospital ward in the Third Hospital of Hebei Medical University.

PATIENTS

A total of 72 patients receiving high tibial osteotomy under general anesthesia were recruited from June 2022 to September 2022.

INTERVENTIONS

Patients were randomly assigned to receive either a classical femoral nerve block (CFNB) or a modified femoral nerve block (MFNB). Patients in the CFNB group received a 30 mL of 0.5% ropivacaine femoral nerve block and patients in the MFNB group received a 20 mL of 0.5% ropivacaine femoral nerve block combined with a 10 mL of 0.5% ropivacaine femoral artery block.

MEASUREMENTS

The primary outcome assessed was the incidence of TH. Data on intraoperative esmolol dosage, analgesic effect, complications and hemodynamics during surgery were also recorded.

MAIN RESULTS

Incidence of TH was significantly higher in the CFNB group compared with the MFNB group (71.88% vs 31.25%, P = 0.002). The systolic blood pressure in the CFNB group was significantly higher than that in the MFNB group at 45, 60, 75 and 90 min after tourniquet inflation (P = 0.029, P = 0.020, P = 0.009, P = 0.007). There was also a significant increase in intraoperative esmolol dosage in the CFNB group (65.63 ± 44.15 vs 22.19 ± 33.74, P < 0.001). Postoperative pain scores and patient satisfaction were not statistically significant between the two groups.

CONCLUSIONS

The present study demonstrated that modified femoral nerve block reduced intraoperative esmolol dosage and the incidence of TH.

Role of an Intercostobrachial Nerve Block in Alleviating Tourniquet Pain: A Randomized Clinical Trial

Introduction

Tourniquet pain may have cutaneous and ischemic components. It is questionable whether blockade of a sensory nerve will help reduce ischemic pain. In addition, complete anesthesia of the axilla in the intercostobrachial nerve (ICBN) distribution is challenging to execute, and ICBN blockade has an inherently higher failure rate because of its variable anatomic location and source of innervation. We sought to determine the utility of an ICBN block for the prevention of tourniquet pain.

Methods

We conducted a single-center randomized controlled trial at a major academic medical center involving patients scheduled to undergo distal upper extremity surgery under ultrasound-guided supraclavicular brachial plexus block. Forty patients were randomized to receive an additional ICBN block or no ICBN block, with 22 allocated to the intervention and 18 to control. We collected data on the incidence of tourniquet pain and systemic anesthetic requirements.

Results

Initial contingency analysis examining the relationship between ICBN block placement and the development of pain using the two-tailed Fisher exact test failed to show that the presence or absence of ICBN block was associated with the development of tourniquet pain. χ² analysis failed to show that tourniquet time was significantly related to the development of tourniquet pain.

Conclusions

The overall incidence of tourniquet pain in the setting of a dense supraclavicular brachial plexus block for surgical anesthesia was low even without an ICBN block and even with tourniquet times greater than 90 min. Tourniquet pain was easily managed with small amounts of systemic analgesics.

Visceral versus somatic pain: an educational review of anatomy and clinical implications

Somatic and visceral nociceptive signals travel via different pathways to reach the spinal cord. Additionally, signals regulating visceral blood flow and gastrointestinal tract (GIT) motility travel via efferent sympathetic nerves. To offer optimal pain relief and increase GIT motility and blood flow, we should interfere with all these pathways. These include the afferent nerves that travel with the sympathetic trunks, the somatic fibers that innervate the abdominal wall and part of the parietal peritoneum, and the sympathetic efferent fibers. All somatic and visceral afferent neural and sympathetic efferent pathways are effectively blocked by appropriately placed segmental thoracic epidural blocks (TEBs), whereas well-placed truncal fascial plane blocks evidently do not consistently block the afferent visceral neural pathways nor the sympathetic efferent nerves. It is generally accepted that it would be beneficial to counter the effects of the stress response on the GIT, therefore most enhanced recovery after surgery protocols involve TEB. The TEB failure rate, however, can be high, enticing practitioners to resort to truncal fascial plane blocks. In this educational article, we discuss the differences between visceral and somatic pain, their management and the clinical implications of these differences.