Refractory primary and secondary headache disorders that dramatically responded to combined treatment of ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks and non-invasive vagus nerve stimulation: a case series.

In 1981, Devoghel achieved an 85.6% success rate in treating patients with treatment-refractory cluster headaches with alcoholization of the pterygopalatine ganglion (PPG) via the percutaneous suprazygomatic approach. Devoghel's study led to the theory that interrupting the parasympathetic pathway by blocking its transduction at the PPG could prevent or treat symptoms related to primary headache disorders (PHDs). Furthermore, non-invasive vagus nerve stimulation (nVNS) has proven to treat PHDs and has been approved by national regulatory bodies to treat, among others, cluster headaches and migraines.In this case series, nine desperate patients who presented with 11 longstanding treatment-refractory primary headache disorders and epidural blood patch-resistant postdural puncture headache (PDPH) received ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks (PPGB), and seven also received nVNS. The patients were randomly selected and were not part of a research study. They experienced dramatic, immediate, satisfactory, and apparently lasting symptom resolution (at the time of the writing of this report). The report provides the case descriptions, briefly reviews the trigeminovascular and neurogenic inflammatory theories of the pathophysiology, outlines aspects of these PPGB and nVNS interventions, and argues for adopting this treatment regime as a first-line or second-line treatment rather than desperate last-line treatment of PDPH and PHDs.

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.

Comparing Spinal Chloroprocaine to Hyperbaric and Isobaric Bupivacaine for Total Hip and Knee Arthroplasties: A Retrospective Study.

INTRODUCTION: Spinal anesthesia is commonly used for total knee and hip arthroplasties (TKA/THA). The rising popularity of ambulatory TKA and THAs require anesthetic techniques that provide rapid recovery of motor and sensory function while minimizing side effects like postoperative urinary retention. This single-center retrospective observational study compares the recovery profile of patients undergoing TKA and THA under chloroprocaine spinals compared to hyperbaric and isobaric bupivacaine spinals. METHODS: One hundred and twelve patients undergoing primary TKA and THA under spinal anesthesia at University of Florida Health were identified between September 1, 2019 and February 21, 2020. Their electronic medical records were reviewed. Patients were categorized based on the local anesthetic used in the spinal. Various demographic, intraoperative, and postoperative data were compiled and compared, including duration of surgery, time to physical therapy, time to post-anesthesia care unit (PACU) discharge, and time to spontaneous micturition. RESULTS: Time to spontaneous micturition and PACU discharge were significantly lower in the chloroprocaine spinal group compared to the hyperbaric bupivacaine group by 193 minutes and 42 minutes, respectively. Fewer patients receiving chloroprocaine spinals had their first physical therapy session limited by residual motor weakness compared to those in both bupivacaine groups. Additionally, mean duration of surgery was shorter in the chloroprocaine group compared to both bupivacaine groups (89 minutes compared to 111 minutes). Time to physical therapy completion was not different. All groups had <10% conversion to general anesthesia. CONCLUSION: Chloroprocaine spinals can be feasible options for TKAs and THAs with improved postoperative recovery profiles compared to bupivacaine spinals.

Rescue therapy for symptomatic spinal cord ischemia after thoracic endovascular aortic repair.

OBJECTIVE: Spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) can cause permanent neurologic deficits and poor long-term survival. Targeted treatment of new SCI symptoms after TEVAR (rescue therapy [RT]) might improve/resolve neurologic symptoms but few data characterize the association of specific interventions with SCI outcomes. We evaluated the effectiveness of post-TEVAR RT at our tertiary aortic center. METHODS: Our institutional TEVAR database was reviewed for SCI incidence and details of RT. This included cerebrospinal fluid drainage (CSFD), medical therapy, and optimization of spinal cord oxygen delivery. SCI outcomes were categorized at discharge as paralysis/paraparesis and temporary/permanent. RESULTS: Nine hundred forty-three TEVAR procedures were performed in 869 patients from 2011 to 2020. Post-TEVAR SCI occurred in 7.8% (n = 74) with permanent paraplegia in 1.5%. Older patient age, chronic obstructive pulmonary disease, and previous abdominal aortic surgery were predictive of SCI. Half (n = 37) of SCI episodes resulted in only temporary paralysis/paraparesis. Rescue postoperative cerebrospinal fluid drains were implanted in 3.7% (n = 35) of procedures and was predicted by higher American Society of Anesthesiologists class, lower serum hemoglobin level, elevated international normalized ratio, bilateral iliac artery occlusion, nonelective procedures, and penetrating atherosclerotic ulcer/intramural hematoma indication. The most commonly used RTs were emergent placement of or increased drainage from an existing cerebrospinal fluid drain (87.8%), induced/permissive hypertension (77.0%), corticosteroid bolus (36.5%), and naloxone infusion (33.8%). Neurologic improvement occurred in 68.9% (n = 51/74). New/increased drainage was associated with improved SCI outcome. CONCLUSIONS: Permanent paraplegia from post-TEVAR SCI is rare (1.5%). Older patients with comorbidities carry greater post-TEVAR SCI risk. SCI symptoms improved/resolved with CSFD and multimodal RT in 68.9% of patients, but no intervention was independently associated with improvement. TEVAR centers should have robust protocols for timely and safe CSFD placement to augment RT strategies for SCI.

Safety of cerebrospinal fluid drainage for spinal cord ischemia prevention in thoracic endovascular aortic repair.

Objective: Spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) is associated with permanent neurologic deficit and decreased survival. Prophylactic cerebrospinal fluid (CSF) drainage (CSFD) in TEVAR is controversial. We evaluated the usage of CSFD in TEVAR at our tertiary aortic center. Methods: Our institutional TEVAR database was reviewed to determine the frequency of CSFD usage/complications. Complications were categorized as mild (headache/CSF leak not requiring intervention, urinary retention), moderate (headache/CSF leak requiring intervention, drain malfunction requiring replacement), or severe (intrathecal hemorrhage, CSFD-attributable neurologic deficit). The relationships between CSFD complications and patient/procedural characteristics, CSFD placement timing, and survival were analyzed. Results: Nine hundred thirty-six TEVAR procedures were performed in 869 patients from 2011 to 2020. Three hundred ninety CSFD drains were placed in 373 (41.7%) TEVAR patients. Most CSFD drains (89.5%) were pre-TEVAR. Most post-TEVAR drains were placed for new SCI symptoms (n = 21). Twenty-five patients (6.4%) suffered 32 CSFD complications. Most (n = 17) were mild in severity. Severe CSFD complications occurred in 5/432 (1.1% CSF drains) patients. No patient/procedural characteristics were predictive of CSFD complications. Post implant CSFD placement for new SCI symptoms conferred an increased risk of CSFD complication (odds ratio, 6.9; 95% CI, 2.42-19.6; P < .01). The long-term survival of the CSFD complication cohort did not differ from the overall population. Conclusions: Post-TEVAR CSFD placement for new SCI symptoms was associated with substantially greater risk of CSFD complications. Avoidance of post-implant therapeutic drain placement might be the key to prevention of CSFD complications, favoring a strategy of selective pre-implant drain placement in patients at higher risk for SCI.

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.

Efficacy of Phrenic Nerve Catheter in Ipsilateral Shoulder Pain After Thoracic Surgery.

The mechanism of ipsilateral shoulder pain (ISP) after thoracic surgery remains unexplained definitively in the literature. Regional techniques targeting specific nerves more precisely will provide practitioners with a better understanding of the pain source. We report the case of a 51-year-old woman who underwent robotic-assisted plication of the right hemidiaphragm. ISP was adequately managed using a low-volume infusion through a continuous phrenic nerve block in addition to a thoracic epidural for her chest pain. ISP after thoracic surgery likely originates from diaphragm manipulation. Phrenic nerve blockade is a successful strategy that does not worsen subjective dyspnea in this setting.

Pterygopalatine Ganglion Block as a Rescue Technique for Failed Epidural Blood Patch.

Placement of an epidural blood patch is the gold standard treatment for a postdural puncture headache when conservative measures have failed. If unsuccessful in relieving the symptoms, a second epidural blood patch may be warranted. However, when the accepted gold standard treatment has failed, alternative therapies may be pursued. A pterygopalatine ganglion block has been shown to be effective as an alternative to epidural blood patch placement. This case demonstrates the use of a suprazygomatic pterygopalatine ganglion block as a rescue technique for failed repeated epidural blood patch, with complete and permanent resolution of the headache.

Vulnerability of different nerves to intrafascicular injection by different needle types and at different approach angles: a mathematical model.

BACKGROUND AND OBJECTIVES: We assume that intrafascicular spread of a solution can only occur if a large enough portion of the distal needle orifice is placed inside the fascicle. Our aim is to present and evaluate a mathematical model that can calculate the theoretical vulnerability of fascicles, analyzing the degree of occupancy of the needle orifice in fascicular tissue by performing simulations of multiple positions that a needle orifice can take inside a cross-sectional nerve area. METHODS: We superimposed microscopic images of two routinely used nerve block needles (22-gauge, 15° needle and 22-gauge, 30° needle) over the microscopic images of cross-sections of four nerve types photographed at the same magnification. Fascicular tissue that was overlapped between 80% and 100% by a needle orifice was considered at risk to possible intrafascicular injection. The effect of three angular approaches was evaluated. RESULTS: There were statistical differences between the vulnerability of fascicular tissue depending on nerve type, the bevel angle of the needle and the angle approach. Fascicular vulnerability was greater in nerve roots of the brachial plexus after using a 22-gauge 30° needle, as was choosing a 45° angle approach to the longitudinal axis of the nerve. CONCLUSIONS: Our results suggest that clinicians may want to consider needle insertion angle and bevel type as they perform peripheral nerve blocks. Furthermore, researchers may want to consider this mathematical model when estimating vulnerabilities of various nerves, needle types and angles of approach of needles to nerves.

Another (Internal) Epineurium: Beyond the Anatomical Barriers of Nerves.

The epineurium has been accepted as the outer anatomical barrier of the peripheral nerves. Our objective was to characterize the microanatomy of the layers surrounding nerves using different tissue-specific staining methods. Two hundred forty-two cross sections of human sciatic and median nerves, and brachial plexuses of eight fresh unembalmed cadavers, were examined. The samples were fixed in formaldehyde solution and stained with hematoxylin-eosin, Masson's trichrome, or epithelial membrane antigen under standard conditions. Because epithelial membrane antigen only stains the perineurium, we demonstrated using hematoxylin-eosin and Masson's trichrome that there were different collagen layers inside and outside the nerves. All fascicles had a collagen layer that surrounded the perineurium and were in close contact with it, with no adipose tissue between them. Unlike the perineurium, this layer, an "internal epineurium," contained no cells, and it surrounded one or a small group of fascicles. Bundling these fascicles or small groups of fascicles together was the true epineurium, and between the true and internal epineurium, we consistently found an adipose-containing compartment. More proximal to this, the tibial and common peroneal nerves were bundled together by another collagen layer, the circumneurium, which also had a fat-cell-containing compartment deep to it. There were scattered collagen fibers among the adipocytes. Using tissue-specific staining, we were able to demonstrate a collagen layer, the "internal epineurium." Outside the nerves, we identified several fat-containing concentric compartments. Those compartments were limited by collagen fiber layers that were also similar to the epineurium. Clin. Anat. 33:199-206, 2020. © 2019 Wiley Periodicals, Inc.

Economic Considerations of Acute Pain Medicine Programs.

Acute pain medicine services influence many different aspects of postoperative recovery and function. Here, we discuss the various stakeholders of an acute pain medicine service, review the direct and indirect impact on said stakeholders, review the shared and competing interests between acute pain medicine programs and various payer systems, and discuss how APM services can help service lines align with the interests of the recent CMS Innovations Comprehensive Care for Joint Replacement Model.