Peripheral Blocks Research Articles

ANTAGONISM IN SYSTEM REGULATION ARTERIAL PRESSURE And ITS CHANGE after THERAPY NICERGOLINE

By the method of fractional trends, when analyzing the dynamic series of blood pressure (АД), an antagonism between the cardiac output block (CB) and the peripheral vascular resistance block (СПС) was revealed in the patient, after 12 weeks of nicergoline therapy, at the 1-3 hierarchical level of systemic regulation. At the subordinate 4-6 levels of the hierarchy, the phenomenon of antagonism was also revealed. When regulating systolic (САД) and diastolic (ДАД) blood pressure, this method revealed that nicergoline has a greater effect on the regulation of ДАД.

Decision Support System in a Memristor-Based Mobile CIM Architecture Applied on Big Data Computation and Storage

Data computation and storage are essential parts of developing big data applications. The memristor device technology could remove the speed and energy efficiency bottleneck in the existing data processing. The present experimental work investigates the decision support system in a new architecture, computation-in-memory (CIM) architecture, which can be utilized to store and process big data in the same physical location at a faster rate. The decision support system is used for data computation and storage, with the aims of helping memory units read, write, and erase data and supporting their decisions under big data communication ambiguities. Data communication is realized within the crossbar by the support of peripheral controller blocks. The feasibility of the CIM architecture, adaptive read, write, and erase methods, and memory accuracy were investigated. The integrated circuit emphasis (SPICE) simulation results show that the proposed CIM architecture has the potential of improving the computing efficiency, energy consumption, and performance area by at least two orders of magnitude. CIM architecture may be used to mitigate big data processing limits caused by the conventional computer architecture and complementary metal-oxide-semiconductor (CMOS) transistor process technologies.

Color Doppler ultrasonography of an agitated solution is predictive of accurate catheter placement for a continuous popliteal sciatic nerve block

BackgroundContinuous peripheral nerve catheters (PNCs) have been shown to provide superior postoperative analgesia, decrease opioid consumption, and improve patient satisfaction compared with single injection techniques. In order to achieve success and reliability, accurate catheter positioning is an essential element of PNC placement. An agitated solution of normal saline, D5W, or a local anesthetic solution can be produced by the introduction of air to the injectate, creating air bubbles that can enhance ultrasonographic visualization and possibly improve block success.MethodsEighty-three patients were enrolled. Ultrasound-guided continuous popliteal sciatic nerve blocks were performed by positioning the tip of a Tuohy needle between the tibial and common peroneal branches of the sciatic nerve and threading a catheter. An agitated local anesthetic solution was injected through the catheter, viewed with color Doppler ultrasound and video recorded. A peripheral block score (lower score = greater blockade, range 0-14) was calculated based upon the motor and sensory testing at 10, 20, and 30 min after block completion. The color Doppler agitation coverage pattern for the branches of the sciatic nerve was graded as follows: complete (> 50%), partial (> 0%, ≤ 50%), or none (0%).ResultsThe degree of nerve blockade at 30 min as judged by median (10th, 90th percentile) peripheral block score was significant for partial or complete color Doppler coverage of the sciatic nerve injectate compared to no coverage [3 (0, 7) vs 8 (4, 14); p < 0.01] and block onset was faster (p = 0.03). The block success was higher in groups with partial or complete coverage of the branches of the sciatic nerve vs no coverage (96% vs 70%; p = 0.02).ConclusionsInjection of an agitated solution through a popliteal sciatic perineural catheter is predictive of accurate catheter placement when partial or complete coverage of the sciatic nerve branches is visualized with color Doppler ultrasound.Trial registrationNCT01591603

Preprocedural ultrasound for neuraxial blockade in nonobstetric patients. Should it be considered as a standard of care?

Preprocedural ultrasound for neuraxial blockade in nonobstetric patients. Should it be considered as a standard of care?

Pain Management Optimisation by an Ultrasound-Guided Analgesic Technique in Outpatients with Plantar Fasciitis during High-Energy Extracorporeal Shock Wave Therapy.

Several studies have demonstrated the efficacy of high-energy extracorporeal shock wave therapy (HESWT) for the treatment of painful foot diseases. A crucial complication of HESWT is the appearance of pain with the subsequent interruption of the procedure. The aim of this study was the evaluation of ultrasound (US)-guided posterior tibial nerve block (PTNB) efficacy in outpatients who discontinued the first application of HESWT due to surge of moderate-severe pain. Twenty-one patients, scheduled for HESWT due to plantar fasciitis, who interrupted the treatment for surge of pain (numeric rating scale [NRS] 5), were enrolled. After interruption of the first treatment, the patients received US-guided PTNB for every subsequent HESWT session. The same skilled anaesthesiologist performed an US-guided PTNB all the times. Once the nerve was identified, the needle was inserted and 5ml mepivacaine 1% were injected. Intensity of pain during each procedure by NRS and evaluation of patient's adherence to the treatment were detected. The HESWT was split into only three applications giving in average about 0.25 mJ mm-2, and all patients completed the treatment sessions. US-guided PTNB showed a significant reduction of NRS (P < 0.01) between the first HEWST without anaesthesia and the three subsequent treatments under peripheral block. US-guided PTNB resulted a valid support for the HEWST in outpatients with plantar fasciitis because it reduced the pain during the procedure, allowing to minimise the patient discomfort and to give the therapeutic doses just in three sessions.

Perbedaan Respon Hemodinamik terhadap Penambahan Clonidin 1 dan 2 mcg/kgbb pada Scalp Block untuk Operasi Kraniotomi

Bacground and Objective: The addition of a levobupivacaine scalp block is effective in reducing hemodynamic responses such as blood pressure, mean arterial pressure (MAP) and pulse rate, especially when pinning, skin incisions, and durameter incisions in craniotomy. Adjuvants are often added to local anesthetics to enhance and prolong the analgesic effect of peripheral nerve blocks. Clonidine has a synergistic action with local anesthetic agents. Clonidine increases sensory and motor blocks in both peripheral and neuraxial blocks. The common dose is 2 mcg/kgbw. The aim of this study was to determine the effectiveness of adding clonidine 2 mcg/kg and 1 mcg/kg on scalp block as craniotomy analgesic. Subjects and Methods: Study on 30 patients met the inclusion criteria. Subjects were divided into three groups, group I: scalp block with levobupivacain 0.25%, group II: scalp block plus clonidine 1 mcg/kg, group III: scalp block plus clonidine 2mcg/kg. All patients were treated with general anesthesia according to the standard then assessed their blood pressure, MAP, pulse rate before intubation, pinning, skin incision and duramater incision. Results: There was a significant difference in the addition of clonidine with the control group, especially in the pulse and diastolic rates. Clonidine 2 mcg/kg at several times showed a significant difference compared to 1 mcg/kgbb dose. Conclusion: The clonidine addition to scalp block of levobupivacaine was effective in maintening hemodynamic responses, especially pulse rate and diastolic blood pressure.

A Survey of Regional Anesthesia Use in Greece and the Impact of a Structured Regional Anesthesia Course on Regional Techniques Knowledge and Practice.

Background: Due to the growing interest in regional anesthesia (RA) techniques and the realization of the need for formalized education in them, the Greek Chapter of the European Society of Regional Anesthesia and Pain Therapy (ESRA-Hellas) has established a structured hands-on training course held annually since 2009, which is quite popular in the community of Greek anesthesiologists. The aim of the current survey was twofold: first, to provide an overview of the current practice of RA in Greece; secondly, to evaluate the effect the aforementioned training course has on participants’ knowledge and attitude towards RA. Methods: An electronic questionnaire was uploaded on SurveyMonkey and a link giving access to the questionnaire was forwarded via email to a mailing list of 825 practicing Greek anesthesiologists held in the electronic database of ESRA Hellas. The survey was totally anonymous and no identifying information was collected throughout. It contained questions relating to the anesthesiologists’ demographic characteristics, their RA practice, and information pertaining to the RA training course. Results: A total of 424 fully completed questionnaires were received, representing an overall response rate of 51.4%. Attendants of the course are more familiar than non-attendants with the performance of peripheral nerve blocks with neurostimulation and/or ultrasound guidance (p < 0.001). Attendants are also less likely to practice exclusively general anesthesia, more likely to use peripheral blocks for lower limb surgery, and more likely to consider taking the European Diploma of RA in comparison to non-attendants (p < 0.001, p = 0.018 and p = 0.002, respectively). Both cohorts consider the course of value and agree that the main reason to use regional techniques is to ensure optimal postoperative analgesia, while the main hindrance to RA practice is the lack of relevant education in the techniques, especially those under ultrasound guidance. Regarding improvement of the course, most participants suggested devoting ampler time in hands-on ultrasound practice and application. Conclusions: Greek anesthesiologists seek educational activities in the field of RA and the course seems to fulfil the majority of attendants’ expectations. There will be further effort by the organizers to improve weaknesses of the current course and undertake further educational initiatives in the field of RA according to international recommendations.

Non-invasive neurostimulation modulates processing of spatial frequency information in rapid perception of faces.

This study used high-frequency transcranial random noise stimulation (tRNS) to examine how low and high spatial frequency filtered faces are processed. Response times were measured in a task where healthy young adults categorised spatially filtered hybrid faces, presented at foveal and peripheral blocks, while sham and high-frequency random noise was applied to a lateral occipito-temporal location on their scalp. Both the Frequentist and Bayesian approaches show that in contrast to sham, active stimulation significantly reduced response times to peripherally presented low spatial frequency information. This finding points to a possible plasticity in targeted regions induced by non-invasive neuromodulation of spatial frequency information in rapid perception of faces.

Ultrasound-guided peripheral trunk block technique: A new approach gradually stepping onto the stage of clinical anesthesia.

In recent years, with the continuous development and validation of new visualization, the ultrasound-guided peripheral trunk block becomes more mature and has a more extensive and broader implementation scope in clinical anesthesia. Based on this, we reviewed and summarized the literature on peripheral trunk nerve block include: paraspinal block, retrolaminar block, plane block of erect spinal muscle, transverse convex to pleural midpoint block, block of the trapezius muscle and anterior serratus muscle, anterior serratus muscle block, thoracic nerve block, abdominal transverse fascia block, type-I block of quadratus lumborum, type-II block of quadratus lumborum, type-III block of quadratus lumborum, block of the sheath of rectus abdominis. This paper reviews the ultrasound-guided peripheral trunk block technique, including development history, anatomic basis, implementation methods, advantages and disadvantages of nerve block technique, and describes the bottleneck and difficulties of nerve block technique at present.

Practice Patterns and Variability in Intraoperative Opioid Utilization: A Report From the Multicenter Perioperative Outcomes Group.

Opioids remain the primary mode of analgesia intraoperatively. There are limited data on how patient, procedural, and institutional characteristics influence intraoperative opioid administration. The aim of this retrospective, longitudinal study from 2012 to 2016 was to assess how intraoperative opioid dosing varies by patient and clinical care factors and across multiple institutions over time. Demographic, surgical procedural, anesthetic technique, and intraoperative analgesia data as putative variables of intraoperative opioid utilization were collected from 10 institutions. Log parenteral morphine equivalents (PME) was modeled in a multivariable linear regression model as a function of 15 covariates: 3 continuous covariates (age, anesthesia duration, year) and 12 factor covariates (peripheral block, neuraxial block, general anesthesia, emergency status, race, sex, remifentanil infusion, major surgery, American Society of Anesthesiologists [ASA] physical status, non-opioid analgesic count, Multicenter Perioperative Outcomes Group [MPOG] institution, surgery category). One interaction (year by MPOG institution) was included in the model. The regression model adjusted simultaneously for all included variables. Comparison of levels within a factor were reported as a ratio of medians with 95% credible intervals (CrI). A total of 1,104,324 cases between January 2012 and December 2016 were analyzed. The median (interquartile range) PME and standardized by weight PME per case for the study period were 15 (10-28) mg and 200 (111-347) μg/kg, respectively. As estimated in the multivariable model, there was a sustained decrease in opioid use (mean, 95% CrI) dropping from 152 (151-153) μg/kg in 2012 to 129 (129-130) μg/kg in 2016. The percent of variability in PME due to institution was 25.6% (24.8%-26.5%). Less opioids were prescribed in men (130 [129-130] μg/kg) than women (144 [143-145] μg/kg). The men to women PME ratio was 0.90 (0.89-0.90). There was substantial variability in PME administration among institutions, with the lowest being 80 (79-81) μg/kg and the highest being 186 (184-187) μg/kg; this is a PME ratio of 0.43 (0.42-0.43). We observed a reduction in intraoperative opioid administration over time, with variability in dose ranging between sexes and by procedure type. Furthermore, there was substantial variability in opioid use between institutions even when adjusting for multiple variables.

Non-Fellowship regional anesthesia training and assessment: an international Delphi study on a consensus curriculum

Background and objectivesWhile there are several published recommendations and guidelines for trainees undertaking subspecialty Fellowships in regional anesthesia, a similar document describing a core regional anesthesia curriculum for non-fellowship trainees...

Temperature-Mediated Nerve Blocks in the Treatment of Pain.

Analgesic hot and cold temperatures have been used for both conservative and ablative therapies for millennia. There are well-known locoregional neurovascular changes associated with the application of heat or ice in the literature and in practice. The oscillation between heat and cold has recently been identified as a synergistic mechanism of action with early translational results in humans. Recent mechanistic work in the feline model has demonstrated that a reliable, reversible nerve block can be achieved within a temperature range that is non-destructive (15-45°C). The underlying mechanism is a newly described hysteresis in the responsiveness of peripheral nerves to alternating thermal stimuli resulting in nerve blockade. Recently presented feasibility data reports positive results in subjects with occipital pain and peripheral scar pain in terms of pain and associated symptom improvement. Temperature-mediated changes in pain and sensation have been observed for hot and cold applications at a variety of temperatures. Recent insights into the synergy between preheating followed by cooling resulting in peripheral nerve fiber block has potential in a variety of conditions in which peripheral nerve etiology is noted. Recent findings in chronic headache patients report decreased pain and symptom improvement. Further studies are ongoing to understand the indications for this novel therapy.

INTRA-ARTICULAR MORPHINE AND ROPIVACAINE INJECTION PROVIDES EFFICACIOUS ANALGESIA COMPARED TO FEMORAL NERVE BLOCK IN THE FIRST 24 HOURS POST-OPERATIVELY AFTER ACL RECONSTRUCTION WITH BTB IN AN ADOLESCENT COHORT

Background:Opioid consumption and patient satisfaction are influenced by a surgeon’s pain management protocol and the use of adjunctive pain mediators. Two commonly utilized adjunctive pain modifiers for anterior cruciate ligament (ACL) reconstruction include femoral nerve blockade and intra-articular injection; however, debate remains as to the most efficacious methodology.Hypothesis/Purpose:We hypothesize that intra-articular injection with ropivacaine and morphine is as efficacious as a femoral nerve block injection of ropivacaine, dexamethasone, and dexmedetomidine for post-operative pain management in the first 24 hours after bone-patellar tendon-bone (BTB) ACL reconstruction.Methods:Charts were retrospectively reviewed for a single pediatric orthopedic surgeon performing BTB ACL reconstructions from 2013-2019. One hundred sixteen patients were identified, of whom 58 received intra-articular injection and 58 received single shot femoral nerve block. All patients were admitted for 24 hours. Pain scores were assessed every 4 hours. Morphine milligram equivalents (MME) consumed were tabulated for each patient.Results:Opioid use was 24.3 MMEs in patients treated with intra-articular injection vs 28.5MMEs in those with peripheral block (p=0.108). Consumption of MMEs was greater in the intra-articular group in the 0-4 hours period (7.1 MMEs vs. 4.6 MMEs, p=0.008). There was significantly less MME consumption in patients receiving intra-articular injection compared with peripheral block at 16-20 and 20-24 hours (3.2 MMEs vs. 5.6 MMEs, p=0.01; 3.8 MMEs vs. 6.5 MMEs, p<0.001 respectively). Mean pain scores were not significantly different over the 24-hour period (peripheral block=2.7, intra-articular injection=3.0, p=0.19).Conclusion:Moving away from the use of peripheral nerve block as an analgesic modality may be challenging given the multidisciplinary role of pain management in these patients. However, as Ramlogan et al. succinctly noted in their recent editorial “Anterior cruciate ligament repair and peripheral nerve blocks: time to change our practice?” in the British Journal of Anesthesia, both orthopedic and anesthesia colleagues alike are beginning to recognize that it is a change that may benefit our patients. Our study strengthens this argument and shows that there is no significant difference in MME consumption between the femoral nerve block and intra-articular injection groups in the first 24 hours post-operatively. While peripheral block is associated with lower opioid consumption in the first 4 hours after surgery, patients receiving intra-articular block require less opioids 16-24 hours post-operatively. Given these findings, we propose that intra-articular injection is a viable alternative for analgesia in pediatric patients undergoing BTB ACL reconstruction.Figure 1.2.Morphine milligram equivalent consumption trend during 24-hour post-operative period. PB=peripheral nerve block; IA=intra-articular injection

Efficacy of dexmedetomidine as an adjuvant in femoral nerve block for post-op pain relief in hip surgery: A prospective randomized double-blind controlled study.

Background and Aims:To determine whether the addition of dexmedetomidine either in peripheral block or via systemic route leads to prolongation of the duration of analgesia is inconclusive. The present study aimed to assess the duration of postoperative analgesia with dexmedetomidine used as an additive with bupivacaine for ultrasound-guided femoral nerve block (FNB) and to compare it with intramuscular dexmedetomidine along with FNB.Material and Methods:A prospective, double-blind randomized clinical trial involving adult patients undergoing elective hip surgery, performed under subarachnoid block. When sensory block receded to T12 after the surgery, FNB was given for postoperative analgesia. Patients were randomized into three groups; Group A received FNB with 40 mL 0.25% bupivacaine and 0.5 mL saline as IM injection, Group B received FNB with 39.5 mL of 0.25% bupivacaine + 0.5 mL (50 mcg) of dexmedetomidine in the affected limb and 0.5 mL saline IM injection, and Group C received FNB with 40 mL of 0.25% bupivacaine and 0.5 mL (50 mcg) of dexmedetomidine as IM injection. Postoperative pain was assessed and for pain with VAS score >3, intravenous tramadol was given as rescue analgesia. Chi-square test for categorical variables and one-way ANOVA for continuous variables.Results:The mean duration of analgesia in groups A, B, and C was 671, 676, and 490 min, respectively which was not significant. A 24 h analgesic requirement was also not different between the groups.Conclusion:The use of dexmedetomidine perineurally or systemically did not prolong the duration of analgesia as compared to bupivacaine alone for femoral nerve block.

Reemplazo de hombro ambulatorio: Presentación de protocolo perioperatorio y resultados iniciales

BackgroundShoulder arthoplasty is an effective procedure to improve pain and function in chronic shoulder pathologies. Considering the risks and costs associated with hospital stay, performing joint replacements on an outpatient setting emerges as an option to optimize this therapeutic strategy. MethodsA prospective analysis was performed in 10 patients undergoing same-day discharge total shoulder arthroplasty with anatomic and reverse prostheses. Pain was managed with a continuous peripheral interscalene block using an elastomeric infusion pump. ASES and SANE scores, pain, patient satisfaction, complications, and readmissions after 90 days were recorded. Results10 patients (average age 59.6 (±3.9) years) underwent outpatient shoulder arthroplasty (50% reverse shoulder arthroplasty, 40% total shoulder arthroplasty and 10% hemiarthroplasty). On post-operative day 4, mean visual analogue scale (VAS) for pain assessment was 1.3 (±0.62) and day 10, 2.7 (±1.1). Pre-operative SANE score was 31 (±9.7), and 90 days after the procedure was 76.1 (±6.8). All patients were satisfied with the procedure. One patient had a mild bronchospasm on day 3 that resolved with bronchodilators on an outpatient basis. One patient had a superficial surgical site infection that resolved completely with oral antibiotics administration. There were no re-admissions or major complications. DiscussionWe present short- to medium-term outcomes of the first case series in our setting of shoulder replacement performed with same-day discharge. This procedure can be performed safely, following a standardized protocol and making a judicious selection of patients.

Focused Ultrasound (FUS) for Chronic Pain Management: Approved and Potential Applications.

Chronic pain is one of the leading causes of disability and disease burden worldwide, accounting for a prevalence between 6.9% and 10% in the general population. Pharmacotherapy alone results ineffective in about 70-60% of patients in terms of a satisfactory degree of pain relief. Focused ultrasound is a promising tool for chronic pain management, being approved for thalamotomy in chronic neuropathic pain and for bone metastases-related pain treatment. FUS is a noninvasive technique for neuromodulation and for tissue ablation that can be applied to several tissues. Transcranial FUS (tFUS) can lead to opposite biological effects, depending on stimulation parameters: from reversible neural activity facilitation or suppression (low-intensity, low-frequency ultrasound, LILFUS) to irreversible tissue ablation (high-intensity focused ultrasounds, HIFU). HIFU is approved for thalamotomy in neuropathic pain at the central nervous system level and for the treatment of facet joint osteoarthritis at the peripheral level. Potential applications include HIFU at the spinal cord level for selected cases of refractory chronic neuropathic pain, knee osteoarthritis, sacroiliac joint disease, intervertebral disc nucleolysis, phantom limb, and ablation of peripheral nerves. FUS at nonablative dosage, LILFUS, has potential reversible and tissue-selective effects. FUS applications at nonablative doses currently are at a research stage. The main potential applications include targeted drug and gene delivery through the Blood-Brain Barrier, assessment of pain thresholds and study of pain, and reversible peripheral nerve conduction block. The aim of the present review is to describe the approved and potential applications of the focused ultrasound technology in the field of chronic pain management.

Regional Analgesia for Cardiac Surgery Part 1. Current status of neuraxial and paravertebral blocks for adult cardiac surgery.

Cardiac surgeries are known to produce moderate to severe pain. Pain management has traditionally been based on intravenous opioids. Poorly controlled pain can result in increased incidence of respiratory complications such as atelectasis and pneumonia leading to prolonged intubation and intensive care unit length of stay and subsequent prolonged hospital stay. Adequate perioperative analgesia improves hemodynamics and immunologic responses, which would result in better outcomes after cardiac surgery. Opioid sparing "Enhanced Recovery After Surgery" protocols are increasingly being incorporated into cardiac surgeries. This will reduce opioid requirements and opioid-related side effects and facilitate fast-tracking of patients. Regional analgesia can be provided by neuraxial blocks, fascial plane blocks, peripheral nerve blocks, or simply by the infiltration of the wound with local anesthetics for cardiac surgery. Neuraxial analgesia is provided through epidural, spinal, and paravertebral routes. Though they are being replaced by peripheral fascial plane blocks, epidural and spinal analgesia are still being used in some centers. In this article, neuraxial forms of analgesia are focused. We sought to review epidural analgesia and its impact in suppressing hemodynamic stress response, reducing pulmonary complications, and development of chronic pain. The relationship between intraoperative heparinization and potential neuraxial hematoma is discussed. Other neuraxial options such as spinal and paravertebral analgesia and their usefulness, benefits, and limitations are also reviewed.

The cause for Nuna breakup in the Early to Middle Mesoproterozoic

The dynamic mechanism responsible for the breakup of Nuna supercontinent (1.6–1.3 Ga) is a key for understanding the early to middle Mesoproterozoic environment, life and mineralization on Earth. Although much research has been done to unravel the dispersion of young supercontinents (e.g., Pangea), efforts by sorting out critical geological records to disclose the driving force for Nuna breakup are still rare. Here we focus on this issue by integrating new whole-rock geochemical data, zircon U–Pb ages, Hf-in-zircon and Nd isotopes for Mesoproterozoic granitoids in the Chinese Central Tianshan (CTB) at the Central Asian Orogenic Belt (CAOB). Moreover, global geological data in the early to middle Mesoproterozoic are compiled to place further constraints. The studied granitoids are I-type granites emplaced at ca. 1480–1450 Ma. They were formed in an active continental margin of CTB that once belonged to the Fennoscandia in the margin of Nuna. These results, together with the available geological records in CTB, CAOB and Fennoscandia, indicate a subduction system existed along the periphery of these domains in the early to middle Mesoproterozoic. This subduction system was temporally and spatially linked to the 1.6–1.3 Ga accretionary belts in the peripheral blocks of Nuna supercontinent, suggesting an encircling subduction system surrounding Nuna supercontinent. The encircling subduction system was accompanied by intermittent Mesoproterozoic plume magmatism, some of which were geochemically overprinted with subduction-related signatures, suggesting a dominant continuous circum-supercontinent subduction operating on the breakup of Nuna supercontinent. Moreover, these episodic plume-related magmatism are temporally and geodynamically linked to the exterior subduction surrounding the Nuna supercontinent. Our study therefore demonstrates that the development of an exterior subduction system gave rise to the breakup of Nuna supercontinent, which was accompanied by subordinate plume activities.

Safety of Ultrasound-Guided Serratus Anterior and Erector Spinae Fascial Plane Blocks: A Retrospective Analysis in Patients Undergoing Cardiac Surgery While Receiving Anticoagulant and Antiplatelet Drugs

Chest wall blocks are an effective strategy for postoperative pain control in minimally invasive cardiac surgery, but, in the absence of clinical trials evaluating their safety in the presence of anticoagulant and antiplatelet drugs, it still is recommended to follow the same guidelines developed for the neuraxial procedures and for peripheral blocks. Retrospective observational study. AOU Città della Salute e della Scienza di Torino, University of Turin, Italy. Between March 28, 2019 and October 19, 2020, 70 patients who underwent mitral valve surgery via right minithoracotomy were enrolled: 35 treated with continuous erector spinae plane block (ESPB) and 35 with continuous serratus anterior plane block (SAPB). The primary objective was the evaluation of the number of blocks performed or catheters removed while coagulation was abnormal or antithrombotic and anticoagulant therapies were in progress. Eleven patients (15.7%) received fascial plane block with international normalized ratio (INR) > 1.40, four patients (5.71%) with a platelet count <80×103, and one patient received ESPB block during dual-antiplatelet therapy. In 16 patients (22.9%), the catheter was removed with an INR > 1.40, in five patients (7.1%) with a platelet count <80×103, and in 53 patients (75.71%) despite low-molecular-weight heparin at therapeutic dose. The median antagonist dose of vitamin K at the time of catheter removal was 2.5 mg (range 2.5-3.44 mg) in both groups. No major adverse effects directly attributable to the blocks were observed. The authors did not find any problems related to the use of continuous ESPB and SAPB, although they were performed in the presence of anticoagulation and in a context with a high risk of bleeding such as cardiac surgery.

Platelet aggregometry for hip fracture surgery in patients treated with clopidogrel: a pilot study.

Surgery for hip fractures should be performed within 48h from patient's admission. However, several factors including chronic antiplatelet therapy could delay operation. Among the totality of patients taking clopidogrel, up to 30% are resistant to the drug and have a normal platelets reactivity. We propose thromboelastography (TEG) with an ADP Platelet Mapping assay kit to assess platelet aggregation, a safe tool that could help to avoid surgery delay in those patients treated with antiplatelet therapy. A patient's blood sample was collected for aggregometry. If MA-ADP and platelets aggregation (%) were within normal values, the patient was fit for immediate surgery with neuraxial anesthesia and ultrasound-guided nerve block. If one of the two parameters or both were deranged, a mortality risk assessment was estimated. In the low risk category, the patients waited till normalization of the parameters, whereas in the high-risk group a general anesthesia and peripheral antalgic block was carried out. Nine patients were enrolled. Four of them showed normal aggregometry and surgery was performed within 24h from admission. Two patients were classified as high mortality risk and surgery was carried out under general anesthesia. Three patients awaited operation till normalization of parameters. No peri or post-operative complications were reported. An aggregometry-guided protocol can safely expedite hip fracture surgery in patients taking clopidogrel. Nonetheless, in presence of a normal platelets function, clinician can opt for a neuraxial instead of general anesthesia reducing the incidence of postoperative delirium and cognitive dysfunction.Trial registration: prospectively registered at clinicaltrials.gov (NCT04642209; date of registration: 23rd November 2020).