Effects of COVID-19 Pandemic in Patients with a Previous Phrenic Nerve Transfer for a Traumatic Brachial Plexus Palsy.

Background With the advent of the coronavirus disease 2019 (COVID-19) pandemic, some doubts have been raised regarding the potential respiratory problems that patients who previously underwent a phrenic nerve transfer could have. Objectives To analyze the effects of the coronavirus infection on two populations, one from Argentina and another from Taiwan. Specific objectives were: (1) to identify the rate of COVID in patients with a history of phrenic nerve transfer for treatment of palsy; (2) to identify the overall symptom profile; (3) to compare Argentinian versus Taiwanese populations; and (4) to determine if any phrenic nerve transfer patients are at particular risk of more severe COVID. Methods A telephonic survey that included data regarding the number of episodes of acute COVID-19 infection, the symptoms it caused, the presence or absence of potential or life-threatening complications, and the status of COVID-19 vaccination were studied. Intergroup comparisons were conducted using the nonparametric Mann-Whitney U test, with categorical variables conducted using either the Pearson χ2 analysis or the Fisher's exact test, as appropriate. Results A total of 77 patients completed the survey, 40 from Taiwan and 37 from Argentina. Fifty-five (71.4%) developed a diagnosis of COVID. However, among these, only four had any level of dyspnea reported (4/55 = 7.3%), all mild. There were also no admissions to hospital or an intensive care unit, no intubations, and no deaths. All 55 patients isolated themselves at home. Conclusions It can be concluded that an acute COVID-19 infection was very well tolerated in our patients. (Level of evidence 3b, case reports).

Multi targets of cannabidiol (CBD) on skeletal mammalian and avian neuromuscular preparations.

Cannabidiol (CBD) has been used in diseases that affect the central nervous system. Its effects on the peripheral synapses are of great interest, since endocannabinoid receptors are expressed in muscles. CBD (0.3 mM) was analysed using mammalian and avian neuromuscular preparations, through myographic techniques in complementary protocols. Mammalian cells were examined by light microscopy while exogenous acetylcholine (40 µM) and potassium chloride (100 mM) were added into avian preparations, before and at the end of experiments. Pharmacological tools such as atropine (2 µM), polyethylene glycol (PEG 400, 20 µM), Ca2+ (1.8 mM), F55-6 (20 µg/mL), and nifedipine (1.3 mM) were assessed with CBD. In mice, CBD causes a facilitatory effect and paralysis, whereas in avian, paralysis. Concluding, CBD is responsible for activated or inhibited channels, for ACh release via muscarinic receptor modulation, and by the inhibition of nicotinic receptors leading to neuromuscular blockade, with no damage to striated muscle cells.

Ultrasound-guided bilateral pulsed radiofrequency of the phrenic nerve for prolonged hiccups: a case report.

Singultus is the sudden onset of erratic diaphragmatic and intercostal muscle contraction immediately followed by laryngeal closure. Pathophysiology involves afferent, central and efferent components. Bilateral phrenic nerve block was performed to a 46-year-old woman with a brain tumor with persistent hiccups, with initially positive response but later symptom recurrence. Bilateral pulsed radiofrequency of the phrenic nerve was performed guided by ultrasonography (US). In the follow-up, absence of hiccups was confirmed. The patient was discharged 24 h later. Persistent or untreatable singultus is an infrequent condition that should not be dismissed. This approach is a safe, accurate and effective therapeutic approach for patient's refractory to conservative treatment. Further studies are needed to establish safety and effectiveness of the treatment.

Changes in phrenic nerve compound muscle action potential in streptozotocin-induced diabetic rats.

PURPOSE: To evaluate the phrenic nerve compound muscle action potential (CMAP) in rats after diabetes mellitus (DM) induction. METHODS: Twenty DM animals (intravenous streptozotocin, 45 mg.kg-1) and 25 controls underwent CMAP analysis before and 30, 60 and 90 days after DM induction. RESULTS: Amplitude (mV) progressively declined in DM group after 30 (Mean difference (MD): -0.915, 95 % Confidence interval (CI) -1.580 to -0.250, p < 0.01), 60 (MD: -1.122, 95 % CI -1.664 to -0.581, p < 0.001) and 90 days (MD: -2.226, 95 % CI -3.059 to -1.393, p < 0.001); as well as the area (mV.ms) after 30 (MD: -3.19, 95 % CI -5.94 to -0.44, p < 0.05), 60 (MD: -3.94, 95 % CI -6.24 to -1.64, p < 0.001) and 90 days (MD: -8.64, 95 % CI -12.08 to -5.21, p < 0.001). Transient differences were observed in latency and duration at 60 days. CONCLUSIONS: The progressive changes in phrenic nerve CMAP observed during DM suggest a decrement in axonal function rather than substantial demyelination.

Terminal Anatomy of Phrenic Nerve: A Deeper Look at Diaphragm Innervation Patterns.

BACKGROUND: Traumatic brachial plexus injuries are devastating lesions, and neurotization is an usually elected surgical therapy. The phrenic nerve has been harvested as a motor fibers donor in brachial plexus neurotization, showing great results in terms of motor reinnervation. Unfortunately, these interventions lack solid evidence regarding long-term safety and possible late respiratory function sequelae, raising crescent concerns after the COVID-19 pandemic onset and possibly resulting in reduced propensity to use this technique. The study of the distal anatomy of the phrenic nerves may lead to a better understanding of their branching patterns, and thus the proposition of surgical approaches that better preserve patient respiratory function. METHODS: Twenty-one phrenic nerves in 10 formalized cadavers were scrutinized. Prediaphragmatic branching patterns were inspected through analysis of the distance between the piercing site of the nerve at the diaphragm and the cardiac structures, number of divisions, and length from the point where the main trunk emits its branches to the diaphragm. RESULTS: The main trunk of the right phrenic nerve reaches the diaphragm near the inferior vena cava and branches into 3 major divisions. The left phrenic nerve reaches the diaphragm in variable locations near the heart, branching into 2-5 main trunks. Moreover, we noticed a specimen presenting 2 ipsilateral parallel phrenic nerves. CONCLUSIONS: The right phrenic nerve presented greater consistency concerning insertion site, terminal branching point distance to this muscle, and number of rami than the left phrenic nerve.

Comparative analysis of origin and branches of phrenic nerve in the diaphragm of the crab-eating fox (Cerdocyon thous) and domestic dog (Canis lupus familiaris).

The crab-eating fox (Cerdocyon thous) is a canid widely distributed throughout South America, considered the only representative of the gender. There is a lack of information about anatomical aspects of the species, mainly regarded of nervous system anatomy. For clinical and surgical approaches of these animals, the domestic dog is adopted as anatomophysiological model. So, the aim of the present study was to analyse origin and branches of the phrenic nerve in the diaphragm of crab-eating fox compared to domestic dog. Four specimens of Cerdocyon thous and four of Canis lupus familiaris were used. The phrenic nerve originated from the ventral branches of the fifth (C5), sixth (C6) and seventh (C7) cervical spinal nerves. Phrenic nerves were distributed in the diaphragm as lumbocostal trunk and sternal branch (100%) in the crab-eating fox, and in costosternal trunk and lumbar branch (75%) and lumbocostal trunk and sternal branch (25%) in the domestic dog. In both species, the lumbar branch innervates the diaphragm pillars, the costal branch addresses all costal region, and the sternal branch distributes in the costal ventrolateral region and the sternal part of the diaphragm, to the left and to the right.

In Situ Effects of Doxycycline on Neuromuscular Junction in Mice.

BACKGROUND: The antibacterial mechanism of doxycycline is known, but its effects on the nerve-muscle system are still not unclear. OBJECTIVE: The aim of the study was to combine molecular targets of the neuromuscular machinery using the in situ neuronal blocker effect of doxycycline, a semisynthetic second-generation tetracycline derivative, on mice neuromuscular preparations. METHODS: The effects of doxycycline were assessed on presynaptic, synaptic cleft, and postsynaptic neurotransmission, along with the muscle fiber, using the traditional myographic technique. Precisely, the effects of doxycycline were categorized into "all" or "nothing" effects depending on the concentration of doxycycline used; "all" was obtained with 4 µM doxycycline, and "nothing" was obtained with 1-3 µM doxycycline. The rationale of this study was to apply known pharmacological tools against the blocker effect of 4 µM doxycycline, such as F55-6 (Casearia sylvestris), CaCl2 (or Ca2+), atropine, neostigmine, polyethylene glycol (PEG 400), and d-Tubocurarine. The evaluation of cholinesterase enzyme activity and the diaphragm muscle histology were performed, and protocols on the neuromuscular preparation submitted to indirect or direct stimuli were complementary. RESULTS: Doxycycline does not affect cholinesterase activity nor causes damage to skeletal muscle diaphragm; it acts on ryanodine receptor, sarcolemmal membrane, and neuronal sodium channel with a postjunctional consequence due to the decreased availability of muscle nicotinic acetylcholine receptors. CONCLUSION: In conclusion, in addition to the neuronal blocker effect of doxycycline, we showed that doxycycline acts on multiple targets. It is antagonized by F55-6, a neuronal Na+-channel agonist, and Ca2+, but not by neostigmine.

Aberrant branches of the subclavian artery and their relationship with the phrenic nerve and the brachial plexus / Ramas aberrantes de la arteria subclavia y su relación con el nervio frénico y el plexo braquial

SUMMARY: Variations in subclavian artery branches are relatively common and may impact surgical procedures and effects. During educational dissection of a male cadaver, we encountered an extremely rare variation of the right subclavian artery branches. The internal thoracic artery, the thyrocervical trunk, and the costocervical trunk arose from the third part of the right subclavian artery. In addition, the phrenic nerve displaced remarkably laterally by the thyrocervical trunk, and the course of the costocervical trunk was between the upper trunk and the middle trunk of the brachial plexus. These variations may pose a potential risk for nerve compression and increase the risk of arterial and nerve puncture. This case report would bring attention to the possibility of other similar cases, and early detection of these variations through diagnostic interventions is helpful to reduce postoperative complications.

RESUMEN: Las variaciones en las ramas de la arteria subclavia son relativamente comunes y pueden afectar los procedimientos y efectos quirúrgicos. Durante la disección educativa de un cadáver masculino, encontramos una variación extremadamente rara de las ramas de la arteria subclavia derecha. La arteria torácica interna, el tronco tirocervical y el tronco costocervical nacían de la tercera parte de la arteria subclavia derecha. Además, el nervio frénico se desplazaba lateralmente por el tronco tirocervical, y el trayecto del tronco costocervical se encontraba entre el tronco superior y el tronco medio del plexo braquial. Estas variaciones pueden suponer un riesgo potencial de compresión nerviosa y aumentar el riesgo de punción arterial y nerviosa. Este reporte de caso llamaría la atención sobre la posibilidad de otros casos similares, y la detección temprana de estas variaciones a través de diagnósticos es útil para reducir las complicaciones postoperatorias.

Hipo y anestesia / Hiccups and anesthesia

Hiccups are a spasmodic and intermittent contraction of the diaphragm and accessory muscles of inspiration, which ends abruptly with the closure of the glottis. It prevents activities of daily living, decreases the quality of life of those who suffer from it and can predispose to regurgitation and dehiscence of the surgical wound. It is usually benign, of unknown cause, being more frequent in men than in women. 70% of the cases present in the ages of 40-60 years and it is the left hemidiaphragm that is affected in most of the cases. There are many causes that originate it, some of them related to anesthesia. In the anesthetized patient, hiccups can interfere with diagnostic studies such as magnetic resonance imaging (MRI), procedures such as radiotherapy and prevent the performance of surgical interventions. The therapeutic options are varied, including non-pharmacological alternatives, pharmacological and invasive procedures.

El hipo es una contracción espasmódica e intermitente del diafragma y de los músculos accesorios de la inspiración, que finaliza de forma brusca con el cierre de la glotis. Impide las actividades de vida diaria, disminuye la calidad de vida de quien lo padece y puede predisponer a la regurgitación y la dehiscencia de la herida quirúrgica. Habitualmente es benigno, de causa desconocida, siendo más frecuente en el hombre que en la mujer. El 70% de los casos se presenta en las edades de 40-60 años, siendo el hemidiafragma izquierdo el más afectado en la mayoría de los casos. Son numerosas las causas que lo originan, algunas de ellas relacionadas con la anestesia. En el paciente anestesiado, el hipo puede interferir con estudios de diagnóstico como la resonancia magnética nuclear (RMN), procedimientos como la radioterapia e impedir la realización de intervenciones quirúrgicas. Las opciones terapéuticas son variadas, incluyendo alternativas no farmacológicas, farmacológicas y procedimientos invasivos.

Transfer of the phrenic nerve to musculocutaneous nerve via sural nerve graft after total brachial plexus injury.

A middle age male presented a right total brachial plexus injury after motorcycle fall one year ago. Subsequent electromyographic evaluation was consistent with C5, C6, C7, C8 and T1 root avulsion. The patient was submitted to a right transfer of the phrenic nerve to musculocutaneous nerve , using rural nerve graft.

Anterior scalene plane block at the superior trunk level relieves referred shoulder pain after liver radiofrequency ablation: a technical report.

We report the first case of using an anterior scalene plane block at the superior trunk level achieving phrenic nerve blockade to treat intolerable referred shoulder pain after liver Radiofrequency Ablation (RFA) of a diaphragm-abutting liver tumor despite prevention with a full-dose non-steroidal anti-inflammatory drug. The anterior scalene plane block rapidly alleviated pain without significant complications.

Pulmonary capacity of patients with total traumatic injury of the brachial plexus submitted to neurotization with the phrenic nerve: a case series / Capacidade pulmonar de pacientes com lesão traumática total do plexo braquial submetidos à neurotização com o nervo frênico: uma série de casos

Total traumatic injury often requires surgical intervention such as neurotization using the phrenic nerve with the aim to recover the elbow function. However, its repercussions on the respiratory kinematics are unknown. Objective: To evaluate the ribcage volume in tricompartments division, kinematics of Duty Cycle, and shortening velocity of the respiratory muscles after nerve phrenic transfer. Methods: Five participants (4 male), aged 18 to 40 years old (32±2), diagnosed with total brachial plexus injury and with nerve phrenic transfer. The optoelectronic plethysmography (OEP) was the instrument to evaluate volume in quiet breathing (QB), inspiratory capacity (IC) and vital capacity (VC) of the rib cage in its tricompartments division (pulmonary rib cage, abdominal rib cage and abdomen rib cage) and in each hemithorax, as well as the shortening velocity of the respiratory muscles, and respiratory rate. Assessments occurred 30 days prior and 30 days after surgery. Results: There was a decrease in the total compartmental distribution in QB with statistical difference only in the abdominal compartment (p <0.05). Four patients showed a reduction in the shortening speed of the left diaphragm muscle. It was not possible to perform a group analysis of respiratory kinematics and volumes in CV, IC due to the variation found in each patient analyzed. Conclusion: There was a reduction in volume in the rib cage as well as a change in the speed of shortening of the respiratory muscles after the transfer of the phrenic nerve one month after surgery.

A lesão traumática total freqüentemente requer intervenção cirúrgica, como neurotização usando o nervo frênico, com o objetivo de recuperar a função do cotovelo. No entanto, suas repercussões na cinemática respiratória são desconhecidas. Objetivo: Avaliar o volume da caixa torácica na divisão dos tricompartimentos, a cinemática do Duty Cycle e a velocidade de encurtamento dos músculos respiratórios após a transferência do nervo frênico. Métodos: Cinco participantes (4 do sexo masculino), com idade entre 18 e 40 anos (32 ± 2), com diagnóstico de lesão total do plexo braquial e transferência do nervo frênico. A pletismografia optoeletrônica (OEP) foi o instrumento para avaliar o volume na respiração silenciosa (QB), a capacidade inspiratória (IC) e a capacidade vital (VC) da caixa torácica em sua divisão tricompartimental (caixa torácica pulmonar, caixa torácica abdominal e caixa torácica do abdômen ) e em cada hemitórax, bem como a velocidade de encurtamento dos músculos respiratórios e a frequência respiratória. As avaliações ocorreram 30 dias antes e 30 dias após a cirurgia. Resultados: Houve diminuição da distribuição compartimental total no QB com diferença estatística apenas no compartimento abdominal (p <0,05). Quatro pacientes apresentaram redução da velocidade de encurtamento do músculo diafragma esquerdo. Não foi possível realizar uma análise de grupo da cinemática respiratória e dos volumes em CV, IC devido à variação encontrada em cada paciente analisado. Conclusão: Houve redução do volume da caixa torácica e também alteração da velocidade de encurtamento dos músculos respiratórios após a transferência do nervo frênico um mês após a cirurgia.

Comparison Between Supraclavicular Versus Video-Assisted Intrathoracic Phrenic Nerve Section for Transfer in Patients With Traumatic Brachial Plexus Injuries: Case Series.

BACKGROUND: The phrenic nerve has been extensively reported to be a very powerful source of transferable axons in brachial plexus injuries. The most used technique used is supraclavicular sectioning of this nerve. More recently, video-assisted thoracoscopic techniques have been reported as a good alternative, since harvesting a longer phrenic nerve avoids the need of an interposed graft. OBJECTIVE: To compare grafting vs phrenic nerve transfer via thoracoscopy with respect to mean elbow strength at final follow-up. METHODS: A retrospective analysis was conducted among patients who underwent phrenic nerve transfer for elbow flexion at 2 centers from 2008 to 2017. All data analysis was performed in order to determine statistical significance among the analyzed variables. RESULTS: A total of 32 patients underwent supraclavicular phrenic nerve transfer, while 28 underwent phrenic nerve transfer via video-assisted thoracoscopy. Demographic characteristics were similar in both groups. A statistically significant difference in elbow flexion strength recovery was observed, favoring the supraclavicular phrenic nerve section group against the intrathoracic group (P = .036). A moderate though nonsignificant difference was observed favoring the same group in mean elbow flexion strength. Also, statistical differences included patient age (P = .01) and earlier time from trauma to surgery (P = .069). CONCLUSION: Comparing supraclavicular sectioning of the nerve vs video-assisted, intrathoracic nerve sectioning to restore elbow flexion showed that the former yielded statistically better results than the latter, in terms of the percentage of patients who achieve at least level 3 MRC strength at final follow-up. Furthermore, larger scale prospective studies assessing the long-term effects of phrenic nerve transfers remain necessary.

Differences in strength fatigue when using different donors in traumatic brachial plexus injuries.

BACKGROUND: The purpose of this study was to assess the results of elbow flexion strength fatigue, rather than the maximal power of strength, after brachial plexus re-innervation with phrenic and spinal accessory nerves. We designed a simple but specific test to study whether statistical differences were observed among those two donor nerves. METHOD: We retrospectively reviewed patients with severe brachial plexus palsy for which either phrenic nerve (PN) or spinal accessory nerve (SAN) to musculocutaneous nerve (MCN) transfer was performed. A dynamometer was used to determine the maximal contraction strength. One and two kilograms circular weights were utilized to measure isometrically the duration of submaximal and near-maximal contraction time. Statistical analysis was performed between the two groups. RESULTS: Twenty-eight patients were included: 21 with a PN transfer while 7 with a SAN transfer for elbow flexion. The mean time from trauma to surgery was 7.1 months for spinal accessory nerve versus 5.2 for phrenic nerve, and the mean follow-up was 57.7 and 38.6 months, respectively. Statistical analysis showed a quicker fatigue for the PN, such that patients with the SAN transfer could hold weights of 1 kg and 2 kg for a mean of 91.0 and 61.6 s, respectively, while patients with transfer of the phrenic nerve could hold 1 kg and 2 kg weights for just a mean of 41.7 and 19.6 s, respectively. Both differences were statistically significant (at p = 0.006 and 0.011, respectively). Upon correlation analysis, endurances at 1 kg and 2 kg were strongly correlated, with r = 0.85 (p < 0.001). CONCLUSIONS: Our results suggest that phrenic to musculocutaneous nerve transfer showed an increased muscular fatigue when compared with spinal accessory nerve to musculocutaneous transfer. Further studies designed to analyze this relation should be performed to increase our knowledge about strength endurance/fatigue and muscle re-innervation.

Estudio histopatológico comparativo del nervio frénico proveniente de cadáveres con enfermedad pulmonar obstructiva crónica y sin esta condición / Comparative Histopathological Study Of The Phrenic Nerve From Corpses With Chronic Obstructive Pulmonary Disease And Without This Condition

Introducción: Los cambios funcionales resultantes de la evolución de la enfermedad pulmonar obstructiva crónica (EPOC) son progresivos e irreversibles, lo que provoca un aumento del trabajo del diafragma debido a la hiperinflación. Los nervios frénicos promueven la inervación del diafragma y pueden verse comprometidos en la condición de EPOC.Objetivo: Comparar la morfología de los nervios frénicos de los cadáveres con y sin EPOC, mediante microscopía óptica. Métodos: Estudio descriptivo, transversal y comparativo de muestras, tanto de los pulmones como de los nervios frénicos de 38 cadáveres, con diagnóstico de EPOC y sin esta condición. Las muestras de tejido fueron fijadas y procesadas por histología convencional con láminas histológicas de hematoxilina-eosina. Las muestras fueron compuestas por pacientes con EPOC (EPOC) y sin EPOC (CTR). Esta clasificación se realizó después del análisis histológico. Las láminas histológicas se analizaron mediante microscopía óptica por un patólogo, que fue un evaluador ciego al estudio. Resultados: De acuerdo con los criterios de inclusión, se incluyeron 31 cadáveres en el grupo de EPOC y 7 cadáveres en el grupo CTR. En el análisis de los nervios frénicos, 8 cadáveres, es decir 25,8% del grupo de EPOC, tuvieron cambios histopatológicos como edema perineural (75%, n=6), atrofia nerviosa (12,5%, n=1) e infiltrado eosinofílico perineural (12,5%, n=1). Conclusión: Los nervios frénicos de los cadáveres con EPOC tienen tendencia a alteraciones histopatológicas, siendo el edema perineural la principal modificación encontrada

Introducción: Los cambios funcionales resultantes de la evolución de la enfermedad pulmonar obstructiva crónica (EPOC) son progresivos e irreversibles, lo que provoca un aumento del trabajo del diafragma debido a la hiperinflación. Los nervios frénicos promueven la inervación del diafragma y pueden verse comprometidos en la condición de EPOC.Objetivo: Comparar la morfología de los nervios frénicos de los cadáveres con y sin EPOC, mediante microscopía óptica. Métodos: Estudio descriptivo, transversal y comparativo de muestras, tanto de los pulmones como de los nervios frénicos de 38 cadáveres, con diagnóstico de EPOC y sin esta condición. Las muestras de tejido fueron fijadas y procesadas por histología convencional con láminas histológicas de hematoxilina-eosina. Las muestras fueron compuestas por pacientes con EPOC (EPOC) y sin EPOC (CTR). Esta clasificación se realizó después del análisis histológico. Las láminas histológicas se analizaron mediante microscopía óptica por un patólogo, que fue un evaluador ciego al estudio. Resultados: De acuerdo con los criterios de inclusión, se incluyeron 31 cadáveres en el grupo de EPOC y 7 cadáveres en el grupo CTR. En el análisis de los nervios frénicos, 8 cadáveres, es decir 25,8% del grupo de EPOC, tuvieron cambios histopatológicos como edema perineural (75%, n=6), atrofia nerviosa (12,5%, n=1) e infiltrado eosinofílico perineural (12,5%, n=1). Conclusión: Los nervios frénicos de los cadáveres con EPOC tienen tendencia a alteraciones histopatológicas, siendo el edema perineural la principal modificación encontrada

Phrenic nerve neurotization utilizing half of the spinal accessory nerve to the functional restoration of the paralyzed diaphragm in high spinal cord injury secondary to brain tumor resection.

The authors present a case of functional improvement of diaphragmatic paralysis in high spinal cord injury, performing a neurotization of the phrenic nerve with accessory spinal nerve hemisection. A C1-C2 injury of the spinal cord was diagnosed in a 12-year-old male, secondary to resection of a brainstem glioma. The patient did not have diaphragmatic motility at the moment that the mechanical ventilation was removed; however, he presented apnea. The patient underwent neurotization of the right phrenic nerve with the right spinal accessory nerve, 5 months after the injury and 6 months after nerve transfer; he had complete mobilization of the right hemidiaphragm, nevertheless persisted with paralysis of the left hemidiaphragm. This achievement reduced the use of mechanical ventilation during the day.

[Hemidiaphragmatic paralysis after ultrasound-guided supraclavicular block: a prospective cohort study]. / Paralisia hemidiafragmática após bloqueio supraclavicular guiado por ultrassom: um estudo coorte prospectivo.

BACKGROUND AND OBJECTIVES: The frequent onset of hemidiaphragmatic paralysis during interscalene block restricts its use in patients with respiratory insufficiency. Supraclavicular block could be a safe and effective alternative. Our primary objective was to assess the incidence of hemidiaphragmatic paralysis following ultrasound-guided supraclavicular block and compare it to that of interscalene block. METHODS: Adults warranting elective shoulder surgery under regional anesthesia (Toulouse University Hospital) were prospectively enrolled from May 2016 to May 2017 in this observational study. Twenty millilitres of 0.375% Ropivacaine were injected preferentially targeted to the "corner pocket". Diaphragmatic excursion was measured by ultrasonography before and 30 minutes after regional anesthesia. A reduction ≥ 25% in diaphragmatic excursion during a sniff test defined the hemidiaphragmatic paralysis. Dyspnoea and hypoxaemia were recorded in the recovery room. Predictive factors of hemidiaphragmatic paralysis (gender, age, weight, smoking, functional capacity) were explored. Postoperative pain was also analysed. RESULTS: Forty-two and 43 patients from respectively the supraclavicular block and interscalene block groups were analysed. The incidence of hemidiaphragmatic paralysis was 59.5% in the supraclavicular block group compared to 95.3% in the interscalene block group (p < 0.0001). Paradoxical movement of the diaphragm was more common in the interscalene block group (RR = 2, 95% CI 1.4-3; p = 0.0001). A similar variation in oxygen saturation was recorded between patients with and without hemidiaphragmatic paralysis (p = 0.08). No predictive factor of hemidiaphragmatic paralysis could be identified. Morphine consumption and the highest numerical rating scale (NRS) at 24 hours did not differ between groups. CONCLUSIONS: Given the frequent incidence of hemidiaphragmatic paralysis following supraclavicular block, this technique cannot be recommended for patients with an altered respiratory function.

Hemidiaphragmatic paralysis after ultrasound-guided supraclavicular block: a prospective cohort study / Paralisia hemidiafragmática após bloqueio supraclavicular guiado por ultrassom: um estudo coorte prospectivo

Abstract Background and objectives: The frequent onset of hemidiaphragmatic paralysis during interscalene block restricts its use in patients with respiratory insufficiency. Supraclavicular block could be a safe and effective alternative. Our primary objective was to assess the incidence of hemidiaphragmatic paralysis following ultrasound-guided supraclavicular block and compare it to that of interscalene block. Methods: Adults warranting elective shoulder surgery under regional anesthesia (Toulouse University Hospital) were prospectively enrolled from May 2016 to May 2017 in this observational study. Twenty millilitres of 0.375% Ropivacaine were injected preferentially targeted to the "corner pocket". Diaphragmatic excursion was measured by ultrasonography before and 30 minutes after regional anesthesia. A reduction ≥25% in diaphragmatic excursion during a sniff test defined the hemidiaphragmatic paralysis. Dyspnoea and hypoxaemia were recorded in the recovery room. Predictive factors of hemidiaphragmatic paralysis (gender, age, weight, smoking, functional capacity) were explored. Postoperative pain was also analysed. Results: Forty-two and 43 patients from respectively the supraclavicular block and interscalene block groups were analysed. The incidence of hemidiaphragmatic paralysis was 59.5% in the supraclavicular block group compared to 95.3% in the interscalene block group (p < 0.0001). Paradoxical movement of the diaphragm was more common in the interscalene block group (RR = 2, 95% CI 1.4-3; p = 0.0001). A similar variation in oxygen saturation was recorded between patients with and without hemidiaphragmatic paralysis (p = 0.08). No predictive factor of hemidiaphragmatic paralysis could be identified. Morphine consumption and the highest numerical rating scale numerical rating scale (NRS) at 24 hours did not differ between groups. Conclusions: Given the frequent incidence of hemidiaphragmatic paralysis following supraclavicular block, this technique cannot be recommended for patients with an altered respiratory function.

Resumo Justificativa e objetivos: O aparecimento frequente de paralisia hemidiafragmática durante o bloqueio interescalênico restringe seu uso em pacientes com insuficiência respiratória. O bloqueio supraclavicular pode ser uma opção segura e eficaz. Nosso objetivo primário foi avaliar a incidência de paralisia hemidiafragmática após bloqueio supraclavicular guiado por ultrassom e compará-lo com o bloqueio interescalênico. Métodos: Os adultos agendados para cirurgia eletiva do ombro sob anestesia regional (Hospital Universitário de Toulouse) foram prospectivamente incluídos neste estudo observacional, de maio de 2016 a maio de 2017. Vinte mililitros de ropivacaína a 0,375% foram injetados, preferencialmente objetivando a interseção da primeira costela e da artéria subclávia. A excursão diafragmática foi medida por ultrassonografia antes e 30 minutos após a anestesia regional. Uma redução ≥ 25% na excursão diafragmática durante um sniff test definiu a paralisia hemidiafragmática. Dispneia e hipoxemia foram registradas na sala de recuperação. Fatores preditivos de paralisia hemidiafragmática (sexo, idade, peso, tabagismo, capacidade funcional) foram explorados. A dor pós-operatória também foi avaliada. Resultados: Quarenta e dois e 43 pacientes dos grupos bloqueio supraclavicular e bloqueio interescalênico, respectivamente, foram avaliados. A incidência de paralisia hemidiafragmática foi de 59,5% no grupo bloqueio supraclavicular em comparação com 95,3% no grupo bloqueio interescalênico (p < 0,0001). O movimento paradoxal do diafragma foi mais comum no grupo bloqueio interescalênico (RR = 2, 95% IC 1,4-3; p = 0,0001). Uma variação semelhante na saturação de oxigênio foi registrada entre os pacientes com e sem paralisia hemidiafragmática (p = 0,08). Nenhum fator preditivo de paralisia hemidiafragmática pôde ser identificado. O consumo de morfina e o maior escore na escala numérica (NRS) em 24 horas não diferiram entre os grupos. Conclusão: Devido à frequente incidência de paralisia hemidiafragmática após bloqueio supraclavicular, essa técnica não pode ser recomendada para pacientes com função respiratória alterada.