Randomized clinical trial comparing pericapsular nerve group (PENG) block and periarticular local anesthetic infiltration for total hip arthroplasty.

BACKGROUND: This randomized trial compared pericapsular nerve group block and periarticular local anesthetic infiltration in patients undergoing primary total hip arthroplasty. We hypothesized that, compared with pericapsular nerve group block, periarticular local anesthetic infiltration would decrease the postoperative incidence of quadriceps weakness at 3 hours fivefold (ie, from 45% to 9%). METHODS: Sixty patients undergoing primary total hip arthroplasty under spinal anesthesia were randomly allocated to receive a pericapsular nerve group block (n=30) using 20 mL of adrenalized bupivacaine 0.50%, or periarticular local anesthetic infiltration (n=30) using 60 mL of adrenalized bupivacaine 0.25%. Both groups also received 30 mg of ketorolac, either intravenously (pericapsular nerve group block) or periarticularly (periarticular local anesthetic infiltration), as well as 4 mg of intravenous dexamethasone.Postoperatively, a blinded evaluator carried out sensory assessment and motor assessment (knee extension and hip adduction) at 3, 6 and 24 hours. Furthermore, the blinded observer also recorded static and dynamic pain scores at 3, 6, 12, 18, 24, 36 and 48 hours; time to first opioid request; cumulative breakthrough morphine consumption at 24 hours and 48 hours; opioid-related side effects; ability to perform physiotherapy at 6, 24 and 48 hours; as well as length of stay. RESULTS: There were no differences in quadriceps weakness at 3 hours between pericapsular nerve group block and periarticular local anesthetic infiltration (20% vs 33%; p=0.469). Furthermore, no intergroup differences were found in terms of sensory block or motor block at other time intervals; time to first opioid request; cumulative breakthrough morphine consumption; opioid-related side effects; ability to perform physiotherapy; and length of stay. Compared with pericapsular nerve group block, periarticular local anesthetic infiltration resulted in lower static pain scores (at all measurement intervals) and dynamic pain scores (at 3 and 6 hours). CONCLUSION: For primary total hip arthroplasty, pericapsular nerve group block and periarticular local anesthetic infiltration result in comparable rates of quadriceps weakness. However, periarticular local anesthetic infiltration is associated with lower static pain scores (especially during the first 24 hours) and dynamic pain scores (first 6 hours). Further investigation is required to determine the optimal technique and local anesthetic admixture for periarticular local anesthetic infiltration. TRIAL REGISTRATION NUMBER: NCT05087862.

Randomized comparison between perineural dexamethasone and combined perineural dexamethasone-dexmedetomidine for ultrasound-guided infraclavicular block.

BACKGROUND: This randomized trial compared perineural dexamethasone with combined perineural dexamethasone-dexmedetomidine for ultrasound-guided infraclavicular block. We hypothesized that the combination of perineural adjuvants would result in a longer motor block. METHODS: Fifty patients undergoing upper limb surgery with ultrasound-guided infraclavicular block (using 35 mL of lidocaine 1%-bupivacaine 0.25% with epinephrine 5 µg/mL) were randomly allocated to receive perineural dexamethasone (2 mg) or combined perineural dexamethasone (2 mg)-dexmedetomidine (50 µg). After the performance of the block, a blinded observer assessed the success rate (defined as a minimal sensorimotor composite score of 14 out of 16 points at 30 min), the onset time (defined as the time required to reach a minimal composite score of 14 points) as well as the incidence of surgical anesthesia (defined as the ability to complete surgery without local infiltration, supplemental blocks, intravenous opioids or general anesthesia).Postoperatively, the blinded observer contacted patients with successful blocks to inquire about the duration of motor block, sensory block and postoperative analgesia. RESULTS: No intergroup differences were observed in terms of success rate, onset time and surgical anesthesia. Compared with dexamethasone alone, combined dexamethasone-dexmedetomidine provided longer durations of motor block (21.5 (2.7) vs 17.0 (3.9) hours; p<0.001; 95% CI 2.6 to 6.4), sensory block (21.6 (3.6) vs 17.2 (3.6) hours; p<0.001; 95% CI 2.2 to 6.5), and postoperative analgesia (25.5 (9.4) vs 23.5 (5.6) hours; p=0.038; 95% CI 1.0 to 7.7). CONCLUSION: Compared with perineural dexamethasone (2 mg) alone, combined perineural dexamethasone (2 mg)-dexmedetomidine (50 µg) results in longer durations of sensorimotor block and analgesia. Further studies are required to determine the optimal dosing combination for dexamethasone-dexmedetomidine. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier: NCT04875039.

Randomized comparison between pericapsular nerve group (PENG) block and suprainguinal fascia iliaca block for total hip arthroplasty.

BACKGROUND: This randomized trial compared ultrasound-guided pericapsular nerve group block and suprainguinal fascia iliaca block in patients undergoing primary total hip arthroplasty. We selected the postoperative incidence of quadriceps motor block (defined as paresis or paralysis of knee extension) at 6 hours as the primary outcome. We hypothesized that, compared with suprainguinal fascia iliaca block, pericapsular nerve group block would decrease its occurrence from 70% to 20%. METHODS: Forty patients undergoing primary total hip arthroplasty under spinal anesthesia were randomly allocated to receive a pericapsular nerve group block (n=20) using 20 mL of adrenalized levobupivacaine 0.50%, or a suprainguinal fascia iliaca block (n=20) using 40 mL of adrenalized levobupivacaine 0.25%. After the performance of the block, a blinded observer recorded pain scores at 3, 6, 12, 18, 24, 36, and 48 hours; cumulative breakthrough morphine consumption at 24 and 48 hours; opioid-related side effects; ability to perform physiotherapy at 24 and 48 hours; as well as length of stay. Furthermore, the blinded observer also carried out sensory assessment (of the anterior, lateral, and medial aspects of the mid-thigh) and motor assessment (knee extension and hip adduction) at 3, 6, and 24 hours. RESULTS: Compared with suprainguinal fascia iliaca block, pericapsular nerve group block resulted in a lower incidence of quadriceps motor block at 3 hours (45% vs 90%; p<0.001) and 6 hours (25% vs 85%; p<0.001). Furthermore, pericapsular nerve group block also provided better preservation of hip adduction at 3 hours (p=0.023) as well as decreased sensory block of the anterior, lateral, and medial thighs at all measurement intervals (all p≤0.014). No clinically significant intergroup differences were found in terms of postoperative pain scores, cumulative opioid consumption at 24 and 48 hours, ability to perform physiotherapy, opioid-related side effects, and length of hospital stay. CONCLUSION: For primary total hip arthroplasty, pericapsular nerve group block results in better preservation of motor function than suprainguinal fascia iliaca block. Additional investigation is required to elucidate the optimal local anesthetic volume for motor-sparing pericapsular nerve group block and to compare the latter with alternate motor-sparing strategies such as periarticular local anesthetic infiltration. TRIAL REGISTRATION NUMBER: NCT04402450.

Single- versus double-injection costoclavicular block: a randomized comparison.

BACKGROUND: The costoclavicular approach targets the brachial plexus in the proximal infraclavicular fossa, where the lateral, medial, and posterior cords are tightly bundled together. This randomized trial compared single- and double-injection ultrasound-guided costoclavicular blocks. We selected onset time as the primary outcome and hypothesized that, compared with its single-injection counterpart, the double-injection technique would result in a swifter onset. METHODS: Ninety patients undergoing upper limb surgery (at or below the elbow joint) were randomly allocated to receive a single- (n=45) or double-injection (n=45) ultrasound-guided costoclavicular block. The local anesthetic agent (35 mL of lidocaine 1%-bupivacaine 0.25%with epinephrine 5 µg/mL and 2 mg of preservative-free dexamethasone) was identical in all subjects. In the single-injection group, the entire volume of local anesthetic was injected between the three cords of the brachial plexus. In the double-injection group, the first half of the volume was administered in this location; the second half was deposited between the medial cord and the subclavian artery. After the performance of the block, a blinded observer recorded the onset time (defined as the time required to achieve a minimal sensorimotor composite score of 14 out of 16 points), success rate (surgical anesthesia) and block-related pain scores. Performance time and the number of needle passes were also recorded during the performance of the block. The total anesthesia-related time was defined as the sum of the performance and onset times. RESULTS: Compared with its single-injection counterpart, the double-injection technique displayed shorter onset time (16.6 (6.4) vs 23.4 (6.9) min; p<0.001; 95% CI for difference 3.9 to 9.7) and total anesthesia-related time (22.5 (6.7) vs 28.9 (7.6) min; p<0.001). No intergroup differences were found in terms of success and technical execution (ie, performance time/procedural pain). The double-injection group required more needle passes than the single-injection group (2 (1-4) vs 1 (1-3); p<0.001). CONCLUSION: Compared with its single-injection counterpart, double-injection costoclavicular block results in shorter onset and total anesthesia-related times. Further investigation is required to determine if a triple-injection technique (with targeted local anesthetic injection around each cord of the brachial plexus) could further decrease the onset time. TRIAL REGISTRATION NUMBER: NCT03595514.

Recomendaciones para la ejecución de anestesia regional no obstétrica en perioperatorio de pacientes COVID-19 / Recommendations for the execution of non-obstetric regional anesthesia in treatment of COVID-19 patients

En diciembre de 2019, surgió una serie de casos de neumonía causada por un nuevo coronavirus, denominado 2019-nCoV o SARS-CoV2. La propagación del virus ha sido extremadamente rápida y la organización mundial de la salud declaró a la enfermedad COVID-19, causada por 2019-nCoV, como una pandemia. En este contexto la Sociedad de Anestesiología de Chile (SACH) ha elaborado recomendaciones generales para el manejo perioperatorio de los pacientes sospechosos y/o portadores de la enfermedad. Sin embargo, dado que durante el levantamiento de evidencia para la confección de dicha guía se objetivó la ausencia de sugerencias específicas para la ejecución de técnicas de anestesia regional fuera del ambiente obstétrico, se solicitó desde el Comité Científico de SACH al Comité de Anestesia Regional de SACH (CARSACH), representante LASRA (LatinAmerican Society of Regional Anesthesia) en Chile, a través de un grupo de expertos, confeccionar recomendaciones locales en esta materia.

Concentración de bupivacaína y preservación de fuerza de cuádriceps en bloqueo femoral para artroplastía total de rodilla / Bupivacaine concentration and quadriceps strength preservation in femoral nerve block for total

INTRODUCTION: The commonly used concentrations of local anesthetics (LA) for femoral nerve block (FNB) cause a significant decrease in the quadriceps strength (QS), limiting physiotherapy and determining a risk factor for patient's falls. The use of more dilute solutions could determine the preservation of motor function without impairing analgesia. METHODS: Five patients scheduled for total knee arthroplasty (TKA) received a preoperative FNB with 20 mL of bupivacaine in decreasing concentrations (0.0875%, 0.075%, 0.0625%, 0.050%, 0.0375%). Sensory block to cold in the anterior knee region, QS, surface electromyography (SEMG) of vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) plus were recorded before and 30 minutes after the blockage. Posteriorly, the clinical data of 20 patients who underwent TKA and received a continuous femoral nerve block (CFNB) with bupivacaine in the most dilute concentration that granted sensory blockade and significantly preserved the QS in the previous analysis were retrospectively analyzed. Postoperative pain at 24 and 48 hours, morphine consumption at 24 hours, the ability to successfully perform physiotherapy on the first postoperative day (POD) and reports of falls were rescued from the patients' files. Finally, seventy-five patients that underwent TKA during 2018 who received a CFNB with a similar dilution, but using levobupivacaine, were also retrospectively analyzed. Postoperative pain, need for advanced rescue analgesia, ability to perform physiotherapy, CFNB related complications and reports of patients falls during the first 72 hours post-surgery were obtained. RESULTS: Biomechanical study: of the 5 concentrations analyzed, either 0.050% or 0.0375% bupivacaine were adequate producing sensory block and preserving 94% and 100% of the basal QS, respectively. With both concentrations, the SEMG showed a similar range of activation with respect to baseline values. Bupivacaine case series: Twenty patients undergoing TKA received a 5-8 mL/hr infusion of 0.037% bupivacaine. The average consumption of morphine at 24 hours was 3.9 (3.6) mg. The median [IQR] of dynamic postoperative pain at 24 and 48 hours was 3 [1-4] and 3 [2-5]. All patients had adequate active joint ranges at 24 hours and physiotherapy was not limited by significant motor block. No falls were reported during the stay. Levobupivacaine case series: seventy-five patients undergoing TKA received a 5-8 mL/hr infusion of 0.037% levobupivacaine. The median [IQR] of at rest (R) and dynamic (D) postoperative pain at 24, 48 and 72 hours were R24: 0 [0-3]; D24: 3 [1-5]; R48: 0 [0-2]; D48: 3 [1.5-5]; R72: 0 [0-1]; D72: 3 [1-4]. 21% of patients required adding a PCA mode to the CFNB and a 7% a morphine PCA. On POD 1, 4% of patients were not able to adequately perform rehabilitation. On POD 2 and 3, all patients had adequate active joint ranges and physiotherapy was not limited by significant motor block. There were also no falls during hospitalization. CONCLUSIONS: The use of diluted solutions of bupivacaine and levobupivacaine for CFNB may represent a good alternative for TKA postoperative analgesia while avoiding significant quadriceps paresis. Additional studies are necessary to determine the ideal concentration and administration regimen to then compare with other quadriceps sparing analgesic alternatives.

INTRODUCCIÓN: Las concentraciones habituales de anestésicos locales (AL) utilizadas para el bloqueo del nervio femoral (BNF) provocan una disminución significativa de la fuerza del cuádriceps (FC), limitando la fisioterapia y constituyendo un factor de riesgo de caídas de pacientes. El uso de soluciones más diluidas podría determinar preservación de la función motora sin perjudicar la analgesia. MÉTODOS: Cinco pacientes programados para artroplastía total de rodilla (ATR) recibieron un BNF preoperatorio con 20 mL de bupivacaína en concentraciones decrecientes (0,0875%, 0,075%, 0,0625%, 0,050%, 0,0375%). Se registró la FC, electromiografía de superficie (EMGS) de vasto lateral (VL), vasto medial (VM) y recto femoral (RF) y el bloqueo sensitivo al frío antes y 30 minutos después del bloqueo. Posteriormente, se analizó retrospectivamente 20 casos sometidos a ATR que recibieron un bloqueo continuo del nervio femoral (BCNF) con bupivacaína en la concentración más diluida que otorgó bloqueo sensitivo y preservó significativamente la fuerza basal del cuádriceps durante el análisis anterior. El dolor postoperatorio a las 24 y 48 horas, el consumo de morfina las primeras 24 horas, la capacidad de realizar con éxito la fisioterapia el primer día postoperatorio (DPO) y reporte de caídas fueron rescatados de los expedientes. Por último, también se analizó retrospectivamente un grupo de 75 pacientes sometidos a ATR durante el 2018 y que recibieron un BCNF con una dilución similar, pero de levobupivacaína. Se obtuvieron datos de dolor, requerimientos de rescate analgésico, capacidad de realizar rehabilitación, complicaciones del BCNF y reporte de caídas durante las primeras 72 horas postoperatorias. RESULTADOS: Estudio biomecánico: de las 5 concentraciones analizadas, tanto bupivacaína 0,05% como 0,0375% produjeron adecuado bloqueo sensorial preservando el 94% y el 100% de la FC, respectivamente. Con ambas concentraciones la EMGS mostró similar rango de activación respecto a valores basales. Serie de casos con bupivacaína: veinte pacientes sometidos a ATR recibieron una infusión de bupivacaína 0,037% a 5-8 mL/h. El consumo promedio de morfina a las 24 horas fue 3,9 (3,6) mg. La mediana [RIC] del dolor dinámico postoperatorio a las 24 y 48 horas fue 3 [1-4] y 3 [2-5]. Todos los pacientes tuvieron rangos articulares activos adecuados a las 24 horas y la fisioterapia no fue limitada por bloqueo motor significativo. No se registraron caídas durante la hospitalización. Serie de casos levobupivacaína: setenta y cinco pacientes sometidos a ATR recibieron una infusión de levobupivacaína 0,037% a 5-8 mL/h. La mediana [RIC] de dolor postoperatorio en reposo (R) y dinámico (D) a las 24, 48 y 72 horas fue R24: 0 [0-3]; D24: 3 [1-5]; R48: 0 [0-2]; D48: 3 [1.5-5]; R72: 0 [0-1]; D72: 3 [1-4]. Un 21% requirió agregar modo PCA al BCNF y 7% una PCA de morfina. En DPO 1, un 4% de pacientes no pudo realizar adecuadamente la rehabilitación. En DPO 2 y 3 todos los pacientes tuvieron rangos articulares activos adecuados y fisioterapia no fue limitada por bloqueo motor significativo. Tampoco se registraron caídas durante la hospitalización. CONCLUSIONES: El uso de soluciones diluidas de bupivacaína y levobupivacaína en BCNF podría representar una buena opción para analgesia postoperatoria en ATR evitando la paresia significativa del cuádriceps. Estudios adicionales son necesarios para determinar la concentración y régimen de administración ideal para luego comparar con otras alternativas analgésicas preservantes del cuádriceps.

Bloqueos de tronco / Truncal blocks

Truncal blocks have recently been positioned as an alternative to neuraxial analgesia. The injection of local anesthetics in interfascial planes was initially guided by anatomical landmarks, to later evolve towards a more selective administration when guided by ultrasound. Successful execution of truncal blocks requires detailed knowledge of the chest and abdominal walls anatomy. The same logic allows us to understand its potential benefits concerning perioperative analgesia, as well as its limitations and therapeutic margins. Secondary to a growing interest in less invasive techniques and analgesic techniques with a more favorable risk-benefit profile, the available evidence in this field is in continuous development. Thus, in the present review, the technical aspects of these blocks will be evaluated, emphasizing the sonoanatomy, and assessing the best evidence to support the use of each technique.

Los bloqueos de tronco se han posicionado recientemente como una alternativa frente a la analgesia neuroaxial. La inyección de anestésicos locales en planos interfasciales inicialmente fue guiado por referencias anatómicas, para posteriormente evolucionar hacia una administración más selectiva al ser guiada por el ultrasonido. La ejecución exitosa de los bloqueos de tronco requiere un conocimiento detallado de la anatomía de las paredes del tórax y abdomen. Esta misma lógica nos permite entender sus potenciales beneficios en relación con la analgesia perioperatoria, como también sus limitaciones y margen terapéutico. La evidencia disponible está en continuo desarrollo, dado el creciente interés que concitan técnicas menos invasivas y con un perfil de riesgo-beneficio potencialmente más favorable. En la presente revisión se evaluarán los aspectos técnicos de cada bloqueo, poniendo énfasis en la sonoanatomía, y evaluando la mejor evidencia que sustente el uso de cada técnica.

Bloqueos de extremidad inferior / Lower extremity blocks

Lower limb blocks are described with emphasis on distribution according to sensitive distribution and its sonoanatomy.

Se describen los bloqueos de la extremidad inferior haciendo énfasis en la distribución de acuerdo a distribución sensitiva y a su sonoanatomia.

Randomized comparison between perineural dexamethasone and dexmedetomidine for ultrasound-guided infraclavicular block.

BACKGROUND: This randomized trial compared perineural dexamethasone (5 mg) and dexmedetomidine (100 µg) for ultrasound-guided infraclavicular brachial plexus block. We hypothesized that both adjuvants would result in similar durations of motor block and therefore designed the study as an equivalence trial (equivalence margin=3.0 hours). METHODS: One hundred and twenty patients undergoing upper limb surgery with ultrasound-guided infraclavicular block (using 35 mL of lidocaine 1%-bupivacaine 0.25% with epinephrine 5 µg/mL) were randomly allocated to receive perineural dexamethasone (5 mg) or dexmedetomidine (100 µg). Patients and operators were blinded to the nature of the perineural adjuvant. After the performance of the block, a blinded observer assessed the success rate (defined as a minimal sensorimotor composite score of 14 out of 16 points at 30 min) as well as the incidence of surgical anesthesia (defined as the ability to complete surgery without local infiltration, supplemental blocks, intravenous opioids, or general anesthesia). Heart rate and blood pressure were recorded before the block as well as during the first 2 hours after its performance. Furthermore, the level of sedation (using the Ramsay Sedation Scale) was recorded in the postanesthesia care unit. Postoperatively, the blinded observer contacted patients with successful blocks to inquire about the duration of motor block, sensory block, and postoperative analgesia. RESULTS: No intergroup differences were observed in terms of success rate and surgical anesthesia. Compared with dexmedetomidine, dexamethasone provided longer durations of motor block (17.4 (4.0) vs 14.3 (3.0) hours; p<0.001; 95% CI 1.7 to 4.5), sensory block (19.0 (4.0) vs 15.0 (3.2) hours; p<0.001; 95% CI 2.6 to 5.4), and analgesia (22.2 (3.6) vs 16.9 (3.9) hours; p<0.001; 95% CI 3.7 to 6.9). Dexmedetomidine resulted in lower heart rate and blood pressure after the performance of the block, as well as an increased level of sedation postoperatively. CONCLUSION: Compared with dexmedetomidine (100 µg), dexamethasone (5 mg) results in longer sensorimotor block and analgesic durations, as well as a decreased level of patient sedation. Further studies are required to compare dexamethasone and dexmedetomidine using different doses, local anesthetic agents, and approaches to the brachial plexus. TRIAL REGISTRATION NUMBER: NCT03610893.

Dural puncture epidural analgesia for labor: a randomized comparison between 25-gauge and 27-gauge pencil point spinal needles.

BACKGROUND: This double-blind, randomized trial compared dural puncture epidural analgesia (DPEA) for labor using 25-gauge and 27-gauge pencil point spinal needles. We hypothesized that both needle sizes would result in similar onset time (equivalence margin=2.5 min) and therefore designed the study as an equivalence trial. METHODS: One hundred and forty patients undergoing labor were randomized to DPEA with 25-gauge (n=70) or 27-gauge (n=70) pencil point spinal needles. After the placement of the epidural catheter, a bolus of 20 mL of bupivacaine 0.125% and fentanyl 2 µg/mL was administered to all subjects. Thereafter, patients received boluses of 12 mL of bupivacaine 0.125% every 2 hours as needed.A blinded investigator recorded the onset time (defined as the temporal interval required to achieve a pain score ≤1 on a 0-10 scale), S2 block, sensory block height (30 min after the initial bolus of local anesthetic), presence of motor block (30 min after the initial bolus of local anesthetic), number of top-up doses required during labor and incidence of postural headache. RESULTS: Out of the 140 recruited patients, 135 were retained for analysis. Compared with their 27-gauge counterparts, 25-gauge pencil point spinal needles provided a 1.6 min shorter DPEA onset (95% CI of the difference of the means: -3.2 to -0.1 min). However, there were no intergroup differences in terms of S2 block, sensory block height, motor block, number of top-up doses and incidence of postural headache. CONCLUSION: Dural puncture epidural analgesia with 25-gauge pencil point spinal needles provides a 1.6 min shorter onset time than DPEA with 27-gauge spinal needles. Although statistically significant, such a difference may not be clinically relevant. Further investigation is required to compare 25-gauge and 27-gauge spinal needles for DPEA in the setting of different local anesthetic infusion strategies. TRIAL REGISTRATION NUMBER: NCT03389945.