A Practical Dosing Algorithm for Deep Neuromuscular Blockade during Total Intravenous Anesthesia: ROCURITHM.

BACKGROUND: The number of trials investigating the effects of deep neuromuscular blockade (NMB) on surgical conditions and patient outcomes is steadily increasing. Consensus on which surgical procedures benefit from deep NMB (a posttetanic count [PTC] of 1 to 2) and how to implement it has not been reached. The European Society of Anaesthesiology and Intensive Care does not advise routine application but recommends use of deep NMB to improve surgical conditions on indication. This study investigates the optimal dosing strategy to reach and maintain adequate deep NMB during total intravenous anesthesia. METHODS: Data from three trials investigating deep NMB during laparoscopic surgery with total intravenous anesthesia (n = 424) were pooled to analyze the required rocuronium dose, when to start continuous infusion, and how to adjust. The resulting algorithm was validated (n = 32) and compared to the success rate in ongoing studies in which the algorithm was not used (n = 180). RESULTS: The mean rocuronium dose based on actual bodyweight for PTC 1 to 2 was (mean ± SD) 1.0 ± 0.27 mg · kg-1 ·h-1 in the trials, in which mean duration of surgery was 116 min. An induction dose of 0.6 mg ·kg-1 led to a PTC of 1 to 5 in a quarter of patients after a mean of 11 min. The remaining patients were equally divided over too shallow (additional bolus and direct start of continuous infusion) or too deep; a 15-min wait after PTC of 0 for return of PTC to 1 or higher. Using the proposed algorithm, a mean 76% of all 5-min measurements throughout surgery were on target PTC 1 to 2 in the validation cohort. The algorithm performed significantly better than anesthesiology residents without the algorithm, even after a learning curve from 0 to 20 patients (42% on target, P ≤ 0.001, Cohen's d = 1.4 [95% CI, 0.9 to 1.8]) to 81 to 100 patients (61% on target, P ≤ 0.05, Cohen's d = 0.7 [95% CI, 0.1 to 1.2]). CONCLUSIONS: This study proposes a dosing algorithm for deep NMB with rocuronium in patients receiving total intravenous anesthesia.

Comparison between conventional-dose and high-dose rocuronium use in general anesthesia for Cesarean section.

Background: There have been few studies comparing the effects of high- and low-dose rocuronium during cesarean section by directly measuring the concentration. Therefore, we conducted a study to examine the blood concentrations and clinical effects of both doses of rocuronium on mothers and fetuses. Methods: Eighteen patients were randomly assigned to two groups: C Group (0.6 mg/kg), and H Group, (1.0 mg/kg). The primary outcome was the comparison of umbilical vein rocuronium concentration between two groups. We assessed ease of intubation, time from rocuronium administration to some TOF points, post-anesthesia care unit (PACU) stay time, infused remifentanil dose, maternal rocuronium concentration, and Apgar scores. Results: No differences were observed in demographic data, ease of intubation, PACU stay time, 1 min Apgar scores, umbilical venous blood gas analysis between both groups. However, the time from rocuronium administration to T3 disappearance was shorter (p=0.009) and time to T1 and T2 reappearance were longer (p=0.003, p=0.009) in H group than that in C group. The administered remifentanil dose (p=0.042) was lower in the H group than in the C group. Rocuronium concentrations in the umbilical vein (p=0.004) and maternal vein before cord clamping (p=0.002) and at discharge (p<0.001) were also found to be higher in the H group than in the C group. Conclusions: We observed no prolongation of PACU stay, and no differences in Apgar scores in H group compared to C group. It suggests that 1.0 mg/kg of rocuronium has no negative effects on the fetus and mother in cesarean section.

Occurrence of hemodynamic changes following administration of rocuronium in a dog presenting for an ophthalmic procedure.

A 10-year-old, neutered male, Golden Retriever dog presented for surgical correction of a descemetocele. Acepromazine (0.02 mg/kg) and methadone (0.5 mg/kg) were administered intramuscularly for sedation, propofol (2 mg/kg) and midazolam (0.2 mg/kg) were administered intravenously for anaesthetic induction and isoflurane in oxygen was utilised for anaesthetic maintenance. Rocuronium (0.5 mg/kg), a neuromuscular blocking agent, was administered intravenously to facilitate central positioning of the eye for surgery. Within 10 min of rocuronium administration, the dog became tachycardic and hypotensive. Hemodynamic aberrations did not resolve with initial interventions but were successfully mitigated with the administration of diphenhydramine (0.8 mg/kg) intravenously. The dog remained stable throughout the remainder of the procedure and experienced a smooth and uneventful recovery. While it is difficult to confirm that the hemodynamic changes observed in this clinical case resulted solely from administration of rocuronium, the observance of the cardiovascular changes, timing of events and response to therapy suggest that rocuronium elicited a histamine response that was successfully treated with diphenhydramine.

Shortened time to neuromuscular recovery with lower doses of rocuronium in elderly patients.

INTRODUCTION: The effect of neuromuscular blocking agents may be reversed by administration of neostigmine, when two twitches are present using train-of-four (TOF) stimulation. However, in elderly patients, limited data are available about when to administer neostigmine. We hypothesised that time to two twitches after TOF (TOF-2) was shorter after rocuronium 0.6 mg/kg than after rocuronium 0.9 mg/kg. Also, we hypothesised that time to TOF-2 would be shorter after rocuronium 0.3 mg/kg than after rocuronium 0.6 mg/kg. METHODS: This was a secondary analysis of 50 elderly patients > 80 years; 16 patients received rocuronium 0.6 mg/kg, another 16 patients received rocuronium 0.9 mg/kg; and, finally, 18 patients received rocuronium 0.3 mg/kg. Patients received total intravenous anaesthesia, and neuromuscular block was monitored with acceleromyography. RESULTS: Time to TOF-2 was shorter after rocuronium 0.6 mg/kg than after rocuronium 0.9 mg/kg: 37 min. versus 59 min. (difference: 22 min. (95% confidence intervals (CI): 10 to 33 min.), p = 0.0007). Time to TOF-2 after rocuronium 0.3 mg/kg was shorter than after rocuronium 0.6 mg/kg: 19 min. versus 37 min. (difference: 18 min. (95% CI: 11 to 25 min.), p = 0.00006). However, only 33% of the patients receiving 0.3 mg/kg obtained full effect i.e. TOF-0. CONCLUSION: Time to TOF-2 was shorter after rocuronium 0.6 mg/kg than after 0.9 mg/kg and shorter after rocuronium 0.3 mg/kg than after 0.6 mg/kg. FUNDING: This work was supported by departmental sources. TRIAL REGISTRATION: This study was a secondary analysis of two clinical trials. CLINICALTRIALS: gov (NCT04512313), (NCT03857750).

Comparison of rocuronium priming vs. standard rapid sequence intubation technique in emergency department patients requiring intubation.

OBJECTIVE: In our study, we aimed to compare the effect of standard rapid sequence intubation protocol and the application of rocuronium priming technique on the procedure time and hemodynamic profile. METHODS: Patients who applied to the emergency department and needed rapid sequence intubation were included in our study, which we conducted with a randomized controlled design. Randomization in the study was made according to the order of arrival of the cases. Rapid sequence intubation was performed in the standard group. In the priming group, 10% of the rocuronium dose was administered approximately 3 min before the induction agent. Intubation time, amount of drug used, vital signs, and end-tidal CO2 level before and after intubation used to confirm intubation were recorded. RESULTS: A total of 52 patients were included in the study, of which 26 patients were included in the standard group and 26 patients in the priming group. While intubation time was 121.2±21.9 s in the standard group, it was calculated as 68.4±11.6 s in the priming group (p<0.001). While the mean arterial pressure was 58.3±26.6 mmHg in the standard group after intubation, it was 80.6±21.1 mmHg in the priming group (p=0.002). CONCLUSION: It was observed that priming with rocuronium shortened the intubation time and preserved the hemodynamic profile better. CLINICAL TRIAL REGISTRATION NUMBER: NCT05343702.

The effects of intra-cerebroventricular administered rocuronium on the central nervous system of rats and determination of its epileptic seizure-inducing dose / Efeitos da administração intracerebroventricular de rocurônio sobre o sistema nervoso central de ratos e determinação da dose indutora de crise epiléptica

Abstract Background: The aim of this study was to investigate the effects of intracerebroventricularly administered rocuronium bromide on the central nervous system, determine the seizure threshold dose of rocuronium bromide in rats, and investigate the effects of rocuronium on the central nervous system at 1/5, 1/10, and 1/100 dilutions of the determined seizure threshold dose. Methods: A permanent cannula was placed in the lateral cerebral ventricle of the animals. The study was designed in two phases. In the first phase, the seizure threshold dose of rocuronium bromide was determined. In the second phase, Group R 1/5 (n = 6), Group 1/10 (n = 6), and Group 1/100 (n = 6) were formed using doses of 1/5, 1/10, and 1/100, respectively, of the obtained rocuronium bromide seizure threshold dose. Results: The rocuronium bromide seizure threshold value was found to be 0.056 ± 0.009 µmoL. The seizure threshold, as a function of the body weight of rats, was calculated as 0.286 µmoL/kg-1. A dose of 1/5 of the seizure threshold dose primarily caused splayed limbs, posturing, and tremors of the entire body, whereas the dose of 1/10 of the seizure threshold dose caused agitation and shivering. A dose of 1/100 of the seizure threshold dose was associated with decreased locomotor activity. Conclusions: This study showed that rocuronium bromide has dose-related deleterious effects on the central nervous system and can produce dose-dependent excitatory effects and seizures.

Resumo Justificativa: O objetivo deste estudo foi investigar os efeitos do brometo de rocurônio administrado intracerebroventricularmente sobre o sistema nervoso central, determinar a dose do limiar convulsivo de rocurônio em ratos e investigar os efeitos de rocurônio no sistema nervoso central em diluições de 1/5, 1/10 e 1/100 da dose do limiar convulsivo determinada. Métodos: Uma cânula permanente foi colocada no ventrículo lateral do cérebro dos animais. O estudo foi projetado em duas fases. Na primeira, a dose do limiar convulsivo do brometo de rocurônio foi determinada. Na segunda, o Grupo R 1/5 (n = 6), o Grupo 1/10 (n = 6) e Grupo 1/100 (n = 6) foram formados com doses de 1/5, 1/10 e 1/100, respectivamente, da dose do limiar convulsivo de brometo de rocurônio obtida. Resultados: Descobrimos que o valor do limiar convulsivo de brometo de rocurônio é 0,056 ± 0,009 µmoL. O limiar convulsivo, como uma função do peso corporal dos ratos, foi calculado como 0,286 µmoL/kg-1. Uma dose de 1/5 da dose do limiar convulsivo causou principalmente abertura postural dos membros e tremores em todo o corpo, enquanto uma dose de 1/10 da dose do limiar convulsivo causou agitação e tremores. Uma dose de 1/100 da dose do limiar convulsivo foi associada à diminuição da atividade locomotora. Conclusões: Este estudo mostrou que o brometo de rocurônio tem efeitos deletérios relacionados com a dose sobre o sistema nervoso central e pode produzir efeitos excitatórios dependentes da dose e convulsões.

Effects of conventional vs high-dose rocuronium on the QTc interval during anesthesia induction and intubation in patients undergoing coronary artery surgery: a randomized, double-blind, parallel trial

Myocardial ischemia, as well as the induction agents used in anesthesia, may cause corrected QT interval (QTc) prolongation. The objective of this randomized, double-blind trial was to determine the effects of high- vs conventional-dose bolus rocuronium on QTc duration and the incidence of dysrhythmias following anesthesia induction and intubation. Fifty patients about to undergo coronary artery surgery were randomly allocated to receive conventional-dose (0.6 mg/kg, group C, n=25) or high-dose (1.2 mg/kg, group H, n=25) rocuronium after induction with etomidate and fentanyl. QTc, heart rate, and mean arterial pressure were recorded before induction (T0), after induction (T1), after rocuronium (just before laryngoscopy; T2), 2 min after intubation (T3), and 5 min after intubation (T4). The occurrence of dysrhythmias was recorded. In both groups, QTc was significantly longer at T3 than at baseline [475 vs 429 ms in group C (P=0.001), and 459 vs 434 ms in group H (P=0.005)]. The incidence of dysrhythmias in group C (28%) and in group H (24%) was similar. The QTc after high-dose rocuronium was not significantly longer than after conventional-dose rocuronium in patients about to undergo coronary artery surgery who were induced with etomidate and fentanyl. In both groups, compared with baseline, QTc was most prolonged at 2 min after intubation, suggesting that QTc prolongation may be due to the nociceptive stimulus of intubation.

Rocuronio en obesos: ¿debe dosificarse por peso real o por peso ideal? / Rocuronium in obese: should be dosed by actual weight or ideal weight?

El aumento universal en la prevalencia de obesidad ha causado que los anestesiólogos se vean frecuentemente enfrentados a anestesiar pacientes obesos. Pese a esto aún existen dudas respecto a cómo dosificar las drogas en estos pacientes. La literatura recomienda dosificar el rocuronio en obesos en base al peso ideal (IBW, iniciales del inglés Ideal Body Weight) pero esta sugerencia está basada más bien en la prudencia que en la evidencia. Se decidió explorar con análisis de sobrevida (análisis tiempo-evento), la duración del rocuronio en obesos al ser dosificado por peso ideal (IBW) y por peso real (TBW, iniciales del inglés de peso corporal total). Al administrar el rocuronio en base al peso real (TBW) se observó una prolongación en su duración de acción con un acortamiento de su latencia en relación con la dosificación en base al peso ideal (IBW). Hubo una marcada prolongación de la duración de acción y el índice de recuperación tanto al dosificar por peso real como peso ideal. Debido a esta sensibilidad aumentada al rocuronio en pacientes obesos recomendamos dosificarlo en base al peso ideal, excepto si se necesita intubar rápidamente...

The universal increase in prevalence of obesity has caused that anesthesiologist are frequently encountered with anesthetizing obese patients. There stills exists doubt on how to dosage drugs to these patients. Literature recommends dosing rocuronium in the obese based on ideal weight (IBW), being this suggestion based more on prudence than on evidence. Randomized control trial was designed for obese patients scheduled for bariatric surgery to study the pharmacodynamics of rocuronium in this population. Patients were randomly assigned into two groups: rocuronium dosage 0.6 mg•kg-1 for real weight (TBW) or rocuronium dosage of 0.6mg•kg-1 for ideal weight (IBW). Ideal weight was calculated according to Lemmens formula. The reference group was the dosage based on IBW. Previous calibration, evaluating the first twitch of train-of-four (T1), we registered onset time, clinical duration, recovery index, level of muscle relaxation to which the first reinforcement was administered and clinical duration of rocuronium reinforcement. A total of 100 patients were part of the study: 54 in group TBW and 46 in group IBW. When administering rocuronium based on real weight (TBW) a prolongation in clinical duration was found: Medium (IQR*); 79.5 (67 - 105) minutes versus 44.5(33 - 63.5 minutes) in the IBW group (p < 0.001) with a decrease in latency in the TBW group 120 (90-150secs.) versus the IBW group 180 (120 - 270 secs.) (p < 0.001). There were no differences in the recovery index between both levels of dosing. There was a marked prolongation of both clinical duration and recovery index in both groups, as supported in some literature. Based on the evidence, we recommend to dose rocuronium in obese patients based on ideal weight, with the exception of cases were quick intubation is required...

Comparison of the variability of the onset and recovery from neuromuscular blockade with cisatracurium versus rocuronium in elderly patients under total intravenous anesthesia

This study was designed to compare the variability of the onset and offset of the effect of two neuromuscular blocking drugs with different elimination pathways in adult and elderly patients during total intravenous anesthesia (TIVA). After Ethics Committee approval and patients’ informed consent, the drugs were compared in 40 adult and 40 elderly patients scheduled for elective surgery under TIVA with tracheal intubation who were randomized to receive a single bolus dose of 0.15 mg/kg cisatracurium or 0.9 mg/kg rocuronium. The time of onset of maximum depression, duration of action, and recovery index time were measured and recorded for each patient and variability is reported as means ± standard deviation. Time of onset was significantly shorter for rocuronium than cisatracurium for the adult and elderly groups (P = 0.000), but the variability of cisatracurium was significantly greater compared with rocuronium for the same age groups (93.25 vs 37.01 s in the adult group and 64.56 vs 33.75 s in the elderly group; P = 0.000). The duration of the effect in the elderly group receiving rocuronium was significantly longer than in the elderly group receiving cisatracurium, and the variability of the duration was significantly greater in the rocuronium group than in the cisatracurium group. Mean time of recovery was significantly longer for the elderly group receiving rocuronium than for the elderly group receiving cisatracurium (P = 0.022), and variability was also greater (P = 0.002). Both drugs favored good intubating conditions. In conclusion, cisatracurium showed less variability in these parameters than rocuronium, especially in the elderly, a fact that may be of particular clinical interest.

The use of rocuronium in giant Amazon turtle Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae) / Uso do rocurônio em tartaruga da Amazônia Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae)

PURPOSE: To determine whether rocuronium would provide safe, short-term immobilization in Podocnemis expansa. METHODS: Twenty P. expansa, weighing on average 1.59 ± 0.28 kg, were subjected to two protocols: G1 0.25 mg/kg IM of rocuronium and 0.07 mg/kg IM of neostigmine, while G2 received 0.50 mg/kg IM of rocuronium and 0.07 mg/kg IM of neostigmine. The drugs were applied, respectively, in the left and right thoracic members. Assessments were made of the anesthetic parameters of respiratory frequency, heartbeat, righting reflex, cloacal relaxation, palpebral and pupilar reflexes, easy handling, muscle relaxation, locomotion, response to pain stimuli in the right thoracic members, pelvic members and tail, ambient humidity and temperature. RESULTS: They were not found statistical differences between the dosages for the majority of the assessments. G1 was as efficient as G2. A consistent neuromuscular blockade effect was recorded 12 ± 4.21 minutes in G1 and G2. All the animals were recovered in 150 minutes. CONCLUSIONS: Administration of rocuronium at dose of 0.25 to 0.5 mg/kg IM is a safe and effective adjunct to clinical proceedings or pre-anesthetics in P. expansa. Because rocuronium does not provide any analgesic or sedative effects, the duration of neuromuscular blockade without anesthesia should be minimized to avoid undue stress.

OBJETIVO: Determinar se o rocurônio promove imobilização segura e de curta duração em Podocnemis expansa. MÉTODOS: Vinte P. expansa com média de peso 1,59 ± 0,28 kg, foram submetidas a dois protocolos: G1 recebeu rocurônio 0,25 mg/kg IM e neostigmina 0,07 mg/kg IM enquanto G2 rocurônio 0,50 mg/kg IM e neostigmina 0,07 mg/kg IM, aplicados no membro torácico esquerdo e direito, respectivamente. Observaram-se os parâmetros anestésicos: freqüência respiratória e cardíaca, reflexo de endireitamento, relaxamento do esfíncter da cloaca, reflexo palpebral e pupilar, facilidade de manipulação, relaxamento muscular, locomoção, resposta aos estímulos dolorosos no membro torácico direito, nos membros pelvinos e na cauda, temperatura e umidade ambiental. RESULTADOS: Não foram encontradas diferenças estatísticas entre as doses para a maioria dos parâmetros e o G1 foi tão eficiente quanto o G2. Um bloqueio neuromuscular consistente foi observado aos 12 ± 4,21 minutos tanto no G1 como no G2. A recuperação de todos os animais ocorreu em até 150 minutos. CONCLUSÕES: Administração de rocurônio nas doses 0,25 e 0,50 mg/kg IM é segura e efetiva para os procedimentos clínicos ou pré-anestésicos em P. expansa. Como o rocurônio não produz efeitos sedativos ou analgésicos, a duração do bloqueio neuromuscular sem anestesia deverá ser minimizado para evitar estresse.

Influência de anestésicos locais sobre o bloqueio neuromuscular produzido pelo rocurônio: ação da lidocaína e da mistura enantiomérica em excesso de 50 por cento de bupivacaína na junção neuromuscular / Influencia de anestésicos locales sobre el bloqueo neuromuscular producido por el rocuronio: acción de la lidocaína y de la mezcla enantiomérica en exceso de 50 por ciento de bupivacaína en la junción neuromuscular / Influence of local anesthetics on the neuromuscular blockade produced by rocuronium: effects of lidocaine and 50 percent enantiomeric excess bupivacaine on the neuromuscular junction

Justificativa e objetivos: Os efeitos dos anestésicos locais (AL) na transmissão neuromuscular e sua influência no bloqueio neuromuscular produzido por bloqueadores neuromusculares competitivos são ainda alvo de pouca investigação. O objetivo do estudo foi avaliar in vitro os efeitos da lidocaína e da mistura enantiomérica em excesso de 50 por cento de bupivacaína (S75-R25) no bloqueio neuromuscular...

Background and objetives: The effects of local anesthetics (LA) on neuromuscular transmission and their influence on the neuromuscular blockade produced by competitive neuromuscular blockers have not been fully investigated. The objective of this study was to evaluate, in vitro, the effects of lidocaine and 50 percent enantiomeric excess bupivacaine (S75-R25) on the neuromuscular blockade produced by rocuronium...

Justificativa y objetivos: Los efectos de los anestésicos locales (AL), en la transmisión neuromuscular y su influencia en el bloqueo neuromuscular producido por bloqueadores neuromusculares competitivos, todavía no se ha investigado lo suficiente. El objetivo del estudio, fue evaluar in vitro los efectos de la lidocaína y de la mezcla enantiomérica en exceso de 50 por ciento de bupivacaína (S75-R25) en el bloqueo neuromuscular...

Estudo comparativo entre uma e duas doses efetivas (DE95) de rocurônio para a intubação traqueal / A comparative study between one and two effective doses (ED95) of rocuronium for tracheal intubation

JUSTIFICATIVA E OBJETIVOS: Os bloqueadores neuromusculares (BNM) são fármacos utilizados para produzir relaxamento da musculatura esquelética e facilitar a intubação traqueal (IT). A literatura descreve como sendo necessárias duas doses efetivas (DE95) o ideal para a IT. O rocurônio é um BNM não-despolarizante do tipo esteróide, sintético e de duração intermediária. O objetivo desse estudo foi avaliar e comparar as condições de intubação traqueal (IT), utilizando uma e duas doses efetivas (DE95) do rocurônio, seguindo os critérios da Conferência de Consenso de Copenhague. MÉTODO: Foram avaliados 60 pacientes divididos aleatoriamente em dois grupos de 30, de ambos os sexos, idades entre 20 e 60 anos, estado físico ASA I e II, Mallampati 1 e 2, índice de massa corporal (IMC) < 35, submetidos a anestesia geral. No Grupo 1 (G1) foi administrado 0,3 mg.kg-1 (1 DE95) e no Grupo 2 (G2), 0,6 mg.kg-1 DE95 (2 DE95) de rocurônio. Os parâmetros para a avaliação da IT foram baseados nos critérios da Conferência de Consenso de Copenhague (Good Clinical Research Practice): laringoscopia, cordas vocais (posição e movimentação), reação à inserção do tubo e/ou a insuflação do balonete (movimento dos membros e tosse). RESULTADOS: Todas as intubações foram consideradas excelentes ou boas (aceitáveis), não havendo, portanto, nenhum caso em que não se logrou êxito ou que tenha sido classificado como ruim (inaceitável). Os resultados da análise estatística não foram significativos. Portanto, não houve diferença clínica significativa em nenhum dos parâmetros avaliados. CONCLUSÕES: O rocurônio tanto na dose de 0,3 mg.kg-1 quanto na de 0,6 mg.kg-1 DE95 proporcionou condições clinicamente aceitáveis de IT nos procedimentos eletivos.

BACKGROUND AND OBJECTIVES: Neuromuscular blockers (NMB) are used to induce relaxation of skeletal muscles and facilitate tracheal intubation (TI). According to the literature, two effective doses (ED95) of NMB are ideal for TI. Rocuronium is a steroid-type, synthetic, non-depolarizing neuromuscular blocker of medium duration. The objective of this study was to evaluate and compare the conditions of tracheal intubation with one and two effective doses (ED95) of rocuronium, following the criteria of the Copenhagen Consensus Conference. METHODS: Sixty patients of both genders, ages 20 to 60 years, physical status ASA I and II, Mallampati 1 and 2, body mass index (BMI) < 35, who underwent general anesthesia, randomly divided in two groups of 30 patients, were evaluated. Group 1 (G1) received 0.3 mg.kg-1 of rocuronium (1 ED95), and Group 2 (G2) received 0.6 mg.kg-1 (2 DE95). Parameters used to evaluate TI were based on the criteria of the Copenhagen Consensus Conference (Good Clinical Research Practice): laryngoscopy, vocal cords (position and movements), reaction to the insertion of the tube and/or filling of the cuff (movements of limbs and cough). RESULTS: All intubations were considered excellent or good (acceptable); therefore, there were no cases of failure or any intubation considered bad (unacceptable). The results of the statistical analysis were not significant. Consequently, we did not observe any clinically significant differences in the parameters evaluated. CONCLUSIONS: Both doses of rocuronium, 0.3 mg.kg-1 and 0.6 mg.kg-1 ED95, provided clinically satisfactory parameters of TI in elective procedures.

JUSTIFICATIVA Y OBJETIVOS: Los bloqueadores neuromusculares (BNM) son fármacos utilizados para producir el relajamiento de la musculatura esquelética y facilitar la intubación traqueal (IT). La literatura describe que son necesarias de los dosis efectivas (DE95) lo ideal para la IT. El rocuronio es un BNM no despolarizador del tipo esteroide, sintético y de duración intermedia. El objetivo de este estudio fue evaluar y comparar las condiciones de intubación traqueal (IT), utilizando una y de los dosis efectivas (DE95) del rocuronio, secundando los criterios de la Conferencia de Consenso de Copenhague. MÉTODO: Se estudiaron 60 pacientes divididos aleatoriamente en 2 grupos de 30, de ambos sexos, edades entre 20 y 60 años, estado físico ASA I y II, Mallampati 1 y 2, índice de masa corporal (IMC) < 35, sometidos a anestesia general. En el Grupo 1 (G1) se administró 0,3 mg.kg-1 (1 DE95) y en el Grupo 2 (G2) 0,6 mg.kg-1 DE95 (2 DE95) de rocuronio. Los parámetros para la evaluación de la IT fueron en base a los criterios de la Conferencia de Consenso de Copenhague (Good Clinical Research Practice): Laringoscopia, cuerdas vocales (posición y movimiento), reacción a la inserción del tubo y/o a la insuflación del globo (movimiento de los miembros y tos). RESULTADOS: Todas las intubaciones se consideraron excelentes o buenas boas (aceptables), y no hubo ningún caso en que no se logró el éxito o que no haya sido clasificado como malo (inaceptable). Los resultados del análisis estadístico no arrojaron nada de importante. Por tanto, no hubo diferencia clínica significativa en ninguno de los parámetros evaluados. CONCLUSIONES: El rocuronio tanto en la dosis de 0,3 mg.kg-1 como en la de 0,6 mg.kg-1 DE95 proporcionó condiciones clínicamente aceptables de IT en los procedimientos de elección.

Uso del sugammadex para la reversión del bloqueo neuromuscular de larga duración con rocuronio: bolos vs infusión continua / Use of sugammadex for reversal of neuromuscular blockade of long duration with rocuronium: bolus vs continuous infusion

Introducción: El bloqueo neuromuscular residual es causa de complicaciones postoperatorias. Objetivo: Identificar la eficacia del sugammadex para revertir el bloqueo neuromuscular con rocuronio, en procederes de larga duración, cuando éste se administra en forma de bolos versus infusión continua. Método: Se realizó un estudio descriptivo exploratorio en una serie de 10 pacientes para tratamiento quirúrgico de más de dos horas, de forma electiva con anestesia general en el Hospital General Universitario de Alicante, España, entre los meses de noviembre y diciembre del 2010. La inducción y el mantenimiento del bloqueo neuromuscular se realizaron mediante bolos (B) o infusión continua (IC), quedando los pacientes divididos en dos grupos. Se compararon los grupos según el tiempo de recuperación mediante la prueba de U-Mann Whitney. Resultados: Existió homogeneidad entre los grupos en cuanto a edad, peso corporal y estado físico según la ASA II – III. La mediana del tiempo quirúrgico para el grupo B fue de 3:55 horas versus 4:20 horas en el grupo de infusión continua. Para alcanzar el cociente T4/T1 > 90%, la mediana del tiempo de recuperación fue de 75.0 minutos para el grupo IC, mientras en el grupo que se utilizaron bolos se observó un tiempo de 140.0 minutos; las diferencias entre ambos grupos resultaron ser estadísticamente significativas (p = 0,008). Conclusiones: La reversión del bloqueo neuromuscular de larga duración inducido por rocuronio fue más rápida cuando el sugammadex se administró en infusión continua en nuestro grupo de pacientes.

Precurarización con rocuronio y d-tubocurarina: otra perspectiva / Precurarization with rocuronium and d-tubocurarine

Objetivo: Estudiar la precurarización de la succinilcolina utilizando d-tubocurarina y rocuronio introduciendo los métodos restrictivo, conceptos de velocidad de acción y recuperación y una nueva semiología para evaluar las fasciculaciones. Material y método: Se administraron succinilcolina (1 mg x Kg-1) (n =21) sola o precedida por rocuronio o d-tubocurarina (60 ó 50 ug x Kg-1) (n =21 c/u), determinándose: la fase inicial de comienzo hasta 80 por ciento de bloqueo, tiempo de comienzo, máximo efecto, duración clínica, tiempo de reversión espontánea entre 10 por ciento y 25 por ciento y 25 por ciento a 50 por ciento. Se calculó la velocidad de acción (inicial, final y global) como la relación tiempo/bloqueo fraccionado y la velocidad de recuperación. El método restrictivo fue empleado para el estudio del tiempo de comienzo, utilizando un rango restringido de bloqueo. Las fasciculaciones fueron evaluadas por su intensidad en seis regiones anatómicas por cuatro observadores imparciales e independientes y las medias de sus valoraciones utilizadas para analizarlas. Resultados: Aparentemente ambos desfasciculantes prolongan la fase inicial, tiempo de comienzo y velocidad de la succinilcolina, pero el método restrictivo únicamente lo confirmó para el tiempo de comienzo y la velocidad global. La velocidad inicial fue más rápida que la final. El rocuronio redujo el efecto y la duración clínica e incrementó la velocidad de recuperación de la succinilcolina. Las fasciculaciones fueron más frecuentes e intensas en el tronco y miembro superior izquierdo, pero los precurarizantes las redujeron tanto en intensidad como localización Discusión: La precurarización no modifica la fase inicial de comienzo, surgiendo la posibilidad de practicar una intubación temprana. Debido al acortamiento que provoca la precurarización con rocuronio se hace evidente la necesidad precoz de nuevas dosis de relajantes.

Objective: To study the precurarization of succinylcholine with d-tubocurarine and rocuronium, using the restrictive method, speed of action and recovery principles and a particular evaluation for fasciculations Material & Methods: Patients received succinylcholine (1 mg x Kg-1) (n =21) either alone or preceded by d-tubocurarine or rocuronium (60 ó 50 micron g x Kg-1) (n =21 e/a), and the following clinical measurements were made: earlyphase of onset time (up to 80 percent blockade), onset time, maximal block, clinical duration and recovery time between 10 percent and 25 percent and 25 percent to 50 percent. Speed of action (initial, final and global)as the ratio between time and fractional blockade and speed of recovery, were calculated. Restrictive method was used for the study of the entire onset time on patients included in a limited range of final block. Intensity of fasciculations was evaluated by four independent observers blind to the drugs used in six anatomical regions and their mean values used for analysis. Results: Apparently, precurarizing drugs prolonged initial phase, onset time and reduced speed for succinylcholine, but only onset time and global speed were confirmed by restrictive method. After rocuronium, maximal effect as well as clinical duration of succinylcholine werereduced and speed of recovery increased. Fasciculations were more frequent and intense at the trunk and left upper arm, but precurarization reduced both intensity and localization prevalence. Discussion: As lack of changes on the initial phase of onset time for succinylcholine inducedby precurarization was noticed, an early tracheal intubation could be contemplated. Due to reduction on clinical duration after rocuronium,new doses of muscle relaxants are sooner necessary. The present method for evaluation of fasciculations shows how far they are spread and how effective precurarization was, given rise to doubts on previous results.

Influência da lidocaína no bloqueio neuromuscular produzido pelo rocurônio: estudo em preparação nervo frênico-diafragma de rato / Influence of lidocaine on the neuromuscular block produced by rocuronium: study in rat phrenic-diaphragmatic nerve preparation

JUSTIFICATIVA E OBJETIVOS: O mecanismo de ação dos anestésicos locais (AL) na junção neuromuscular motivou a realização de vários estudos. Em baixas doses eles não interferem na transmissão neuromuscular, mas em altas doses podem comprometer a transmissão neuromuscular e potencializar os efeitos de bloqueadores neuromusculares. O objetivo do estudo foi avaliar, em diafragma de rato, a interação da lidocaína com o rocurônio através da influência no grau de bloqueio neuromuscular. MÉTODO: Foram utilizados ratos, com peso entre 250 e 300 g. A preparação foi feita de acordo com a técnica descrita por Bulbring. Formaram-se grupos (n = 5) de acordo com a droga em estudo: lidocaína - 20 µg.mL-1 (Grupo I); rocurônio - 4 µg.mL-1 (Grupo II) e rocurônio - 4 µg.mL-1 com lidocaína - 20 µg.mL-1 (Grupo III). Foram avaliadas: 1) a amplitude das respostas do músculo diafragma à estimulação indireta, antes e 60 minutos após a adição da lidocaína e do bloqueador neuromuscular; 2) os potenciais de membrana (PM) e potenciais de placa terminal em miniatura (PPTM); 3) a eficácia da neostigmina e 4-aminopiridina na reversão do bloqueio neuromuscular. RESULTADOS: A lidocaína isoladamente não alterou a amplitude das respostas musculares. Com o uso prévio de lidocaína o bloqueio neuromuscular do rocurônio foi de 82,8 por cento ± 1,91 por cento, com diferença significativa (p = 0,0079) em relação ao grupo com rocurônio isolado (57,8 por cento ± 1,9 por cento). O bloqueio foi parcial e totalmente revertido pela neostigmina e 4-aminopiridina, respectivamente. A lidocaína não alterou o potencial de membrana e ocasionou aumento inicial na freqüência dos PPTM, seguido de bloqueio. CONCLUSÕES: A lidocaína potencializou o bloqueio neuromuscular produzido pelo rocurônio. As alterações do PPTM identificam ação pré-sináptica. O antagonismo completo da 4-aminopiridina sugere componente pré-sináptico, idéia que é suportada pelo antagonismo parcial pela neostigmina.

Corrección de la curva dosis-respuesta acumulativa de atracurio y rocuronio / Correction of the cumulative dose-response to atracurium and rocurionium

Introducción: La curva dosis-respuesta acumulativa es un método práctico para evaluar las dosis efectivas de atracurio y rocuronio. Debido a sus características farmacocinéticas, los resultados de dicha curva subestiman la potencia de ambos fármacos en comparación con los que resultan de la administración de dosis únicas. El objetivo de la presente investigación es corregir aquella técnica y hacer las dos estadísticamente equivalentes. Material y métodos: En dos grupos de pacientes electivos se utilizó atracurio o rocuronio para calcular sus potencias por el método de las dosis únicas (n = 45 c/u) o acumulativas (n = 11 c/u). El efecto de cada dosis se determinó por electromiografía, y después de sus transformaciones logaritmo-probits, considerando gamma como la relación probit/log, se obtuvieron las DE 50 y 90 resolviendo la ecuación de Hill para cada sujeto. La técnica acumulativa se corrigió al utilizar las cifras actuales para las dosis y sus efectos, en lugar de los valores acumulativos a partir de la segunda administración. Resultados: Las DE 50 de las técnicas de dosis única, acumulativa y corregida fueron: 172 ± 73, 264 ± 52 y 162 ± 81 mcg/kg respectivamente, cuando se utilizó rocuronio, y 141 ± 61, 193 ± 53 y 141 ± 70 respectivamente, cuando se utilizó atracurio. En el caso de las DE 90' los valores fueron 233 ± 98, 327 ± 65, 254 ± 126 y 222 ± 96, 279 ± 77 y 254 ± 126, en el mismo orden. No se detectaron diferencias significativas entre los métodos de dosis única y corregida, mientras que los valores de las dosis acumulativas fueron significativamente mayores. Discusión y conclusiones: En las condiciones de la presente investigación, una sencilla corrección del método acumulativo reproduce razonable y estadísticamente la potencia del atracurio y del rocuronio evaluada por las dosis únicas.

Introduction: The cumulative dose-response curve is a practical method to evaluate the effective doses of atracurium and rocuronium. When compared with those obtained by single administrations, the resulting figures underestimate their potency due to pharmacokinetic features. The purpose of this trial is to correct the cumulative technique and to make both statistically equivalent. Material & Methods: Single (n = 45 e/a) or cumulative (n = 11 e/a) doses of atracurium or rocuronium were administered to elective patients and maximal effect assessed by electromyography. A regression line was obtained after log dose-probit effect transformation, and considering gamma as the probit/log ratio, ED 50 and 90 were calculated resolving the Hill equation for each patient. The cumulative technique was corrected by using actual figures instead of cumulative ones, starting at second administration. Results: ED 50 were 172 ± 73, 264 ± 52 y 162 ± 81 mcg/kg as single, cumulative dose or corrected respectively for rocuronium and 141 ± 61, 193 ± 53 y 141 ± 70 for atracurium. ED 90 was 233 ± 98,327 ± 65, 254 ± 126, 222 ± 96, 279 ± 77 y 254 ± 126 in the same order. Non-significant differences between single dose and corrected method were noticed. Cumulative values were significantly larger. Conclusion: In keeping with the conditions of the present trial, a simple correction made to the cumulative method reasonably and statistically reproduces atracurium and rocuronium potencies evaluated by single dose-responses technique.

Introdução: A curva dose-resposta acumulativa é um método prático de avaliação das doses efetivas de atracúrio e rocuronio. Dada suas características farmacocinéticas, os resultados dessa curva subestimam a potência de ambos fármacos em comparação com os resultados decorrentes da administração de dose únicas. O objetivo da presente pesquisa é corrigir aquela técnica e tornar as duas estatisticamente equivalentes. Material e métodos: Dois grupos de pacientes eletivos receberam atracúrio ou rocurônio com o objetivo de calcular as potências destes fármacos pelo método das doses únicas (n = 45 c/u) ou acumulativas (n = 11 c/u). Foi determinado o efeito de cada dose por eletromiografia, e por transformação log-probits (considerando gama a relação probit/log), obtiveram-se as DE 50 e 90 resolvendo a equação de Hill para cada sujeito. A técnica acumulativa foi corrigida utilizando as cifras atuais para doses e seus efeitos, em lugar dos valores acumulativos, a partir da segunda administração. Resultados: As DE 50 das técnicas de dose única, acumulativa e corrigida foram: 172 ± 73, 264 ± 52 e 162 ± 81 mcg/kg, respectivamente, quando se utilizou rocurônio, e 141 ± 61, 193 ± 53 e 141 ± 70, respectivamente, quando se utilizou atracúrio. No caso das DE 90' os valores foram 233 ± 98, 327 ± 65, 254 ± 126 e 222 ± 96, 279 ± 77 e 254 ± 126, na mesmo ordem. Não foram observadas diferenças significativas entre os métodos (de dose única e corrigida), ao passo que os valores das doses acumulativas foram significativamente maiores. Discussão e conclusões: Nas condições da presente pesquisa, uma simples correção do método acumulativo reproduz de forma razoável e estatisticamente as potências do atracúrio e rocuronio avaliadas por doses únicas.

Debilidad muscular y tolerancia de dosis bajas de rocuronio en voluntarios sanos despiertos y con respiración espontánea / Muscle weakness and tolerance of low doses of rocuronium in healthy awake volunteers breathing spontaneously

OBJETIVOS: Investigar en voluntarios sanos la debilidadmuscular producida por dosis bajas de rocuronio ysu tolerancia, con la idea general de producir una breverelajación muscular esquelética potencialmente aplicableen situaciones clínicas.PACIENTES Y MÉTODOS: Tras autorización del Comitéde Ética e Investigación Clínica de nuestro hospital, nospropusimos estudiar en voluntarios sanos los efectos detres dosis de rocuronio (0,1, 0,05 ó 0,075mg Kg-1), administradasen diferentes días, sobre la fuerza muscular anivel subjetivo y objetivo (medida con un dinamómetrode puño), y la aparición de efectos adversos previstos(diplopia, disartria, disfagia).RESULTADOS: Se incluyeron cinco voluntarios. En elprimer sujeto la dosis de 0,1 mg Kg-1 de rocuronio resultóinadecuada por exceso de efecto (debilidad extrema dela musculatura esquelética; experiencia desagradablepor diplopia, disartria y disfagia) y la dosis de 0,05 mgKg-1 fue bien tolerada, pero sin sensación de debilidad niefectos apreciables sobre la dinamometría. Estas dosdosis no se administraron al resto de sujetos. En losotros cuatro voluntarios, la dosis de 0,075 mg Kg-1 produjouna breve sensación de debilidad muscular consideradaaceptable (aunque los resultados estuvieroninterferidos por dos dinamometrías basales deficientestécnicamente), con leve y breve sensación desagradable(por disfagia principalmente).CONCLUSIONES: Dosis de rocuronio de 0,075 mg Kg-1en sujetos sanos conscientes y respiración espontáneason aceptablemente toleradas y producen un breve estadode debilidad muscular que podría ser de utilidad ensituaciones que precisen momentos puntuales de relajaciónmuscular esquelética(AU)

OBJETIVES: To study muscle weakness caused by lowdoses of rocuronium and rocuronium intolerance inhealthy volunteers, with the general aim of producingbrief skeletal-muscle relaxation that would havepotential applications in clinical situations.PATIENTS AND METHODS: After receiving authorizationfrom the clinical research ethics committee of ourhospital, we set out to study the effects on subjective andobjective muscle strength of injecting 3 doses ofrocuronium (0.1 mg.kg-1, 0.05 mg.kg-1, and 0.075 mg.kg-1)in healthy volunteers, each dose on a different day.Objective muscle strength was measured using a handdynamometer. We also recorded the development ofexpected adverse effects (diplopia, dysarthria, anddysphagia).RESULTS: Five volunteers (all authors) were studied.In the first subject, the dose of 0.1 mg.kg-1 of rocuroniumwas unsatisfactory because it was too strong, causingextreme skeletal-muscle weakness and discomfort due todiplopia, dysarthria, and dysphagia. The dose of 0.05mg.kg-1 was well tolerated but caused no subjectivefeeling of weakness or any effect measurable ondynamometry. These doses were not administered to theother subjects. In the 4 remaining volunteers, the dose of0.075 mg.kg-1 caused a brief feeling of muscle weaknessthat was considered to be acceptable, though thefindings were compromised by 2 technically defectivebaseline dynamometry readings. The volunteers alsoreported brief, mild discomfort, principally due todysphagia.CONCLUSIONS: Doses of 0.075 mg.kg-1 of rocuronium inhealthy awake subjects breathing spontaneously areacceptably tolerated and cause brief muscle weaknessthat may be of use in situations that require skeletalmuscle relaxation at specific moments(AU)

Comparación de bolus de fentanilo con perfusión de remifentanilo en el control de larespuesta hemodinámica a la laringoscopia e intubación orotraqueal: estudioprospectivo, randomizado y doble ciego / Bolus administration of fentanyl vs continuous perfusion of remifentanil for control of hemodynamic response to laryngoscopy and orotracheal intubation: a randomized double-blind trial

OBJETIVOS: Comparar la eficacia y seguridad del fentanilocon remifentanilo en la prevención de la respuestahemodinámica asociada a la laringoscopia directa eintubación orotraqueal, y su repercusión sobre la saturaciónperiférica de oxígeno en mujeres normotensasprogramadas para cirugía ginecológica.MATERIAL Y MÉTODO: Estudio clínico prospectivo enpacientes ASA I-II sometidas a cirugía ginecológica. Sedistribuyeron de forma aleatoria en dos grupos: grupoR, remifentanilo 1 μg Kg–1 min–1 hasta la intubación ygrupo F, fentanilo 2 μg Kg–1. Para la inducción anestésicautilizamos etomidato (0,3 mg Kg–1) y bromuro derocuronio (0,6 mg Kg–1). Se realizaron siete medicionesseriadas de la presión arterial sistólica, diastólica ymedia, frecuencia cardiaca y saturación periférica deoxígeno durante los periodos: control, desnitrogenación,postinducción, postintubación y posteriormente cada dosminutos tres determinaciones consecutivas.RESULTADOS: Se incluyeron 54 pacientes. El grupo R mostróun efecto estadísticamente significativo de atenuación dela respuesta hemodinámica postintubación tanto en la presiónarterial (p = 0,0001), como en la frecuencia cardiaca(p = 0,031) respecto de su valor basal. Sin embargo, con elgrupo del fentanilo (grupo F), no se observó dicho efecto protector.No se observaron diferencias en la saturación periféricade oxígeno en ambos grupos durante el estudio.CONCLUSIONES: A las dosis utilizadas, el remifentanilocomparativamente con el fentanilo, ofrece mayor controlhemodinámico. No se observaron efectos secundarios enambos grupos atribuibles a los opiáceos(AU)

OBJETIVES: To compare the efficacy and safety offentanyl and remifentanil in the prevention ofhemodynamic responses to direct laryngoscopy andorotracheal intubation, and to compare the effects ofthese techniques on peripheral blood oxyhemoglobinsaturation in normotensive women undergoingscheduled gynecologic surgery.MATERIAL AND METHODS: Prospective clinical trial inASA 1-2 patients undergoing gynecologic surgery. Thepatients were randomized to 2 groups: the remifentanilgroup received a perfusion of 1 μg·kg-1·min-1 untilintubation whereas the fentanyl group received a bolusdose of 2 μg·kg-1. Etomidate (0.3 mg·kg-1) and rocuroniumbromide (0.6 mg·kg-1) were used for anesthetic induction.Seven serial measurements of systolic, diastolic, and meanarterial pressure were recorded in addition to heart rateand peripheral blood oxyhemoglobin saturation at thefollowing times: baseline, denitrogenation, postinduction,and 3 more times at consecutive 2-minute intervals.RESULTS: Fifty-four patients were enrolled. Astatistically significant attenuation of the postintubationhemodynamic response was observed in the remifentanilgroup. The effect was evident on arterial pressure(P=.0001) and heart rate (P=.031) with respect tobaseline values. That protective effect was not seen in thefentanyl group. No differences in peripheral bloodoxyhemoglobin saturation were observed.CONCLUSIONS: Remifentanil provides greaterhemodynamic control than fentanyl at the doses utilized.No adverse effects attributable to these opioids wereobserved in either group(AU)

Consideraciones anestésicas en un paciente con déficit de pantotenato cinasa (enfermedad de Hallervorden-Spatz) para estimulación cerebral profunda / Anesthesia considerations for deep-brain stimulation in a patient with type-2 pantothenate kinase deficiency (Hallervorden-Spatz disease)

La neurodegeneración asociada al déficit de pantotenatocinasa es una entidad autosómica recesiva secundariaa las mutaciones del gen pantotenato cinasa 2(PANK2). Clínicamente se caracteriza por anormalidadesprogresivas del movimiento y demencia. El tratamientomédico de la enfermedad es limitado y la distoníasuele ser refractaria, por lo cual la cirugíaestereotáctica con colocación de electrodos cerebralesprofundos es una opción terapéutica cada vez más usadaen estos pacientes. Describimos una paciente de 32 añosde edad con distonía severa asociada a déficit dePANK2. Fue programada para tomografía computarizadaestereotáctica y colocación bilateral de electrodos ennúcleo pálido medial, bajo anestesia general para tratarla distonía debilitante y la rigidez generalizada asociadaa su enfermedad. Durante la intervención se realizó elmantenimiento anestésico con propofol, rocuronio yremifentanilo en perfusión, sin ninguna incidencia a destacardurante el procedimiento. Tras la intervención lapaciente fue trasladada a la unidad de cuidados intensivosbajo sedación farmacológica con remifentanilo paraproceder a una educción lentamente progresiva. Lapaciente pudo ser dada de alta tras la colocación delgenerador y en el seguimiento posterior se ha evidenciadomejoría de los movimientos distónicos(AU)

Neurodegeneration associated with pantothenate kinasedeficiency is an autosomal recessive condition caused bymutations in the pantothenate kinase 2 gene (PANK2).Clinical characteristics include progressive motorimpairment and dementia. Medical treatment is limited andthe dystonia tends to be refractory, making stereotacticsurgery with placement of deep-brain electrodes an optionthat is being adopted with greater frequency in thesepatients. We report the case of a 32-year-old woman withsevere dystonia associated with PANK2 protein deficiency.The patient was scheduled for stereotactic bilateralplacement of electrodes in the medial globus pallidus,guided by computed tomography and under generalanesthesia, to treat the debilitating dystonia and generalizedstiffness associated with her condition. Anesthesia wasmaintained with propofol, rocuronium and remifentanil inperfusion during the intervention, which was uneventful.After the procedure, the patient was transferred to theintensive care unit and sedation was provided withremifentanil to allow slow, gradual emergence fromanesthesia. The patient was discharged from hospital afterplacement of the implanted pulse generator, and subsequentfollow-up showed improvement of the dystonia(AU)

Correlación entre la concentración molar del rocuronio y su tiempo de comienzo o velocidad de acción / Correlation between molar concentration of rocuroniom and its time of onset or speed of action

Objetivo: Estudiar la correlación entre dosis subparalizantes de rocuronio con el tiempo de comienzo y utilizarla para su predicción. Material y método: Cinco grupos de pacientes recibieron 0.34, 0.68, 1, 1.38 o 2.8 x DE50 de rocuronio, y se determinó el máximo efecto, el tiempo para alcanzarlo (TC), las concentraciones molares (µM/kg) y la velocidad de acción (VA), relación entre tiempo y efecto o viceversa de cada dosis. Para la correlación, los valores se convirtieron en logaritmos (log) o raíz cuadrada (V2). De la línea de regresión se obtuvieron la fórmula, R al cuadrado y la significación estadística. Resultados: La correlación entre log µM/kg con Tc y VA (seg/por ciento o por ciento/seg) se tradujo en los siguientes resultados: R2= 0.972,0.845 y 0.845, y una p= 0.001, 0.027 y 0.027, respectivamente. Al resolver las fórmulas de regresión se puedo predecir el TC y VA. Cuando los valores se transforman en V al cuadrado los resultados fueron similares. Discusión: El TC de un bloqueante neuromuscular está ligado a su efecto, y la permeabilidad al tamaño de sus moléculas o µM/kg, la cual a su vez es función de la dosis. El estudio no comprueba la similitud propuesta del TC entre las bajas dosis de los relajantes musculares. Los resultados demuestran que existe una alta y significativa correlación entre la µM/kg de las dosis subparalíticas de rocuronio con las tres formas de estudiar el período de comienzo. También pone en evidencia que a través de la misma correlación es posible hacer predicciones sobre los parámetros de comienzo.